Richard J. Bouchard

Radiation-related pericarditis

To determine the incidence of pericardial effusion in patients undergoing upper mantle radiation therapy, 81 patients with Hodgkins disease, stages I to IIIB, were selected from a protocol series of 98 patients. Twenty-four patients (29.6 percent) met X-ray criteria for the presence of pericardial effusion. Eleven of the 24 also underwent right heart catheterization to confirm the presence of pericardial effusion and to define any hemodynamic abnormality. Fourteen patients were found to have transient effusion. Five of the 11 patients have had partial pericardiectomy for symptoms and signs of cardiac tamponade. There has been no evidence of recurrent Hodgkins disease in these surgically treated patients. Ninety-two percent of the pericardial effusions occurred in the first 12 months after the end of radiation therapy. Therapeutic implications depend on elucidation of the natural history of this process. At present close follow-up is necessary with surgical intervention for signs or symptoms of cardiac tamponade.

Diagnosis of Obstructive Coronary Disease by Maximal Exercise and Atrial Pacing

The reliability of graded maximal exercise treadmill testing and right atrial pacing in diagnosing significant obstructive coronary artery disease was evaluated in 74 consecutive patients referred to a cardiac unit with chest pain consistent with angina pectoris. The results of maximal exercise testing and right atrial pacing, with regard to the presence or absence of the patients characteristic chest pain or discomfort and ischemic ST segment depression, were compared with the findings determined by selective coronary arteriography. Ischemic ST segment depression was defined as a downward displacement of one full mm or more of a horizontal or downward sagging ST segment.Forty-nine of the 74 patients studied were found to have significant coronary arteriographic obstruction, i.e., greater than 75% obstruction of one major coronary artery. The occurrence of the patients characteristic chest pain or discomfort during maximal exercise testing or right atrial pacing is an excellent indicator of the presence of obstructive coronary artery disease, since all of the 41 patients developing their characteristic pain on maximal exercise testing had coronary arteriograms positive for obstructive coronary disease (no false positives), and 46 of 47 patients with characteristic chest pain on right atrial pacing had selective coronary arteriograms positive for obstructive coronary disease. When present, one mm ST depression during maximal exercise treadmill testing also reliably indicates arteriographic obstructive coronary disease (26 of 27 patients). However, the presence or absence of ischemic ST depression during right atrial pacing is a particularly unreliable indication of the presence or absence of arteriographic obstructive coronary disease: 15 of 25 false positive tests, and 13 of 49 false negative tests.

Objective evidence of occult myocardial dysfunction in patients with frequent ventricular ectopy without clinically apparent heart disease

Eighteen asymptomatic persons without apparent cardiac disease were incidentally discovered to have frequent ventricular ectopic activity (VEA) (more than a mean of 100 b/hr during 24-hour ambulatory ECG examination) and were found by cardiac catheterization to have normal coronary arteriograms. Thirteen persons (72%) also demonstrated complex (multiform or repetitive patterns) VEA and eight persons were found to have undiagnosed hypertension. Examination of left ventricular (LV) angiographic and hemodynamic data of these persons showed elevated LV end-systolic volume index in 10 persons (56%), elevated LV and end-diastolic volume index in 12 persons (67%) and elevated LV end-diastolic pressure in 11 persons (61%). Although ejection fractions of all but three persons were normal, impaired myocardial contractility, as measured by decreased mean velocity of circumferential fiber shortening (less than 1.0 circ/sec), was found in 10 persons (56%). Abnormalities of LV function were more prevalent in persons with higher mean frequencies of VEA (more than 300 b/hr), but did not seem related to the presence of complex VEA. Etiologic mechanisms of the frequent and complex VEA could not be defined. We conclude that subclinical evidence of myocardial dysfunction is present in some persons without apparent cardiac disease who have frequent VEA as evidence by subtle abnormalities of increased LV volumes and end-diastolic pressure and decreased mean velocity of myocardial circumferential fiber shortening.

Coronary Artery Status of Apparently Healthy Subjects with Frequent and Complex Ventricular Ectopy

Twenty-five subjects from a cohort of 62 asymptomatic, apparently healthy subjects incidentally discovered to have frequent and complex ventricular ectopy were studied with cardiac catheterization and coronary angiography. Fourteen had normal coronary arteries, five noncritical coronary artery disease (less than 50% luminal narrowing), and six significant coronary artery disease (greater than or equal to 50% luminal narrowing). Slightly elevated left ventricular end diastolic pressures were found in all subject subgroups. Characteristics of the ventricular ectopy detected by maximal exercise testing or 24-hour Holter ambulatory electrocardiography did not differentiate those subjects with coronary artery disease from those with normal coronary arteries. This study documents that a minority of apparently healthy subjects with frequent and complex ventricular arrhythmia have significant coronary artery disease and supports a conservative approach to the management of such patients.

The prognostic value of systolic time intervals in angina pectoris patients.

Eighty-five subjects with stable angina pectoris and proven obstructive coronary disease were followed prospectively (mean follow-up 4.2 ± 2.0 years) to assess the value of various predictors of longevity. After patients with congestive heart failure, hypertension, left bundle branch block, valvular heart disease or recent propranolol therapy were excluded, subjects were followed until a major cardiac event (new acute myocardial infarction, cardiac surgery or death) occurred. During follow-up, 22 patients died, 49 survived without events, nine underwent coronary bypass surgery, and five had nonfatal myocardial infarctions. The measurements made at the onset of the study, including cardiothoracic ratio (C/T) on chest x-ray, resting electrocardiographic abnormalities, maximum exercise tolerance testing (METT) data, systolic time interval (STI) measurements (before exercise and 34 minutes after METT), and results of cardiac catheterization (55 patients), were analyzed at its conclusion to determine the best predictor of subsequent mortality. Of these measurements, left ventricular ejection fraction, endurance time on METT and C/T were shown to be useful prognostic indicators of subsequent mortality. However, the pre-ejection phase-to-left ventricular ejection time (PEP/LVET) ratio (0.40 ± 0.05 in survivors vs 0.50 + 0.09 in nonsurvivors) in the resting pre-exercise state wa1s significantly more predictive of mortality than the other measurements. On life-table analysis, the difference in survival between subjects with a resting PEP/LVET < 0.50 and those with a resting PEP/LVET 2 0.50 was highly significant. The measurement of the STIs after maximal exercise testing failed to improve upon the prognostic ability of the simple determination of PEP/LVET in the resting, supine state. STIs provided highly specific noninvasive prognostic information in this group of patients with stable angina pectoris.