[Spontaneous Closure of Atrial Septal Defect Caused Severe Heart Failure in a Child with Pulmonary Atresia and Intact Ventricular Septum Having an Extracardiac Total Cavopulmonary Connection;Report of a Case].

: Unobstructed atrial communication is a prerequisite for favorable pulmonary circulation in patients with single-ventricle physiology and atrial-communication-dependent pulmonary venous drainage. It might also be a prerequisite for favorable coronary circulation in patients with single-ventricle physiology and atrial-communication-dependent coronary venous drainage. Obstruction of atrial communication, on which coronary venous drainage depends, has not yet been documented. We report a patient with pulmonary atresia and an intact ventricular septum having an extracardiac total cavopulmonary connection. Spontaneous closure of the atrial septal defect( ASD), measuring 10 mm before the total cavopulmonary connection, led to a leftward ventricular septal shift and left ventricular wall thickening, causing severe left ventricular diastolic dysfunction which resolved after surgical ASD creation. Detection of spontaneous ASD closure by ultrasound was challenging because the to-and-fro blood flow in the dilated coronary sinus mimicked a patent ASD. Prophylactic ASD enlargement accompanying the cavopulmonary connection procedure is advised in such patients.