The atrioventricular junction in the univentricular heart: a two-dimensional echocardiographic analysis

Anatomoechocardiographic correlation double inlet left ventricle

Double inlet left ventricle (LV) is a type of atrioventricular connection in which the morphologically LV receives more than 50% of the atrioventricular valves when they are separate, or more than 75% of a common atrioventricular valve. The aim of this study was to establish an anatomoechocardiographic correlation between the morphologic features of equivalent anatomic specimens and the echocardiographic images of patients to provide a means of interpreting the image correctly and a more precise diagnosis of the cardiac defect. Echocardiography was used to study 18 patients with LV double inlet who were seen in a congenital heart disease clinic. The morphology of 17 hearts with this malformation from the department of embryology was analyzed to compare the anatomic features with their echocardiographic images. Echocardiography proved to be a noninvasive diagnostic tool that allowed characterization of anatomic and functional aspects of double inlet LV.

Double-inlet single left ventricle: echocardiographic anatomy with emphasis on the morphology of the atrioventricular valves and ventricular septal defect

The echocardiographic anatomy of double-inlet single left ventricle was studied in 57 patients, aged 1 day to 27 years (mean 6 years); the variables examined included morphology, size and function of the atrioventricular (AV) valves and ventricular septal defect and their relation to pulmonary stenosis, aortic stenosis and aortic arch obstruction. The visceroatrial situs was solitus and the heart was in the left side of the chest in all 57 patients. A d-loop ventricle was present in 21 patients and an l-loop ventricle in 36. The great arteries were normally related (Holmes heart) in 8 patients and transposed in 49. In all hearts, the right AV valve was anterior to the left AV valve. In 53 patients, the tricuspid valve (right valve in d-loop and left valve in l-loop) was closer to and had attachments on the septum. The tricuspid valve straddled the outflow chamber in eight patients. No significant difference was noted in the mean AV valve diameter when comparing mitral and tricuspid valves within the same group or between the groups with a d- or l-loop ventricle. The right AV valve diameter had a significant direct correlation with the aortic valve diameter and the size of the ventricular septal defect regardless of ventricular loop. Both AV valves were functionally normal in 34 patients. Among patients with AV valve dysfunction, the tricuspid valve tended to be stenotic in patients with an l-loop ventricle and regurgitant in patients with a d-loop ventricle. Mitral valve dysfunction was uncommon. The ventricular septal defect (46 patients) was separated from the semilunar valves in 24 patients (muscular defect) and adjacent to the anterior semilunar valve as a result of hypoplasia or malalignment, or both, of the infundibular septum (subaortic defect) in 19 patients. Multiple defects were present in three patients. The defect was unrestrictive in 26 patients, restrictive in 23 and could not be evaluated in 8. Pulmonary artery banding had been performed in 8 of the 26 patients with an unrestrictive defect and in 10 of the 23 patients with a restrictive defect. Only 4 of 19 subaortic defects compared with 16 of 24 muscular defects were restrictive. The size of the defect was significantly correlated with the measured pressure gradient. Among patients with transposition, only 2 of 13 with pulmonary stenosis had a restrictive ventricular septal defect compared with 15 of 30 without pulmonary stenosis. In patients with transposition, the defect size was significantly smaller when coarctation was present.

Echocardiographic spectrum of double inlet ventricle: evaluation of the interventricular communication

To determine the spectrum and associated anomalies of double inlet ventricle (single ventricle), echocardiographic data of 50 patients with double inlet ventricle were reviewed and compared with the data obtained by cardiac catheterization, cardiac surgery and autopsy. Standard echocardiographic planes were used to determine the cardiac anatomy and the size of the interventricular communication. Double inlet by way of two perforate valves was found in 44 patients. In 42 of the 44 patients the dominant ventricular morphology was of the left ventricular type (double inlet left ventricle); in 13 of these 42 patients stenosis of one atrioventricular (AV) valve was found. Double inlet right ventricle and double inlet indeterminate ventricle were each found in one patient. Double inlet by way of a common AV valve was found in six patients, all of whom had atrial isomerism. The diagnosis of double inlet ventricle was accurate by two-dimensional echocardiography in all 44 patients. A restrictive interventricular communication was shown in 13 patients and a nonrestrictive communication in 17 patients by cardiac catheterization. Patients with a restrictive interventricular communication had a significantly smaller interventricular communication area normalized by the body surface area (mean +/- SD 1.21 +/- 0.53 cm2/m2) than did those with a nonrestrictive interventricular communication (2.33 +/- 0.71 cm2/m2) (p less than 0.01). Infants with an aortic anomaly had a significantly smaller interventricular communication area (1.35 +/- 0.65 cm2/m2) than did those without an aortic anomaly (2.57 +/- 0.76 cm2/m2) (p less than 0.05). Echocardiography provides an accurate noninvasive diagnosis in patients with double inlet ventricle, offering reliable information about the restrictive interventricular communication.

Cross-sectional and pulsed Doppler echocardiography of the atrioventricular junction of hearts with univentricular atrioventricular connexion

The atrioventricular junction of 52 consecutive patients with univentricular atrioventricular connexion was examined by cross-sectional and pulsed Doppler echocardiography. The echocardiographic features were then compared with catheterisation and cineangiographic findings. In the diagnosis of the mode of atrioventricular connexion, cross-sectional echocardiography was superior to cineangiography in differentiating single inlet with absence of one atrioventricular connexion from double inlet with a common atrioventricular valve. Straddling atrioventricular valves were diagnosed by echocardiography alone. Using pulsed Doppler echocardiography, the diagnostic sensitivity of atrioventricular valvar regurgitation was 92.6% and the specificity 100%. By mapping the regurgitant jet with pulsed Doppler echocardiography, an index was derived to evaluate the severity of atrioventricular valvar regurgitation. The indices obtained correlated well with cineangiographic grading on a three-point scale (Spearman rank correlation coefficient: rs = 0.9). Thus, cross-sectional echocardiography coupled with a range-gated Doppler system provide accurate anatomical details of the atrioventricular junction and reliable assessment of atrioventricular valvar regurgitation in patients with univentricular atrioventricular connexion.