A 23-year-old man comes to the physician for evaluation of a murmur. He has no complaints and describes his exercise tolerance as 'excellent.' He has no other medical conditions and takes no medications. He does not use tobacco, alcohol, or illicit drugs. His paternal uncle died from an unknown cause at a young age.
Physical examination reveals a IV/VI holosystolic murmur which is best heard at the fourth intercostal space along the left sternal border. It is accompanied by a palpable thrill. Carotid pulses are 2+ bilaterally without delay. Otherwise, his physical examination is unremarkable.
Which of the following is the most likely diagnosis?

Question

A 23-year-old man comes to the physician for evaluation of a murmur.  He has no complaints and describes his exercise tolerance as 'excellent.'  He has no other medical conditions and takes no medications.  He does not use tobacco, alcohol, or illicit drugs.  His paternal uncle died from an unknown cause at a young age.
Physical examination reveals a IV/VI holosystolic murmur which is best heard at the fourth intercostal space along the left sternal border.  It is accompanied by a palpable thrill.  Carotid pulses are 2+ bilaterally without delay.  Otherwise, his physical examination is unremarkable.
Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

11ec193a_9737_3d6b_853d_bdc99975c851_MD0002_00 This asymptomatic patient's murmur is most likely due to the presence of a ventricular septal defect (VSD). A VSD causes a loud holosystolic murmur with maximal intensity over the third or fourth left intercostal space along the left sternal border, accompanied by a systolic thrill. This patient likely has a small VSD and is relatively asymptomatic. Observation would be the ideal management in this patient since the VSD closes spontaneously in up to 10% of adults. However, patients who progress will develop symptoms of volume overload, left ventricular dilatation, and have an increased chance of endocarditis. Surgery is indicated for patients who develop any of these complications and/or significant Eisenmenger syndrome. (Choice A) The low velocity flow across an atrial septal defect does not result in a murmur. A large defect causes a mid-systolic pulmonic ejection murmur due to increased flow across the pulmonic valve. This is best heard in the left second intercostal space and is usually not associated with a palpable thrill. (Choice B) The presence of a bicuspid aortic valve typically causes a prominent ejection click followed by a mid-systolic murmur heard best over the right second intercostal space. In severe aortic stenosis, carotid pulses are delayed and diminished in amplitude (parvus et tardus). (Choice C) Ebstein anomaly is characterized by apical displacement of the tricuspid valve leaflets, decreased volume of the right ventricle, and atrialization of the right ventricle. It is associated with tricuspid regurgitation, which results in a holosystolic murmur best heard over left second or third intercostal space or at the subxiphoid area. A thrill is not usually palpable. Ebstein anomaly (Choice D) Supravalvular aortic stenosis causes a loud ejection systolic murmur which is best heard over right first intercostal space. A thrill is palpable in the suprasternal notch or the right first intercostal space. Educational objective: Ventricular septal defects cause a loud holosystolic murmur which is best heard over the third or fourth intercostal space along the left sternal border. It can be distinguished from other systolic murmurs by its characteristic location and presence of a palpable thrill. __________ References: Small ventricular septal defect: long-term expectant clinical management. (http://www.ncbi.nlm.nih.gov/pubmed/19629304) The prevalence of ventricular septal defect in elementary school children in the City of Toronto. (http://www.ncbi.nlm.nih.gov/pubmed/5923473)

A 23-Year-Old Man Comes to the Physician for Evaluation of a Murmur