How are innocent and pathologic systolic murmurs differentiated?
Innocent murmurs are soft flow murmurs without physiologic consequences. Pathologic murmurs are loud, pansystolic, or late systolic and associated with a cardiac anomaly. The most common lesion associated with a sys-tolic murmur in the young infant is a ventricular septal defect or patent ductus arteriosus. This infant has signs of mild congestive heart failure (tachypnea and tachycardia) and should undergo a cardiology evaluation prior to sur-gery. Transthoracic echocardiography is presently the fastest, most accurate, and least invasive diagnostic tool to establish an exact anatomic diagnosis in the majority of patients with congenital heart disease.