Which conditions typically increase in murmur intensity with squatting?

Which conditions typically increase in murmur intensity with squatting?

• A. Mitral valve prolapse and hypertrophic cardiomyopathy
• B. Aortic stenosis and mitral stenosis
• C. Tricuspid regurgitation and pulmonary hypertension
• D. Ventricular fibrillation and atrial flutter

Answer: (A)

Squatting raises both preload (venous return) and afterload (peripheral resistance). Murmurs that become louder under these conditions are typically those created by a greater pressure gradient across a valve or by increased regurgitant flow when afterload rises. The aortic stenosis murmur often loudens because the higher afterload increases LV systolic pressure, widening the gradient across the aortic valve. Mitral regurgitation usually sounds louder as afterload increases and more blood regurgitates into the left atrium during systole. By contrast, hypertrophic cardiomyopathy and mitral valve prolapse tend to soften or shift timing with increased preload, since the obstruction and prolapse dynamics are reduced when loading rises. Murmurs from tricuspid regurgitation or pulmonary hypertension aren’t classically driven to intensify simply with squatting, and arrhythmias don’t produce the same murmur changes. Thus, murmurs that typically increase with squatting are those of aortic stenosis and mitral regurgitation.

Squatting raises both preload (venous return) and afterload (peripheral resistance). Murmurs that become louder under these conditions are typically those created by a greater pressure gradient across a valve or by increased regurgitant flow when afterload rises. The aortic stenosis murmur often loudens because the higher afterload increases LV systolic pressure, widening the gradient across the aortic valve. Mitral regurgitation usually sounds louder as afterload increases and more blood regurgitates into the left atrium during systole. By contrast, hypertrophic cardiomyopathy and mitral valve prolapse tend to soften or shift timing with increased preload, since the obstruction and prolapse dynamics are reduced when loading rises. Murmurs from tricuspid regurgitation or pulmonary hypertension aren’t classically driven to intensify simply with squatting, and arrhythmias don’t produce the same murmur changes. Thus, murmurs that typically increase with squatting are those of aortic stenosis and mitral regurgitation.