Persistence of atrioventricular valve regurgitation and electrocardiographic abnormalities following transient myocardial ischemia of the newborn.

To determine the sequelae of transient myocardial ischemia (TMI) in term infants, we reviewed clinical and investigative data in 59 infants (37 male, 22 female) with structurally normal hearts admitted over the 2-year period of 1983-1985. Twenty-three were diagnosed prior to admission as cases of birth asphyxia (5-min Apgar score less than 6), and 36 had signs of persistent fetal circulation with electrocardiographic (ECG) changes of ischemia greater than 24 h after birth. Murmurs of atrioventricular valve regurgitation (AVVR), detected in 28 patients, were confirmed in 23 of the 24 patients investigated. The murmurs resolved over a 2-day to 6-month period (median 6 days). In three patients, AVVR, left ventricular dyskinesia, and ECG anomalies persisted for 2 months (until death), 4 months, and 48 months. Initial ECGs were abnormal in 57 patients, and (of those reviewed) 60% returned to normal over a 6-day to 7-month period (median 2 months). Residual ECG anomalies included second-degree AV block and persistent ST-T wave changes. Ten patients died from noncardiac causes. Neither the presence nor resolution of AVVR correlated significantly with the severity of birth asphyxia using the Apgar score, nor with the severity of the ischemic changes on the ECG. Although the cardiovascular sequelae of myocardial ischemia are usually transient, the data should prompt the need for careful review after the initial admission.