Recent trends in cardiac sarcoidosis research in Japan.

Our recent survey of the Japanese literature, actual case experience, and previous studies revealed the following results. Fifty-three cases were reported in which the main cause of death in sarcoidosis was congestive heart failure (11 of 17 cases, 64.7%) and not sudden death as was previously believed. ECG analysis revealed that third degree AV block, bundle branch block, and ventricular arrhythmias were the most frequent findings indicating the presence of cardiac sarcoidosis. It was recognized that in the Japanese population fatal myocardial sarcoidosis or clinical diagnosed cardiac sarcoidosis occurred most frequently in females over the age of 40 years. It is suggested that myocardial changes progress independently of granulomatous changes. This is due to the detection of a high incidence of basal lamina layering of myocardial capillaries (14 of 18 cases, 77.8%) and is considered to play a significant role in the progression of this disease. Radionuclide studies showed that thallium scintigraphy or technetium ventriculography were positive in those cases where ECG abnormalities are prominent, indicating the presence of myocardial disease. Previous therapeutic studies of cardiac sarcoidosis have shown a decrease in the incidence of sudden death; death due to congestive heart failure occurred more frequently despite pacemaker implantation. Control of congestive heart failure is thus regarded as the most important aspect of improved treatment and prognosis.