Real Time three dimensional (RT3-D)‎ and two dimensional echocardiography evaluation of atrioventricular septal defect (AVSD)‎

Abstract EN

The study included 60 patients with repaired AVSD that were scannedby 2-D echocardiography to detect and evaluate the degree of residual mitral regurge (MR) and to assess cardiac function.Preoperative data including age, weight, , associated anomalies or Down syndrome and two dimentional echocardiography were reviewed.

Using real time 3-D echocardiography, the three components of mitral valve (superior, inferior and lateral or mural leaflets) surface areas were measured in 20 out of these 60 patients A common AW orifice was present in 73.3% (first group), the rest had separate A W orifice (second group).

The prevalence of associated cardiac anomalies was significantly higher in the first group(p=0.027).

Down syndrome was present in 22 cases, 12 of them in the first group and 10 in the second group.

It was also observed that late repair (< ly) was a risk factor for post operative MR.

So that the first year of life is the golden time for definitive repair of AVSD.

postoperatively, 38.6%, of patients with common orifice AVSD had their mitral regurgitation worsened compared with 25% in patients with separate orifice A VSD.

This postoperative worsening of mitral regurgitation was significantly higher in patients with delayed operation (>12 months) than those with early operation (< 12 months) and in those with associated cardiac anomalies than those without associated cardiac anomalies Severe post operative mitral valve regurgitation was the most frequent indication for reoperation?! 1%).

Common orifice AVSD was associated with insignificant higher rate of reoperation for mitral regurgitation (13%) in comparison with separate orifice defect 6%.

Preoperatively left ventricular end-diastolic dimension (LVED) and left atrial diameter (LA ) were statistically significantly higher in 96% of patients with A VSD than in normal infants with matching age group, however, postoperatively L VED returned to the normal values in all A VSD patients while the LA diameter was still statistically significantly higher in 51.7% of A VSD patients.

Using 3*D real time volumetric machine that, to our knowledge was not previously reported and it is described by us for the first time to measure mitral leaflets'surface areas revealed that the mean superior anterior leaflet comprised 43% of the total surface leaflet area while the inferior leaflet was 34% and the mural leaflet was 23%.

The lateral leaflet comprised 17% of the total mitral valve area inpatients with separate orifice defect versus 27.1% in those with common orifice defect (p^O.

002).

The origin of postoperative MR jet was found statistically significantly related to the individual leaflet surface area : When the jet was directed medially, there was an associated smaller inferior component than when the jet was laterally directed where there was an associated smaller mural leaflet of the mitral valve.

Conclusion From this study it can be concluded that, late (> 12 months) repair of AVSD and associated cardiac anomalies were identified to be significant risk factors for persistence of MR postoperatively.

To improve surgical results of AVSD repair, operation should best be done before the first year of life.

Real time 3-D echocardiography pre operative scanning of the surface areas of the mitral valve leaflets may give a guide to the best procedure of repair.

Real time 3-D echocardiography avoids deficiencies encountered with reconstructive 3-D techniques by acquiring volumertric data at a rate sufficient to show real time movements of the heart and intracardiac structures, in a very short time, neither ECG nor respiratory gating is necessary and unlike 3-D reconstruction in which sedation is often usedfor infants and children less than 6 years of age to limit motion artifact, no sedation is required in RT3-D echocardiograph