Our Patient's Summary

We can now summarize our patient's history and physical examination. He is an 18-year-old man referred for evaluation of a heart murmur discovered during a pre college physical examination. He reported no cardiac symptoms, normal growth and development and no family history of either congenital or young age onset heart disease. This history suggests no specific diagnosis. Several diagnostic possibilities merit consideration. Discovery of a congenital heart defect for the first time at age eighteen years can occur with mild abnormalities. Acquired heart disease at age eighteen rarely manifests only as an asymptomatic murmur. An innocent murmur represents by far the most likely explanation.

Physical examination demonstrated a healthy young man with normal blood pressure, venous and arterial pulses, precordial movements and lung auscultation. Cardiac auscultation demonstrated entirely normal findings in all locations, with the only noteworthy observation and reason for the patient's referral, being the presence at the upper left sternal edge of a short, early peaking, crescendo-decrescendo, systolic murmur. The systolic murmur, in and of itself, raises concern regarding the possibility of some type of right heart abnormality.

An atrial septal defect causes several expected physical findings in addition to the systolic murmur. These include palpable right ventricular and pulmonary trunk systolic impulses due to dilation of both the right ventricle and pulmonary trunk. A widely split and fixed second heart sound due to constant high pulmonary blood flow and a mid diastolic murmur at the lower left sternal edge, reflecting enhanced right ventricular filling. Pulmonic valve stenosis also causes pertinent additional findings. Significant obstruction produces a right ventricular impulse due to right ventricular hypertrophy induced by elevated right ventricular pressure. Opening of a stenotic pulmonic valve produces an ejection sound heard along the left sternal edge, just after the first sound. The ejection sound varies with respiration, being loudest in expiration. The systolic murmur of pulmonic stenosis is longer and later peaking in systole in proportion to the degree of obstruction. The murmur radiates more over the left lung fields than the right because of the anatomic arrangement of the right and left pulmonary arteries in relation to the pulmonary trunk. Finally, the absence of any of these additional findings suggests that the murmur is innocent.

Considering all of our patient's history and physical examination, we have only the finding of a systolic murmur at the upper left sternal edge. The absence of additional findings, particularly on physical examination, leads to the conclusion that the murmur is innocent and due only to turbulence produced by normal pulmonary systolic blood flow. This is the second of the two most common innocent murmurs in infants, children and young adults. The other being the Still's vibratory, mid systolic murmur heard over the lower precordium. Recognition of the murmur as innocent depends to a significant degree on careful examination to confirm absence of other findings. In other words, murmur evaluation requires evaluation of the company that it does or does not keep.