Left ventricular function in patients with mitral valve prolapse. A radionuclide evaluation.

Thirty patients with cineangiographically confirmed mitral valve prolapse (MVP) were studied by radionuclide angiography at rest and during exercise. Twelve patients had isolated MVP and 18 patients had associated coronary artery disease. All patients had normal resting left ventricular ejection fraction and wall motion. Of 18 patients with MVP and coronary artery disease, the left ventricular ejection fraction remained unchanged during exercise in 15 patients, decreased in two patients, and increased in one patient. Of 12 patients with MVP without associated coronary artery disease, ejection fraction increased during exercise in 6 patients, remained unchanged in 4 patients, and decreased in 2 patients. We conclude that an abnormal left ventricular function response during exercise does not always indicate the presence of coronary artery disease and may occur in patients with isolated MVP. Furthermore,the left ventricular dysfunction of patients with isolated MVP may be obvious only during exercise.