An 11-year-old boy is brought to the office for a routine checkup prior to enrollment at summer camp. The patient and his mother report no health concerns. Family history is significant for his father passing away suddenly from a heart condition 2 years ago. The patient is at the 75th and 80th percentiles for height and weight, respectively. Vital signs are normal. Physical examination shows a well-appearing child. The lungs are clear to auscultation. Cardiac auscultation findings at the left lower sternal border are given below. The auscultatory abnormality intensifies with the handgrip exercise. Which of the following is the most likely diagnosis?

Question

An 11-year-old boy is brought to the office for a routine checkup prior to enrollment at summer camp.  The patient and his mother report no health concerns.  Family history is significant for his father passing away suddenly from a heart condition 2 years ago.  The patient is at the 75th and 80th percentiles for height and weight, respectively.  Vital signs are normal.  Physical examination shows a well-appearing child.  The lungs are clear to auscultation.  Cardiac auscultation findings at the left lower sternal border are given below.  The auscultatory abnormality intensifies with the handgrip exercise.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

11ec160b_3aa6_48b0_9249_f760e691a42f_MD0001_00 The presentation of a ventricular septal defect (VSD) depends on its size. Large defects result in high-volume shunting of blood across the VSD, leading to a low interventricular pressure gradient and a soft or absent murmur; the large degree of shunting may lead to heart failure in infancy (eg, difficulty feeding, tachypnea, failure to thrive). In contrast, small defects allow only a small amount of blood to flow across the VSD; most patients are asymptomatic and have loud murmurs that are detected incidentally on cardiac auscultation. This patient's harsh holosystolic murmur best heard at the left lower sternal border is indicative of blood flow through a small, hemodynamically insignificant VSD. The handgrip maneuver increases systemic vascular resistance, resulting in increased aortic and left ventricular (LV) pressure that intensifies the murmur. (Choice A) Aortic regurgitation causes a decrescendo early diastolic murmur that is best heard at the left sternal border when due to valvular disease. Like a VSD murmur, an aortic regurgitation murmur is also accentuated by maneuvers that increase afterload (eg, handgrip). (Choice B) Aortic stenosis causes a crescendo-decrescendo systolic murmur best heard at the right upper sternal border with radiation to the carotids. The murmur decreases with the handgrip maneuver due to increased afterload decreasing the transvalvular pressure gradient. (Choice C) The typical murmur of an atrial septal defect is not caused by flow through the defect itself; instead, it results from increased right-sided blood volume with increased flow across the pulmonic valve (ie, pulmonic flow murmur). It is recognized as a faint systolic murmur best heard at the left upper sternal border and with wide and fixed splitting of S2. (Choice D) Hypertrophic cardiomyopathy causes a systolic ejection murmur best heard at the left midsternal border. However, handgrip maneuver decreases the murmur intensity due to increased LV volume and consequently reduced LV outflow tract obstruction. (Choice E) A patent ductus arteriosus produces a continuous flow murmur best heard at the left infraclavicular or posterior interscapular region. Affected patients usually develop symptoms (eg, poor feeding, respiratory difficulty) during early childhood. Educational objective: A ventricular septal defect (VSD) commonly causes a harsh, holosystolic murmur at the left lower sternal border; the murmur increases in intensity during maneuvers that increase left ventricular afterload (eg, handgrip maneuver). A small VSD is usually asymptomatic and produces a relatively loud murmur due to a high interventricular pressure gradient. __________ References: Evaluation and management of heart murmurs in children. (http://www.ncbi.nlm.nih.gov/pubmed/22010618)

An 11-Year-Old Boy Is Brought to the Office for a Routine