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Heusch G. Coronary blood flow in heart failure: cause, consequence and bystander. Basic Res Cardiol 2022; 117:1. [PMID: 35024969 PMCID: PMC8758654 DOI: 10.1007/s00395-022-00909-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 12/20/2021] [Accepted: 12/21/2021] [Indexed: 01/31/2023]
Abstract
Heart failure is a clinical syndrome where cardiac output is not sufficient to sustain adequate perfusion and normal bodily functions, initially during exercise and in more severe forms also at rest. The two most frequent forms are heart failure of ischemic origin and of non-ischemic origin. In heart failure of ischemic origin, reduced coronary blood flow is causal to cardiac contractile dysfunction, and this is true for stunned and hibernating myocardium, coronary microembolization, myocardial infarction and post-infarct remodeling, possibly also for the takotsubo syndrome. The most frequent form of non-ischemic heart failure is dilated cardiomyopathy, caused by genetic mutations, myocarditis, toxic agents or sustained tachyarrhythmias, where alterations in coronary blood flow result from and contribute to cardiac contractile dysfunction. Hypertrophic cardiomyopathy is caused by genetic mutations but can also result from increased pressure and volume overload (hypertension, valve disease). Heart failure with preserved ejection fraction is characterized by pronounced coronary microvascular dysfunction, the causal contribution of which is however not clear. The present review characterizes the alterations of coronary blood flow which are causes or consequences of heart failure in its different manifestations. Apart from any potentially accompanying coronary atherosclerosis, all heart failure entities share common features of impaired coronary blood flow, but to a different extent: enhanced extravascular compression, impaired nitric oxide-mediated, endothelium-dependent vasodilation and enhanced vasoconstriction to mediators of neurohumoral activation. Impaired coronary blood flow contributes to the progression of heart failure and is thus a valid target for established and novel treatment regimens.
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Affiliation(s)
- Gerd Heusch
- grid.5718.b0000 0001 2187 5445Institute for Pathophysiology, West German Heart and Vascular Center, University of Essen Medical School, University of Duisburg-Essen, Hufelandstr. 55, 45147 Essen, Germany
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Abstract
Unlike acute myocardial infarction with reperfusion, in which infarct size is the end point reflecting irreversible injury, myocardial stunning and hibernation result from reversible myocardial ischaemia-reperfusion injury, and contractile dysfunction is the obvious end point. Stunned myocardium is characterized by a disproportionately long-lasting, yet fully reversible, contractile dysfunction that follows brief bouts of myocardial ischaemia. Reperfusion precipitates a burst of reactive oxygen species formation and alterations in excitation-contraction coupling, which interact and cause the contractile dysfunction. Hibernating myocardium is characterized by reduced regional contractile function and blood flow, which both recover after reperfusion or revascularization. Short-term myocardial hibernation is an adaptation of contractile function to the reduced blood flow such that energy and substrate metabolism recover during the ongoing ischaemia. Chronic myocardial hibernation is characterized by severe morphological alterations and altered expression of metabolic and pro-survival proteins. Myocardial stunning is observed clinically and must be recognized but is rarely haemodynamically compromising and does not require treatment. Myocardial hibernation is clinically identified with the use of imaging techniques, and the myocardium recovers after revascularization. Several trials in the past two decades have challenged the superiority of revascularization over medical therapy for symptomatic relief and prognosis in patients with chronic coronary syndromes. A better understanding of the pathophysiology of myocardial stunning and hibernation is important for a more precise indication of revascularization and its consequences. Therefore, this Review summarizes the current knowledge of the pathophysiology of these characteristic reperfusion phenomena and highlights their clinical implications.
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Sharif D, Matanis W, Sharif-Rasslan A, Rosenschein U. Doppler echocardiographic myocardial stunning index predicts recovery of left ventricular systolic function after primary percutaneous coronary intervention. Echocardiography 2016; 33:1465-1471. [PMID: 27543440 DOI: 10.1111/echo.13305] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Myocardial stunning is responsible for partially reversible left ventricular (LV) systolic dysfunction after successful primary percutaneous coronary intervention (PPCI) in patients with acute ST-elevation myocardial infarction (STEMI). AIM To test the hypothesis that early coronary blood flow (CBF) to LV systolic function ratios, as an equivalent to LV stunning index (SI), predict recovery of LV systolic function after PPCI in patients with acute STEMI. METHODS Twenty-four patients with acute anterior STEMI who had successful PPCI were evaluated and compared to 96 control subjects. Transthoracic echocardiography with measurement of LV ejection fraction (EF), LV, and left anterior descending (LAD) coronary artery area wall-motion score index (WMSI) as well as Doppler sampling of LAD blood velocities, early after PPCI and 5 days later, were performed. SI was evaluated as the early ratio of CBF parameters in the LAD to LV systolic function parameters. RESULTS Early SI-LVEF well predicted late LVEF (r=.51, P<.01) and the change in LVEF (r=.48, P<.017). Early SI-LVMSI predicted well late LVEF (r=.56, P<.006) and the change in LVEF (r=.46, P<.028). Early SI-LADWMSI predicted late LVEF (r=.44, P<.028). Other SI indices measured as other LAD-CBF to LV systolic function parameters were not predictive of late LV systolic function. CONCLUSIONS LV stunning indices measured as early LAD flow to LVEF, LVWMSI, and LADWMSI ratios well predicted late LVEF and the change in LVEF. Thus, greater early coronary artery flow to LV systolic function parameter ratios predict a better improvement in late LV systolic function after PPCI.
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Affiliation(s)
- Dawod Sharif
- Cardiology Department, Bnai Zion Medical Center, Haifa, Israel. .,Technion, Israel Institute of Technology, Haifa, Israel.
| | - Wisam Matanis
- Technion, Israel Institute of Technology, Haifa, Israel
| | - Amal Sharif-Rasslan
- Technion, Israel Institute of Technology, Haifa, Israel.,Department of Mathematics, The Academic Arab College, Haifa, Israel
| | - Uri Rosenschein
- Cardiology Department, Bnai Zion Medical Center, Haifa, Israel.,Technion, Israel Institute of Technology, Haifa, Israel
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Miller DD. Analytic Reviews : Detection of Viable Myocardium after Myocardial Infarction. J Intensive Care Med 2016. [DOI: 10.1177/088506669000500104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Grover S, Srinivasan G, Selvanayagam JB. Evaluation of myocardial viability with cardiac magnetic resonance imaging. Prog Cardiovasc Dis 2011; 54:204-14. [PMID: 22014488 DOI: 10.1016/j.pcad.2011.06.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Assessment of myocardial viability is of clinical and scientific significance. Traditionally, the detection of myocardial viability (either stunning or hibernation) has been used in aiding diagnosis before revascularization, especially in high-risk patients. There is a considerable body of observational evidence showing substantial improvement after revascularization in patients with significant left ventricular dysfunction and myocardial viability. Recent randomized evidence has questioned the benefit of viability testing but must be interpreted with caution. Dobutamine stress echocardiography, nuclear imaging, and cardiovascular magnetic resonance are the mainstays of viability testing and provide information on contractile function, cellular metabolism, and myocardial fibrosis, respectively. Larger, multicenter trials with outcome data are needed to define the nature of viability testing and, particularly, cardiovascular magnetic resonance in moderate-to-severe ischemic cardiomyopathy.
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Affiliation(s)
- Suchi Grover
- Department of Cardiovascular Medicine, Flinders Medical Centre, Australia
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Klug G, Trieb T, Schocke M, Nocker M, Skalla E, Mayr A, Nowosielski M, Pedarnig K, Bartel T, Moes N, Pachinger O, Metzler B. Quantification of regional functional improvement of infarcted myocardium after primary PTCA by contrast-enhanced magnetic resonance imaging. J Magn Reson Imaging 2009; 29:298-304. [DOI: 10.1002/jmri.21498] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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Park SM, Miyazaki C, Prasad A, Bruce CJ, Chandrasekaran K, Rihal C, Bell MR, Oh JK. Feasibility of prediction of myocardial viability with Doppler tissue imaging following percutaneous coronary intervention for ST elevation anterior myocardial infarction. J Am Soc Echocardiogr 2009; 22:183-9. [PMID: 19121567 DOI: 10.1016/j.echo.2008.11.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2008] [Indexed: 11/16/2022]
Abstract
BACKGROUND In patients with acute ST elevation myocardial infarction (STEMI), it is clinically important to determine the viability of akinetic segments soon after acute reperfusion therapy. The purpose of this study was to determine whether Doppler tissue imaging can predict myocardial viability in this clinical setting. METHODS Twenty-four consecutive patients with the first acute anterior STEMI with akinetic apical segments were enrolled. Color-coded Doppler tissue imaging was performed. Myocardial velocity and strain values were determined from the septal and lateral walls at the normal basal and akinetic apical levels of the left ventricle on day 1 after percutaneous coronary intervention. The presence of isovolumic contraction of tissue velocity (TVivc) and strain rate (SRivc) were also determined. RESULTS Twenty patients (mean age 62 +/- 15 years; 11 men) returned for follow-up echocardiography to assess wall motion recovery and viability. Ten patients who had recovery of akinetic segments showed lower baseline E/e' ratios than those without recovery (13.4 +/- 5.9 vs 19.1 +/- 5.7; P = .04). There was no difference between 19 recovered and 21 nonrecovered apical segments in all TV, SR, and strain values except early diastolic SR (SRe; 0.64 +/- 0.35 vs 0.43 +/- 0.25 s(-1); P = .04) at day 1. With a cutoff value of 0.32 s(-1) for SRe, the receiver operating characteristic curve for the prediction of recovery showed the highest sensitivity of 84%. The presence of TVivc had sensitivity and specificity of 79% and 33%, respectively, and for SRivc, sensitivity and specificity were 84% and 63%, respectively. With the combination of SRe and SRivc, specificity was increased to 78%. CONCLUSION Patients with functional recovery from anterior STEMI showed better diastolic function, better SRe, and more isovolumic contraction. These parameters appear to be promising predictors for myocardial viability, and SR imaging was found to be a better method than TV imaging for the identification of viable myocardium in patients with STEMIs who underwent percutaneous coronary intervention.
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Affiliation(s)
- Seong-Mi Park
- Division of Cardiology, Korea University College of Medicine, Seoul, South Korea
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Kontos MC, Haney A, Ornato JP, Jesse RL, Tatum JL. Value of simultaneous functional assessment in association with acute rest perfusion imaging for predicting short- and long-term outcomes in emergency department patients with chest pain. J Nucl Cardiol 2008; 15:774-82. [PMID: 18984452 DOI: 10.1007/bf03007358] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2007] [Accepted: 05/26/2008] [Indexed: 11/30/2022]
Abstract
BACKGROUND Rest tomographic myocardial perfusion imaging (MPI) has significant utility for clinical decision making in emergency department chest pain patients. The role of functional data, commonly acquired with perfusion, has not been systematically evaluated. METHODS AND RESULTS Low- to moderate-risk patients undergoing rest MPI for risk stratification were included. The patients' MPI findings were classified as normal (normal perfusion or function), abnormal (perfusion defect with abnormal regional function), or discordant (perfusion defect with normal regional function). Ejection fraction was determined from the gated MPI studies. Events based on perfusion classifications and ejection fraction were evaluated. A total of 2,826 consecutive patients (abnormal MPI results in 40%, normal in 32%, and discordant in 27%) were studied. Outcomes were similar for those with normal MPI results versus those with discordant MPI results (myocardial infarction [MI] based on troponin I [TnI], 3.5% vs 4.0%; MI based on creatine kinase-MB, 1.5% vs 1.7%; revascularization, 5.2% vs 5.5%; and MI/revascularization based on TnI, 7.9% vs 8.1%) (P = not significant for all). Both groups had significantly fewer events (P < .001 for all) when compared with patients with abnormal MPI studies (MI based on TnI, 15%; MI based on creatine kinase-MB, 10%; revascularization, 17%; MI based on TnI or revascularization, 24%). The mortality rate was not different among the 3 groups. Multivariate analysis showed that mild/moderate and severe systolic dysfunction were independent predictors of 30-day and 1-year mortality rates (P = .001). CONCLUSIONS The concurrent evaluation of perfusion and function (regional and global) with MPI provides significant risk/outcome predictive power.
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Affiliation(s)
- Michael C Kontos
- Department of Internal Medicine, Cardiology Division, Virginia Commonwealth University, Richmond, VA 23298-0051, USA.
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Abstract
This review briefly synthesizes the molecular biology of troponin, which is currently the best biochemical marker for the detection of cardiac injury and, thus, acute myocardial infarction as well. Potential new uses for the marker based on these insights, with a specific interest in cardiac troponin fragments that potentially could be linked to distinct clinical conditions, are described. Some of the clinical problems clinicians are faced with including how to use the markers in renal failure and the difficulties associated with the heterogeneity of current troponin assays are also discussed. Finally, we present the possibility of specific cardiac troponin fragments resulting from modification or degradation, associated with distinct pathological processes, as new potential uses for this biomarker.
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Affiliation(s)
- Vlad C Vasile
- Mayo Clinic & Mayo Medical School, Department of Internal Medicine, Division of Cardiovascular Diseases & Department of Laboratory Medicine & Pathology, Rochester, Minnesota, USA
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Abstract
Over the last decade, major advances have been made in the treatment of acute coronary syndromes (ACSs). However, effective implementation of these treatments requires timely and accurate identification of the high-risk patient among all those presenting to the emergency department (ED) with symptoms suggestive of ACS. The opportunity for improving outcomes is time-dependent, so that early identification of the patient who has true ACS is essential. This necessity further increases the need for rapid triage tools, especially in the current setting of ED and hospital overcrowding that has become the norm in large urban centers.
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Affiliation(s)
- Michael C Kontos
- Virginia Commonwealth University, VCU Medical Center, Richmond, VA 23298-0051, USA.
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Abstract
The prevalence of left ventricular (LV) dysfunction and resultant congestive heart failure is increasing. Patients with this condition are at high risk for cardiac death and usually have significant limitations in their lifestyles. Although there have been advances in medical therapy resulting in improved survival and well being, the best and most definitive therapy, when appropriate, is revascularization. In the setting of coronary artery disease, accounting for approximately two thirds of cases of congestive heart failure, LV dysfunction often is not the result of irreversible scar but rather caused by impairment in function and energy use of still viable-myocytes, with the opportunity for improved function if coronary blood flow is restored. Patients with LV dysfunction who have viable myocardium are the patients at highest risk because of the potential for ischemia but at the same time benefit most from revascularization. It is important to identify viable myocardium in these patients, and radionuclide myocardial scintigraphy is an excellent tool for this. Single-photon emission computed tomography perfusion scintigraphy, whether using thallium-201, Tc-99m sestamibi, or Tc-99m tetrofosmin, in stress and/or rest protocols, has consistently been shown to be an effective modality for identifying myocardial viability and guiding appropriate management. Metabolic imaging with positron emission tomography radiotracers frequently adds additional information and is a powerful tool for predicting which patients will have an improved outcome from revascularization, including some patients referred instead for cardiac transplantation. Other noninvasive modalities, such as stress echocardiography, also facilitate the assessment of myocardial viability, but there are advantages and disadvantages compared with the nuclear techniques. Nuclear imaging appears to require fewer viable cells for detection, resulting in a higher sensitivity but a lower specificity than stress echocardiography for predicting post-revascularization improvement of ventricular function. Nevertheless, it appears that LV functional improvement may not always be necessary for clinical improvement. Future directions include use of magnetic resonance imaging, as well as larger, multicenter trials of radionuclide techniques. The increasing population of patients with LV dysfunction, and the increased benefit afforded by newer therapies, will make assessment of myocardial viability even more essential for proper patient management.
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Affiliation(s)
- Mark I Travin
- Department of Nuclear Medicine, Montefiore Medical Center, Bronx, NY 10467-2490, USA.
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Toyama T, Hoshizaki H, Seki R, Isobe N, Oshima S, Taniguchi K, Higuchi K, Seki H, Hatori T, Kurabayashi M, Endo K. Evaluation of myocardial viability following acute myocardial infarction using 201Tl SPECT after thallium-glucose-insulin infusion--comparison with 18F-FDG positron emission tomography. Ann Nucl Med 2005; 18:463-8. [PMID: 15515744 DOI: 10.1007/bf02984561] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
OBJECTIVE AND METHODS The aim of this study was to evaluate myocardial viability in patients after acute myocardial infarction (AMI). We compared 201Tl SPECT after 201Tl with GIK (10% glucose 250 ml, insulin 5 U and KCl 10 mEq) infusion (GIK-201Tl) with resting 201Tl and 99mTc-pyrophosphate (PYP) dual SPECT, positron emission computed tomography (PET) using 18F-fluorodeoxyglucose (18F-FDG) in 21 patients with their first AMI, who all underwent successful reperfusion. GIK-201Tl SPECT, 201Tl and 99mTc-PYP dual SPECT were done within 10 days after admission and 18F-FDG-PET was performed at 3 weeks. GIK-201Tl SPECT was obtained after 30 min of GIK-201Tl infusion. 18F-FDG (370 MBq) was injected intravenously after oral glucose (1 g/ kg) loading, and then PET was obtained. PET and SPECT images were divided into 20 segments. Regional tracer uptake was scored using a 4-point scoring system (3 = normal to 0 = defect), and summed to a regional uptake score (RUS). Regional area means the infarcted area in which 99mTc-PYP accumulated. The number of decreased uptake segments (ES) was then determined. The infarcted area was defined as the area of 99mTc-PYP uptake. RESULTS The ESs for the GIK-201Tl and 18F-FDG-PET images were significantly lower than the number of 99mTc-PYP uptake segments. The RUS for GIK-201Tl was higher than that for resting-201Tl imaging and similar to those for 18F-FDG-PET. CONCLUSIONS In the detection of myocardial viability following AMI, GIK-201Tl imaging is useful with findings similar to those of 18F-FDG-PET.
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Yao SS, Chaudhry FA. Assessment of Myocardial Viability with Dobutamine Stress Echocardiography in Patients with Ischemic Left Ventricular Dysfunction. Echocardiography 2005; 22:71-83. [PMID: 15660693 DOI: 10.1111/j.0742-2822.2005.04030.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The noninvasive assessment of myocardial viability has proved clinically useful for distinguishing hibernating and/or stunned myocardium from irreversibly injured myocardium in patients with chronic ischemic heart disease or recent myocardial infarction, with marked regional and/or global left ventricular (LV) dysfunction. Noninvasive techniques utilized for the detection of viability in asynergic myocardial regions include positron emission tomographic imaging of residual metabolic activity, single photon emission tomography (SPECT) of radioisotope uptake with thallium-201, low-dose dobutamine echocardiography assessment of inotropic reserve and myocardial contrast echocardiography for evaluation of microvascular integrity. Of these techniques, dobutamine stress echocardiography is a safe, widely available and relatively inexpensive modality for the identification of myocardial viability for risk stratification and prognosis. Low-dose dobutamine response can accurately predict improvement of dysfunctional yet viable myocardial regions, and thus identify a subset of patients whose LV function will improve following successful coronary revascularization.
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Affiliation(s)
- Siu-Sun Yao
- Division of Cardiology, Department of Medicine, St. Luke's Roosevelt Hospital Center, Columbia University College of Physicians and Surgeons, New York, NY 10025, USA
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Affiliation(s)
- Michael C Kontos
- Department of Internal Medicine, Medical College of Virginia, Richmond, USA
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Toyama T, Hoshizaki H, Seki R, Isobe N, Adachi H, Naito S, Oshima S, Taniguchi K. Evaluation of Salvaged Myocardium After Acute Myocardial Infarction Using Single Photon Emission Computed Tomography After 201Tl-Glucose-Insulin Infusion. Circ J 2004; 68:348-54. [PMID: 15056833 DOI: 10.1253/circj.68.348] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND GIK-201Tl imaging reportedly improves the detection of viable myocardium, so the present study evaluated whether it can detect myocardial viability after acute myocardial infarction (AMI). METHODS AND RESULTS Resting 201Tl and 99mTc-pyrophosphate (PYP) dual single photon emission computed tomography (SPECT) and 201Tl SPECT after 201Tl with GIK (10% glucose, insulin 5 U, and KCl 10 mmol) infusion (GIK-201Tl) were performed in 25 AMI patients within 10 days of admission. GIK-201Tl SPECT images were obtained immediately and 4 h after infusion. Left ventriculography (LVG) was performed within 3 weeks and at 6 months when follow-up 201Tl SPECT was also performed. From 20 SPECT segments, both the summed defect score (RDS) and the number of defect segments (ES) were calculated. The infarcted area was defined as 99mTc-PYP uptake segments. Wall motion was estimated in 7 LVG segments. The ES of R-201Tl (5.5 +/- 2.8), immediate GIK-201Tl (4.0 +/- 2.3), and 4-h GIK-201Tl (5.6 +/- 2.7) were lower than that of 99mTc-PYP (7.5 +/- 4.1) (p<0.05), and the ES had significantly declined 6 months later on 201Tl (3.5 +/- 2.8) (p<0.05). Although the RDS of R-201Tl (11.3 +/- 7.9) and 4-h GIK-201Tl (11.2 +/- 6.3) were greater than at the 6-month 201Tl (7.1 +/- 6.5), immediate GIK-201Tl (7.4 +/- 6.5) was equivalent to follow-up 201Tl. The sensitivity of immediate GIK-201Tl was highest among the imaging methods. CONCLUSION To detect myocardial viability after AMI, early imaging with GIK-201Tl is more useful than resting 201Tl imaging.
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Affiliation(s)
- Takuji Toyama
- Gunma Prefectural Cardiovascular Center, Maebashi, Japan
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Kontos MC, Tatum JL. Imaging in the evaluation of the patient with suspected acute coronary syndrome. Semin Nucl Med 2003; 33:246-58. [PMID: 14625838 DOI: 10.1016/s0001-2998(03)00030-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Patients presenting to the emergency department with chest pain have a common problem. Definitive diagnosis at presentation is difficult due to limitations of the initial evaluation, and, thus, the majority of patients are admitted. Recognition of these limitations has driven the investigation of alternative evaluation techniques and protocols to attempt to improve diagnostic sensitivity without increasing overall costs. Acute myocardial perfusion imaging has been a highly valuable technique for risk stratification of intermediate to low-risk patients with chest pain. However, for a variety of reasons, it has not been widely embraced. In the past few years, alternative techniques have been investigated for use in the diagnosis of acute coronary syndromes in the acute setting. Coronary calcium scoring and cardiac magnetic resonance imaging show promise as new tools in the armamentarium for acute coronary syndromes. The challenge now lays in developing a strategy that uses these and future techniques most appropriately to support optimal medical decision making.
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Affiliation(s)
- Michael C Kontos
- Virginia Commonwealth University, VCU Medical Center, Medical College of Virginia Hospitals, Richmond, VA, USA
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Kasama S, Toyama T, Kumakura H, Takayama Y, Ichikawa S, Suzuki T, Kurabayashi M. Low-dose dobutamine stress 99mTc tetrofosmin quantitative gated SPECT performed during the acute phase of myocardial infarction predicts subsequent myocardial viability and detects stunned myocardium. Nucl Med Commun 2003; 24:167-74. [PMID: 12548041 DOI: 10.1097/00006231-200302000-00009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
This study evaluated the ability of low-dose dobutamine stress 99mTc tetrofosmin (DSTF) quantitative gated single photon emission computed tomography (QGS) performed during the acute phase of myocardial infarction to predict subsequent myocardial viability and detect stunned myocardium. Twenty-four patients suffering their first acute myocardial infarction (AMI) underwent coronary angioplasty after coronary angiography (CAG) immediately following admission. Follow-up CAG and left ventriculography (LVG) were performed 10 days and 6 months later. All patients underwent DSTF QGS to measure left ventricular ejection fraction (LVEF) at rest and during dobutamine infusion (10 microg.kg(-1).min(-1)) 14 days after angioplasty. No patient suffered coronary restenosis. After 6 months, the LVEF measured by LVG improved >5% in 12 patients (group A), and did not improve in the remaining 12 patients (group B). The culprit coronary artery, the peak serum creatine phosphokinase concentration, the recanalization time, and the LVEF during the acute phase were similar in the two groups. However, the increase in the LVEF was greater in group A than in group B during dobutamine infusion (deltaLVEF) as measured by DSTF QGS (11.2+/-3.8% vs 2.9+/-4.7%, P <0.001). If a cut-off value of 6.5% for the deltaLVEF was used to predict the improvement in LVEF during the chronic phase, then the sensitivity of this test was 83.3% and its specificity was 83.3%. It is concluded that DSTF QGS during AMI can be used to predict myocardial viability and detect stunned myocardium.
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Affiliation(s)
- S Kasama
- Second Department of Internal Medicine, Gunma University School of Medicine, 3-39-15 Showa-machi, Maebashi, Gunma 371-0034, Japan.
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Grech ED, Sutton AG, Campbell PG, Ashton VJ, Price DJ, Hall JA, de Belder MA. Reappraising the role of immediate intervention following thrombolytic recanalization in acute myocardial infarction. Am J Cardiol 2000; 86:400-5. [PMID: 10946032 DOI: 10.1016/s0002-9149(00)00954-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Early studies indicated that after successful thrombolytic recanalization, adjunctive percutaneous transluminal coronary angioplasty (PTCA) was not appropriate, even when a significant residual stenosis was present. The aim of this study was to assess in-hospital clinical outcomes of patients with acute myocardial infarction (AMI) who underwent successful recanalization after thrombolytic therapy. The relation between repeat AMI/unstable angina and the severity of the stenosis, as well as other angiographic and clinical features was also examined. One hundred patients with AMI of <10 hours underwent coronary angiography 2 hours after receiving thrombolytic therapy. Salvage PTCA +/- stenting was performed if recanalization was unsuccessful (Thrombolysis In Myocardial Infarction [TIMI] trial grade 0 to 2), and no PTCA was undertaken if there was brisk anterograde flow (TIMI 3). Angiographic analysis was performed to assess the severity of the residual lesion, as well as the presence or absence of thrombus. Forty patients had unsuccessful recanalization, and of these, 36 underwent attempted PTCA. Of the 60 patients with TIMI 3 flow, 15 required repeat angiography and PTCA after repeat AMI (n = 13) or unstable angina (n = 2) within 5 days. Receiver-operating characteristic analysis indicated an optimum percent diameter stenosis predictor of 85% for repeat AMI/unstable angina. There was no additional relation to age, gender, time to thrombolysis, the infarct-related artery, or the presence of culprit lesion thrombus. After recanalization, a high-grade stenosis >85% is common (n = 25, 42.4%). This is associated with a 54% repeat AMI/unstable angina risk-a ninefold increase in the incidence of such events than in patients with lesions <85%. Thus, patients with narrowings >85% may benefit from early intervention rather than a conservative approach. Narrowings <85% have a 94% probability of no repeat AMI/unstable angina and do not require early intervention.
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Affiliation(s)
- E D Grech
- Department of Cardiology, Cardiothoracic Division, South Cleveland Hospital, Cleveland, United Kingdom.
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Abstract
Although the pathogenesis of myocardial stunning has not been definitively established, the two major hypotheses are that it is caused by the generation of oxygen-derived free radicals on reperfusion and by a loss of sensitivity of contractile filaments to calcium. These hypotheses are not mutually exclusive and are likely to represent different facets of the same pathophysiological cascade. For example, a burst of free radical generation after reperfusion could alter contractile filaments in a manner that renders them less responsive to calcium. Increased free radical formation could also cause cellular calcium overload, which would damage the contractile apparatus of the myocytes. There is now considerable evidence that myocardial stunning occurs clinically in various situations in which the heart is exposed to transient ischemia, such as unstable angina, acute myocardial infarction with early reperfusion, exercise-induced ischemia, cardiac surgery, and cardiac transplantation. Recognition of myocardial stunning is clinically important and may impact patient treatment. Although no ideal diagnostic technique for myocardial stunning has yet been developed, thallium-201 scintigraphy or dobutamine echocardiography are available and can be useful to identify viable myocardium with reversible wall motion abnormalities. An intriguing possibility is that so-called chronic hibernation may in fact be the result of repetitive episodes of stunning, which have a cumulative effect and cause protracted postischemic left ventricular dysfunction. A better understanding of myocardial stunning will expand our knowledge of the pathophysiology of myocardial ischemia and provide a rationale for developing new therapeutic strategies designed to prevent postischemic dysfunction.
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Affiliation(s)
- R Bolli
- Division of Cardiology, University of Louisville, KY 40292, USA
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Stewart KJ, McFarland LD, Weinhofer JJ, Cottrell E, Brown CS, Shapiro EP. Safety and efficacy of weight training soon after acute myocardial infarction. JOURNAL OF CARDIOPULMONARY REHABILITATION 1998; 18:37-44. [PMID: 9494881 DOI: 10.1097/00008483-199801000-00005] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND To determine if weight training used during cardiac rehabilitation as soon as 4 weeks after myocardial infarction (MI) is safe, and if weight training combined with aerobic exercise improves aerobic fitness and muscle strength more than aerobic exercise alone. METHODS Twenty-three men within 6 weeks of an acute MI and without exercise-induced ischemia, complex arrhythmias, anterior Q wave MI, or ejection fraction < 40% were randomly assigned to combined weight and cycle training versus cycle training for 10 weeks. The main measures were change in maximal oxygen uptake (VO2max), muscle strength, resting left ventricular (LV) wall segment motion and early diastolic filling by resting echocardiograms, exercise ECG, heart rate, and blood pressure responses [corrected]. RESULTS VO2max increased 14% (P < 0.01) and cycle time increased 10% (P < 0.01) in the combined training group. The 8% increases in VO2max (P = 0.15) and cycle time (P = 0.08) in the cycling group were not significant. Arm and leg strength increased (P < 0.01) in each group. However, the change was greater for the combined training group--31% versus 16% (P < 0.03) for leg strength and 20% versus 10% (P < 0.001) for arm strength. There were no changes for either group in resting hemodynamics, body weight and composition, LV wall segment motion, LV fractional shortening, and early diastolic function, and no adverse clinical events or exercise-related complications. CONCLUSIONS Combined training soon after MI improved aerobic and muscle fitness more than cycling alone, and was performed without complication.
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Affiliation(s)
- K J Stewart
- Cardiac Rehabilitation and Prevention Program, Johns Hopkins Bayview Medical Center, Baltimore, Maryland, USA
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Christian TF, Gitter MJ, Miller TD, Gibbons RJ. Prospective identification of myocardial stunning using technetium-99m sestamibi-based measurements of infarct size. J Am Coll Cardiol 1997; 30:1633-40. [PMID: 9385887 DOI: 10.1016/s0735-1097(97)00409-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVES We sought to prospectively identify patients with stunning and hyperkinesia at hospital discharge on the basis of mismatches between left ventricular (LV) function and infarct size as assessed by technetium-99m (Tc-99m) sestamibi perfusion tomographic imaging. BACKGROUND Mechanical indexes of LV function may not accurately reflect myocardial damage after acute myocardial infarction (MI) because of myocardial stunning and compensatory hyperkinesia in noninfarct-related territories. Myocardial perfusion techniques are unaffected by these variables. METHODS Eighty-four patients with acute MI underwent hospital admission and discharge Tc-99m-sestamibi tomographic imaging. Global LV ejection fraction (LVEF) was measured at hospital discharge and 6 weeks later. The perfusion defect size was quantified and expressed as a percentage of the LV. The discharge perfusion defect, which is a measure of infarct size, was used to predict the 6-week LVEF for each patient based on a previously reported regression equation. Patients were classified into one of three groups depending on whether their LVEF at hospital discharge fell within, above or below one standard error (6.8 LVEF points) of the predicted 6-week LVEF. RESULTS There were 48 patients classified as having a "match" between function and infarct size; these patients demonstrated no significant change in LVEF at 6 weeks. There were 21 patients (25%) classified as "mismatch stunned" who had discharge LVEFs lower than those predicted by infarct size. These patients demonstrated a significant improvement in mean LVEF at 6 weeks (mean [+/-SD] discharge LVEF 0.41 +/- 0.08, 6-week LVEF 0.47 +/- 0.10; p = 0.003). Fifteen patients (18%) were classified as "mismatch-hyperkinetic." The mean LVEF for these patients significantly declined at 6 weeks (discharge LVEF 0.64 +/- 0.06, 6-week LVEF 0.58 +/- 0.09; p = 0.002). There was a marked increase in LVEF within the infarct zone (8 +/- 15 LVEF points; p = 0.03) for patients predicted to have stunning and a marked decline in LVEF outside the infarct zone (9 +/- 15 LVEF points; p = 0.06) in patients predicted to have hyperkinesia. Both discharge LVEF (p < 0.0001) and group classification (p = 0.005) were independent predictors of LVEF 6 weeks later. CONCLUSIONS Perfusion imaging with Tc-99m-sestamibi can identify post-MI patients at hospital discharge in whom LV function is discordant with the measured infarct size. Patients with stunning have late increases in LVEF; patients with hyperkinesia have late decreases. This methodology, performed at discharge, is predictive of late changes in LV function.
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Affiliation(s)
- T F Christian
- Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.
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23
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Holman ER, Buller VG, de Roos A, van der Geest RJ, Baur LH, van der Laarse A, Bruschke AV, Reiber JH, van der Wall EE. Detection and quantification of dysfunctional myocardium by magnetic resonance imaging. A new three-dimensional method for quantitative wall-thickening analysis. Circulation 1997; 95:924-31. [PMID: 9054752 DOI: 10.1161/01.cir.95.4.924] [Citation(s) in RCA: 125] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Regional left ventricular dysfunction is a major consequence of myocardial ischemia, and its extent determines long-term prognosis. Accurate and reproducible analysis of left ventricular dysfunction is therefore useful for risk stratification and patient management. METHODS AND RESULTS Short-axis cardiac cine magnetic resonance (MR) imaging was performed in 25 patients after anterior myocardial infarction at 21 +/- 2.1 days after the acute onset. The MR images were analyzed with the use of a dedicated analytical software package (MASS version 1.0), which includes a modified centerline method and a new three-dimensional analysis approach. A database of 48 healthy volunteers was constructed to objectively depict myocardial dysfunction in the patients; this database was compared with enzymatically determined infarct size. The mean (+/-SEM) quantity of dysfunctional myocardium and enzymatically calculated infarct size equaled 24.0 +/- 3.0 and 22.3 +/- 2.9 g, respectively (P = .69). Enzymatically determined infarct size correlated strongly with left ventricular dysfunction determined by cine MR imaging (y = 0.90x + .92. P < .0001). Segments related to the distribution of the left anterior descending coronary artery showed a significantly lower percentage wall thickening in patients than did corresponding segments of 48 normal subjects (46.0 +/- 8.22% versus 87.1 +/- mean SEM, respectively; P < .001). The mean (+/-SEM) end diastolic wall thickness of the infarcted segment did not differ from that of corresponding normal segments (7.4 +/- 0.33 versus 7.5 +/- 0.15 mm; P = .75). CONCLUSIONS We conclude that the use of three-dimensional quantitative analysis of cine MR images accurately quantities the extent of regional left ventricular dysfunction in the infarcted heart. This method of analysis may be useful in assessing the effect of interventional therapies.
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Affiliation(s)
- E R Holman
- Department of Cardiology, University Hospital, Leiden, Netherlands
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Conversano A, Walsh JF, Geltman EM, Perez JE, Bergmann SR, Gropler RJ. Delineation of myocardial stunning and hibernation by positron emission tomography in advanced coronary artery disease. Am Heart J 1996; 131:440-50. [PMID: 8604622 DOI: 10.1016/s0002-8703(96)90521-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
With positron emission tomography, the resting flow abnormalities underlying reversible left ventricular dysfunction in 17 patients with chronic coronary artery disease were delineated. The level of flow in reversible dysfuncTional segments (i.e., those demonstrating improvement after revascularization) was markedly variable, ranging from 0.32 to 1.25 ml/gm/min. In 20 of these segments, flow was preserved, whereas in 12 segments, flow was reduced, when compared with that in, age-matched controls. Preservation of flow was associated with preservation of myocardial oxygen consumption and no alterations in myocardial substrate use. In contrast, a reduction in flow resulted in a decrease myocardial oxygen consumption and an increase in myocardial glucose use. Thus resting reversible left ventricular dysfunction in patients with chronic coronary artery disease can reflect a diversity of resting flow abnormalities. Moreover, myocardial perfusion at rest is frequently within normal limits, suggesting that the reversible mechanical dysfunction in these patients is attributable to intermittent myocardial stunning and not hibernation.
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Affiliation(s)
- A Conversano
- Division of Nuclear Medicine, Mallinckrodt Institute of Radiology, St. Louis, Missouri 63110, USA
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Herregods MC, Bijnens B, Vandeplas A, De Geest H, Van de Werf F. Can dobutamine echocardiography distinguish necrotic from ischemic myocardium, early after myocardial infarction? INTERNATIONAL JOURNAL OF CARDIAC IMAGING 1995; 11:171-5. [PMID: 7499906 DOI: 10.1007/bf01143106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
UNLABELLED The aim of this study was to evaluate the usefulness of dobutamine echocardiography (DE) in distinguishing necrotic from ischemic myocardium in infarct zones. We performed DE in 39 patients, 3 to 5 days after admission for a first, acute myocardial infarction, treated with thrombolysis. DE was considered positive if wall motion in the infarct zone worsened progressively during increasing dose of dobutamine or if wall motion in the infarct zone initially improved at low dose of dobutamine and deteriorated at higher dose. The results of DE were correlated to the evolution of wall motion in the infarct zone after 3 months and to the need for supplementary balloon dilatation. In 15 of the 39 patients, there was evidence of residual ischemia in the infarct zone. Twenty of the 39 patients had a positive dobutamine echocardiogram. Eleven of these 20 patients had evidence of residual ischemia in the infarct zone. They showed generalized changes of wall motion in the total infarct territory during DE. The other 9 patients demonstrated only localized changes of wall motion in isolated segments of the infarct zone during DE. None of these patients had evidence of residual ischemia. IN CONCLUSION DE seems worthwhile in the detection of residual ischemia in the region of infarction. To reduce the number of false positive DE early after myocardial infarction, only extensive changes of wall motion in the total infarct territory should be accepted as indicative of residual ischemia in the infarct zone.
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Affiliation(s)
- M C Herregods
- University Hospital Gasthuisberg, Department of Cardiology, Leuven, Belgium
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27
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Herskowitz A, Wu TC, Willoughby SB, Vlahov D, Ansari AA, Beschorner WE, Baughman KL. Myocarditis and cardiotropic viral infection associated with severe left ventricular dysfunction in late-stage infection with human immunodeficiency virus. J Am Coll Cardiol 1994; 24:1025-32. [PMID: 7930193 DOI: 10.1016/0735-1097(94)90865-6] [Citation(s) in RCA: 129] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVES The purpose of this study was to characterize the histologic and immunopathologic results of 37 endomyocardial biopsy samples from patients infected with human immunodeficiency virus type 1 (HIV-1) who were evaluated for unexplained global left ventricular dysfunction. BACKGROUND Recent studies have identified a growing number of patients infected with HIV-1 who develop unexplained left ventricular dysfunction and congestive heart failure. Myocarditis has been confirmed at autopsy in small numbers of such patients, although a pathogenic opportunistic infectious agent can rarely be identified. METHODS All patients had moderate to severe global left ventricular hypokinesia on two-dimensional echocardiography. Endomyocardial biopsy samples were evaluated by standard histologic studies, immunoperoxidase staining and in situ hybridization for cytomegalovirus and HIV-1 gene sequences. RESULTS Twenty-eight patients presented with New York Heart Association functional class III or IV congestive heart failure. Four patients had myocarditis secondary to known etiologies (opportunistic infection n = 2; drug-induced hypersensitivity myocarditis n = 2). Of the remaining 33 samples, 17 (51%) showed histologic evidence of idiopathic active or borderline myocarditis. Immunohistologic findings revealed induced expression of major histocompatibility class I antigen on myocytes and increased numbers of infiltrating CD8+ T lymphocytes. Specific hybridization within myocytes was observed in 5 of 33 samples with the HIV-1 antisense riboprobe and in 16 of 33 samples with the cytomegalovirus immediate early (IE-2) antisense riboprobe. All but one patient with specific myocyte hybridization presented with congestive heart failure; all patients had myocarditis and CD4+ cell counts < 100/mm3. CONCLUSIONS This study demonstrates that cardiotropic virus infection and myocarditis may be important in the pathogenesis of symptomatic HIV-associated cardiomyopathy.
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Affiliation(s)
- A Herskowitz
- Department of Medicine, School of Public Health and Hygiene, Johns Hopkins Medical Institutions, Baltimore, Maryland
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Hayashi H, Takatsu F, Sone T, Mizutani N, Hirayama H, Osugi J, Yamauchi K, Ogawa H, Watanabe T, Saito H. Effects of intravenous SM-9527 (double-chain tissue plasminogen activator) on left ventricular function in the chronic stage of acute myocardial infarction. Clin Cardiol 1993; 16:409-14. [PMID: 8504575 DOI: 10.1002/clc.4960160508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Clinical effects of thrombolytic agent SM-9527 (double-chain tissue plasminogen activator) on left ventricular (LV) function were assessed in patients with acute myocardial infarction (AMI). A dose of 30 x 10(6) IU SM-9527 was given intravenously to patients with AMI within 6 h after onset. Of 159 candidates, 20 were excluded from the trial due to diseases other than myocardial infarction or failure to meet the protocol requirements; 114 of the remaining 139 were subjected to LV function analysis. The following results were obtained: (1) Patients with successful reperfusion in response to SM-9527 in the acute stage without later reocclusion revealed a significant improvement of LV function in the chronic stage. (2) Adverse effects were noted in 15 patients (10.8%), but none were serious; all were bleeding related to catheterization. (3) Hemagglutination fibrinolysis system test revealed no problems. It is concluded that early thrombolytic therapy with intravenous SM-9527 for AMI provides significant improvement of LV function in the chronic stage.
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Affiliation(s)
- H Hayashi
- Department of Internal Medicine, Nagoya University School of Medicine, Japan
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Herskowitz A, Vlahov D, Willoughby S, Chaisson RE, Schulman SP, Neumann DA, Baughman KL. Prevalence and incidence of left ventricular dysfunction in patients with human immunodeficiency virus infection. Am J Cardiol 1993; 71:955-8. [PMID: 8465788 DOI: 10.1016/0002-9149(93)90913-w] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The prevalence and incidence of left ventricular (LV) dysfunction was examined in patients infected with the human immunodeficiency virus (HIV). Sixty-nine randomly selected patients diagnosed with HIV infection who were followed in HIV clinics were prospectively evaluated by 2-dimensional echocardiography. Mean follow-up duration was 11 months. Additionally, 39 consecutive HIV-infected patients referred to the Cardiomyopathy Service and found to have LV dysfunction by 2-dimensional echocardiography were also studied. Of the 39 referred patients, 34 (87%) were referred for recent onset, unexplained, congestive heart failure. During this time, the HIV clinic population comprised 1,819 alive and actively followed patients; the 39 cardiomyopathy referrals therefore constituted a crude rate of 2.1% for this population. Of the 69 prospectively studied patients without clinical heart disease, a 14.5% prevalence of global LV hypokinesia and an incidence of 18%/patient-year were found. During a maximal 18-month follow-up period, 4 prospective patients (5.8%) developed symptoms of congestive heart failure. A greater proportion of prospective and referred patients with LV dysfunction had CD4 counts < 100/mm3 (62 and 79%, respectively) than did that of those without LV dysfunction (35%). In conclusion, the high rate of unexpected LV dysfunction in this HIV-infected population suggests that early cardiac contractile abnormalities may involve a significant number of patients, most of whom have low CD4 counts. A subgroup of these patients appears to progress to symptomatic congestive heart failure.
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Affiliation(s)
- A Herskowitz
- Department of Medicine, School of Public Health and Hygiene, Johns Hopkins Medical Institutions, Baltimore, Maryland
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30
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Affiliation(s)
- R Bolli
- Department of Medicine, Baylor College of Medicine, Houston, Tex. 77030
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31
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Popma JJ, Califf RM, Ellis SG, George BS, Kereiakes DJ, Samaha JK, Worley SJ, Anderson JL, Stump D, Woodlief L. Mechanism of benefit of combination thrombolytic therapy for acute myocardial infarction: a quantitative angiographic and hematologic study. J Am Coll Cardiol 1992; 20:1305-12. [PMID: 1430679 DOI: 10.1016/0735-1097(92)90241-e] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVES The goal of this study was to lend insight into the mechanisms responsible for the beneficial effects of combination thrombolytic therapy. BACKGROUND Combination thrombolytic therapy for acute myocardial infarction has been associated with less reocclusion and fewer in-hospital clinical events than has monotherapy. METHODS Infarct-related quantitative coronary dimensions and hemostatic protein levels were evaluated in 287 patients with acute myocardial infarction during the early (90-min) and convalescent (7-day) phases after administration of recombinant tissue-type plasminogen activator (rt-PA), urokinase or combination rt-PA and urokinase. RESULTS Minimal lumen diameter was similar in the 90-min and 7-day phases after treatment with rt-PA, urokinase and combination rt-PA and urokinase (0.72 +/- 0.45 mm, 0.62 +/- 0.53 mm and 0.75 +/- 0.58 mm, respectively, at 90 min, p = 0.16; and 1.05 +/- 0.56 mm, 1.12 +/- 0.72 mm and 0.94 +/- 0.54 mm, respectively, at 7 days, p = 0.22). In-hospital clinical event and reocclusion rates were less frequent in patients receiving combination therapy than in those receiving monotherapy (25% vs. 38% and 32% for rt-PA and urokinase, respectively, p = 0.084; and 3% vs. 13% and 9% for rt-PA and urokinase, respectively, p = 0.03), but these events were unrelated to early or late coronary dimensions. Patients receiving combination therapy or urokinase monotherapy had significantly higher peak fibrin degradation products (1,307 +/- 860 and 1,285 +/- 898 micrograms/ml vs. 435 +/- 717 micrograms/ml, respectively, p < 0.0001) and lower nadir fibrinogen levels (0.85 +/- 1.00 and 0.75 +/- 0.53 g/liter vs. 1.90 +/- 0.86 g/liter, respectively, p < 0.0001) than did those receiving rt-PA monotherapy. Peak fibrinogen degradation products indirectly correlated (p = 0.004) and baseline (p = 0.026) and nadir (p = 0.089) fibrinogen levels directly correlated with reocclusion. CONCLUSIONS Lower in-hospital clinical event and reocclusion rates observed with combination thrombolytic therapy may relate to systemic hematologic factors rather than to the residual lumen obstruction after thrombolysis.
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Affiliation(s)
- J J Popma
- Department of Internal Medicine (Cardiology Division), University of Michigan Medical Center, Ann Arbor
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Abstract
Although the mechanisms involved in stunning remain incompletely defined, it appears that intracellular calcium overload, sarcoplasmic reticulum dysfunction, and the generation of OFR are important components of post-ischemic myocyte dysfunction. It is likely that a variety of mechanisms, some possibly remaining to be elucidated, are operative in the pathogenesis of stunning, and that the contribution of a particular process may be influenced by the model and the method of inducing ischemia. Myocardial stunning has been shown to be prevalent in patients with diverse cardiac diseases. Small clinical trials have suggested that electrocardiography, echocardiography, and radionuclide imaging techniques may be useful in identifying patients with stunned myocardium. In patients with depressed cardiac performance due to stunning, therapy with inotropic agents may recruit the viable but injured myocardium to contract and improve cardiac output in the short term. An important issue that will be addressed over the next decade is whether aggressive therapy aimed at reducing myocardial stunning in stable patients should be attempted. Some authorities have suggested that stunning may represent an adaptive response to limit reperfusion injury, and that interfering with this response may not be beneficial in the long term. Further investigation into the cellular and molecular basis of ischemic injury should provide insight into these and other important aspects of myocardial stunning. Methods of attenuating postischemic ventricular dysfunction that appear convincing in the research laboratory may not translate to clinical benefit when applied to humans.
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Affiliation(s)
- B D Scott
- Department of Medicine, University of Iowa College of Medicine, Iowa City
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Katz AS, Harrigan P, Parisi AF. The value and promise of echocardiography in acute myocardial infarction and coronary artery disease. Clin Cardiol 1992; 15:401-10. [PMID: 1617820 DOI: 10.1002/clc.4960150603] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Two-dimensional and Doppler echocardiography have become extremely useful in the management of patients with acute myocardial infarction (AMI). Echocardiography is noninvasive, relatively inexpensive, and has no known biohazards. It offers unequaled information about cardiac anatomy and function. In the acute setting it is useful in the diagnosis of AMI and its complications. It is an excellent tool for monitoring therapy. Echocardiography has been shown to be useful in risk stratification upon presentation to the emergency ward and prior to hospital discharge. Stress echocardiography has broadened and sharpened the diagnostic and prognostic information. Contrast echocardiography has promise for demonstrating coronary artery flow. Research in ultrasonic myocardial tissue characterization shows potential for differentiating ischemic myocardium from infarcted myocardium. Thus, echocardiography is likely to become increasingly important in the future management of patients with AMI.
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Affiliation(s)
- A S Katz
- Department of Medicine, Miriam Hospital, Providence, RI 02906
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34
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Abstract
Experimental studies have demonstrated that myocardium reperfused after reversible ischemia exhibits prolonged depression of contractile function ("stunning"). Despite the multiplicity of clinical situations in which myocardial stunning would be expected to occur, investigation of this phenomenon in humans has been hindered by several major problems, including the limited accuracy of the methods available to measure regional left ventricular function, the inability to quantify regional myocardial blood flow during acute ischemia, the difficulty in establishing with certainty, the beginning and end of an ischemic episode, and the uncontrolled influence of variables (such as preload, afterload, adrenergic tone, and inotropic therapy) that have a major impact on postischemic dysfunction. The main problem is to discern whether a reversible defect of contractility is caused by stunning, silent ischemia, or hibernation (i.e., chronic ischemia). This differential diagnosis requires the simultaneous measurement of regional myocardial function and flow, which thus far has not been generally possible. Despite these limitations, however, numerous clinical observations suggest that stunning does occur in various settings in which the myocardium is exposed to transient ischemia, including coronary angioplasty, exercise-induced angina, angina at rest (unstable or variant), acute myocardial infarction with early reperfusion, open-heart surgery, and cardiac transplantation. Recognition of this entity is important, amongst other reasons, because it is likely to cause significant morbidity and because it is potentially correctable with inotropic therapy or even preventable with antioxidant therapy. In addition, the appreciation of the phenomenon of myocardial stunning should allow the clinician to assess the efficacy of reperfusion therapy with greater accuracy and to recognize that patients should not be denied mechanical revascularization solely because of an abnormal left ventricular wall motion. Perhaps the most intriguing clinical implication of the concept of myocardial stunning is the possibility that in patients who exhibit frequent episodes of ischemia in the same territory, the myocardium may not be able to fully recover between episodes and thus may remain reversibly depressed for prolonged periods of time, or even chronically, which could account for some cases of "ischemic cardiomyopathy." Our understanding of myocardial stunning in humans is still relatively crude and will not significantly improve until studies are performed that measure simultaneously regional myocardial perfusion and function (so that stunning can be differentiated from silent ischemia and hibernation). Future important areas of research should also include the elucidation of whether stunning can become chronic and the evaluation of therapies (such as antioxidant treatments) designed to prevent this contractile abnormality.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- R Bolli
- Department of Medicine, Baylor College of Medicine, Houston, TX 77030
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35
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Kaul S. Role of Doppler echocardiography in coronary artery disease. J Intensive Care Med 1991; 6:238-56. [PMID: 10149576 DOI: 10.1177/088506669100600503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Doppler echocardiography can have a major role in the evaluation of patients with coronary artery disease. This review deals with the imaging planes in relation to coronary vascular territories and the role of Doppler echocardiography in evaluating patients with acute and chronic ischemic syndromes.
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Affiliation(s)
- S Kaul
- Division of Cardiology, University of Virginia, Charlottesville 22908
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36
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de Zwaan C, Cheriex EC, Braat SH, Stappers JL, Wellens HJ. Improvement of systolic and diastolic left ventricular wall motion by serial echocardiograms in selected patients treated for unstable angina. Am Heart J 1991; 121:789-97. [PMID: 2000745 DOI: 10.1016/0002-8703(91)90190-s] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The purpose of the study was to evaluate the effect of antiischemic treatment on left ventricular function in selected patients with unstable angina pectoris that was due to severe proximal left anterior descending coronary artery narrowing and to identify subgroups liable to an adverse outcome (mean term 2.7 years). Effect of antiischemic treatment on systolic and diastolic left ventricular wall motion was studied in 35 patients who had unstable angina pectoris and an electrocardiogram that indicated severe proximal left anterior descending coronary artery narrowing. Treatment consisted of either a revascularization procedure (17 patients) or antianginal drug therapy (18 patients). All patients underwent a two-dimensional echocardiographic study within 48 hours (mean 20 hours) of entry into the study. This study semiquantitatively analyzed systolic performance of the ischemia-related segments by calculation of a total wall motion score. In 16 patients this investigation was combined with a continuous detailed recording of only the apical interventricular septal wall motion. This detailed study included measurements for regional function by providing a typification of the pattern of systolic and early diastolic excursion of the endocardial border of the apical interventricular septum. A repeat ultrasonic study was performed at least 1 month (median 2 months, 7 days) after admission. Results of the systolic wall motion analyses of all 35 patients showed, in both treatment groups, a significant improvement in systolic wall motion of the anterior and apical segments (mean total wall motion score at early study vs late study: revascularization, 6.9 vs 2.2 and medical therapy, 4.6 vs 1.0).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- C de Zwaan
- Department of Cardiology, University of Limburg, Academic Hospital Maastricht, The Netherlands
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Wilkes NP, Jones MP, O'Rourke MF, Nelson GI. Determinants of recurrent ischaemia and revascularisation procedures after thrombolysis with recombinant tissue plasminogen activator in primary coronary occlusion. Int J Cardiol 1991; 30:69-76. [PMID: 1899409 DOI: 10.1016/0167-5273(91)90126-a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
This paper reports the immediate effects of thrombolysis and their subsequent influence on revascularisation procedures and clinical outcome over the subsequent twelve months. Coronary arteriography was performed at 21 days on 131 of 145 patients who received recombinant tissue plasminogen activator (n = 68) or placebo (n = 63) within 2.5 hours of symptom onset after primary coronary occlusion. Patency rates (TIMI grades 2 and 3) of the infarct-related artery were 81% with plasminogen activator and 63% with placebo (P = 0.02). Early (within 21 days) angiography for recurrent ischaemia was necessary in 31 (21%) patients (20 plasminogen activator, 11 placebo NS) and definite reinfarction occurred in 8 (5%) patients (4 plasminogen activator, 4 placebo). During one year follow-up without planned secondary intervention, coronary artery bypass grafting was more frequent in patients who had received thrombolytic therapy (23% plasminogen activator, 4% placebo P = 0.001); coronary angioplasty procedures were similar in both groups (12% plasminogen activator, 11% placebo NS). Mortality at 21 days was 5% (4 plasminogen activator, 4 placebo) and at one year was 7% (5 plasminogen activator, 5 placebo). Logistic regression analysis identified models comprising characteristics predictive of subsequent bypass grafting (plasminogen activator, multivessel disease, occluded infarct-related artery) and coronary angioplasty (non-q wave infarction, severe (91-99%) residual stenosis, left anterior descending infarct-related artery). Initial non-q wave infarction was the only predictor of early recurrent ischemia (odds ratio 4, P = 0.02) irrespective of residual stenosis severity.
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Affiliation(s)
- N P Wilkes
- Royal North Shore Hospital, Sydney, Australia
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38
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Jolly SR, Jordan JC, Rose GC. Stimulation of myocardial function after brief regional ischemia by glucagon. Drug Dev Res 1991. [DOI: 10.1002/ddr.430220203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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39
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Christian TF, Behrenbeck T, Pellikka PA, Huber KC, Chesebro JH, Gibbons RJ. Mismatch of left ventricular function and infarct size demonstrated by technetium-99m isonitrile imaging after reperfusion therapy for acute myocardial infarction: identification of myocardial stunning and hyperkinesia. J Am Coll Cardiol 1990; 16:1632-8. [PMID: 2147706 DOI: 10.1016/0735-1097(90)90313-e] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Quantitation of perfusion defect size using tomographic imaging with technetium-99m-hexakis-2-methoxy isobutyl isonitrile was performed at the time of hospital discharge in 32 patients with a first myocardial infarction who underwent successful coronary reperfusion within 8 h of the onset of chest pain. Reperfusion was accomplished with thrombolysis or primary coronary angioplasty. Radionuclide angiography was performed at discharge and 6 weeks later. There was a close correlation between perfusion defect size and values for ejection fraction and regional wall motion both at discharge (r = -0.80 and -0.75, respectively) and 6 weeks later (r = -0.81 and -0.81, respectively). There was no overall group difference in ejection fraction between the value at discharge and at 6 weeks; however, five patients had a significant increase (greater than or equal to 0.08) and six had a significant decrease (greater than or equal to 0.08) in ejection fraction. In patients with a significant increase at 6 weeks, ejection fraction was significantly lower at discharge than the value predicted from perfusion defect size (0.37 +/- 0.09 measured versus 0.47 +/- 0.13 predicted, p less than 0.05) and it improved at 6 weeks to near predicted values (0.51 +/- 0.07). In patients with a significant decrease at 6 weeks, ejection fraction was significantly higher at discharge than the value predicted from perfusion defect size (0.60 +/- 0.10 measured versus 0.50 +/- 0.10 predicted, p less than 0.05) and it decreased at 6 weeks to near predicted levels (0.51 +/- 0.09). Left ventricular ejection fraction at the time of hospital discharge is a potentially misleading index of the efficacy of reperfusion therapy for myocardial infarction. In a significant minority (34%) of patients this index does not accurately reflect perfusion defect size, apparently because of the effects of myocardial stunning and compensatory hyperkinesia.
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Affiliation(s)
- T F Christian
- Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic, Rochester, Minnesota 55905
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40
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Abstract
Myocardial salvage can be maximized by the early institution of thrombolytic therapy and aspirin. Certain patients may benefit from the administration of intravenous heparin, beta blockers, or nitroglycerin. The routine use of percutaneous transluminal coronary angioplasty (PTCA) or calcium-channel blockers does not appear to be warranted. Recurrent myocardial ischemia should be vigorously treated with medical therapy and there may be value in cardiac catheterization, followed by PTCA or bypass surgery, depending upon the extent of myocardium at risk and the underlying coronary anatomy. Long-term morbidity and mortality may be reduced by instituting aspirin and beta blockers as well as by modifying risk factors. There is no evidence for the long-term benefit from any calcium-channel blocker. Oral anticoagulation may be warranted in those patients with a mural thrombus, congestive heart failure, or atrial fibrillation. ACE inhibitors may be of value in the presence of left ventricular dysfunction and certainly in the presence of symptomatic congestive heart failure. Antiarrhythmic therapy is generally indicated only for symptomatic or life-threatening arrhythmias. Residual myocardial ischemia should be sought by exercise testing, and those patients with poor exercise tolerance generally warrant cardiac catheterization in consideration for revascularization.
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Affiliation(s)
- D Massel
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
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41
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Kussmaul WG, Kleaveland JP, Zeevi GR, Hirshfeld JW. Accuracy of subjective and computer-assisted assessments of angiographic left ventricular regional wall motion. CATHETERIZATION AND CARDIOVASCULAR DIAGNOSIS 1990; 20:153-64. [PMID: 2194662 DOI: 10.1002/ccd.1810200302] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
To evaluate the accuracy of angiographic methods for analysis of left ventricular regional wall motion, we measured the ability of a carefully performed subjective analysis (three independent observers) and that of three computer-assisted methods (centerline, radial, and area) to detect the presence of significant coronary artery disease. Normal ranges were established in 90 studies showing normal wall motion, and accuracy was tested in a second, consecutive series of 43 ventriculograms. The results show that the subjective method best separated those regions with from those without significant coronary disease. The subjective method also demonstrated sensitivity comparable to the centerline and radial methods. Among the computer-assisted methods, the area method was least sensitive but most specific for both anterior and inferior region coronary disease. The centerline and radial methods were highly sensitive, but less specific. When coronary disease was defined by electrocardiographic Q-waves, the area method had superior accuracy. Further analysis showed the following: 1) For the centerline and radial methods, long-axis reregistration of the end-systolic frame resulted in loss of sensitivity but increased specificity for anterior wall coronary disease, and little change in analysis of the inferior wall; 2) inclusion or exclusion of the apex had little effect on predictive accuracy for anterior wall coronary disease; 3) as expected, sensitivity and specificity results of all methods were dependent on the selection of a normal range cutoff value; but when performance was optimized, the subjective and area methods had a higher overall predictive accuracy than the centerline method; 4) It is likely that all three computer-assisted methods could be calibrated to give indications of degrees of hypokinesis, as their results correlated well with subjective observers' evaluations over the entire range of scores. These results should assist in selection of the optimal method for regional wall motion analysis in clinical and research applications. As currently applied, the area method is the most specific of the computer-assisted methods tested; the centerline and radial methods have highest sensitivity and therefore are most suited to detection of mild degrees of hypokinesis.
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Affiliation(s)
- W G Kussmaul
- Cardiac Catheterization Laboratory, Hospital of the University of Pennsylvania, Philadelphia 19104
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42
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Abstract
Echocardiography has a major role in the evaluation of patients with CAD. To obtain the maximal amount of information using this technique, certain basic principles relating to regional myocardial mechanics during ischemia and flow-function relations are required. In addition, a detailed knowledge of cardiac anatomy and the three-dimensional orientation of the heart within the chest cavity is required to access meaningful information from two-dimensional planes. Furthermore, skill is also required in acquiring data in proper imaging planes and in separating true (actual pathology) from the false (artifacts, etc.). Echocardiography is not a "mature" technology. It is still developing and it is sometimes difficult to keep up with the advances. However, keeping abreast of these developments is essential to fully exploit the advantages of this technique. In addition, knowledge of the ever-changing aspects of CAD is required in order to correctly interpret visual information in context of a particular patient. Finally, more clinical studies are needed to further define the role of echocardiographic techniques in patients with CAD.
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Affiliation(s)
- S Kaul
- Cardiac Computer Center, University of Virginia, Charlottesville
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Rogers WJ, Baim DS, Gore JM, Brown BG, Roberts R, Williams DO, Chesebro JH, Babb JD, Sheehan FH, Wackers FJ. Comparison of immediate invasive, delayed invasive, and conservative strategies after tissue-type plasminogen activator. Results of the Thrombolysis in Myocardial Infarction (TIMI) Phase II-A trial. Circulation 1990; 81:1457-76. [PMID: 2110033 DOI: 10.1161/01.cir.81.5.1457] [Citation(s) in RCA: 142] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
To assess the value and timing of percutaneous transluminal coronary angioplasty (PTCA) after thrombolytic therapy for acute myocardial infarction (AMI), 586 patients in the Thrombolysis in Myocardial Infarction Study Phase II-A were randomized among three treatment strategies, one using immediate coronary arteriography followed by PTCA if appropriate (immediate invasive strategy group, n = 195), a second that deferred angiography and PTCA for 18-48 hours (delayed invasive strategy group, n = 194), and a third, more conservative, approach in which PTCA was used only if ischemia occurred spontaneously or at the time of predischarge exercise testing (conservative strategy group, n = 197). Predischarge contrast left ventricular ejection fraction, the primary study end point, was similar among the patients in all three treatment groups and averaged 49.3%. The finding of a patent infarct-related artery at the time of predischarge arteriography was equally common among the patients in the three groups (mean, 83.7%); however, the mean residual infarct artery stenosis was greater in the patients in the conservative strategy group (67.2%) as compared with the patients in the immediate invasive (50.6%) and the delayed invasive strategy groups (47.8%) (p less than 0.001). Immediate invasive strategy led to a higher rate of coronary artery bypass graft surgery (CABG) after PTCA (7.7%) than did delayed invasive and conservative strategies (2.1% and 2.5%, respectively; p less than 0.01). Furthermore, among patients not undergoing CABG during the first 21 days, blood transfusion of more than 1 unit was used in 13.8% of the patients in the immediate invasive strategy group, 3.1% of the patients in the delayed invasive strategy group, and 2.0% of the patients in the conservative strategy group (p less than 0.001). At 1-year follow-up, the three treatment groups had similar cumulative rates of mortality (8.7%, pooled over all groups), fatal and nonfatal reinfarction (8.5%), combined death and reinfarction (14.5%), and CABG (17.2%), although the cumulative performance rate of PTCA remained higher in the invasive groups (immediate invasive strategy group, 75.8%; delayed invasive strategy group, 64.3%; and conservative strategy group, 23.9%; p less than 0.001). Thus, because conservative strategy achieves equally good short- and long-term outcome with less morbidity and a lower use of PTCA, it seems to be the preferred initial management strategy.
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Affiliation(s)
- W J Rogers
- Thrombolysis in Myocardial Infarction, Coordinating Center, Baltimore, Maryland
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Lundgren C, Bourdillon PD, Dillon JC, Feigenbaum H. Comparison of contrast angiography and two-dimensional echocardiography for the evaluation of left ventricular regional wall motion abnormalities after acute myocardial infarction. Am J Cardiol 1990; 65:1071-7. [PMID: 2330892 DOI: 10.1016/0002-9149(90)90316-s] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Regional left ventricular wall motion abnormalities were assessed using 2-dimensional echocardiography and contrast ventriculography within 12 hours of the onset of chest pain in 20 patients with acute myocardial infarction (AMI); 10 patients had anterior infarctions and 10 had inferior. End-diastolic and end-systolic sinus beats from right anterior oblique contrast ventriculograms were analyzed using the center-line chord technique with both a standard overlap method of chord assignment and a nonoverlap method. Echocardiograms were obtained in parasternal long- and short-axis and apical 2- and 4-chamber views and analyzed using a 16-segment scoring system to derive anterior and infero-posterolateral wall motion indexes using both overlap (10 segments for anterior, 8 inferior) as well as nonoverlap (9 segments anterior, 7 inferior) methods of segment assignment. There was a significant inverse correlation between the standard (nonoverlap) echocardiographic analysis and the standard (overlap) angiographic analysis for infarct regions (y = -0.43 X +1.11, r = -0.59, p less than 0.05). Fifteen of 18 patients with angiographic infarct regional score less than or equal to -1 standard deviation/chord had an echocardiographic index greater than or equal to 1.5, while 15 of 16 patients with echocardiographic regional infarct index greater than or equal to 1.5 had an angiographic score less than or equal to -1 standard deviation/chord. Correlation between the 2 methods for noninfarct territories was poor (r = -0.34) because the angiographic method assesses hyperkinesis while the echocardiographic method does not.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- C Lundgren
- Department of Medicine, Indiana University School of Medicine, Indianapolis
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Sobel BE, Sarnoff SJ, Nachowiak DA. Augmented and sustained plasma concentrations after intramuscular injections of molecular variants and deglycosylated forms of tissue-type plasminogen activators. Circulation 1990; 81:1362-73. [PMID: 2107986 DOI: 10.1161/01.cir.81.4.1362] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We have previously explored induction of coronary thrombolysis with tissue-type plasminogen activator (t-PA) administered intramuscularly. Absorption-enhancing agents that rendered the approach feasible were identified, but large amounts of activator were required and initial elevations of concentrations in plasma could not be sustained. The present study was designed to determine whether more therapeutically favorable plasma concentrations could be induced by genetically engineering or chemically modifying t-PA to prolong its half-life based on the hypothesis that the ratio of absorption to clearance would be increased. Each of four genetically engineered variants (one variant with growth factor and kringle 1 domains deleted and kringle 2 duplicated, a second variant with a cysteine for Arg substitution in the growth factor domain, a third variant with an additional urokinase kringle inserted, and a fourth variant with the growth factor domain deleted) and enzymatically deglycosylated t-PA exhibited prolonged half-life after bolus intravenous injection in rabbits. Each elicited substantially higher and more sustained elevations in plasma after intramuscular injection in rabbits or dogs with absorption-enhancing agents as compared with wild-type t-PA that were not accompanied by a systemic lytic state. Thus, use of molecular variants of t-PA with prolonged half-lives in the circulation permits induction of augmented and sustained elevations of plasma concentrations after intramuscular injection with absorption-enhancing agents as compared with wild-type t-PA, rendering potentially therapeutic blood levels more attainable with relatively modest amounts of material.
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Affiliation(s)
- B E Sobel
- Cardiovascular Division, Washington University School of Medicine, St. Louis, Missouri 63110
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46
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Piérard LA, De Landsheere CM, Berthe C, Rigo P, Kulbertus HE. Identification of viable myocardium by echocardiography during dobutamine infusion in patients with myocardial infarction after thrombolytic therapy: comparison with positron emission tomography. J Am Coll Cardiol 1990; 15:1021-31. [PMID: 2312956 DOI: 10.1016/0735-1097(90)90236-i] [Citation(s) in RCA: 574] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
To assess the presence of viable myocardium salvaged by coronary artery reperfusion, 17 patients with acute anterior myocardial infarction were studied. Each received intravenous thrombolysis within the first 3 h of symptoms and underwent two-dimensional echocardiography before and during dobutamine infusion (10 micrograms/kg per min) 7 +/- 4 days after admission and positron emission tomography 9 +/- 5 days after admission. Echocardiography and positron emission tomography were again performed 9 +/- 7 months later. Six comparable segments specific for the territory of the left anterior descending artery were selected for comparison of the two techniques. Wall thickening was evaluated by using an echocardiographic score index. Segmental perfusion and glucose uptake were measured and normalized to the peak activity. A ratio of glucose uptake to perfusion was calculated for each segment. Concordant interpretation of the two techniques was found in 79% of affected segments for both acute and follow-up studies. Positron emission tomography revealed the presence of viable myocardium in 11 patients (group 1); perfusion was within normal limits in 5 of these (group 1A). Myocardial thickening improved with dobutamine infusion in these five patients, the echocardiographic score index decreasing from 12 +/- 2 at rest to 7.8 +/- 1.3 during dobutamine infusion (p = 0.003). Functional recovery was demonstrated in all five patients (follow-up score index 7.4 +/- 1.7). Six patients exhibited decreased perfusion but an abnormally high glucose to perfusion ratio (group 1B); their score index improved with dobutamine from 14.8 +/- 2.2 to 12 +/- 2.1 (p = 0.05), but late functional recovery was found in only one of the six patients (mean follow-up score index in group 1B 16 +/- 1.7). In the six remaining patients in whom no viable myocardium was detected with positron emission tomography (group 2), the echocardiographic score index did not change with dobutamine (15 +/- 0.9 to 14.7 +/- 0.8, p = NS) and there was no functional recovery (follow-up score index 15.5 +/- 1.0). Echocardiography during dobutamine infusion is a promising method to unmask viable myocardium in acute myocardial infarction. Early recovery of perfusion in the area at risk is associated with a good functional outcome, whereas a high glucose to perfusion ratio indicates jeopardized myocardium that frequently loses viability.
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Affiliation(s)
- L A Piérard
- Department of Medicine, University of Liège, Belgium
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47
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Santoro GM, Bisi G, Sciagrà R, Leoncini M, Fazzini PF, Meldolesi U. Single photon emission computed tomography with technetium-99m hexakis 2-methoxyisobutyl isonitrile in acute myocardial infarction before and after thrombolytic treatment: assessment of salvaged myocardium and prediction of late functional recovery. J Am Coll Cardiol 1990; 15:301-14. [PMID: 2137147 DOI: 10.1016/s0735-1097(10)80053-1] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Single photon emission computed tomography (SPECT) with technetium-99m hexakis 2-methoxyisobutyl isonitrile was investigated as a method to evaluate the results of intravenous thrombolytic treatment in 14 patients (11 men and 3 women) with acute myocardial infarction admitted to the coronary care unit within 4 h of the onset of symptoms. All patients received an injection of 740 MBq of the tracer before starting the thrombolytic therapy, and isonitrile tomography was performed 3 to 4 h later. The tomographic study was repeated 5 days after the acute event. The results of thrombolytic treatment were independently evaluated taking into account the clinical, electrocardiographic (ECG) and enzymatic data and the findings of left ventricular and coronary angiography. Furthermore, all patients were studied with two-dimensional echocardiography on admission, 5 days later and 1 month later. The site and extent of the perfusion defects on admission scintigraphy were consonant with the ECG and echocardiographic findings. A good correlation could be established between the 5 day scintigraphic estimate of infarct dimension and the enzymatic infarct size (r = 0.907, p less than 0.00002). The comparison between pre- and postthrombolytic treatment images enabled the identification of successful and unsuccessful reperfusion even in patients whose other noninvasive findings were inconclusive. Finally, the reduction in defect size predicted late functional improvement that was demonstrated by echocardiography performed 1 month later (r = 0.89, p less than 0.00005). The results of the study suggest the feasibility and the possible usefulness of isonitrile tomography in demonstrating the presence and size of myocardial damage and in assessing the extent of myocardial salvage after thrombolytic therapy in acute myocardial infarction.
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Affiliation(s)
- G M Santoro
- Division of Cardiology, Careggi Hospital, Florence, Italy
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48
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49
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Bourdillon PD, Broderick TM, Sawada SG, Armstrong WF, Ryan T, Dillon JC, Fineberg NS, Feigenbaum H. Regional wall motion index for infarct and noninfarct regions after reperfusion in acute myocardial infarction: comparison with global wall motion index. J Am Soc Echocardiogr 1989; 2:398-407. [PMID: 2516742 DOI: 10.1016/s0894-7317(89)80041-0] [Citation(s) in RCA: 128] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A regional wall motion index has been derived from two-dimensional echocardiograms by use of a 16-segment model that was subdivided into anterior (nine segments) and infero-postero-lateral (seven segments) regions. This new method is compared with the use of a previously described global wall motion index for the analysis of serial echocardiograms after reperfusion in 23 patients who had acute myocardial infarction. Mean global index improved from 1.84 +/- 0.46 to 1.56 +/- 0.37 at 24 hours (p less than 0.01) and to 1.50 +/- 0.29 after 3 days to 7 days (p less than 0.02), whereas mean regional index for infarct regions improved from 2.28 +/- 0.73 to 1.82 +/- 0.58 at 24 hours (p less than 0.01) and to 1.70 +/- 0.42 after 3 to 7 days (p less than 0.01), with no significant change in the noninfarct index (1.34 +/- 0.32 initially and 1.28 +/- 0.36 after 3 to 7 days). Although both global and regional indexes effectively demonstrate early recovery of left ventricular function, (within 24 hours in many patients), the regional index for infarct regions is higher than the global index and effectively distinguishes between infarct and noninfarct segments. An overlap index in which an additional apical segment is included in the anterior region (10 segments) for anterior infarctions and in the infero-postero-lateral region (eight segments) for inferior infarctions results in a greater differentiation between infarct and noninfarct regions, with the mean initial noninfarct overlap index (1.17 +/- 0.33) significantly less than the nonoverlap index.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- P D Bourdillon
- Department of Medicine, Indiana University School of Medicine, Indianapolis
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50
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Josephson RA, Weiss JL, Becker LC, Shapiro EP. Dipyridamole echocardiography in the detection of vulnerable myocardium in the early postinfarction period. J Am Soc Echocardiogr 1989; 2:324-30. [PMID: 2629871 DOI: 10.1016/s0894-7317(89)80007-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
To evaluate the effect of dipyridamole on regional wall motion after myocardial infarction two-dimensional echocardiograms were obtained on 21 postinfarction patients immediately before and 7 to 10 minutes after the intravenous infusion of ddipyridamole (0.60 mg/kg). All patients underwent coronary angiography, and 20 patients underwent scintigraphy with dipyridamole thallium immediately subsequent to dipyridamole echocardiography. Dipyridamole augmented noninfarct zone regional wall motion in 20 of 31 regions supplied by nonstenotic coronary arteries. In contrast, only one of eight regions of noninfarct zone myocardium supplied by coronary arteries with greater than a 70% luminal diameter narrowing (vulnerable myocardium) was able to augment the regional wall motion subsequent to dipyridamole administration (p = 0.05). Dipyridamole echocardiography appears to be a safe and sensitive technique that may be useful in the detection of vulnerable myocardium in the early postinfarction period.
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