SUMMARYA 25-year-old female developed high-grade atrioventricular block and markedly elevated central venous pressure after sustaining a crushing injury to the chest while driving a car. An echocardiographic examination with color Doppler revealed severe tricuspid regurgitation due to a torn papillary muscle. An extensive review of the literature showed the following: 1) correct diagnosis is often delayed because of coexisting multisystem involvement and the subtleness of abnormal physical signs, 2) identification of abnormally elevated right atrial pressure with a prominent "v" wave, and characteristic electrocardiogram appeared to be the key to early diagnosis, and 3) the final diagnosis may be confirmed by echocardiography with Doppler and/or cardiac catheterization. The role of echocardiographic examination with color Doppler technique deserves special emphasis because the final diagnosis can be easily reached during the acute phase at the bedside noninvasively. (Jpn Heart J 34: 361-375, 1993.)