Search

Myocardial perfusion was studied in 12 patients with mitral valve prolapse concurrent with cardiac arrhythmias by using two-dimensional 201Tl myocardial scintigraphy at rest and during exercise test. Signs of myocardial ischemia were revealed only in one case. Five patients were found to have steady-state perfusion defects whose extent correlated with the depth of mitral valve prolapse. There was an irregular distribution of myocardial blood flow, which ceased on exercise in 10 out of 12 patients. Patients with ventricular premature contraction displayed a decreased reserve of myocardial blood flow as compared to those with supraventricular premature contraction, presumably by enhancing myocardial perfusion at rest.

A method for quantitative determination of the percentage of left ventricular myocardial 201Tl isotope uptake at rest and during dipyridamole test was first used in patients with dilated cardiomyopathy and coronary heart disease complicated by circulatory insufficiency or chronic myocarditis. This method makes it possible to judge the level of myocardial blood flow and perfusion reserve in these diseases. The most common differences were found between patients with coronary heart disease and those with chronic myocarditis. The patients with chronic myocarditis exhibited the greatest sizes of perfusion defects, highest values of 201Tl uptake at rest and a lower myocardial perfusion reserve during dipyridamole test. In response to exercise, most patients with chronic myocarditis had diminished perfusion defects, whereas those with coronary heart disease displayed increased defects. The myocardial perfusion was varied in patients with dilated cardiomyopathy. Some patients had a scintigraphic pattern close to that in patients with chronic myocarditis and others had a pattern identical to that in patients with coronary heart disease.

Holter monitoring was performed in 61 patients with essential hypertension. Painless, silent ST segment depression was found in 34 patients. Exercise myocardial scintigraphy indicated the occurrence of transient perfusion defects without abnormal clearance (Group 1) and those with abnormal clearance (Group 2). The patients from Group 1 showed more severe myocardial hypertrophy, higher platelet aggregation, coronary atherosclerosis was detected in 1 case. The patients from Group 2 exhibited less myocardial hypertrophy, lower platelet aggregation. Coronary atherosclerosis was revealed in 4 cases. The patients from the two groups had elevated plasma norepinephrine levels at the onset of silent myocardial ischemia.

Radionuclide ventriculography using the technique of first label passage through cardiac cavities was performed in 60 male patients (mean age 46.8 years) who had suffered myocardial infarction (MI) 3-8 months prior to the investigation. Total and local left-ventricular functions were assessed on the basis of the ejection fraction. In MI survivors, cardiac contractility was reduced significantly as compared to that of clinically normal subjects. No significant differences of ejection fraction could be found in patients with various MI localization. A close relationship was established between the number of low-contractility areas and total ejection fraction magnitude. Post-infarction patients and subjects with abnormal Q wave on their electrocardiograms exhibited the greatest number of hypokinetic areas. Patients with low post-infarction scar localization had more normo-kinetic areas. The number of hyperkinetic areas was somewhat greater in patients with anterior MI, this difference, however insignificant, probably having compensatory value.

A study of 20 patients with essential hypertension, stage IIB, asymmetrical myocardial hypertrophy and chest pains has suggested that the pain syndrome, presenting as "possible angina", positive functional tests and reduced label accumulation around the ventricular septum may be indicative of coronary insufficiency.

Possible use of loading myocardial 201T1 scintigraphy is considered for patients with blocked left peduncle of His' bundle. The procedure is shown to be of considerable value for the prognosis of coronary heart disease in such patients.