A 31-year-old man is evaluated for a murmur. He has no other symptoms and his past medical history is unremarkable. He jogs 3 times per week and rides a bicycle on the weekend. His blood pressure is 122/70 mm Hg on the right arm and 125/75 mm Hg in both ankles. On physical examination, a harsh, 4/6 holosystolic murmur is heard at the 4th left intercostal space close to the sternal border accompanied by a thrill. The rest of the physical examination is within normal limits. Which of the following is the most likely diagnosis?
A)Atrial septal defect
B)Mitral valve prolapse
C)Tetralogy of Fallot
D)Tricuspid valve stenosis
E)Ventricular septal defect

Question

A 31-year-old man is evaluated for a murmur.  He has no other symptoms and his past medical history is unremarkable.  He jogs 3 times per week and rides a bicycle on the weekend.  His blood pressure is 122/70 mm Hg on the right arm and 125/75 mm Hg in both ankles.  On physical examination, a harsh, 4/6 holosystolic murmur is heard at the 4th left intercostal space close to the sternal border accompanied by a thrill.  The rest of the physical examination is within normal limits.  Which of the following is the most likely diagnosis?
A)Atrial septal defect
B)Mitral valve prolapse
C)Tetralogy of Fallot
D)Tricuspid valve stenosis
E)Ventricular septal defect

Quizplus · Accepted Answer

Explanation: This patient's clinical presentation with a loud, harsh holosystolic murmur in the 4th left intercostal space and a palpable thrill is typical for ventricular septal defect (VSD). VSD is the most common congenital heart defect at birth, with spontaneous closure in 40%-60% of the patients during early childhood. A small restrictive VSD is associated with a loud murmur, but a large nonrestrictive VSD is associated with a softer murmur which occurs early in systole due to early equalization of right and left ventricular pressures. Adult patients who have a persistent small restrictive defect with small left-to-right shunting usually have favorable hemodynamics and normal right-sided heart pressures. These patients remain asymptomatic, and this condition is often detected during routine clinical evaluation due to the typical harsh holosystolic murmur with maximal intensity over the 3rd and 4th intercostal spaces along the left sternal border. (Choice A) Cardiac auscultation in patients with atrial septal defects and large left-to-right shunts reveals a characteristic wide and fixed splitting of the second heart sound. Patients may also have a mid-systolic ejection murmur resulting from increased flow across the pulmonic valve, and a mid-diastolic rumble resulting from increased flow across the tricuspid valve. (Choice B) Patients with mitral valve prolapse (MVP) typically have single or multiple non-ejection clicks and/or mid to late systolic murmur of mitral regurgitation that is best heard at or just medial to the cardiac apex. The systolic murmur of MVP starts earlier (and is longer and softer) with standing, Valsalva, and inhalation of amyl nitrate. Conversely, it is delayed in onset (and shorter in duration) with squatting, leg elevation, and handgrip. (Choice C) Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart defect. It has 4 characteristic anatomical features: right ventricular outflow tract (RVOT) obstruction, overriding aorta, right ventricular hypertrophy, and VSD. As RVOT obstruction increases, it leads to decreased pulmonary blood flow, resulting in cyanosis early in life. It is extremely rare that an active individual with TOF would remain undiagnosed until adulthood. (Choice D) Tricuspid valve stenosis is associated with a mid-diastolic rumble that is best heard along the left sternal border. Educational objective: Patients with a ventricular septal defect (VSD) typically have a harsh holosystolic murmur with maximal intensity over the left 3rd and 4th intercostal spaces accompanied by a thrill. Small restrictive VSDs are associated with a louder murmur, but large nonrestrictive VSDs have a softer and early systolic murmur. References: Ventricular septal defects in adults. (http://www.ncbi.nlm.nih.gov/pubmed/11694106) Small ventricular septal defects in adults. (http://www.ncbi.nlm.nih.gov/pubmed/9820997)

A 31-Year-Old Man Is Evaluated for a Murmur