Resolution of late potentials with improvement in left ventricular systolic function in patients with first acute myocardial infarction

BACKGROUND

Ventricular late potentials predict subsequent arrhythmic events and sudden death in postinfarction patients. Late potentials are recorded in the infarcted area, but it should be pointed out that they probably represent micropotentials in the area of delayed conduction found among isolated areas of scar tissue and normal myocardium.

HYPOTHESIS

The study was undertaken to investigate the relationship between chronic reversible myocardial ischemia, such as stunned or hibernating myocardium, and late potentials in 38 patients with a first myocardial infarction.

METHODS

The patients were divided into two groups, one with (Group 1) and one without (Group 2) resolution of late potentials recorded by signal-averaged electrocardiogram at 6 months after onset of myocardial infarction. We investigated the clinical, echocardiographic, and signal-averaged electrocardiographic characteristics of Groups 1 and 2.

RESULTS

In the chronic phase of myocardial infarction, a higher incidence of patency of the infarct-related artery and an improvement of wall motion score were found in Group 1, and left ventricular ejection fraction was better preserved in Group 1 than in Group 2.

CONCLUSIONS

These results suggest that the resolution of late potentials was influenced by the improvement of left ventricular systolic function and patency of the infarct-related artery. We concluded that chronic reversible myocardial ischemia, such as stunned or hibernating myocardium, might be the substrate that generated late potentials.

Clinical significance of coronary flow to the infarct zone before successful primary percutaneous transluminal coronary angioplasty in acute myocardial infarction

STUDY OBJECTIVE

To assess the effect of coronary flow to the infarct zone before primary coronary angioplasty on hospital complications in patients with acute myocardial infarction (MI).

DESIGN

Consecutive case series analysis.

SETTING

Coronary-care unit in a university hospital.

PATIENTS

Two hundred sixty-four consecutive patients with ST-elevation acute MIs who had successful primary percutaneous transluminal coronary angioplasty.

INTERVENTIONS

Coronary angiography on hospital admission and serial echocardiography.

MEASUREMENTS AND RESULTS

The status of infarct-related artery flow before primary angioplasty was evaluated on hospital admission. Left ventricular wall motion and pericardial effusions were studied by echocardiography. One hundred ninety patients had total occlusions (Thrombolysis in Myocardial Infarction [TIMI] flow grade, 0 to 1) in the infarct-related artery (group 1), and 74 patients had antegrade flow (TIMI flow grade, 2 to 3) [group 2] before undergoing primary angioplasty procedures. When group 1 was subdivided into two groups (for the presence and absence of collateral flow), the patients with total occlusions and no collateral flow had a higher incidence of left ventricular aneurysmal wall motion (11% vs 1%, respectively; p = 0.03) and pericardial friction rub (15% vs 3%, respectively; p = 0.03) than did those in group 2. Moreover, those patients with total occlusions and no collateral flow had higher incidences of pericardial effusion (34% vs 17%, respectively; p = 0.02; and 34% vs 9%, respectively; p < 0.01) and in-hospital mortality (8% vs 1%, respectively; p = 0.04; and 8% vs 1%, respectively; p = 0.06) than did those patients in the other two groups.

CONCLUSIONS

Despite successful primary angioplasty, the absence of antegrade flow in the infarct-related artery and collateral flow to the infarct zone before angioplasty resulted in a higher incidence of in-hospital complications.

Evidence for infection with Helicobacter pylori in patients with acute myocardial infarction

BACKGROUND

Anti-Helicobacter pylori (HP) IgA and IgG antibody titers were measured in patients with ischemic heart diseases.

METHODS

There were 60 healthy individuals that served as control subjects, and 21 patients with acute myocardial infarction (AMI), 34 with old myocardial infarctions (OMI), 35 with effort angina (AP) and 41 with vasospastic angina (VSA).

RESULTS

In the control group, the IgA and IgG anti-HP antibody titers were positively correlated with age. When the IgA and IgG antibody titers were compared among patient groups, IgG did not significantly differ between each patient group and the control group, whereas IgA was significantly higher in the AMI group (5.10+/-1.25 EV) than in the OMI (p<0.01), AP, or the control (p<0.05). Moreover, the positivity rate for IgA anti-HP antibody was the highest in the AMI group (90%), with an odds ratio to the age-matched control group of 4.09, whereas the positivity rate for IgG did not significantly differ between the groups when either the 10 or 55 U/ml cut-off value was used.

CONCLUSIONS

These results suggest that an increased IgA antibody titer, which is an index of the active phase of HP infection, should be an etiological marker for acute myocardial infarction.

TIMI frame count immediately after primary coronary angioplasty as a predictor of functional recovery in patients with TIMI 3 reperfused acute myocardial infarction

OBJECTIVES

The purpose of this study was to evaluate whether higher coronary blood flow, estimated by the corrected Thrombolysis In Myocardial Infarction (TIMI) frame count (CTFC), is related to better functional and clinical outcome after successful percutaneous transluminal coronary angioplasty (PTCA) in patients with acute myocardial infarction (AMI).

BACKGROUND

Experimental studies have found that functional recovery of the infarcted myocardium was associated with increased blood flow (reactive hyperemia) to the infarcted bed shortly after reperfusion.

METHODS

We measured CTFC immediately after successful (TIMI 3) primary PTCA in 104 consecutive patients with their first AMI. Wall motion score index (WMSI) and the presence of pericardial effusion were assessed by two-dimensional echocardiography before and one month after PTCA.

RESULTS

The patients were divided into two groups according to mean CTFC for corresponding coronary artery of the control group: TIMI 3 slow group (45 patients, 40 > CTFC > or = 23) and TIMI 3 fast group (59 patients, CTFC < 23). There were no significant differences in the baseline characteristics and WMSI before reperfusion between the two groups. Improvement of WMSI in the TIMI 3 fast group was significantly greater than that of the TIMI 3 slow group (1.33 +/- 0.52 vs. 0.60 +/- 0.34, p < 0.001). Pericardial effusion and intractable heart failure were observed more frequently in the TIMI 3 slow group than in the TIMI 3 fast group (27 vs. 10%; p < 0.05, 36 vs. 17%; p < 0.05). Corrected TIMI frame count, assessed as a continuous variable, had a significant correlation with the change in WMSI (r = 0.60, p < 0.001) after adjusting for age, gender, history of hypertension, history of diabetes, elapsed time to PTCA, collateral grade, presence of antegrade flow before PTCA and number of diseased vessels.

CONCLUSIONS

Lower CTFC of the infarct-related artery immediately after PTCA was associated with greater functional recovery; and hence, CTFC can predict clinical and functional outcome in patients with successful PTCA.

Urinary excretion of biopyrrins, oxidative metabolites of bilirubin, increases after spasm provocation tests in patients with coronary spastic angina

BACKGROUND

Bilirubin apparently functions as an antioxidant in vivo by reacting with reactive oxygen species, and, as a result, becomes oxidized. The urinary excretion of oxidative metabolites of bilirubin, biopyrrins, could be a biological marker for in vivo production of reactive oxygen species. The purpose of this study was to examine the extent of oxidative stress in patients with possible ischemic heart diseases (n=44) by measuring urinary biopyrrins by enzyme-linked immunosorbent assay before and after the spasm provocation test (SPT).

METHODS

Spot urine samples were collected five times; 1 day before, in the morning just before, immediately after, 6 h after, and 1 day after the SPT. Nineteen patients were positive to SPT judged from the specific changes in electrocardiogram for myocardial ischemia following intracoronary injections of ergonovine.

RESULTS

The baseline data such as age, sex, number of risk factors and concentrations of serum bilirubin, and the measured hemodynamic parameters of heart rate, blood pressure, left ventricular end-diastolic pressure and left ventricular ejection fraction were not different between the positive and negative groups. The baseline concentrations of biopyrrins during the control period were not significantly different between the two groups. However, they increased significantly after the SPT, thereby the magnitude of increases immediately after and 6 h after the SPT were significantly (P<0.001 and P<0.01, respectively) greater in the positive group than in the negative.

CONCLUSION

The present findings strongly suggest that coronary arterial occlusion augments production of biopyrrins, which indicates exposure to oxidative stress in patients with ischemic heart diseases.

Implantation of bone marrow mononuclear cells into ischemic myocardium enhances collateral perfusion and regional function via side supply of angioblasts, angiogenic ligands, and cytokines

BACKGROUND

Bone marrow implantation (BMI) was shown to enhance angiogenesis in a rat ischemic heart model. This preclinical study using a swine model was designed to test the safety and therapeutic effectiveness of BMI.

METHODS AND RESULTS

BM-derived mononuclear cells (BM-MNCs) were injected into a zone made ischemic by coronary artery ligation. Three weeks after BMI, regional blood flow and capillary densities were significantly higher (4.6- and 2.8-fold, respectively), and cardiac function was improved. Angiography revealed that there was a marked increase (5.7-fold) in number of visible collateral vessels. Implantation of porcine coronary microvascular endothelial cells (CMECs) did not cause any significant increase in capillary densities. Labeled BM-MNCs were incorporated into approximately 31% of neocapillaries and corresponded to approximately 8.7% of macrophages but did not actively survive as myoblasts or fibroblasts. There was no bone formation by osteoblasts or malignant ventricular arrhythmia. Time-dependent changes in plasma levels for cardiac enzymes (troponin I and creatine kinase-MB) did not differ between the BMI, CMEC, and medium-alone implantation groups. BM-MNCs contained 16% of endothelial-lineage cells and expressed basic fibroblast growth factor>>vascular endothelial growth factor>angiopoietin 1 mRNAs, and their cardiac levels were significantly upregulated by BMI. Cardiac interleukin-1beta and tumor necrosis factor-alpha mRNA expression were also induced by BMI but not by CMEC implantation. BM-MNCs were actively differentiated to endothelial cells in vitro and formed network structure with human umbilical vein endothelial cells.

CONCLUSIONS

BMI may constitute a novel safety strategy for achieving optimal therapeutic angiogenesis by the natural ability of the BM cells to secrete potent angiogenic ligands and cytokines as well as to be incorporated into foci of neovascularization.

Scintigraphic predictor of left ventricular size after acute myocardial infarction

The aim of this study was to evaluate the relation between thallium-201 scintigraphic indices and left ventricular size after acute myocardial infarction. Forty-seven patients with acute myocardial infarction underwent rest-redistribution thallium-201 scintigraphy at 2 weeks and left ventriculography at 4 weeks, after the onset of myocardial infarction. Percent (%) fixed defect, %redistribution and %reverse redistribution, calculated as a percentage of whole left ventricular area, were quantified with computer-generated unfolded map method of the myocardial radioactivity. Despite no significant difference in peak plasma creatine phosphokinase between the two groups, patients with anterior myocardial infarction (28 patients) had larger %fixed defect (p < 0.01), which was associated with higher end-diastolic pressure (p < 0.05) and larger end-diastolic volume index (p < 0.01) than those with inferior myocardial infarction (19 patients). End-diastolic volume index was not related to %redistribution and %reverse redistribution, but there was a good relation between end-diastolic volume index and %fixed defect in anterior (r = 0.79, p < 0.001) and in inferior (r = 0.73, p < 0.001) myocardial infarction. However, left ventricular end-diastolic volume index in anterior myocardial infarction was larger than that of inferior myocardial infarction at any given %fixed defect. Thus, site as well as size of fixed defect at 2 weeks after the onset of acute myocardial infarction was related to left ventricular end-diastolic volume at chronic phase.

Clinical significance of denervated but viable myocardium in patients with recanalized acute myocardial infarction

In patients with acute myocardial infarction (MI), myocardial sympathetic innervation evaluated by 123I-metaiodobenzylguanidine myocardial scintigraphy is more sensitive to ischaemia than the associated perfusion abnormality of 201Tl myocardial scintigraphy. The purpose of this study was to evaluate the scintigraphic indices related to the recovery of left ventricular function after acute MI. 123I-metaiodobenzylguanidine and 201Tl-chloride imaging were performed in 15 patients (mean age 60 years, 13 men and 2 women) 2 weeks after the onset of acute MI. Using a 20-segment visual interpretation of the 201Tl image, myocardial segments were classified into persistent defect, redistribution or reverse redistribution, and normal 201Tl uptake. The extent of denervated segments showed a fair correlation with the ejection fraction on admission (r = -0.53, P = 0.04), whereas the extent of persistent defect had a close correlation with the ejection fraction at 4 months (r = -0.79, P = 0.01). There was a good correlation between the extent of denervated but viable myocardium and the change in ejection fraction from admission to 4 months (r = 0.68, P = 0.01). Thus, denervated but viable myocardium is a scintigraphic index related to the functional recovery of left ventricular pump function after acute MI.

Pseudoaneurysm of the left ventricle progressing from a subepicardial aneurysm

A 56-year-old man presented with an inferior myocardial infarction and a huge pseudoaneurysm below the inferior surface of the left ventricle, which had progressed from a small subepicardial aneurysm over a 6-month period. Transthoracic echocardiography, Doppler color flow images, radionuclide angiocardiography, magnetic resonance imaging and contrast ventriculography all revealed an abrupt disruption of the myocardium at the neck of the pseudoaneurysm, where the diameter of the orifice was smaller than the aneurysm itself, and abnormal blood flows from the left ventricle to the cavity through the orifice with an expansion of the cavity in systole and from the cavity to the left ventricle with the deflation of the cavity in diastole. Coronary angiography revealed 99% stenosis at the atrioventricular nodal branch of the right coronary artery. At surgery the pericardium was adherent to the aneurysmal wall and a 1.5-cm orifice between the aneurysm and the left ventricle was seen. Pathological examination revealed no myocardial elements in the aneurysmal wall. The orifice was closed and the postoperative course was uneventful. Over-intense physical activity as a construction worker was considered to be the cause of the large pseudoaneurysm developing from the subepicardial aneurysm. These findings indicate that a subepicardial aneurysm may progress to a larger pseudoaneurysm, which has a propensity to rupture, however, it can be surgically repaired.

Angiotensin II type 2 receptor is upregulated in human heart with interstitial fibrosis, and cardiac fibroblasts are the major cell type for its expression

The expression pattern of angiotensin (Ang) II type 2 receptor (AT2-R) in the remodeling process of human left ventricles (LVs) remains poorly defined. We analyzed its expression at protein, mRNA, and cellular levels using autopsy, biopsy, or operation LV samples from patients with failing hearts caused by acute (AMI) or old (OMI) myocardial infarction and idiopathic dilated cardiomyopathy (DCM) and also examined functional biochemical responses of failing hearts to Ang II. In autopsy samples from the nonfailing heart group, the ratio of AT1-R and AT2-R was 59% and 41%, respectively. The expression of AT2-R was markedly increased in DCM hearts at protein (3.5-fold) and mRNA (3.1-fold) levels compared with AMI or OMI. AT1-R protein and mRNA levels in AMI hearts showed 1.5- and 2.1-fold increases, respectively, whereas in OMI and DCM hearts, AT1-R expression was significantly downregulated. AT1-R-mediated response in inositol phosphate production was significantly attenuated in LV homogenate from failing hearts compared with nonfailing hearts. AT2-R sites were highly localized in the interstitial region in either nonfailing or failing heart, whereas AT1-R was evenly distributed over myocardium at lower densities. Mitogen-activated protein kinase (MAPK) activation by Ang II was significantly decreased in fibroblast compartment from the failing hearts, and pretreatment with AT2-R antagonist caused an additional significant increase in Ang II-induced MAPK activity (36%). Cardiac hypertrophy suggested by atrial and brain natriuretic peptide levels was comparably increased in OMI and DCM, whereas accumulation of matrix proteins such as collagen type 1 and fibronectin was much more prominent in DCM than in OMI. These findings demonstrate that (1) AT2-R expression is upregulated in failing hearts, and fibroblasts present in the interstitial regions are the major cell type responsible for its expression, (2) AT2-R present in the fibroblasts exerts an inhibitory effect on Ang II-induced mitogen signals, and (3) AT1-R in atrial and LV tissues was downregulated during chronic heart failure, and AT1-R-mediated functional biochemical responsiveness was decreased in the failing hearts. Thus, the expression level of AT2-R is likely determined by the extent of interstitial fibrosis associated with heart failure, and the expression and function of AT1-R and AT2-R are differentially regulated in failing human hearts.

Coronary artery diameter and left ventricular function in patients on maintenance hemodialysis treatment: comparison between diabetic and nondiabetic patients

BACKGROUND/AIMS

This study examined the role of diabetes mellitus on determining left ventricular function by evaluating coronary artery diameter in patients with end-stage renal disease on maintenance hemodialysis treatment.

METHODS

We studied 12 diabetic and 12 nondiabetic patients on maintenance hemodialysis treatment without significant stenoses of the major epicardial coronary arteries. Patients were matched for age, sex distribution, duration of dialysis and incidence of major coronary risk factors. Left ventricular wall thickness (septal and posterior walls) and left ventricular diameter (end-diastolic and systolic phases), were measured by echocardiography. Hemodynamic measurements and coronary angiography were performed on the day of hemodialysis and coronary artery diameter at the proximal and mid portion of three major coronary arteries were measured using the computed densitometry method.

RESULTS

Right and left anterior descending and circumflex coronary artery diameters were all significantly smaller and the frequency of coronary artery calcification was higher in diabetic (58%) compared to nondiabetic (8%) patients. Although there were no significant differences in left ventricular wall thickness, left ventricular diameter, mean right atrial pressure and cardiac index between the two groups, left ventricular end-diastolic pressure was significantly higher in diabetic (22 +/- 9 mm Hg) compared to nondiabetic patients (14 +/- 5 mm Hg).

CONCLUSION

Despite that there were no significant stenoses of the major epicardial coronary arteries, diffuse luminal narrowing of the epicardial coronary arteries in diabetic patients on maintenance hemodialysis treatment was associated with increased left ventricular end-diastolic pressure.

Serial assessment of sympathetic reinnervation in a patient with myocardial infarction

Resting [123I]MIBG and 201TI imaging were performed at 2 wk and 4 and 12 mo after successfully reperfused myocardial infarction. Although [123I]MIBG uptake of the infarcted segments revealed significant improvement in the early image at 4 mo, delayed image displayed decreased [123I]MIBG uptake. However, decreased [123I]MIBG uptake of the delayed image became almost uniform at 12 mo. These observations suggest that reinnervation initially occurs in norepinephrine uptake and then in retention ability. On the other hand, a 201TI defect remained in the infarcted segments at 12 mo. Thus, reinnervation can occur not only in the peri-infarct area but also in the infarcted area.

Frequency of pericardial friction rub ("pericarditis") after direct percutaneous transluminal coronary angioplasty in Q-wave acute myocardial infarction

The clinical significance of infarct-associated pericarditis was examined in 201 consecutive patients with acute Q-wave myocardial infarction with successful direct percutaneous transluminal angioplasty. A pericardial rub was a reliable clinical sign of extensive myocardial damage in patients with direct angioplasty.

Clinical significance of S-T segment elevation in lead aVR in anterior myocardial infarction. Assessment by thallium-201 exercise scintigraphy

The significance of exercise-induced S-T elevation in aVR was studied in 57 patients with recent anterior infarction and single-vessel disease. S-T elevation in aVR was found at peak exercise in 24 patients. Although the initial defect area was similar in the groups with and without S-T elevation in aVR, the redistribution area was larger in the former group (p < 0.01). When three electrocardiographic criteria were used in the multivariate analysis, S-T elevation in aVR was the significant variable related to redistribution in the anterior wall. Thus, S-T elevation in aVR may indicate ischemia of the anterior wall.

The effect of successful angioplasty on variables of signal-averaged electrocardiogram and ventricular wall motion in patients with a first myocardial infarction

The correlation among three variables of late potentials (LPs) obtained by signal-averaged electrocardiography (SAECG) and improvement of ventricular wall motion estimated by echocardiography were studied in 66 patients with a first acute myocardial infarction (MI). Patients with bundle-branch block, intraventricular conduction delay, multi-vessel disease, previous MI, repeat percutaneous transluminal coronary angioplasty (PTCA), or evidence of reinfarction during a 6-month follow-up were excluded. A total of 66 patients was divided into two groups, with (Group 1: n = 27, age 56 +/- 11) or without (Group 2: n = 39, age 61 +/- 10) improvement of ventricular wall motion. Three variables of LPs and ventricular wall motion index (WMI) estimated and scored by echocardiography at admission (WMI 1) and at 6 months after MI (WMI 2) were compared in each group. In Group 1 (WMI 1 vs. WMI 2, p < 0.002), 20 of 27 patients underwent successful angioplasty; in Group 2 (WMI 1 vs. WMI 2, p = NS), 7 of 39 patients had successful emergency angioplasty. There were significant differences in three variables of LPs between the time of admission and at 6 months after MI in Group 1 but not in Group 2. Higher incidence of LPs and greater frequency of successful emergency PTCA were found in Group 1 compared with Group 2. These results suggest that because myocardial ischemia is reversed by successful angioplasty, ventricular wall motion is improved and the arrhythmogenic substrate that generates LPs is stabilized electrically. Stunned or hibernating myocardium may be the arrhythmogenic substrate that generates LPs.

Quantification of infarct size by thallium-201 single-photon emission computed tomography using the unfolded map method. Comparison with QRS score and angiographic infarct size at 4 weeks after infarction

A new technique of data processing, the unfolded map method, was used with thallium-201 single-photon emission computed tomography to quantify infarct size in 35 patients with single-vessel disease at 4 weeks after their first myocardial infarction (24 anterior and 11 inferior infarcts), and the results were compared with those obtained by electrocardiography and contrast left ventriculography. The myocardial borders and the infarcted region were defined using the threshold technique and a cutoff value of 55%. Count profile data for each short-axis slice were unfolded zonally into single planes with the same ratio, and their areas were calculated from the slice thickness and radius. Thus, the size of the unfolded map represented the actual left ventricular myocardial area Infarct size was quantitated from the ratio of pixels in the infarcted region to those in the whole map, and the ratio itself was used as the percent infarct size. Although a defect 1 cm in diameter (0.8 cm2) could not be detected in a phantom study, defects > or = 2 cm in diameter (> or = 3.1 cm2) could be measured satisfactorily. The infarct size and percent infarct size determined by the unfolded map method correlated well with the QRS score (r = 0.841 and r = 0.838), the percentage of abnormally contracting segments on left ventriculography (r = 0.835 and r = 0.877), and the ejection fraction (r = -0.835 and r = 0.856). These data indicate that the unfolded map method provides adequate quantification of infarct size, even in the chronic phase, without complicated data processing.

Late potentials during left ventricular healing of acute myocardial infarction

BACKGROUND

Late potentials and left ventricular remodeling are important factors in the prognosis of acute myocardial infarction. However, the relationship between late potentials and ventricular remodelling has not been fully evaluated.

METHODS

We evaluated clinical characteristics, coronary angiographic findings and radionuclide angiographic measures about 1 month after an acute myocardial infarction in patients with and without late potentials.

RESULTS

Although the left ventricular ejection fraction of patients with late potentials was not different from that of patients without late potentials, the left ventricular end-diastolic volume of patients with late potentials was larger than that of patients without late potentials (P < 0.05). There was a significant positive correlation between the left ventricular end-diastolic volume and the filtered QRS duration (r = 0.53, P < 0.001). The root mean square of the voltage in the terminal 40 ms and the low-amplitude signal duration of < 40 microV in the terminal QRS sequence were also correlated with the left ventricular end-diastolic volume (r = 0.40, P < 0.02, and r = 0.39, P < 0.02, respectively). Patency of the infarct-related vessel in the late phase of an acute myocardial infarction was an important factor associated with the occurrence of late potentials (P < 0.01).

CONCLUSION

A larger left ventricular end-diastolic volume in patients with late potentials might be associated with left ventricular remodeling during the first month after an acute myocardial infarction.

Effect of sex on left ventricular pump function in patients with anterior wall myocardial infarction treated with primary angioplasty

BACKGROUND

The prognosis of acute myocardial infarction (AMI) is distinctly worse in postmenopausal women than in age-matched men. Unstable angina before AMI is reported to protect left ventricular pump function during the left ventricular remodeling process in patients who have undergone successful percutaneous transluminal coronary angioplasty (PTCA). We postulate that left ventricular pump function may be different in postmenopausal women and age-matched men with unstable angina before AMI and successful PTCA.

METHODS

Twenty-three postmenopausal women (aged 63 +/- 7 years) and 31 age-matched men (aged 65 +/- 6 years) with unstable angina before AMI and successful PTCA were investigated using radionuclide angiography in the late hospital phase.

RESULTS

Global ejection fraction (EF), regional EF of the non-infarcted area, and the ratio of systemic arterial systolic blood pressure to left ventricular end-systolic volume (P:V ratio) were lower in women compared with those in men. Global EF, regional EF of the non-infarcted area, and the P:V ratio in women with left ventricular end-diastolic volume (EDV) > or = 140 ml were significantly lower than in those with a left ventricular EDV of less than 140 ml, but no significant differences were noted in these indexes with regard to left ventricular EDV in men.

CONCLUSION

Sex may play an important role in the left ventricular remodeling process in postmenopausal women, especially those with a dilated left ventricle.

[Magnetic resonance imaging for cardiovascular masses]

We examined 10 patients with cardiovascular masses using 0.15 tesla permanent magnetic resonance imaging (MRI) incorporating an ECG-gated spin echo technique, and investigated the usefulness of MRI in the noninvasive diagnosis of cardiovascular masses. Patients were one with rhabdomyoma, one with leiomyosarcoma, one with malignant mesothelioma (diffuse type), three with pulmonary arterial invasions by lung carcinoma, one with left atrial invasion by lung carcinoma, and three with the superior vena cava (SVC) syndrome. 1. Each image obtained with TE of 40 msec, and TR of one R-R interval clearly defined the mass by its intermediate signal intensity. 2. In the case of rhabdomyoma occupying the right ventricle, leiomyosarcoma growing from the inferior vena cava into the right atrium and malignant mesothelioma diffusely invading the mediastinum, the morphology and the extent of each mass in relation to the surrounding structures were distinctly identified in the coronal, sagittal or oblique sections for situation, in addition to the routine transaxial section. 3. In the cases of pulmonary arterial invasion by lung carcinoma and the SVC syndrome, the masses invading the pulmonary artery or narrowing large vessels were clearly separated from adjacent structures on the sections through each of the large vessels. 4. In the case without left atrial invasion, which was proved by autopsy, a high intensity line due to mediastinal fat demarcated the mass distinctly. This finding is a useful sign for evaluating the extension of a tumor. 5. The image obtained with TE of 80 msec, and TR of double R-R interval (long SE image) showed a different contrast from the image obtained with TE of 40 msec and TR of one R-R interval. Leiomyosarcoma had a more heterogenous intensity on the long SE image which may result from a different T2 value caused by necrotic, edematous or fibrotic changes within the tumor. These results indicate that MRI also provides some information about the differentiation between benign and malignant masses.

[Infarct size related to the distribution and site of coronary artery lesions studied by the unfolded map technique using single photon emission computed tomography]

To assess the relative importance of the anatomical characteristics of the coronary artery distribution and the sites of the arterial stenoses in relation to infarct size, 21 patients with old myocardial infarction and angiographically-proven 90% or greater stenoses (AHA classification) of one of the major coronary arteries were studied. The infarct size was evaluated by a new quantitative method, the unfolded map, derived from single photon emission computed tomography (SPECT). Eleven patients had right coronary artery disease (Group RCA: segment 1; five patients and segment 2; six patients). Seven patients who had the large left anterior descending artery (LAD) which was distributed to the inferior portion of the apical area were defined as Small R, and four patients with large RCA as Large R. Ten patients each had a significant stenosis in the LAD (Group LAD: segment 6; six patients and segment 7; four patients). Four patients with significant stenosis proximal to segment 9 were defined as Pre-9, and seven patients with stenosis distal to the segment, as Post-9. Stress T1-201 scintigraphy with SPECT was performed and the unfolded map was obtained with data of the maximal count circumferential profiles in the redistribution image. Infarction was defined as a defect below 55% of the standard value. The necrotic area ratio expressed as percentage of the defect area to the entire map area was calculated and used as the indicator of infarct size. Although there was no significant difference in the necrotic area ratio between segment 1 and 2 lesions. Large R had the significantly larger necrotic area ratios (24.9 +- 4.6%) than did Small R (9.7 +- 4.4%; p less than 0.01). In the Group LAD, there was no significant difference in the necrotic area ratio between segment 6 and 7 lesions, but Pre-9 had the larger ratio (30.4 +- 3.3%) than did Post-9 (15.4 +- 7.7%; p less than 0.01). These data suggest that the factors related to infarct size are either the distribution of the coronary arteries in the apical area in the Group RCA or the sites of the stenotic lesions relative to the branching portion of the first diagonal branch in the Group LAD.