BACKGROUND To identify the overall effects of pulmonary thromboembolism (PTE) on the heart, we evaluated the heart findings and clinical characteristics of deceased patients diagnosed with PTE. MATERIAL AND METHODS PTEs were classified into 2 categories: fatal and contributory. Cases with a history of cardiopulmonary disease or a finding of significant disease at autopsy, including valvular heart disease and coronary artery obstruction >50%, were excluded from the cardiac evaluation. We defined an LV wall ≥1.2 cm thick and an RV wall ≥0.8 cm thick as abnormal. RESULTS Forty-eight cases were included to the study (21 males and 27 females). The mean age was 41.42 ± 16.5 years. Of the 48 cases, 5 were excluded due to cardiopulmonary diseases for determining heart findings. The thicknesses of the LV and RV walls were not measured in some patients. In the 43 cases, cardiac hypertrophy was detected in 28 patients (65.1%). The mean heart weight was 387 ± 83.5 g. The mean thickness of the left ventricle (LV) wall was 1.40 ± 0.41 cm in 40 cases, and the mean thickness of the RV wall was 0.41 ± 0.135 cm in 41 cases. The LV walls of 35 (87.5%) cases and the RV walls of 2 cases met criteria for abnormal wall thickness. There were histopathological findings of heart in 24/43 cases (56%); these findings were necrosis, fibrosis, and hypertrophy. CONCLUSIONS The RV is affected by massive pulmonary embolism; however, the LV may also play a role in the pathogenesis of PTE.