Exercise electrocardiography as an estimation of cardiac function

Clinical features of prognosis of Japanese patients with anomalous origin of the coronary artery

Anomalous origin of the coronary artery can lead to angina pectoris, acute myocardial infarction or even sudden death in the absence of atherosclerosis. However, in Japan, this anomaly is usually treated medically rather than surgically. To clarify the clinical features of anomalous origin of the coronary artery in Japanese and the prognosis of such patients who are treated medically, we reviewed 56 patients with anomalous origin of the coronary arteries. The mean age of these patients was 55.9 +/- 11.5 years. Anomalous origin of the right coronary artery from the left sinus of Valsalva was seen most frequently (78.6%). In contrast, we found no cases of anomalous origin of the left coronary artery from the right sinus of Valsalva traversing between the aorta and the pulmonary trunk. A history of syncope (14.3%) and aorta regurgitation (21.4%) was frequent and serious complications during exercise stress testing occurred in 5 patients. These patients were treated medically, such as by limiting exercise or by the oral administration of medicine. During the follow up period (mean 5.6 +/- 4.2 years), death directly related to anomalous origin of the coronary artery was not found despite the lack of surgical treatment. Our results suggest that the prognosis of these middle-aged-to-elderly patients without atherosclerosis is relatively good, despite the lack of surgical treatment.

Ability of the R-wave change during stress testing to accurately detect coronary disease in the presence of left bundle branch block at rest

The treadmill stress test and antiographic records of 18 patients with left bundle block on resting ECG were reviewed retrospectively. Thirteen of the patients had significant coronary artery disease defined as greater than or equal to 70% cross-sectional narrowing of one or more vessels, while 5 patients were hemodynamically and angiographically normal. The R-wave and ST-segment response to exercise were determined in each case and compared. A positive R-wave response was an exercise-induced increase or no change in amplitude over the baseline level, while a positive ST-segment response was greater than or equal to 2 mm of excerise-induced depression over the baseline level. The sensitivity for the R-wave response was 69% (9 of 13), the specificity was 100% (5 of 5), and the predictive value was 100% (9 of 9). For ST depression these values were 46% (6 of 13), 40% (2 of 5)8 and 67% (6 of 9). Although the number of patients in this study is small--a reflection of the fact that ST depression in the presence of left bundle branch block with exercise is associated with many false positive responses and hence less referral for stress testing--it appears that the R-wave response to exercise in the presence of left bundle branch block can accurately detect coronary artery disease.

Is the treadmill exercise test useful for evaluating coronary artery disease in patients with complete left bundle branch block?

To aid in the study of coronary artery disease, 57 patients with complete left bundle branch block underwent clinical evaluation, treadmill exercise testing and cardiac catheterization. The patients were classified into two groups according to coronary angiographic findings: 30 patients with significant stenosis (70 percent or greater luminal narrowing) of at least one major vessel and 27 with no significant coronary artery disease. There was no difference in age, presenting symptoms or previous medical treatment between the two groups. There were more men in the group with coronary artery disease. Exercise-induced S-T changes were similar in the two groups; the sensitivity and specificity of these changes for the diagnosis of coronary artery disease were unacceptable irrespective of the criterion chosen. With additional S-T depression of either 1 or 2 mm below the baseline value, the predictive accuracy was only 53 percent. Combined exertional chest pain and 1 mm S-T depression increased the predictive accuracy of exercise testing to 71 percent. These data indicate that exercise-induced electrocardiographic changes do not facilitate detection of coronary artery disease in patients with complete left bundle branch block.

The electrocardiographic response to maximal treadmill exercise of asymptomatic men with left bundle branch block

This study presents the results of maximal treadmill testing and coronary angiography in 31 asymptomatic USAF aircrewmen with acquired left bundle branch block. There were two subgroups: 26 men with normal coronary angiography and five men with significant angiographic coronary angiography and five men with significant angiographic coronary artery disease. The mean amount of maximal ST-segment depression induced by treadmill exercise was --0.5 mv. for both groups and the range in the normal subgroup was --0.3 to --1.0 mv. No significant differences were found between the groups. We concluded that apparently healthy, asymptomatic men with acquired left bundle branch block can have considerable ST-segment depression in response to maximal treadmill testing and that their ST-segment response cannot be used to make diagnostic decisions about them.

Percutaneous myocardial biopsy of the left ventricle. Experience in 198 patients

A thin-walled Silverman needle has been used for 254 percutaneous punch biopsies of the left ventricle in 198 patients with closed chests at the Cleveland Clinic. The technic is described. The biopsy specimens were adequate for diagnosis in 192 patients. In all but three patients (who had lupus erythematosus, scleroderma, and chronic glomerulonephritis with congestive heart failure) cardiac catheterization and selective cardioangiographic studies were performed. There was angiographic evidence of primary myocardial disease, coronary atherosclerosis, or both, or rheumatic valvular disease in 175 patients. Cardiac catheterization and angiographic studies demonstrated no evidence of organic heart disease in 20 patients.

Cardiac tamponade was a complication of myocardial biopsy in eight patients. Post-pericardiotomy syndrome occurred in four patients and ventricular fibrillation in one patient.

Myocardium with no pathologic diagnosis and interstitial fibrosis or myocardial hypertrophy or both were the light microscopic findings in 165 patients. Representative sections of the biopsy in 27 patients demonstrated small-vessel disease, basophilic degeneration, focal interstitial myocarditis, amyloidosis, Aschoff's nodules, or vacuolar degeneration. The current experience suggests that myocardial biopsy combined with selective cardioangiography is of experimental value, improves the accuracy of diagnosis, and plays a role in the management of some patients.

Coronary arteriographic appearances in patients with left bundle-branch block

Left bundle-branch block (LBBB) was found to be associated with an unusually short left main coronary artery in 11 of 12 patients studied by selective coronary arteriography. The average length of the left coronary artery in this group of 12 patients with LBBB was 4.5 ± 1.7 mm as compared to 12.8 ± 0.8 mm in a control group. Four of the 12 had evidence of ischemic heart disease, one had mild aortic regurgitation, one had myocardiopathy, and one had a patent ductus arteriosus. No etiology was discovered for the LBBB in the remaining five patients. Mechanical and hemodynamic explanations for this association of a particular pattern of coronary anatomy with LBBB are proposed.