Which of the following conditions will increase in seventy with Valsalva maneuver?

The Valsalva maneuver decreases preload and left ventricular volume, which exacerbates left ventricular outflow tract obstruction in hypertrophic obstructive cardiomyopathy (HOCM). This results in an increase in the gradient and severity of obstruction and symptoms during the maneuver.

Aortic valve stenosis, aortic regurgitation, and mitral regurgitation typically decrease or do not significantly change during Valsalva because of decreased flow and pressure.

This physiological response is detailed in the "Textbook of Clinical Echocardiography, 6e", Chapter on Dynamic Left Ventricular Outflow Obstruction and Maneuvers【20:370-375†Textbook of Clinical Echocardiography】.