[Absence of right and left atrioventricular connexion]

Fifty seven hearts with absence of atrioventricular (A-V) connection were studied morphologically to specify their types of ventriculoarterial connection and their associated anomalies; the anatomic features of the hearts were correlated with their echocardiographic and cardioangiographic images in order to establish their mutual correspondence. Fifty six hearts had situs solitus; fifty specimens had right absent A-V connection and six had left absent A-V connection. One had situs inversus. All the specimens had: A deep A-V sulcus at the site of the absent A-V connection, a dimple in the muscular floor of the involved atrium connected with the dilated and hypertrophic left ventricle, incomplete right ventricle without inlet portion, ventricular septal defect of variable dimensions (it was obliterated in two), atrial septal defect, the ventricular septum deviated from the crux cordis. The left absent A-V connection had ventricular inversion and discordant ventriculoarterial connection. In the right absent A-V connection the ventriculoarterial connections were concordant in thirty eight hearts, from which thirty four had pulmonary stenosis both infundibular and valvular (five had the tetrad of Fallot), two had pulmonary valve atresia and two had a dilated pulmonary artery; discordant in nine hearts, one with aortic atresia; double outlet, from the right ventricle in two, (one with the tetrad of Fallot) and from the left ventricle in one. The heart in situs inversus had ventricular inversion, right absent A-V connection (left-sided), single (right) ventricle and atresia of the left ventricle. The correlations between cardiac morphology and imaging were precise. Developmentally, this cardiopathy is the result of an ectopic unequally lateralized septation of the common atrioventricular canal, which separates two canals, one stenotic leading to atresia and the other which develops too wide.