Acute mitral regurgitation with cardiogenic shock in a patient with hypertrophic cardiomyopathy: A critical management dilemma

Patients with hypertrophic cardiomyopathy (HCM) may have hyperdynamic systolic function, left ventricular outflow tract obstruction, systolic anterior motion of the mitral valve, and mitral regurgitation. 15 Stress, volume depletion and peripheral vasodilation can all result in an increased degree of outflow obstruction,~ increased systolic anterior motion of the mitral valve, worsening mitral regurgitation, and hemodynamic collapse. 6 Patients with mild or moderate HCM, small intraventricular gradients, no systolic anterior motion of the mitral valve, and no mitral regurgitation normally have a benign prognosis. 1 We report a patient with mild HCM without a significant intraventricular gradient, and with no systolic anterior motion of the mitral valve or mitral regurgitation who developed acute, severe left ventricular outflow tract obstruction with systolic anterior motion of the mitral valve, severe mitral regurgitation, and hemodynamic collapse following cardiac catheterization and successful coronary angioplasty for single-vessel coronary disease. Conventional therapy directed at hypotension and pulmonary edema (i.e., positive inotropic agents and diuretics) may exacerbate the underlying decompensated HCM, but alternative therapies for HCM (i.e., negative inotropic agents and fluid resuscitation) are potentially lethal in the same circumstances. This case illustrates the critical management dilemma existing in such patients. A 71-year-old man with coronary artery disease underwent coronary artery bypass surgery of the left anterior descending, right coronary artery, and first obtuse marginal branch in 1983. He did well until 1 month prior to admission, when he developed recurrent chest pain for which he underwent successful coronary angioplasty of an intermediate artery. The saphenous vein grafts were patent. He