A Synopsis of AFPs "Evaluation and Management of Heart Murmurs in Children"

Evaluation and Management of Heart Murmurs in Children
JENNIFER E. FRANK, MD, and KATHRYN M. JACOBE, MD, University of Wisconsin Fox Valley Family Medicine Residency Program, Appleton, Wisconsin
Am Fam Physician. 2011 Oct 1;84(7):793-800.
http://www.aafp.org/afp/2011/1001/p793.pdf

     Heart murmurs are exceedingly common in the newborn and are usually asymptomatic. Rarely, it is a sign of a structural heart disease.  Although a murmur is often the only sign of a problem, other features that may suggest a structural problem include feeding problems. failure to thrive, chest pain, palpitations, dizziness, family history (SIDS, hypertrophic cardiomyopathy, or congenital heart disease), aneuploidy, connective tissue disorders, kawasaki disease, exposure to alcohol, toxins or SSRIs, and others. Symptoms or a structural problem include dyspnea, nausea, vomiting, exercise tolerance, fatigue and cough. A physical exam including vital signs, looking for other congenital anomalies (dysmorphic features), breath sounds, chest contour, and heart sounds are important in proper care of the child.
     Heart murmurs are graded into 6 classes:
grade 1- barely audible
grade 2- faint but audible
grade 3- loud
grade 4- easily heard over wide area of chest
grade 5- loud with precordial thrill
grade 6- can be heard with stethoscope off chest
Innocent murmurs will often change in intensity with a change in patient position. Gallops may be normal. Examples of innocent murmurs include peripheral pulmonary stenosis, still murmur, pulmonary flow murmur, aortic systolic murmur, and venous hum. According to this article the seven key features of innocent heart murmurs include
 1. sensitive (with change with a change in position)
 2. short duration (not a holosystolic murmur)
 3. single (gallops or clicks are absent)
 4. small (murmur is only found in a small area and is not radiating)
 5. soft (low amplitude)
 6. sweet (murmur does not sound harsh)
 7. systolic
Red flags for a structural disease include a holosystolic murmur, a harsh sound, an abnormal S2, maximal intensity in the upper left sternal border, a systolic click, a diastolic murmur, and a murmur that is louder with standing. Pathologic heart murmurs may also have systolic ejection murmurs such as ASD, pulmonary stenosis, coarctation of the aorta, aortic stenosis, transposition of the great vessels, total anomalous pulmonary venous connection, tetralogy of fallot, and hypoplastic left heart syndrome. ASD will have a wide fixed S2. In pulmonary stenosis, the murmur is heard best in the upper left sternal border. Aortic stenosis is best heard in the upper right sternal border. Coarctation may cause a delayed femoral pulse. Murmurs that may have holosystolic components (left lower sternal border), include tetralogy of fallot, transposition, tricuspid atresia, and truncus arteriosus (or a diastolic rumble).  All the murmurs that start with "T" may present with cyanosis (tetralogy, transposition, truncus arteriosus, total anomalous...., and tricuspid atresia. More detail can be found on table 5 of this article.    
     ECG and x ray are usually not helpful in diagnosis of murmurs in children less than six weeks old. A diagnosis of an innocent murmur can be made if there are the following criteria; no abnormal findings on exam, negative review of systems, negative history of features that may increase the risk of structural heart disease, and positive auscultatory sounds of an innocent murmur. If this cannot be achieved, then a referral to a pediatric cardiologist should be made. Suspicion of a neonatal murmur should be referred as well. Evaluation includes 24 hour pulse oximetry monitoring.