Neonatal circulatory changes following elective cesarean section: an echocardiographic study

Right ventricular systolic time intervals have been used in neonates to demonstrate both normal and abnormal cardiovascular adaptation to extrauterine life.1,2 The ratio of these intervals, which include the right ventricular preejection period (RVPEP) and right ventricular ejection time (RVET), correlates closely with pulmonary vascular resistance (PVR) and pulmonary artery diastolic pressure.3 Previous echocardiographic studies in normal newborns have demonstrated the decline in PVR, but have excluded babies delivered by cesarean section (CS).1 Many respiratory abnormalities are noted following both elective and emergency CS. These are attributed to respiratory distress syndrome, transient tachypnea of the newborn (TTN), aspiration syndromes, and persistent fetal circulation (PFC).4-9