A 54-year-old man comes to the office due to light-headedness when walking his dog in the morning. He has had no chest pain, shortness of breath, weakness, or headaches. Cardiac auscultation findings at the right sternal border are heard in the exhibit.

Which of the following is the most likely cause of this patient's symptoms?

Question

A 54-year-old man comes to the office due to light-headedness when walking his dog in the morning. He has had no chest pain, shortness of breath, weakness, or headaches. Cardiac auscultation findings at the right sternal border are heard in the exhibit.

Which of the following is the most likely cause of this patient's symptoms?

Quizplus · Accepted Answer

Cardiac auscultation in this patient reveals a harsh, crescendo-decrescendo systolic ejection murmur which is classic for aortic stenosis (AS). The murmur is typically best heard at the right upper sternal border with radiation to the carotids. Patients with AS usually remain asymptomatic for a long time and gradually develop symptoms (eg, exertional dyspnea, angina, syncope) as the stenosis becomes severe. This patient's light-headedness while walking likely represents exertional presyncope due to inadequate cardiac output from severe AS. Rheumatic heart disease is the most common cause of AS worldwide. However, in the United States, AS most commonly results from age-related calcification of a normal trileaflet or a congenitally abnormal bicuspid aortic valve. Calcification of a bicuspid aortic valve is accelerated, causing patients to develop AS at a younger age compared to those with a normal trileaflet valve. (Choice B) Infective endocarditis (IE) usually causes a regurgitant, rather than a stenotic, murmur. IE affecting the mitral valve can cause a systolic murmur of mitral regurgitation, but the murmur is usually holosystolic and best heard at the cardiac apex. In addition, IE presenting with exertional presyncope would be unusual; fever and fatigue are more typical. (Choice C) Marfan syndrome is associated with aortic root dilation, which can cause aortic regurgitation. However, the murmur of aortic regurgitation is a decrescendo diastolic murmur. (Choice D) Mitral valve prolapse produces a midsystolic click that may be followed by a late systolic murmur of mitral regurgitation, best heard at the cardiac apex. (Choice E) A ventricular septal defect (VSD) typically causes a holosystolic murmur best heard at the left lower sternal border. A VSD first presenting in an adult age >50 would be rare and would typically present with symptoms of heart failure (eg, dyspnea) rather than exertional presyncope. Educational objective: A bicuspid aortic valve is a common cause of aortic stenosis in the United States. The classic auscultatory finding in aortic stenosis is a harsh, crescendo-decrescendo systolic ejection murmur best heard at the right upper sternal border with radiation to the carotids.

A 54-Year-Old Man Comes to the Office Due to Light-Headedness