The effect of malignant neoplasms on the heart. A study on the electrocardiographic abnormalities 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. 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 the patients with and without cardiac involvement were analysed. The incidence of cardiac involvement by malignant tumor was 12.7% (79 out of 622 cases). Involvement by breast and pulmonary cancer was found to be very common, while intestinal and gastric cancer uncommonly metastasised to the heart. The incidence of epicardial involvement was higher than that of the pericardium, myocardium, or endocardium. A significant difference was observed in the ECG findings recorded within 3 months before death between the groups with and without cardiac involvement. Cases of myocardial metastasis were always associated with the pattern of myocardial damage in the ECG. The findings in this study are discussed in the light of previous reports.