A 38-year-old woman comes to the physician complaining of occasional palpitations. She describes a fast and irregular heartbeat. She has had 3 such episodes over the past 2 months, each lasting about 2 hours. The patient has no associated chest pain, shortness of breath, cough, or ankle swelling. She drinks alcohol on social occasions and does not smoke. She has no other medical problems and takes no medications. Her temperature is 37.1°C (98.9°F), blood pressure is 130/70 mm Hg, pulse is 80/min, and respirations are 14/min. The apical impulse is displaced to the left, and a third heart sound is heard at the apex in the left decubitus position. There is also a holosystolic murmur that is loudest at the apex and radiates to the axilla. Which of the following is the most likely cause of this patient's condition?

Question

A 38-year-old woman comes to the physician complaining of occasional palpitations.  She describes a fast and irregular heartbeat.  She has had 3 such episodes over the past 2 months, each lasting about 2 hours.  The patient has no associated chest pain, shortness of breath, cough, or ankle swelling.  She drinks alcohol on social occasions and does not smoke.  She has no other medical problems and takes no medications.  Her temperature is 37.1°C (98.9°F), blood pressure is 130/70 mm Hg, pulse is 80/min, and respirations are 14/min.  The apical impulse is displaced to the left, and a third heart sound is heard at the apex in the left decubitus position.  There is also a holosystolic murmur that is loudest at the apex and radiates to the axilla.  Which of the following is the most likely cause of this patient's condition?

Quizplus · Accepted Answer

11ec25c8_d0af_c63f_bc81_5fdbb908df22_MD0003_00 This patient's examination findings (displaced apical impulse, holosystolic murmur, and third heart sound) are consistent with chronic severe mitral regurgitation (MR). Mitral valve prolapse (MVP) is the most common cause of chronic MR in developed countries. MVP occurs due to myxomatous degeneration of the mitral valve leaflets and chordae and causes a mid-systolic click followed by a mid-to-late systolic murmur. As the severity of leaflet dysfunction and MR worsens, the murmur becomes holosystolic and the click may not be audible. The third heart sound is from left ventricular volume overload and does not necessarily represent congestive heart failure. Chronic severe MR can cause left atrial dilation, which can eventually lead to atrial fibrillation (symptoms of palpitations). (Choice A) Infective endocarditis can cause MR due to inadequate leaflet coaptation or, rarely, leaflet perforation. It is unlikely in this patient, who has no accompanying signs or symptoms (eg, fever, embolic findings) suggesting infective endocarditis. (Choice B) Mitral annular calcification refers to a degenerative process involving the fibrous annulus of the mitral valve. It is a common incidental finding in older adults and is usually associated with mild-to-moderate MR. Mitral annular calcification is less likely to cause significant MR in a younger patient. (Choice C) Myocardial ischemia can cause papillary muscle dysfunction, which in turn can cause MR. It usually presents with chest discomfort, dyspnea, or sudden onset of pulmonary edema. (Choice E) Rheumatic heart disease can cause mitral stenosis, MR, and aortic regurgitation. However, it is a much less common cause of chronic MR than MVP. Educational objective: Mitral valve prolapse is the most common cause of mitral regurgitation (MR) in developed countries. It usually causes mild MR with mid-systolic click and mid-to-late systolic murmur. Patients with severe leaflet dysfunction and prolapse can develop severe MR and holosystolic murmur on physical examination. Chronic severe MR causes left atrial and ventricular enlargement leading to atrial fibrillation, left ventricular dysfunction, and congestive heart failure. References: Mitral valve prolapse. (http://www.ncbi.nlm.nih.gov/pubmed/22248324)

A 38-Year-Old Woman Comes to the Physician Complaining of Occasional