Assessment of intracardiac anomalies in two adults with Ivemark's syndrome.

Ivemark's syndrome consists of intracardiac anomalies, abnormal lobation of the lungs, and abdominal heterotaxy. A frequent intracardiac anomaly seen in Ivemark's syndrome is a common atrium, which is associated with left-to-right shunting. The increased blood flow and resistance within the pulmonary vasculature creates pulmonary hypertension and eventual reversal of the shunt physiology. In the absence of additional cyanotic malformations, survival into adulthood without prior surgical septation of the common atrium depends on the extent of pulmonary hypertension and intracardiac right-to-left shunting. We present two patients with a common atrium in the setting of Ivemark's syndrome who survived into adulthood without prior operation. Two-dimensional echocardiography assessed their intracardiac structures. One patient had right atrial isomerism manifested by asplenia and a common atrium, into which the hepatic veins drained directly, and the other patient had left atrial isomerism manifested by polysplenia, a common atrium, and a ventricular septal defect with a single atrioventricular valve. Neither patient had additional cyanotic malformations, including obstruction to pulmonary venous return, transposition of the great vessels, or pulmonic valve stenosis. The 2-dimensional echocardiogram guides the clinician to refer patients for surgical septation of the common atrium before the right-to-left shunt physiology predominates. The medical and surgical treatment of these patients is discussed.