Images in cardiovascular medicine. Three-dimensional echocardiography in criss-cross heart: could a specimen be better?

A 9-day-old neonate weighing 3 kg was referred to our institution for cyanosis and a systolic murmur. A 2-dimensional echocardiogram suggested SDL, levocardia, criss-cross heart with double-outlet right ventricle, hypoplasia of the tricuspid valve and right ventricle, and severe pulmonary stenosis. A real-time 3-dimensional echocardiogram (Sonos 7500, Philips Medical Systems, Andover, Mass) demonstrated the complex anatomy of the criss-cross heart as clearly as if one were viewing an anatomic specimen. The atria were situated in relatively normal positions, with normal venous connections. The left atrium was posterior and communicated via the mitral valve with the morphologically left ventricle situated inferiorly and extending to the right (Figure 1). The right atrium was anterior and communicated by means of a tricuspid valve with the hypoplastic morphologically right ventricle, positioned superiorly and extending to the left (Figure 2). The right atrium–right ventricle axis was nearly orthogonal to, rather than parallel to, the left atrium–left ventricle axis so that the atrioventricular valves were seen to cross each other, as viewed in the frontal plane (Figure 3 and Movies I and II). The ventricles appeared to have been twisted clockwise about their long axes when viewed from the apex, whereas the base of the heart remained fixed. This gave the characteristic appearance of each atrium emptying into the contralateral ventricle. Given the rarity of this cardiac defect and the specimen-like quality of the images, the 3-dimensional echocardiogram was very useful not only for clinical diagnosis but also for didactic purposes.