Criss-Cross Heart

Criss cross heart (CCH) is a cardiac malformation where the inflow streams of the two ventricles cross due to twisting of the heart about its major axis. The clinical features depend on the particular cardiac defects associated, like simple or corrected transposition of the great arteries and ventricular septal defects.

Epidemiology

The birth prevalence of CCH is 1 /125, 000 live births and accounts for <0.1% of all congenital heart defects.

Clinical description

CCH is a congenital disorder which can manifest by severe dyspnea with nasal flaring, retraction of sternal notch, subcostal and intercostal indrawing, diaphoresis, cyanosis, pallor, feeding difficulty, systolic murmur at the left sternal edge and accentuated P2 heart sound, depending on the associated lesions. The most common associations are ventricular septal defect (VSD), complete or congenitally corrected transposition of the great arteries, double outlet right ventricle, pulmonary branch stenosis, straddling mitral or tricuspid valve, mitral stenosis, and subpulmonary, subaortic or supravalvular aortic stenosis (see these terms).

Etiology

CCH is caused by abnormal rotation (clockwise or counterclockwise) of the ventricular mass along its long axis during embryonic development. The developmental mechanisms and causes of CCH are still elusive but some studies in mice have linked mutations in the Gja1 gene to the pathogenesis of CCH.

Diagnostic methods

Diagnosis is confirmed by 2-dimensional and color Doppler echocardiography revealing the crossing of the atrioventricular connections, without mixing, at the level of the atrioventricular (AV) valves. Failure to obtain a characteristic 4-chamber view (4CV) is a key diagnostic feature of CCH. Biventricular function is normal but perimembranous ventricular septal defects are usually observed. MRI and angiography may be used for the diagnosis of anomalies of the coronary circulation.

Differential diagnosis

Differential diagnosis includes straddling mitral or tricuspid valve, severe forms of Ebstein malformation (the tricuspid valve opens to the infundibulum, giving the appearance of crossing the valves) (see these terms), and double atrial outlet (an outlet orifice apparently crosses the other valve).

Antenatal diagnosis

Prenatal diagnosis can be achieved with a color Doppler ultrasound, by identifying key features of CCH that include the inability to obtain a 4CV at the standard transverse plane through the fetal chest and visualization of the criss cross arrangement of the inflow tracts into the two ventricles simultaneously in the transverse plane of the fetal chest.

Management and treatment

The surgical management of CCH consists of the repair of major and limiting malformations, with ventricular rotation itself being excluded as the reason for the correction. The initial management is determined by the presence or absence of pulmonary stenosis, and its severity. Where the pulmonary flow is inadequate, early intervention with prostaglandin E1 is indicated for maintaining the patency of the patent arterial duct. When anatomic correction fails, balance in pulmonary flow can be achieved with the construction of a systemic-pulmonary shunt. The corrective surgery is determined by the potential use of both ventricles. The Fontan correction may be indicated as a palliative repair option. Jatene's surgical technique (the arterial switch operation) may be proposed to patients where CCH is associated with transposition of the great arteries, VSD, atrial septal defect and patent arterial duct (see these terms).

Prognosis

The prognosis is unfavorable without surgical treatment. However, after correction of the main defect, normal physical, psychomotor and cardiovascular development may be achieved.