The Effect of Malignant Neoplasms on the Heart A Study on the Electrocardiographic Abnomalities and the Anatomical Findings in Cases with and without Cardiac Involvement

Six hundred and twenty-two autopsies of patients with malignant neoplasm were used for this study in order to analyze the incidence of cardiac involvement in relation to the sites of the primary tumor, the anatomical distribution within the heart, and the ECG findings in tumor patients with and without cardiac involvement. Our findings were then discussed in the light of previous reports. 1) The overall incidence of cardiac involvement by malignant tumor was 12.7% (79 outof 622 cases), and the average incidences in carcinomas, sarcomas and the other groups were 1 3.0%, 7.7%, and 17.0%, respectively. Among various carcinomas, breast and pulmonary cancer showed a very high incidence of cardiac involvement, while intestinal and gastric cancer were found to metastasise infrequently to the heart. 2) The incidence of epicardial involvement was very high (65.8%) and that of involvement of the pericardium, myocardium and endocardium was 38.0%, 29. 1% and 19.0%, respectively. 3) No significant difference was observed in the ECG findings recorded between 3 to 6 months, or over 6 months before death between the groups with and without cardiac involvement. 4) A significant difference in the incidence of myocardial damage pattern, arrhythmia and/or intraventricular conduction disturbance (such as ST-T depression, sinus tachycardia or incomplete right bundle branch block) was observed in the ECG recorded within 3 months before death when comparing with the groups with and without cardiac involvement. 5) The cases with metastases to the myocardium were always associated with the pattern of myocardial damage on the ECG.