Recurrent cardiogenic shock caused by dynamic mitral regurgitation in a patient with hypertrophic obstructive cardiomyopathy: a case report.

: A 68-year-old man with hypertrophic obstructive cardiomyopathy developed recurrent cardiogenic shock due to dynamic mitral regurgitation. The pressure gradient in the left ventricular outflow tract under medication was 30 mmHg, and he complained of no symptom. He developed shock with dyspnea suddenly after bathing and defecation. Echocardiography and left ventriculography revealed massive mitral regurgitation and mild increment of pressure gradient in the left ventricular outflow tract (50 mmHg). He underwent successful mitral valve replacement following treatment with beta-blocker under intraaortic balloon pumping support. This case illustrates that exacerbation of the systolic anterior motion of the mitral anterior leaflet can cause dynamic severe mitral regurgitation with 'mild' increment of pressure gradient in the left ventricular outflow tract, resulting in cardiogenic shock with severe lung edema.