Heterotaxy syndrome associated with left ventricular non-compaction

Abstract

A 20-year-old asymptomatic man was referred to our clinic for the evaluation of a 2/6 grade systolic cardiac murmur. The ECG was normal. On his transthoracic echocardiography (TTE), subaortic membrane causing peak 25 mm Hg gradient on left ventricular outflow tract as the cause of the murmur (Fig. 1A) and an enlarged coronary sinus (CS) (Fig. 1B) were detected. We also suspected left ventricular non-compaction (Fig. 1C, D). We performed agitated saline injection via left antecubital vein for diagnosis of persistent left superior vena cava (PLSVC) and bubbles reached to CS before right atrium, indicating PLSVC. The injection was repeated via right antecubital vein to evaluate the right superior vena cava (RSVC) because of that the absence of RSVC may be associated with PLSVC. After the injection, the coronary sinus was opacified before right atrium, indicating the absence of RSVC. Left ventricular non-compaction was confirmed with cardiac magnetic resonance imaging (Fig. 2A, B). Thoracal computed tomographic (CT) venography was performed, and it confirmed the PLSVC and also revealed the absence of RSVC (Fig. 3A). Surprisingly, it also demonstrated absent inferior vena cava (IVC). Therefore, it forced us to perform abdominal CT angiography. It revealed the venous return of lower limbs and abdomen maintaining with dilated hemiazygous vein, indicating absent IVC. His abdominal CT faced us to another interesting findings, polysplenia (Fig. 3B). Subsequently, all findings in the entire story reached us to diagnose heterotaxy syndrome (HS). Coexistence of HS, subaortic membrane and left ventricular non-compaction has not been reported in the literature.