The present study shows that CCH is a rare congenital disorder that is manifest commonly by dyspnea, cyanosis, and tachycardia. Pallor, clubbing, tachypnea, or feeding difficulties are less frequent manifestations. CCH is not an isolated defect. However, it is usually associated with other congenital defects such as ventricular septal defect, double outlet right ventricle, cardiomegaly, pulmonary stenosis, and L transposition of great arteries. Some cases may have a straddled mitral or tricuspid valve or subvalvular stenosis. According to the geographical variations, the disease tends to spread in Asian and North American countries. Male patients occupy the most incidence compared to female ones. The prognosis depends mainly on the aggravation of its associated defects and its atrioventricular type, which is either concordant or discordant rotation. Our analysis shows that patients with AV concordant type of CCH usually undergo surgical intervention more frequently than the other type next to their large higher incidence.
Imaging features
CCH is distinguished by the inability to achieve a typical 4-chamber vision. Two-dimensional echocardiogram (2-D echo) can reveal features of intracardiac anatomy, particularly AV valve anatomy. The expert operator can recognize the 3-D structure of the heart as well as the orientation of the heart and major vessels within the chest using this approach. Individual chamber size can also be evaluated using 2-D echo, allowing measurement of the right ventricular sinus and infundibulum. In rare circumstances, 2-D echo has been used to identify crisscross heart. [50]–[54] A 48-year-old woman was referred for heart murmur evaluation. The patient had dextrocardia and an undamaged interventricular septum. The transthoracic echocardiography revealed that the patient had situs solitus and dextrocardia. The patient also had a hypoplastic right ventricle with an intact interventricular septum and significant infundibular pulmonary stenosis. The atrioventricular and ventriculoarterial connections were found to be in agreement. The left atrioventricular valve was normal, crossed behind the right valve, and opened to the right side of the morphological left ventricle. The right atrium was dilated and opened into the trabeculated morphological right ventricle on the left side via a thin tricuspid valve. Cardiac magnetic resonance imaging (MRI) confirmed the crisscrossing of the atrioventricular valves. An angiocardiogram indicated that the dilated right atrium was linked to the morphologically hypoplastic right ventricle on the left side, which was then linked to a posterior pulmonary artery, confirming the crisscross atrioventricular linkage. The interventricular septum was found to be intact on the left ventricular angiography. [20]
A case of a 1-year-old child with bluish discoloration of the body and quick breathing tachypnea was recently presented. Cardiac CT revealed atria in a solitus position, with a morphological right atrium on the right side and a morphological left atrium on the left. The morphologically right ventricle was found to be to the right of the morphological left ventricle, indicating dextro-loop architecture. The left and right atriums were shown to have a superior-inferior connection. Atrioventricular discordance and crossing axis of atrioventricular connections were seen, with the right atrium draining into the morphological left ventricle and the left atrium draining into the morphologically right ventricle. There was a significant intake ventricular septal defect that extended into an outlet underneath the pulmonary valve. Figure.4. (a) showed the left atrium residing on top of the right atrium. [34] in a 1-month-old male child with a crisscross heart, the bloodstreams in the ventricular inflow tracts revealed by color Doppler and the spatial correlations of the cardiac segments revealed by MRI are critical for making an accurate non-invasive diagnosis of this complex abnormality. [8] Three-dimensional volume rendering of CCH displayed left and right ventricular relationships and connections, aided in comprehending the spatial relationship of the atrioventricular connections. Figure.4. (b) [41] Furthermore, 3D color Doppler rendering imaging defined the typical crossing of the inflow streams, which is difficult to discern with 2D color Doppler since the two AV valves are not shown on the same plane due to the heart's twisting.[55]
Neonatal imaging
Because two-dimensional color Doppler flow imaging could not show the relative direction of intracardiac blood flows in the fetal chest's transverse plane. Tsukimori et al. demonstrated the spatial organization of the two atrioventricular inlets in a fetus using 4-dimensional color Doppler rendering, resulting in the crisscross look. This revealed a crisscross heart with a double-outlet right ventricle and a ventricular septal defect. The prenatal diagnosis of CCH with double-outlet right ventricle and the ventricular septal defect was confirmed by neonatal echocardiography and chest computed tomography, necessitating surgical repair for this infant. [56]
Pathological images
The angiocardiograms of two pathological specimens revealed a strange distortion of atrioventricular and ventriculoarterial connections. The tricuspid valve shifted anteriorly and leftward in both cases, while the infundibular areas and semilunar valves shifted rightward. A probable explanation of the anomaly is abnormal AV canal enlargement, possibly caused by malrotation of the heart tube. One of the hearts had significant sub-pulmonary stenosis caused by a well-differentiated valve-like structure with a full annulus and chordate tendineae inserted in a parachute-like fashion on the infundibular septum. This structure had a distinct shape from the fibrous tags described in other abnormalities. Its origin is unknown. These defects have significant consequences for the nomenclature and classification of congenital cardiac malformations, and they highlight the importance of recent improvements to the segmental method. [39] Unless kept in an enlarged form, anatomic specimens do not contribute to comprehending the 3-dimensional structure of the beating heart. Furthermore, determining the position of the heart within the thorax from the heart specimen alone is difficult. Angiograms rarely discriminate between the right ventricular sinus and the infundibulum satisfactorily. [57] It is difficult to estimate the proportional size of these chambers. Furthermore, angiography provides little information about the architecture and attachments of the AV valves. [13]
Outcome of CCH patients
The outcome of patients of CCH depends on the severity of the associated defects. Most patients are diagnosed accidentally or when there is an increase in the predisposing factors of associated malformations. The surgical management is determined by the potential disability of both ventricles. For patients with difficulty to repair ventricular septation, such as in straddle valve or ventricular hypoplasia, Fontan operation may be the choice for palliative repair. [58]