The Circulatory Response to the Valsalva Maneuver of Patients with Mitral Stenosis with and without Autonomic Blockade

Patients with clinically significant mitral stenosis have been demonstrated to differ from other subjects in their circulatory responses to the Valsalva maneuver. During forced expiration most patients with mitral stencsis are able to maintain systolic pressure in the brachial artery at a level equal to or greater than the resting value, whereas most control subjects cannot. Autonomic blockade does not affect the ability of patients with mitral stenosis to maintain systolic pressure, whereas it abolishes such ability, when it is present, in control subjects. The unique response of patients with mitral stenosis under autonomic blockade is attributed to the physiologic consequences of the volume of blood in the dilated left atrium.