The angulation of the septal structures impacts ventricular imbalance in atrioventricular septal defects with a common atrioventricular junction.
OBJECTIVE
Multiplanar re-formatting of full-volume three-dimensional echocardiography data sets offers new insights into the morphology of atrioventricular septal defects. We hypothesised that distortion of the alignment between the atrial and ventricular septums results in imbalanced venous return to the ventricles, with consequent proportional ventricular hypoplasia.


METHODS
A single observer evaluated 31 patients, with a mean age of 52.09 months, standard deviation of 55, and with a range from 2 to 264 months, with atrioventricular septal defects, of whom 17 were boys. Ventricular imbalance, observed in nine patients, was determined by two-dimensional assessment, and confirmed at surgical inspection in selected cases when a univentricular strategy was undertaken. Offline analysis using multiplanar re-formatting was performed. A line was drawn though the length of the ventricular septum and a second line along the plane of the atrial septum, taking the angle between these two lines as the atrioventricular septal angle. We compared the angle between 22 patients with adequately sized ventricles, and those with ventricular imbalance undergoing univentricular repair.


RESULTS
In the 22 patients undergoing biventricular repair, the septal angle was 0 in 14 patients; the other eight patients having angles ranging from 1 to 36, with a mean angle of 7.4°, and standard deviation of 11.1°.The mean angle in the nine patients with ventricle imbalance was 28.6°, with a standard deviation of 3.04°, and with a range from 26 to 35°. Of those undergoing univentricular repair, two patients died, with angles of 26 and 30°, respectively.


CONCLUSIONS
The atrioventricular septal angle derived via multiplanar formatting gives important information regarding the degree of ventricular hypoplasia and imbalance. When this angle is above 25°, patients are likely to have ventricular imbalance requiring univentricular repair.
1Department of Paediatric Cardiology and Cardiothoracic Surgery,Southampton University Hospital,Southampton,United Kingdom.
Zaheer
Z
Ahmad
1Department of Paediatric Cardiology and Cardiothoracic Surgery,Southampton University Hospital,Southampton,United Kingdom.
Zek
Z
Lim
1Department of Paediatric Cardiology and Cardiothoracic Surgery,Southampton University Hospital,Southampton,United Kingdom.
Kevin
K
Roman
2Congenital Heart Center,Helen DeVos Children Hospital,Grand Rapids Michigan,Michigan,United States of America.
Marcus
M
Haw
3Institute of Genetic Medicine,Newcastle University,Newcastle-upon-Tyne,United Kingdom.
Robert H
RH
Anderson
2Congenital Heart Center,Helen DeVos Children Hospital,Grand Rapids Michigan,Michigan,United States of America.
Joseph
J
Vettukattil
D006348:Cardiac Surgical Procedures / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000000981:diagnostic imaging* / Q000601:surgery; D006343:Heart Septal Defects / Q000000981:diagnostic imaging* / Q000601:surgery; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000601:surgery; D006801:Humans; D007223:Infant; D008297:Male; D011379:Prognosis; D054088:Ventricular Septum / Q000000981:diagnostic imaging* / Q000601:surgery
CHD; Echocardiography; imaging