Low lymphocyte count and cardiovascular diseases

Inflammation plays a crucial pathophysiological role in the entire continuum of the atherosclerotic process, from its initiation, progression, and plaque destabilization leading ultimately to an acute coronary event. Furthermore, once the clinical event has occurred, inflammation also influences the left ventricular remodelling process. Under the same paradigm, there is evidence that lymphocytes play an important role in the modulation of the inflammatory response at every level of the atherosclerotic process. Low lymphocyte count (LLC) is a common finding during the systemic inflammatory response, and clinical and animal studies suggest that LCC plays a putative role in accelerated atherosclerosis. For instance, there is recent evidence that LLC is associated with worse outcomes in patients with heart failure, chronic ischemic heart disease and acute coronary syndromes. Further indirect evidence supports the pathologic role of LLC related to the fact that 1) lymphopenia--due to a decreased count of lymphocyte T cells--normally occurs as a part of the human ageing process, and 2) increased incidence of cardiovascular events has been reported in conditions where lymphopenia is common, such as renal transplant recipients, human immunodeficiency virus infection, survivors of nuclear disasters and autoimmune diseases. The aim of the present article is to review: a) the pathophysiological mechanisms that have been proposed for the observed association between LLC and cardiovascular diseases (CVD), b) the available evidence regarding the diagnostic and prognostic role attributable to LLC in patients with CVD, and; c) the potential therapeutic implications of these findings.

Relationships between heart rate variability, functional capacity, and left ventricular function following myocardial infarction: an evaluation after one week and six months

BACKGROUND

Relationships between heart rate (HR) variability and different prognostic markers such as ejection fraction, functional capacity, and patency of the infarct-related artery, as well as the comparison of their time courses are not fully elucidated.

HYPOTHESIS

The aim of study was to assess prospectively the early postinfarction changes in HR variability and its evolution over a period of 6 months: the relationships between HR variability and functional capacity in exercise testing; left ventricular function in cardiac catheterization: status of the infarct-related artery; and the comparison of their time courses.

METHODS

In 42 patients with anterior myocardial infarction, a study was made of the early changes in HR variability analyzed by the complex demodulation method, its evolution over a period of 6 months. and the relationships between HR variability and (1) functional capacity in exercise testing, (2) left ventricular function in cardiac catheterization, and (3) status of the infarct-related artery.

RESULTS

At 1 week HR variability parameters correlated directly with functional capacity indicators such as METS, percent change in HR from rest to peak exercise (%deltaHR), difference between initial and peak HR (HR range), percent peak theoretical HR (% peak HR), left ventricular ejection fraction (EF), and, inversely, with end-systolic volume (ESV). Stepwise multiple regression analysis to establish HR variability parameters (recorded at 1 week) as related to functional capacity and left ventricular function at 1 week and 6 months postinfarction established the following variables: (1) At 1 week: standard deviation (SD) of the RR cycles in relation to %deltaHR (r = 0.60, p <0.0001), HR range (r = 0.43, p < 0.01), and EF (r = 0.79, p < 0.0001). (2) At 6 months, the sole accepted HR variability parameter was the SD in relation to %deltaHR (r = 0.38, p < 0.05) and HR range (r = 0.45, p < 0.01). No variability parameter was accepted in relation to METS, % peak HR, or ESV. Relationship between EF or ESV and HR variability parameters was not significant when both were evaluated at 6 months. At that time, there was a significant increase in all HR variability parameters among all surviving patients (n = 39), with the exception of the LF/HF ratio and mean RR cycle. The percent increase in HR variability between the first week and 6 months was greater among those patients with the lowest basal EF. No relation was established between HR variability and patency of the infarct-related artery.

CONCLUSION

The decrease in HR variability observed following myocardial infarction is associated with a diminished functional capacity and an increased alteration of the EF. This does not affect the recovery of HR variability, which was observed in all surviving patients.

Predictors of early and late ventricular remodeling after acute myocardial infarction

BACKGROUND

The determinants of the early and late stages of the ventricular remodeling process after infarction are not well defined.

HYPOTHESIS

The study was undertaken to evaluate the factors that condition the time course of left ventricular dilation during the first 6 months after infarction.

METHODS

The study group consisted of 74 patients with a first intermediate-large (> or = 4 Q waves) acute myocardial infarction. Contrast left ventricular and coronary angiograms were performed at 7 +/- 1 and 175 +/- 25 days after infarction. Left ventricular volumes, regional function and infarction artery status were quantified. Percutaneous transluminal coronary angioplasty (PTCA) was performed in the early angiogram in 31 patients.

RESULTS

In the early angiogram, 13 patients showed ventricular remodeling (end-diastolic volume > 90 ml/m2). A larger extent of dysfunction was the only predictor (p < 0.002) of early remodeling. At 6 months, a smaller, early end-diastolic volume (p < 0.0001) and a poorer regional function recovery (p < 0.05) were independently related to late diastolic enlargement, and a poorer regional function recovery (p < 0.0001) and a smaller, early end-systolic volume (p < 0.009) were independently related to late systolic enlargement. One patient with compared with 20 patients without early remodeling (p < 0.04) presented with late remodeling (increment of the end-diastolic volume > 20% at 6 months). In patients with early remodeling, the end-diastolic volume did not change significantly (101 +/- 13 vs. 94 +/- 22 ml/m2, NS) at 6 months; despite this, they maintained larger diastolic volumes than patients with late remodeling (81 +/- 12 ml/m2, p < 0.04) at 6 months. Infarction artery status did not influence the evolution of ventricular volumes and regional function.

CONCLUSIONS

(1) A large infarct size is the main determinant of postinfarction remodeling. (2) Such infarct size-dependent ventricular dilation occurs early and does not tend to increase in late stage; in contrast, some cases of intermediate-large size infarcts without early remodeling exhibit late remodeling associated with a poor late recovery of regional function. (3) Recovery of regional function (indicating myocardial viability) rather than infarction artery status plays a role in the late ventricular remodeling process.

Combination of clinical risk profile, early exercise testing and circulating biomarkers for evaluation of patients with acute chest pain without ST-segment deviation or troponin elevation

OBJECTIVE

To investigate the combination of clinical data, exercise testing and biomarkers for the evaluation of patients with chest pain without ST-segment deviation or troponin elevation.

DESIGN

Prospective cohort design. SETTTING: Two teaching hospitals in Spain.

PATIENTS

422 patients presenting to the emergency department were studied. Leukocyte count, C-reactive protein (CRP), pregnancy-associated plasma protein A (PAPP-A) and N-terminal pro-brain natriuretic peptide (NT-proBNP) were determined. A validated clinical risk score (number of points according to pain characteristics and risk factors) was used for clinical evaluation and early exercise testing was performed.

MAIN OUTCOME MEASURES

Adverse events (death, myocardial infarction or revascularisation) during a median 60 weeks follow-up.

RESULTS

By receiver operating characteristic curve analysis, the association between death or myocardial infarction and adverse events was not significant with leukocyte count (p = 0.3, p = 0.3) or CRP (p = 0.5, p = 0.8), was borderline significant with PAPP-A (p = 0.07, p = 0.04) and strongly significant with NT-pro-BNP (p = 0.0001, p = 0.0001). By Cox regression including clinical risk score, exercise testing result and biomarkers, exercise testing was the independent predictor of revascularisation (p = 0.0001), whereas risk score (p = 0.03) and NT-proBNP (p = 0.0004) predicted death or myocardial infarction. The inclusion of NT-proBNP improved the accuracy of the model for death or myocardial infarction (C-statistic 0.84 versus 0.76, p = 0.01). The combination of clinical score and NT-proBNP afforded the stratification in high (17.2%, p = 0.0001), intermediate (5.3%) and low (1.1%) risk categories of death or myocardial infarction.

CONCLUSIONS

NT-proBNP provides incremental prognostic information above that given by clinical history and exercise testing in patients with chest pain without ST-segment deviation and negative troponin.

Prognostic value of leukocytosis in acute coronary syndromes: the cinderella of the inflammatory markers

In recent years, numerous studies have validated the role of inflammation in the pathogenesis of atherosclerosis. Several of such studies have produced compelling evidence that inflammation participates in both, the initiation and perpetuation of the atherosclerotic process. Furthermore, epidemiological observations have found basal white blood cell (WBC) count is strongly associated with future cardiovascular disease (CVD), highlighting the participation of leukocytes in the pathogenesis of the ischemic damage that occurred during an acute coronary event, in particularly during the acute myocardial infarction (MI). Fundamentally, an acute MI triggers a systemic response to a necrotic insult characterized by leukocytosis and acute-phase protein synthesis. In this setting, elevated WBC count plays a central role in the reparative process that takes place to replace the necrotic tissue for collagen. In addition to be a proxy for the intensity of the peri-infarction inflammatory response, recent evidence has also shown that an elevated WBC counts, measured during the acute phase of MI, to be associated with adverse outcomes. This relationship holds true even when adjusting for classical prognostic variables some of which are surrogates for the extension of the infarcted-area. WBC count prognostic value in absence of necrosis marker elevation (like unstable angina), however, remains unclear and controversial. Additionally, and essentially due to its simplicity, cost-effectiveness and wide availability, WBC count has drawn the attention of researchers as a potential stratification tool in acute coronary syndromes (ACS). However, a formal comparison is needed between WBC count with other inflammatory markers such high-sensitive C-reactive protein to fully characterize its diagnostic accuracy.

Microvascular perfusion 1 week and 6 months after myocardial infarction by first-pass perfusion cardiovascular magnetic resonance imaging

OBJECTIVE

To characterise the evolution of myocardial perfusion during the first 6 months after myocardial infarction by first-pass perfusion cardiovascular magnetic resonance imaging (CMR) and determine its significance.

DESIGN

Prospective cohort design.

SETTING

Single-centre study in a teaching hospital in Spain.

PATIENTS

40 patients with a first ST-elevation myocardial infarction, single-vessel disease and thrombolysis in myocardial infarction (TIMI) grade 3 flow (stent in 33 patients) underwent rest and low-dose dobutamine CMR 7 (SD 1) and 184 (SD 11) days after infarction. Microvascular perfusion was assessed at rest by visual assessment and quantitative analysis of first-pass perfusion CMR. Of the 640 segments, 290 segments subtended by the infarct-related artery (IRA) were focused on.

RESULTS

Both 1 week and 6 months after infarction, segments with normal perfusion showed more wall thickening, contractile reserve and wall thickness, and less transmural necrosis, p <0.05 in all cases. Of 76 hypoperfused segments at the first week, 47 (62%) normalised perfusion at the sixth month. However, 42 segments (14% of the whole group) showed chronic abnormal perfusion; these segments showed worse CMR indices in the late phase (p<0.05 in all cases).

CONCLUSIONS

In patients with an open IRA, more than half of the segments with abnormal perfusion at the first week are normally perfused after six months. First-pass perfusion CMR shows that in a small percentage of segments, abnormal perfusion may become a chronic phenomenon-these areas have a more severe deterioration of systolic function, wall thickness, contractile reserve and the transmural extent of necrosis.

Niveles de glucemia en pacientes no diabéticos. ¿Es un factor pronóstico en el síndrome coronario agudo?

INTRODUCTION

The role of glucose elevation above levels considered normal in non- diabetic patients with acute coronary syndromes (ACS) is not adequately defined. The aim of this study was to determine the association between serum glucose at admission and 1-year mortality in this type of patients.

METHODS

We studied 648 non diabetic patients admitted consecutively with ACS. Serum glucose was determined at admission, together with classical risk factors, biochemical and inflammatory markers. The primary endpoint was all cause mortality at one year follow-up.

RESULTS

Patients with normal glucose had lower mortality than patients with impaired fasting glucose (14.1% vs 5.7% 1-year mortality) or with glucose levels in diabetic range (24.7% vs 5.7% 1-year mortality).

CONCLUSIONS

In non-ST elevation acute coronary syndromes, elevated levels of glucose in non-diabetic patients are strong predictors of all cause death at one year follow-up. This prognostic value is independent of other risk factors biochemical and inflammatory markers.

Risk stratification of patients with acute chest pain and normal troponin concentrations

OBJECTIVE

To investigate the outcome of patients with acute chest pain and normal troponin concentrations.

DESIGN

Prospective cohort design.

SETTING

Single centre study in a teaching hospital in Spain.

PATIENTS

609 consecutive patients with chest pain evaluated in the emergency department by clinical history (risk factors and a chest pain score according to pain characteristics), ECG, and early (< 24 hours) exercise testing for low risk patients with physical capacity (n = 283, 46%). All had normal troponin concentrations after serial determination.

MAIN OUTCOME MEASURES

Myocardial infarction or cardiac death during six months of follow up.

RESULTS

29 events were detected (4.8%). No patient with a negative early exercise test (n = 161) had events versus the 6.9% event rate in the remaining patients (p = 0.0001). Four independent predictors were found: chest pain score > or = 11 points (odds ratio (OR) 2.4, 95% confidence interval (CI) 1.1 to 5.5, p = 0.04), diabetes mellitus (OR 2.3, 95% CI 1.1 to 4.7, p = 0.03), previous coronary surgery (OR 3.1, 95% CI 1.3 to 7.6, p = 0.01), and ST segment depression (OR 2.8, 95% CI 1.3 to 6.3, p = 0.003). A risk score proved useful for patient stratification according to the presence of 0-1 (2.7% event rate), 2 (10.2%, p = 0.008), and 3-4 predictors (29.2%, p = 0.0001).

CONCLUSIONS

A negative troponin result does not assure a good prognosis for patients coming to the emergency room with chest pain. Early exercise testing and clinical data should be carefully evaluated for risk stratification.

QT dispersion within the first 6 months after an acute myocardial infarction: relationship with systolic function, left ventricular volumes, infarct related artery status and clinical outcome

INTRODUCTION

We analysed QT dispersion within the first 6 months postinfarction, its relationship with the main established risk stratifiers and its clinical value.

METHODS AND RESULTS

In 55 patients with a first Q-wave myocardial infarction the 12-lead electrocardiogram was scanned and digitised for analysis of QT dispersion (QT maximum-QT minimum) at first day (72 [61-96] ms), first week (69 [47-90] ms), first month (67 [46-88] ms) and sixth month (47 [40-74] ms; P<0.0001 vs. first day). Cardiac catheterization was performed at first week and at sixth month; QT dispersion was not related to ejection fraction, left ventricular volumes, infarct related artery status or contractile reserve (improvement of the infarcted area with low-dose dobutamine); no relation was found between QT dispersion decrease from first week to sixth month with regional systolic function improvement. Finally, during a mean follow-up period of 35+/-22 months QT dispersion was not independently related to clinical events.

CONCLUSION

QT dispersion decreases progressively during the first months after myocardial infarction. These changes should be taken into account to define cut-off values of clinical interest in this phase. This variable does not seem related to the classic prognosis predictors. In a nonselected postinfarction population it has a low clinical value.

ST-segment elevation on Q-leads during exercise in patients with ST-segment elevation at rest after myocardial infarction

INTRODUCTION

ST-segment elevation on Q-leads after an acute myocardial infarction is related to a greater infarct size. The meaning of a further exercise-induced ST-segment elevation in these patients has not been analyzed.

METHOD

Thirty-six patients with ST-segment elevation on Q-leads were studied after a first acute myocardial infarction. Exercise testing and cardiac catheterization were performed at the first week. Left ventricular volumes (ml/m(2)); the extent of abnormal wall motion (AWM: chords); contractile reserve (AWM improvement with low dose dobutamine) and coronary patency in the culprit artery were analyzed. Cardiac catheterization was repeated at the sixth month in 20 patients; systolic recovery (AWM improvement), left ventricular volumes and coronary patency were again evaluated.

RESULTS

Patients with exercise-induced ST-segment elevation in two or more Q-leads (n=21) showed lesser contractile reserve (6+/-6 vs. 12+/-7 chords, P=0.01) than patients without exercise-induced ST-segment elevation (n=13). AWM (F=8.1) and absence of exercise-induced ST-segment elevation (F=9.5; positive predictive value: 80%; negative predictive value: 68%) were the only independent predictors of contractile reserve. Nevertheless, this electrocardiographic sign was not related to left ventricular volumes, coronary patency or systolic function and it did not predicted late systolic recovery.

CONCLUSIONS

In patients with baseline ST-segment elevation on Q-leads an exercise-induced ST-segment elevation is independently related to a lesser contractile reserve but not to the evolution of volumes or regional dysfunction during the first 6 months post-infarction. Therefore, the clinical value of this sign seems to be limited to the non-invasive detection of myocardial viability during the early post-infarction phase.

Changes in left ventricular filling pattern during dobutamine stress Doppler echocardiography

AIMS

To study the left ventricular filling pattern during stress Doppler echocardiography and its utility in the detection of myocardial ischaemia.

METHODS AND RESULTS

Fifty-seven consecutive patients underwent dobutamine stress echocardiography. The left ventricular filling pattern (E-wave velocity; A-wave velocity; E/A ratio; E-wave deceleration time) was analysed at baseline and at maximum heart rate reached. The percentage increase in these parameters from baseline to peak heart rate was also determined. Myocardial ischaemia (regional contractility worsening) was induced in 19 cases (ischaemic group) but not in 38 cases (non-ischaemic group). There were no differences between both groups at baseline. E-wave deceleration time decreased in the non-ischaemic group (197+/-63 vs. 167+/-65 ms, P=0.01) and increased in the ischaemic group (203+/-42 vs. 315+/-135 ms, P<0.0001). A percentage increase in E-wave deceleration time of >30% showed a positive predictive value of 93% and a negative predictive value of 86% for detecting ischaemia, and in the multivariate analysis it was the only Doppler parameter (P<0.0001) that predicted the induction of ischaemia.

CONCLUSION

We conclude that myocardial ischaemia provokes an increase in E-wave deceleration time. Analysis of left ventricular filling could help in the identification of those cases which are positive for ischaemia.

Anticoagulant therapy modifies fibrinolytic dysfunction in chronic atrial fibrillation

OBJECTIVE

We evaluated the changes in fibrinolytic activation markers before starting anticoagulation, at 1 and 6 months following the introduction of anticoagulant therapy.

DESIGN AND METHODS

Tissue plasminogen activator (t-PA), its endothelial inhibitor (PAI-1), plasmin:antiplasmin complexes (PAPc), modified antithrombin III (ATM), D dimer (D-D) and fibrinogen (FIB) were measured in 36 patients with chronic atrial fibrillation. Fifteen of them had rheumatic mitral stenosis and 21 had nonrheumatic atrial fibrillation. Basal levels were compared with a sex- and age-matched healthy control group.

RESULTS

At baseline, patients with atrial fibrillation showed significantly higher plasma levels of PAI-1, ATM, D-D and FIB levels (p < 0.05) than controls, and no differences in t-PA and PAPc concentrations. Levels of t-PA, PAI-1, ATM and D-D decreased significantly under anticoagulant therapy, whereas FIB levels were not significantly modified. PAPc levels were significantly increased at 6 months in the rheumatic group but did not differ significantly in the nonrheumatic group.

CONCLUSIONS

Patients with chronic atrial fibrillation show a hypercoagulant state and a relatively low fibrinolytic function. After 6 months of anticoagulant therapy, an improvement in fibrinolytic function markers was detected.

[Determinants of contractile reserve in the infarction area. A quantitative study using dobutamine in contrast left ventriculography]

AIM

The aim of this study was to relate the contractile reserve in infarction segments to the dysfunction at rest and to the residual coronary stenosis.

METHODS

The study group consisted of 95 patients with a first myocardial infarction. Contrast left ventricular at baseline and after dobutamine infusion at 7.5 microg/kg/min and coronary angiograms were performed. The centerline method was used to quantify the extent of dysfunction (percentage of chords with dysfunction in the territory of the infarction artery) and its maximum severity (maximum units of standard deviation [SD] below the normal wall motion reference). Reduction of dysfunction extent with dobutamine was measured.

RESULTS

On increasing baseline dysfunction severity, both the magnitude of the response to dobutamine ( 2 SD 3 SD 4 SD +/- 5 SD [n = 15] = 9+/-13%, > 5 SD [n = 13] = 3+/-4%, p = 0,0001), and the number of patients with a significant (> or =15%) positive response ( 2 SD 3 SD 4 SD 5 SD = 0%, p<0,0001) decreased. There were no differences in dobutamine improvement among the subgroups with (n = 84) or without (n = 11) significant stenosis in the infarction artery (18+/-15 vs. 16 +/-18%), or between the subgroups with a patent (n = 76, 18+/-19%) or occluded (n = 19, 11+/-11%) artery.

CONCLUSIONS

Dobutamine response is related to dysfunction severity in the infarction area: when the severity is 5 (high negative response prevalence), dobutamine testing does not seem indicate. The existence of residual coronary stenosis does not attenuate contractile reserve at low dobutamine doses.

Wall motion of noninfarcted myocardium. Relationship to regional and global systolic function and to early and late left ventricular dilation

We studied the wall motion of the noninfarcted area and its role in left ventricular remodeling. The study group consisted of 43 patients with a first Q-wave acute myocardial infarction and single-vessel disease. Cardiac catheterization was performed at the first week, and was repeated six months later. Left ventricular volumes, wall motion at the infarcted and noninfarcted area, ejection fraction and infarction-related artery status were quantified. Hyperkinesia was only found at the first week in 22% of cases, and at the sixth month in 26% of cases. Wall motion at the noninfarcted area correlated with wall motion at the infarcted area (one week: r=0.53 p<0.0001; six months: r=0.52 p=0.01), ejection fraction (one week: r=0.69 p<0.0001; six months: r=0.56 p=0.006), end-diastolic volume (one week: r=-0.48 p=0.002; six months: r=-0.48 p=0.02) and end-systolic volume (one week: r=-0.70 p<0.0001; six months: r=-0.64 p=0.001). The improvement of the noninfarcted area (from the first week to the sixth month) was only related to basal (one week) wall motion in this area (r=-0.58 p=0.003). We conclude that after an intermediate-large infarction, most patients exhibit a normal or hypokinetic noninfarcted area. Patients with a more depressed infarcted area show poorer contractility at the noninfarcted area. area exhibit greater progressive improvement.

Prothrombotic state and elevated levels of plasminogen activator inhibitor-1 in mitral stenosis with and without atrial fibrillation

Patients with mitral stenosis in sinus rhythm are in a prothrombotic state and have fibrinolytic dysfunction, shown by an increase in levels of the inhibitor of tissue plasminogen activator, D-dimer, and modified antithrombin III. This state may be observed even in patients without dilated left atria (diameter < or =45 mm).

ST-segment elevation on Q leads at rest and during exercise: relation with myocardial viability and left ventricular remodeling within the first 6 months after infarction

BACKGROUND

Resting ST-segment elevation on Q leads after an acute myocardial infarction has been related to a greater infarct size. Otherwise, the relation between exercise-induced ST-segment elevation and myocardial viability is controversial. We investigated the relation between ST-segment elevation on Q leads at rest and during exercise and regional dysfunction and its evolution, contractile reserve, left ventricular dilation, and coronary patency.

METHODS AND RESULTS

Exercise testing and cardiac catheterization were performed at the first week after infarction in 51 patients. The study group was divided according to the existence (in 2 or more Q leads; n = 36) or not (n = 15) of resting ST-segment elevation and according to the existence (n = 28) or not (n = 23) of exercise-induced ST-segment elevation. Left ventricular end-diastolic and end-systolic volumes (mL/m2), regional wall motion (SD/chord), contractile reserve (wall motion percentage improvement with low-dose dobutamine), and coronary patency in the culprit artery were analyzed. Cardiac catheterization was repeated at the sixth month in 35 patients; systolic recovery (wall motion percentage improvement), left ventricular volumes, and coronary patency were again evaluated. Patients with resting ST-segment elevation showed poorer wall motion (2.1 +/- 0.8 SD/chord vs 1.2 +/- 1 SD/chord, P =.002), lesser contractile reserve (17% [0% to 39%] vs 41% [4% to 92%], P =.04), greater end-systolic volume (32 +/- 15 mL/m2 vs 23 +/- 11 mL/m2, P =.04), and higher percentage of occlusion (36% vs 7%, P =.04) than did patients without ST-segment elevation. Likewise, patients with exercise-induced ST-segment elevation showed lesser contractile reserve (8% [0% to 40%] vs 35% [12% to 86%], P =.03) than did patients without exercise-induced ST-segment elevation. The only independent predictors of contractile reserve were wall motion <2 SD/chord (odds ratio [OR] 7.1, confidence interval [CI] 6.3 to 7.9, P =.01) and the absence of exercise-induced ST-segment elevation (OR 5.7, CI 4.9 to 6.5, P =. 02). There were no significant differences between patients with and those without ST-segment elevation (at rest or during exercise) in systolic recovery or left ventricular volumes at the sixth month.

CONCLUSIONS

ST-segment elevation on Q leads at rest is related to a poorer systolic function (more severe regional dysfunction, greater end-systolic volume, and less response to dobutamine). ST-segment elevation during exercise is independently related to a lesser contractile reserve. ST-segment elevation (at rest or during exercise) is not related to the evolution of volumes or regional dysfunction during the first 6 months after infarction.

Acute cardiac rupture complicating pre-discharge exercise testing. A case report with complete echocardiographic follow-up

The case of a 76 year-old male who suffered acute free wall rupture and sudden hemodynamic deterioration during the recovery phase of a pre-discharge exercise testing (performed 7 days after a noncomplicated myocardial infarction) is presented. Usefulness of echocardiography in early diagnosis, management (guiding pericardiocentesis) and follow-up is remarked and, on the other hand, medical treatment after a successful resuscitation is confirmed as an alternative option in these cases.

Low-dose dobutamine testing using contrast left ventriculography in the same session as coronary angiography predicts the improvement of left ventricular function after coronary angioplasty in postinfarction patients

The role of percutaneous transluminal coronary angioplasty (PTCA) in the subacute or chronic phases of myocardial infarction remains controversial. This study investigates the usefulness of dobutamine contrast left ventriculography in a single session with coronary angiography for predicting the improvement of ventricular function after PTCA. The study group consisted of 30 patients in whom a contrast left ventricular angiogram and PTCA were performed after a first myocardial infarction. The centerline method was used to calculate dysfunction extent at baseline and its variation during dobutamine infusion at 7.5 microg/kg/min; contractile reserve was defined as a significant (> or = 15%) reduction of dysfunction extent. A second ventricular angiogram was performed 6 months later in all patients. Abnormal wall motion extent decreased at 6 months after PTCA (84+/-21% vs 70+/-29%, p = 0.0001). Wall motion improvement after PTCA correlated with the response to dobutamine (r = 0.54, p = 0.002). Ten patients showed a significant reduction (> or = 15%) of dysfunction extent at 6 months; dobutamine testing had a 80% sensitivity, 84% specificity, 67% positive predictive value, and 89% negative predictive value in detecting regional function improvement. In the subgroup of 21 patients without restenosis, both the correlation between dysfunction improvement after PTCA and response to dobutamine (r = 0.72, p = 0.0001) and the accuracy of dobutamine testing (sensitivity 88%, specificity 92%, positive predictive value 88%, and negative predictive value 92%) increased. The ejection fraction significantly increased (>5%) after PTCA in 6 patients; dobutamine testing had a 67% sensitivity, 74% specificity, 44% positive predictive value, and 88% negative predictive value in predicting the increase in the ejection fraction. In the subgroup without restenosis the improvement of the ejection fraction correlated with the response to dobutamine (r = 0.63, p = 0.007), and the sensitivity of dobutamine testing was 80%, specificity 83%, positive predictive value 67%, and negative predictive value 91%. In conclusion, dobutamine contrast left ventriculography testing in the same session as coronary angiography predicts regional function and ejection fraction improvement after PTCA in postinfarction patients, particularly when restenosis does not develop.

[The assessment of cardiac involvement in a case of a thoracic injury from a firearm]

We report the case of a patient with a gunshot wound in the chest with a multiple small-caliber intrathoracic projectiles. The different noninvasive techniques employed to evaluate the anatomical location of these projectiles are discussed, together with their cardiac structural repercussions. The data provided by a simple chest X-ray, Computed Tomography (CT) and transthoracic echocardiography are commented on. A simple chest X-ray was unable to discern the location of the projectiles, in contrast to CT, which was able to identify both the number of projectiles and their location. The information provided was enhanced by transthoracic echocardiography, particularly in relation to those projectiles situated in anterior cardiac regions.

Role of infarction artery status in left ventricular remodeling after acute myocardial infarction

The aim of this study was to evaluate the relation between the infarction artery status and left ventricular volumes, independently of regional ventricular dysfunction, at 4-6 weeks after a first myocardial infarction. The study group consisted of 100 patients, of whom 80 received thrombolytic treatment. Coronary and contrast left ventricular angiograms were performed at 36+/-5 days postinfarction. Left ventricular end-diastolic and end-systolic volumes were measured. The centerline chord motion method was used to calculate the extent of wall motion abnormality (percentage of chords with hypokinetic motion) and its severity (maximum units of S.D. below the normal wall motion reference). Minimum lumen diameter, patency and collateral flow in the infarction artery were also analyzed. Eight patients (group I) showed occlusion with poor collateral flow in the infarction artery, 22 patients (group II) occlusion with good collateral flow, 38 patients (group III) severe residual stenosis (minimum lumen diameter < or = 1 mm), and 32 patients (group IV) non-severe residual stenosis (minimum lumen diameter > 1 mm). Patients from group I presented greater wall motion abnormality in terms of both extent (P=0.005) and severity (P=0.007), and greater end-diastolic (P=0.07) and end-systolic (P=0.0008) volumes; there were no differences among groups II, III and IV. By stepwise multivariate regression analysis, the extent of wall motion abnormality was the main determinant of end-diastolic (P=0.0001) and end-systolic (P=0.0001) volumes; occlusion with poor collateral flow was also a significant independent factor for end-systolic volume (P=0.03). Total occlusion (including both with and without collaterals) and the minimum lumen diameter did not correlate with end-diastolic and end-systolic volumes. We concluded that (A) the extent of regional dysfunction is the primary determinant of left ventricular volumes at 4-6 weeks postinfarction. (B) The status of the infarction artery is a weak predictor of end-diastolic volume, which is the best descriptor of ventricular remodeling, although occlusion with poor collateral flow is associated to larger end-systolic volume.

[Cardiac angiosarcoma]

We report a case of a 29-year-old patient with recurrent hemorrhagic pericardial effusion secondary to a right atrial mass detected by transthoracic echocardiography. A more detailed anatomic study was provided by transesophageal echocardiogram and nuclear magnetic resonance imaging. During surgery, a biopsy confirmed the diagnosis of angiosarcoma. We discuss the contribution of echocardiography and other noninvasive methods to evaluate intracardiac tumors. A brief review of treatment and prognosis is made.

[Persistence of the left superior vena cava associated with aortic insufficiency: diagnostic and therapeutic considerations]

In the course of the routine evaluation of a 26-years-old male for acquired aortic valve disease the persistence of a left superior vena cava draining into the coronary sinus was detected. This is a frequent congenital malformation of the systemic venous system that has no hemodynamic consequences in itself, though it may be associated to other congenital or acquired cardiac malformations that may require surgery. The preoperatory detection of the anomaly prevents unexpected problems when connecting the cardiopulmonary bypass. We emphasize the importance of procedures that suggest the diagnosis and characterize the anatomo-functional nature of the condition--including transthoracic and transesophageal echocardiography using echocardiographic contrast, and cardiac catheterization with cardiac and vascular angiography.

Stunned myocardium after thrombolytic treatment. Identification by dobutamine echocardiography and role of the residual stenosis in the infarction artery

The aim of this study was to identify post-thrombolysis stunned myocardium using low dose (10 micrograms/kg/min) dobutamine echocardiography, and to elucidate the role of the residual stenosis in the infarction artery in wall motion recovery. Forty-seven consecutive patients treated with thrombolytic agents for a first non-complicated myocardial infarction were included. An early dobutamine echocardiogram was performed 7 +/- 2 days after thrombolysis to calculate a wall motion score index at baseline and with dobutamine. A late resting echocardiogram 36 +/- 7 days and a coronariography 41 +/- 8 days after thrombolysis were also performed. In 12 patients no baseline regional dysfunction was observed in the early echocardiogram (Group I), whereas 35 patients (Group II) presented regional dysfunction which improved with dobutamine in 11 cases (Group IIA), but not in 24 (Group IIB). Maximum creatine kinase peak was smaller in Group I (458 +/- 162, P < or = 0.01) and in Group IIA (931 +/- 593, P < or = 0.05) than in Group IIB (1547 +/- 886). Late resting echocardiogram was performed in 44 patients: all 12 from Group I, 10 from Group IIA and 22 from Group IIB; all patients from Group I persisted with normal wall motion, while the baseline score index improved in seven patients (70%) from Group IIA vs. three patients (14%) from Group IIB (P < or = 0.01). Quantitative angiographic parameters in the infarction artery failed to differentiate the subgroup of patients in whom wall motion improved in the late echocardiogram. By simple regression, smaller creatine kinase peak (P < or = 0.05) and a positive response to dobutamine in the early echocardiogram (P < or = 0.001) correlated with wall motion recovery, but the minimum lumen diameter in the infarction artery did not correlate; by multiple logistic regression, only a positive response to dobutamine in the early echocardiogram independently predicted late wall motion improvement (P < or = 0.001).

CONCLUSIONS

(1) Low dose dobutamine echocardiography early after thrombolytic treatment identifies dysfunctional myocardium with potential late spontaneous improvement (stunned myocardium). (2) Myocardial stunning tends to occur in small infarctions. (3) Late wall motion improvement can occur despite severe residual stenosis in the infarction artery.

Recovery curve and concealed conduction in the His-Purkinje system of the rabbit heart: effects of radiofrequency modification of the low AV junction

The aim of this study was to analyze the recovery curve and concealed conduction in the normal His-Purkinje system and after delivering radiofrequency current in the low AV junction, in the perfused rabbit heart. Twenty-one rabbit hearts were studied. Radiofrequency current (5 W) was delivered in the low AV junction to induce an incomplete His-Purkinje AV block (HV prolongation with 1:1 AV conduction); this was achieved in 9 experiments (Group I), while 12 experiments developed a complete block (Group II). Atrial stimulation was performed in both Groups at baseline, and in Group I after radiofrequency delivery, as follows: (1) pacing at increasing rates to determine the His-Purkinje AV block cycle length; (2) atrial extrastimulus test (A1A2) to calculate the His-Purkinje effective refractory period and the fitting of the recovery curve (H1H2 vs H2V2) to the exponential equation delta HV = a.e(-b)x(H1H2); (3) concealed conduction protocol (in 15 experiments) consisting of an atrial extrastimulus test with an interposed beat (A1-A0-A2) at a fixed A1A0 coupling interval. The baseline recovery curve fitted an exponential equation in 17 experiments (with a 93% +/- 42% maximum H2V2 increase at the shortest H1H2), but did not in 4 experiments (the maximum H2V2 increase being only 22% +/- 7%). Radiofrequency application prolonged the HV interval (25 +/- 6 ms vs 46 +/- 16 ms; P = 0.001) and His-Purkinje effective refractory period (167 +/- 28 ms vs 217 +/- 57 ms; P = 0.02). The percentage increment was greater for HV than for refractory period (99% +/- 65% vs 35% +/- 32%; P = 0.02); however, the increment of the His-Purkinje block cycle length (77% +/- 74%) only correlated with that of the refractory period (r = 0.95; P = 0.0001). The recovery curve after radiofrequency delivery fitted an exponential equation in all experiments, showing a rightward shift expressed by an increment of the constant ln a (2.7 +/- 1.9 vs 5.5 +/- 5.5; P = 0.02). Concealed conduction appeared in only three experiments at baseline. After radiofrequency, however, it was observed in all experiments, producing a rightward shift of the recovery curve and an ln a increase (2.87 +/- 1.2 vs 9.9 +/- 2.7; P = 0.0001). When Ho was conducted, the curve rightward shift and ln a increase (26 +/- 7.5; P = 0.0001) were greater.

CONCLUSION

(1) His-Purkinje physiology, as in AV nodal physiology, can be described by a recovery curve that fits an exponential equation, especially if conduction becomes depressed with radiofrequency current. (2) Radiofrequency application in the low AV junction modifies His-Purkinje conduction more than refractoriness, though the refractoriness increase determines the degree of block at fast atrial rates. (3) Concealed conduction is uncommon in the normal His-Purkinje system during atrial pacing, but very frequent after modifying the low AV junction with radiofrequency current.

[Apical hypertrophic myocardiopathy and multiple fistulae between the coronary vessels and the left ventricle]

A male patient presented with symptoms of angor under effort. Echocardiography and angiocardiography revealed apical hypertrophic myocardiopathy, associated with multiple fistulas connecting the anterior descending coronary artery and right coronary artery with the cavity of the left ventricle, as demonstrated by coronariography. We comment on the hypothesis that support a causal relationship between the two anomalies, microfistulas being the possible cause of the reactive hypertrophy through the induction of a coronary steal phenomenon with local ischemia; alternatively, the myocardiopathy itself might be the cause of microfistulas formation by inducing an anomaly in the Thebesius venous system. A pathogenic relationship is suggested between the syndrome of angor and these two rare pathological entities.

[Hypertrophic myocardiopathy and ostium primum]

A 45-year-old male with palpitations and a heart murmur was investigated. Echocardiography and haemodynamic study revealed the presence of a ostium primum type interatrial communication with left-right shunting and asymmetric hypertrophic heart disease. There was no subaortic obstruction, but anterior systolic movement of the mitral valve was detected that did not contact with the interventricular septum--in part due to the paradoxical motion of the latter. The possible benefit of surgery in this infrequent association is discussed, and a review is made of the literature.