A high pitched holosystolic murmur best heard at the lower left sternal border that may decrease with inspiration corresponds to which condition?

• A. Tricuspid Regurgitation
• B. Aortic Stenosis
• C. Mitral Stenosis
• D. Pulmonary Regurgitation

Answer: (A)

A holosystolic murmur heard best at the lower left sternal border points to regurgitant flow through the tricuspid valve during systole. Right-sided murmurs, including tricuspid regurgitation, typically become louder with inspiration because inspiration increases venous return to the right heart (the Carvallo sign). So, a high-pitched holosystolic murmur at the left lower sternal border that varies with respiration best fits tricuspid regurgitation.

The other options don’t match this pattern: aortic stenosis is a systolic murmur heard at the right upper sternal border with a crescendo–decrescendo quality and often radiates to the carotids; mitral stenosis is a diastolic murmur heard at the apex; pulmonary regurgitation is a diastolic murmur heard at the left upper sternal border.