Which condition is the most common cause of a systolic ejection murmur?

Which condition is the most common cause of a systolic ejection murmur?

• A. Mitral stenosis
• B. Pulmonary stenosis
• C. Aortic regurgitation
• D. Aortic stenosis

Answer: (D)

A systolic ejection murmur arises from turbulent flow across a semilunar valve during ventricular ejection. The most common cause is aortic stenosis, where the aortic valve is narrowed (often from calcific degeneration with age or a bicuspid valve). This obstruction creates a characteristic crescendo-decrescendo murmur best heard at the right upper sternal border and often radiating to the carotids. Mitral stenosis produces a diastolic murmur with an opening snap, not a systolic ejection murmur. Aortic regurgitation is a diastolic decrescendo murmur from backward flow. Pulmonary stenosis can cause a systolic murmur as well, but it is far less common overall than aortic stenosis.

A systolic ejection murmur arises from turbulent flow across a semilunar valve during ventricular ejection. The most common cause is aortic stenosis, where the aortic valve is narrowed (often from calcific degeneration with age or a bicuspid valve). This obstruction creates a characteristic crescendo-decrescendo murmur best heard at the right upper sternal border and often radiating to the carotids.

Mitral stenosis produces a diastolic murmur with an opening snap, not a systolic ejection murmur. Aortic regurgitation is a diastolic decrescendo murmur from backward flow. Pulmonary stenosis can cause a systolic murmur as well, but it is far less common overall than aortic stenosis.