Concordant criss cross AV connection

A heart with a criss-cross atrioventricular (AV) connection is a cardiopathy in which the ventricles are positioned contralaterally to the atria to which they are connected; the ventricular inflow tracts are crossed, hence the name criss-cross.

In 1961 various cases of AV discordance with or without ventriculoarterial (VA) discordance were described. One of those cases presented as situs solitus with dextrorotation of the cardiac loop, which could correspond to the description of this abnormality.1 In 1973, for the first time, in Mexico a report was published of a 4-month-old boy with situs solitus with AV concordance, VA discordance, and crossing of the ventricular inflow chambers, with anterosuperior right ventricle (RV) and posterior and inferior left ventricle (LV), ventricular septal defect (VSD), and pulmonary stenosis (PS).2 These cases were later given the name of criss-cross.3

In the later years, other cases were described: 37 with situs solitus, 2 with situs inversus, and 1 with isomerism, most with AV concordance.4,5

The most common VA connection was discordant transposition of the great arteries (TGA), followed by double outlet RV (DORV), associated with PS and even more rarely with pulmonary atresia.4-6

The most common is atrial situs solitus presentation with right atrium (RA) connected to left-sided RV with anterior tricuspid valve and left aorta, as well as left atrium (LA) connected to right-sided LV with mitral valve oriented in the posterior direction. Criss-cross heart is often associated with superior-inferior ventricles; this ventricular relationship can present in other cardiopathies.7

In many cases, the size of the ventricles (small on many occasions) is conditioned by the size of the annulus of the AV valves.8,9

The physiology is determined by the discordant or concordant AV and VA connection and the associated cardiac defects, such as displaced and/ or straddling left AV valve, VSD (which always presents), valvular or subvalvular PS, small RV, and juxtaposition of the atrial appendages.7,10-12

Another of its hemodynamic characteristics is that the systemic and pulmonary venous systems are crossed at the AV level, although without mixing.

Two-dimensional echocardiography, with subcostal and 4-chamber views, can be used to identify the ventricular morphology and position, the AV valves, the AV and VA connection, and the characteristics of the great vessels. The artery connection can be seen more clearly in the parasternal window.13