Evolution of the electrocardiographic changes in patients with hypertrophic cardiomyopathy

In 75 patients with hypertrophic cardiomopathy (HCM) followed for a mean period of 5.5 years (range 2-20 years), evolution of the electrocardiographic (EKG) changes was assessed. Progression of EKG abnormalities occurred in 35 patients (47%). It was manifested by an increase in precordial QRS voltage in 33 patients, development of new P-wave mitral in 11 patients, and development or disappearance of pathologic Q waves in 14 patients. With follow-up times greater than 5 years, 5-8 years, and greater than 8 years, EKG progression was present in 27, 41, and 80% of patients, respectively. Age less than 30 years at the beginning of study and left ventricular outflow obstruction predisposed to EKG progression within 5-8 years. Patients with progressive EKG changes were more prone to experience clinical deterioration than those without EKG progression (63 vs. 15%, p less than 0.001). With chronic verapamil administration, progression of EKG abnormalities occurred insignificantly less often than with propranolol treatment (35 vs. 64%, p = 0.20). It is concluded that with long-term follow-up, HCM tends to progress in a significant proportion of adult patients.

[Complete atrioventricular block in Becker-type muscular dystrophy]

A case is described of Becker type muscular dystrophy in a man aged 52 years, in whom complete atrioventricular block was found with Morgagni-Adams-Stokes attacks. The pathogenesis of the syndrome and the necessity of implantation of a pacemaker are discussed.

[Value of endomyocardial biopsy in the assessment of the degree of the changes in myocarditis]

Right ventricular diagnostic biopsy was performed in 25 patients (12 females and 13 males) aged 19-48 (mean 32) with suspicion of acute or subacute myocarditis for definitive diagnosis verification and to determine indications for therapy with corticosteroids or azathioprine. 3-4 specimens taken from different sites of ventricle were estimated under the light microscope according to Dallas classification distinguishing active myocarditis with or without fibrosis from borderline myocarditis with inflammatory infiltration not causing myocytes damage. Routine clinical and laboratory tests, echocardiographic examination, ECG Holter monitoring and nuclear examination to evaluate left ventricular ejection fraction were performed in all patients. 6 patients underwent coronarography to exclude atherosclerotic changes in coronary arteries. Bioptic examination result confirmed myocarditis suspicion in all patients. Active inflammation was stated in 18 patients including 7 with coexisting fibrosis. Borderline myocarditis was stated in 7 cases. Comparison of clinical examination results with those of pathomorphologic study made possible to state, that tachycardia, cardiac murmur, arrhythmias and left ventricular function impairment were frequent observed in the group of active myocarditis. Ejection fraction less than 30% was observed only in patients with active myocarditis and mainly in those with coexisting fibrosis. Based on performed study we consider that myocardial biopsy allows not only to diagnose myocarditis but also is helpful for lesion extent assessment in myocardium with all clinical implications.

Assessment of the intracardiac left to right shunts with a single scintillation probe

In order to assess the accuracy of pulmonary time-activity curves obtained at bedside with a single scintillation probe and Technetium-99m-labelled erythrocytes, pulmonary to systemic flow ratio (Qp:Qs) was calculated for radionuclide and hemodynamic investigations in 104 patients with suspected intracardiac left to right shunts. Cardiac catheterization confirmed the presence of shunts in 76 patients. Pulmonary time-activity curve was 100% sensitive, 88% specific, and 96% accurate in detecting the shunt. Correlation between the radionuclide and hemodynamic Qp:Qs was excellent (r = 0.93). Results were classified in four quantitative categories according to the Qp:Qs values. In 76 patients (73%) radionuclide and hemodynamic data fell in the same category. We conclude that radionuclide pulmonary time-activity curves generated with a scintillation probe is a reliable method in quantitative assessment of intracardiac left to right shunts.

Depolarization changes early in the course of myocardial infarction: significance of changes in the terminal portion of the QRS complex

Studies of patients during variant angina have revealed that there are specific changes in the terminal part of the QRS complex that provide information regarding the location of the ischemia. Extending these studies to acute myocardial infarction, the electrocardiogram (ECG) obtained from 32 patients within 5 h of the onset of chest pain was analyzed to determine if similar inferences could be made. A preinfarction ECG was available from each patient for comparison and 30 patients underwent coronary arteriography within 3 weeks of the infarction. The 10 patients with anterior infarction had a decrease (p less than 0.05) in the S wave in leads V2 (0.80 +/- 0.50 mV) and V3 (0.65 +/- 0.43 mV). In 23 patients with inferior infarction an increase (p less than 0.05) in the R wave of lead III (0.47 +/- 0.35 mV), S wave of lead aVL (0.31 +/- 0.23 mV) and R wave of lead aVF (0.37 +/- 0.30 mV) occurred. A strong positive correlation between the R wave changes in leads III and aVF and the S wave in lead aVL (r = 0.94 and 0.91, respectively) suggests that the R and S wave changes in these leads are expressions of the same phenomenon and indicates that the terminal QRS complex is chiefly affected. Eight of 23 patients with inferior infarction and ST depression in the anterior precordial leads had a normal left anterior descending coronary artery. All had an increase in S wave amplitude in leads V2 and V3. Eight patients had inferior infarction, ST depression in anterior leads and severe lesions in the left anterior descending artery or anterior wall motion abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)

Significance of early and late anterior precordial ST-segment depression in inferior myocardial infarction

In 24 patients with acute inferior myocardial infarction, the presence and duration of ST-segment depression in lead V2 correlated with the presence of left anterior descending coronary artery (LAD) stenosis and depressed left ventricular ejection fraction (LVEF). Early changes in lead V2 (within 4 hours after the onset of pain) were 67% sensitive and only 42% specific, whereas late changes (after onset of inferior Q waves and more than 6 hours after the onset of pain) were 42% sensitive, but 100% specific for the presence of LAD stenosis or decreased LVEF or both. Thus, in patients with inferior infarction, only the late repolarization change is helpful in identifying those with LAD stenosis or decreased LVEF. The absence of lead V2 ST-segment depression on either early or late electrocardiograms does not imply a normal LAD or LVEF.

Segmental analysis of thallium 201 myocardial perfusion scintigraphy: its value in a community hospital

In a community hospital, we correlated results of thallium 201 myocardial scintigraphy with coronary arteriographic data in 79 patients. Scintigraphy was 92% sensitive and 85% specific in detecting coronary artery disease. There were no false-negative scintigrams in patients with double or triple vessel disease. The most important factors determining sensitivity of the method in detecting individual coronary stenoses were (1) location of the stenosis in the coronary tree, (2) number of vessels involved, and (3) degree of obstruction. Higher prevalence of perfusion defects in areas of 90% to 99% stenosis as compared with 50% to 89% lesions was of borderline statistical significance (86% vs 59%; P = .06). Myocardial perfusion scintigraphy was unable to predict the number of significantly narrowed coronary vessels. Predictive value of a perfusion defect for a significant coronary stenosis was 87% for anterior, 88% for septal, 90% for lateral, 89% for posterior, and 78% for inferior segment. We conclude that segmental analysis of myocardial scintigrams may be of value in a community hospital.

Left ventricular end-diastolic pressure-volume relationships in hypertrophic cardiomyopathy. Changes induced by verapamil

In 16 patients with hypertrophic cardiomyopathy, an acute response of the left ventricular end-diastolic pressure and volume index to intravenously administered verapamil was assessed. Verapamil decreased the left ventricular end-diastolic pressure from 20 +/- 6 to 17 +/- 5 mm Hg(p less than 0.001) and increased the end-diastolic volume index from 82 +/- 22 to 91 +/- 23 ml/sqm (p less than 0.01). In 13 (81 percent) of 16 patients, an improvement of end-diastolic pressure-volume relationships occurred. In hypertrophic cardiomyopathy, intravenous verapamil exerts a beneficial effect on left ventricular filling conditions, producing an augmentation of filling volume at a lower filling pressure.