Autonomic cardiovascular regulation was evaluated in 35 women, 19 with mitral valve prolapse 16 healthy controls. Heart rate responses to the diving reflex to phenylephrine infusion were diminished in patients. Noninvasive measures of cardiac output, heart rate, blood pressure, forearm flow leg volume during lower body negative pressure (LBNP) showed that patients had less lower extremity pooling of blood had lower forearm conductance. Blood pressures during LBNP rose or remained unchanged despite decreases in cardiac output of 20–25%. These data indicate that mitral valve prolapse patients have an increased venous arterial vasoconstrictor activity. Cardiac output at rest echocardiographic indices of contractility were normal. Patients with a history of significant ventricular arrhythmias had higher heart rates lower forward stroke volumes than the other patients or controls.
The combined data demonstrate autonomic dysfunction in women with the mitral valve prolapse syndrome suggest decreased parasympathetic, increased α-normal β-adrenergic tone responsivenes.