Author: Michael A. Evans, MD – Ann & Robert H. Lurie Children’s Hospital of Chicago, Northwestern Feinberg School of Medicine
A 12-month-old boy presents for planned myringotomy and tympanostomy tube placement for otitis media. A mid-systolic murmur is auscultated at the left lower sternal border that becomes louder when the child bears down. Based on this child’s murmur, which of the following echocardiographic findings is MOST LIKELY to be found?
Correct!
Wrong!
Question of the Week 320
The murmur present in patients with hypertrophic cardiomyopathy (HCM) can easily be confused with the benign Still’s murmur as both are vibratory mid-systolic murmurs that are loudest at the apex or left lower sternal border. However, the murmur of HCM becomes louder with Valsalva, and a Still’s murmur lessens or even disappears with Valsalva. The Valsalva maneuver results in an acute increase in intrathoracic and intraabdominal pressure that results in decreased venous return to the heart with subsequently decreased preload. The decrease in preload leads to a decreased left ventricular end-diastolic volume (LVEDV). This decreased LVEDV worsens left ventricular outflow tract obstruction (LVOTO) in patients with obstructive HCM, which increases the severity of the murmur. Patients with asymmetric septal hypertrophy due to hypertrophic obstructive cardiomyopathy will have a murmur similar to the patient in the question.
Still’s murmur refers to a benign murmur that is thought to be the result of elevated flow across the aortic valve in high cardiac output or high contractility states. Still’s murmur is frequently found in young children but often disappears in adolescents. It is often described as “musical” or “vibratory” in quality.
The murmur of aortic stenosis is a systolic ejection murmur that is best auscultated at the right upper sternal border with radiation to the carotid arteries. The intensity decreases with Valsalva as the decreased LVEDV results in decreased transvalvular flow, which decreases the severity of the murmur. Additionally, the murmur of HCM does not radiate to the carotids.
A patent ductus arteriosus produces a machine-like murmur heard continuously throughout systole and diastole at the left upper sternal border. It is often described as a crescendo-decrescendo murmur with a crescendo in systole and decrescendo into diastole.
References
1. Sumski CA, Goot BH. Evaluating Chest Pain and Heart Murmurs in Pediatric and Adolescent Patients. Pediatr Clin North Am. 2020; 67(5): 783-799. doi:10.1016/j.pcl.2020.05.003
2. Biancaniello T. Innocent murmurs. Circulation. 2005; 111(3): e20-22. doi: 10.1161/01.CIR.0000153388.41229.CB. PMID: 15668345.
3. Salazar SA, Borrero JL, Harris DM. On systolic murmurs and cardiovascular physiological maneuvers. Adv Physiol Educ. 2012; 36(4): 251-256. doi:10.1152/advan.00128.2011
4. Frank JE, Jacobe KM. Evaluation and management of heart murmurs in children. Am Fam Physician. 2011; 84(7): 793-800.
5. Stein PD, Sabbah HN. Aortic origin of innocent murmurs. Am J Cardiol. 1977; 39(5): 665-671. doi:10.1016/s0002-9149(77)80126-4
Still’s murmur refers to a benign murmur that is thought to be the result of elevated flow across the aortic valve in high cardiac output or high contractility states. Still’s murmur is frequently found in young children but often disappears in adolescents. It is often described as “musical” or “vibratory” in quality.
The murmur of aortic stenosis is a systolic ejection murmur that is best auscultated at the right upper sternal border with radiation to the carotid arteries. The intensity decreases with Valsalva as the decreased LVEDV results in decreased transvalvular flow, which decreases the severity of the murmur. Additionally, the murmur of HCM does not radiate to the carotids.
A patent ductus arteriosus produces a machine-like murmur heard continuously throughout systole and diastole at the left upper sternal border. It is often described as a crescendo-decrescendo murmur with a crescendo in systole and decrescendo into diastole.
References
1. Sumski CA, Goot BH. Evaluating Chest Pain and Heart Murmurs in Pediatric and Adolescent Patients. Pediatr Clin North Am. 2020; 67(5): 783-799. doi:10.1016/j.pcl.2020.05.003
2. Biancaniello T. Innocent murmurs. Circulation. 2005; 111(3): e20-22. doi: 10.1161/01.CIR.0000153388.41229.CB. PMID: 15668345.
3. Salazar SA, Borrero JL, Harris DM. On systolic murmurs and cardiovascular physiological maneuvers. Adv Physiol Educ. 2012; 36(4): 251-256. doi:10.1152/advan.00128.2011
4. Frank JE, Jacobe KM. Evaluation and management of heart murmurs in children. Am Fam Physician. 2011; 84(7): 793-800.
5. Stein PD, Sabbah HN. Aortic origin of innocent murmurs. Am J Cardiol. 1977; 39(5): 665-671. doi:10.1016/s0002-9149(77)80126-4
