A hyperactive pulmonary vasculature in response to chronic mitral regurgitation.

A subset of patients with mitral valve disease has a marked rise in pulmonary vascular resistance (PVR) that is disproportionate to elevations in pulmonary venous pressure. Termed a "hyperactive" pulmonary vasculature, the elevation in PVR falls promptly and dramatically in response to mitral valve replacement. We report a 55-year-old man with progressive, exertional dyspnea of several months' duration who had signs of congestive heart failure (CHF) with moderate mitral valvular regurgitation and aortic stenosis by echocardiographic interrogation. These lesions in combination, together with his CHF and disproportionate elevation in pulmonary artery systolic pressure (90 mm Hg) and PVR (527 dyne x s x cm(-5)), raised the prospect of valvular replacement. There followed a normalization of PVR and marked improvement in his symptoms and signs of CHF in response to pharmacologic management with an ACE inhibitor, loop diuretic, and aldosterone receptor antagonist to negate any further consideration of surgery.