The patient:    4 week old female infant with past medical history of meconium aspiration at birth with APGAR scores of 2,4,6. Intubated and given nitric oxide for pulmonary hypertension. Weaned in NICU over 10 days. Echocardiogram during that time showed stiff pulmonic valve. This ECG was obtained at follow up appointment. Infant is eating well, no cyanotic spells. Four- week echo continues to show pulmonic valve stenosis. We do not know chamber measurements. Patient scheduled for a balloon valvuloplasty.  

Babies are born with relatively symmetrical hearts.  Unlike adult hearts, the right ventricle comparatively large due to the work it has to do to pump against the high pulmonary pressure before birth.  Because newborns’ hearts are more to the right side, we often do right-sided chest leads in addition to the standard 12-lead ECG.

 The ECG:   In spite of the pulmonary valve stenosis, this ECG is within normal limits for this 4-week old. Some of the ECG findings here that would be abnormal for an adult ECG, but are normal for this 4-week-old baby are: