A 20-year-old woman comes to the office with intermittent chest pain for the past 3 weeks. She describes the pain as sharp, located to the left of the sternum, and lasting 5-10 seconds each episode. There is no associated fever, cough, breathlessness, palpitations, or syncope. The patient does not use tobacco, alcohol, or illicit drugs. Cardiac auscultation reveals a systolic murmur at the apex that shortens with squatting. Which of the following is the most likely diagnosis?

Question

A 20-year-old woman comes to the office with intermittent chest pain for the past 3 weeks.  She describes the pain as sharp, located to the left of the sternum, and lasting 5-10 seconds each episode.  There is no associated fever, cough, breathlessness, palpitations, or syncope.  The patient does not use tobacco, alcohol, or illicit drugs.  Cardiac auscultation reveals a systolic murmur at the apex that shortens with squatting.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

11ec25c8_d244_48d6_bc81_8b85ec98cb1c_MD0003_00 A short systolic murmur at the cardiac apex that disappears with squatting is most consistent with mitral valve prolapse (MVP). Cardiac auscultation in patients with MVP typically shows nonejection clicks and/or mid to late systolic murmurs of mitral regurgitation (MR). Squatting from a standing position increases venous return (ie, preload), which in turn causes an increase in left ventricular size and volume. This leads to a delay in the valve prolapse, with a later click and shorter murmur. However, in patients with severe MR (from MVP or otherwise), the murmur may increase in intensity with squatting due to an increase in afterload. Echocardiogram is used to confirm the diagnosis. Several nonspecific symptoms (atypical chest pain, dyspnea, palpitations, dizziness, anxiety, and panic disorder) and nonspecific electrocardiographic changes have been attributed to MVP. These signs and symptoms in patients with MVP is often called MVP syndrome. However, MVP syndrome is not a validated entity, and patients should be reassured about the benign nature of the symptoms. (Choice A) Normally functioning bicuspid aortic valves typically produce a prominent ejection click followed by a mid-systolic murmur best heard over the right second intercostal space. (Choice B) Infective endocarditis can cause MR, but patients usually have signs and symptoms of systemic illness. MR murmurs typically increase in intensity with squatting. (Choice D) Rheumatic heart disease is uncommon in developed countries. It may lead to MR, but mitral stenosis is a more common complication. The murmur of mitral stenosis is diastolic, often with presystolic accentuation. (Choice E) Ventricular septal defect normally causes a loud holosystolic murmur with maximal intensity over the third or fourth left intercostal space. The intensity of the holosystolic murmur increases with squatting. Educational objective: Cardiac auscultation in patients with mitral valve prolapse typically shows a systolic click and/or mid to late systolic murmurs of mitral regurgitation. Squatting from a standing position increases preload and left ventricular volume, decreasing the intensity of the murmur. References: Mitral valve prolapse. (http://www.ncbi.nlm.nih.gov/pubmed/15705461)

A 20-Year-Old Woman Comes to the Office with Intermittent Chest