Important Newborn Cardiac Diagnostic Dilemmas for the Neonatologist and Cardiologist–A Clinical Perspective

Abstract

Most congenital heart disease (CHD) is readily recognisable in the newborn. Forewarned by previous fetal scanning, the presence of a murmur, tachypnoea, cyanosis and/or differential pulses and saturations all point to a cardiac abnormality. Yet serious heart disease may be missed on a fetal scan. There may be no murmur or clinical cyanosis, and tachypneoa may be attributed to non-cardiac causes. Tachypnoea on day 1 is usually non-cardiac except arising from ventricular failure or a large systemic arteriovenous fistula. A patent ductus arteriosus (PDA) may support either pulmonary or systemic duct dependent circulations. The initially high pulmonary vascular resistance (PVR) limits shunts so that murmurs even from large communications between the systemic and pulmonary circulations take days/weeks to develop. At times despite expert input, serious CHD maybe difficult to diagnose and warrants close interaction between the neonatologist and cardiologist to reach a timely diagnosis. Such conditions include obstructed total anomalous pulmonary venous connections (TAPVC) and the need to distinguish it from persistent pulmonary hypertension in the newborn (PPHN)–the treatment of the former is surgical the latter medical. A large duct shunting right to left may overshadow a suspected hypoplastic aortic isthmus and/or coarctation. Is the right to left shunting because of severe aortic obstruction or resulting from a high PVR with little obstruction. The diagnosis of pulmonary vein stenosis (PVS) remains problematic often developing in premature infants with ongoing bronchopulmonary dysplasia (BPD), still being cared for by the neonatologist. While there are other diagnostic dilemmas including deciding the contribution of a recognised CHD in a sick neonate, this paper will focus on the above-mentioned conditions with suggestions on what may be done to arrive at a timely diagnosis to achieve optimal outcomes.