MKSAP quiz: medical history of mitral regurgitation
A 45-year-old man undergoes a pre-employment physical examination. Medical history is notable for aortic coarctation with an end-to-end anastomosis performed at 4 years of age. During a physical exam, a grade 2/6 mid-peaking systolic murmur is noted at the second right intercostal space. What is the most likely cause of this patient's systolic murmur?
A 45-year-old man undergoes a pre-employment physical examination. Medical history is notable for aortic coarctation with an end-to-end anastomosis performed at 4 years of age. He reports no symptoms, works full time, and performs regular exercise without limitation. He takes no medications.
On physical examination, vital signs are normal. An ejection click is noted at the left lower sternal border. A grade 2/6 mid-peaking systolic murmur is noted at the second right intercostal space. The femoral pulses are normal, and no radial artery–to–femoral artery pulse delay is present. The remainder of the physical examination is normal.
Which of the following is the most likely cause of this patient's systolic murmur?
A. Aortic stenosis
B. Hypertrophic cardiomyopathy
C. Mitral regurgitation
D. Recurrent coarctation
MKSAP Answer and Critique
The correct answer is A. Aortic stenosis. This content is available to MKSAP 18 subscribers as Question 100 in the Cardiovascular Medicine section. More information about MKSAP is available online.
This patient most likely has a bicuspid aortic valve with associated aortic stenosis. A bicuspid aortic valve is present in more than 50% of patients with aortic coarctation. The systolic ejection click at the left sternal border suggests a bicuspid aortic valve. The murmur is mid peaking instead of late peaking, and the S2 is still audible, suggesting mild to moderate aortic stenosis. A bicuspid aortic valve may occur with other cardiovascular and systemic abnormalities, such as aneurysm of the sinuses of Valsalva and patent ductus arteriosus. Patients with a bicuspid aortic valve are predisposed to aortic aneurysm and dissection owing to aortic connective tissue abnormalities. In patients with bicuspid aortic valve, the ascending aortic diameter should be assessed by echocardiography, with the evaluation interval determined by degree and rate of aortic dilation.
Hypertrophic cardiomyopathy is not an expected sequela of aortic coarctation or previous repair. The murmurs in hypertrophic cardiomyopathy characteristically include an ejection-quality systolic murmur at the left sternal border related to outflow obstruction and a late systolic murmur at the apex related to mitral regurgitation from systolic anterior motion of the mitral valve. An ejection click is not heard in patients with hypertrophic cardiomyopathy.
Mitral regurgitation is not an expected finding in a patient with aortic coarctation, with or without previous repair. Clinical features in patients with mitral regurgitation include a holosystolic murmur, heard best at the apex and generally radiating to the axilla.
Recurrent coarctation occurs in approximately 20% of patients with previous coarctation repair. Clinical features include hypertension that is difficult to control with medical therapy and occasional claudication. Other features of recurrent coarctation not demonstrated in this patient include a radial artery–to–femoral artery pulse delay and a systolic murmur over the left anterior or posterior chest.
Key Point
- A bicuspid aortic valve is present in more than 50% of patients with aortic coarctation.