This case report describes a 5-week-old boy with an unusual presentation of gastric pneumatosis caused by suspected necrotizing enterocolitis (NEC) after cardiogenic shock. Postnatally, a pulmonary atresia with intact ventricular septum was supplied by a modified Blalock–Taussig shunt. On transthoracic echocardiography in week 5, primarily performed to rule out pericardial effusion, air bubbles have been apparent in the right atrium. Intracardiac air found on echocardiogram is generally associated with an indwelling venous catheter but—as exemplified by this case report—may also occur in the setting of NEC. An abdominal radiograph showed an isolated gastric pneumatosis, which is an unusual location of NEC. It is speculated that air moved through the connecting veins to the right atrium, the pneumatosis located in the gastric wall being a prerequisite to this pathophysiology.
Conclusion: The suspected NEC was located in the stomach enabling the intramural air to pass through connecting veins to the right atrium. The first specific sign of NEC in our case was air bubbles in the right atrium on echocardiography.