A 32-year-old woman comes to the office due to exertional dyspnea that has progressed over the last year. She can hardly walk a block without stopping to rest. The patient's mother died of "heart failure" at age 40. During auscultation, the pulmonary component of S2 is louder than the aortic component in the right and left second intercostal space. An accentuated impulse can also be palpated along the left upper sternal border. Chest x-ray shows clear lungs. Which of the following is the most likely cause of this patient's findings?

Question

A 32-year-old woman comes to the office due to exertional dyspnea that has progressed over the last year.  She can hardly walk a block without stopping to rest.  The patient's mother died of "heart failure" at age 40.  During auscultation, the pulmonary component of S2 is louder than the aortic component in the right and left second intercostal space.  An accentuated impulse can also be palpated along the left upper sternal border.  Chest x-ray shows clear lungs.  Which of the following is the most likely cause of this patient's findings?

Quizplus · Accepted Answer

11ec160b_3b4a_0213_9249_2983af619f8c_MD0001_00 This patient's clinical presentation is consistent with pulmonary hypertension. The disease most commonly presents with progressive dyspnea, and patients may also experience exertional angina or syncope. Physical examination reveals a loud pulmonic component (P2) of S2, caused by forceful pulmonic valve closure in the setting of high pulmonary arterial pressure. In addition, the right ventricle becomes enlarged due to increased pressure load (ie, concentric right ventricular hypertrophy), which can create an accentuated impulse palpated at the left sternal border (left parasternal lift due to right ventricular heave). Pulmonary arterial hypertension describes pulmonary hypertension directly caused by vascular remodeling of the small pulmonary arteries/arterioles; relatively young women are most commonly affected. Fatigue and exertional dyspnea are common and result from decreased cardiac output due to the inability of the right ventricle to pump blood through the lungs. Right-sided heart failure eventually develops, but because left ventricular function remains intact, there is an absence of pulmonary edema in pulmonary arterial hypertension. (Choice A) Hypertensive heart disease occurs as the result of prolonged systemic hypertension. It involves concentric left ventricular hypertrophy, leading to impaired ventricular compliance and diastolic heart failure. Pulmonary edema is expected with diastolic heart failure that is severe enough to cause dyspnea. (Choice B) Hypertrophic cardiomyopathy typically demonstrates a crescendo-decrescendo systolic murmur best heard at the left sternal border. The murmur intensifies with maneuvers that decrease left ventricular blood volume (eg, abrupt standing, Valsalva strain phase). (Choice C) Left bundle branch block can delay closure of the aortic valve, leading to later occurrence of the aortic component (A2) of S2 and narrowed or paradoxical splitting. However, left bundle branch block is unlikely to significantly affect the relative audible intensity of A2 and P2. (Choice E) Pulmonic valve stenosis can delay the occurrence of P2 (later valve closure) but typically leads to a softer intensity of P2. Educational objective: Pulmonary hypertension can be recognized on physical examination by a loud pulmonic component of S2 and an accentuated, palpable impulse at the left sternal border (left parasternal lift due to right ventricular heave).

A 32-Year-Old Woman Comes to the Office Due to Exertional