The star shows the created atrial septal … Figure 7. Post-operative trans-oesophageal echocardiography, showing the diastolic flow across the two atrioventricular valve orifices CTEP on the left side of the pericardial patch. The patient had a smooth post-operative course and was discharged from hospital after 5 days. The

post-operative echo showed trivial right and left AV valve regurgitation. The mean diastolic gradient across the left AV valve was 4 mmHg. There was no significant gradient across the left ventricular outflow tract. The patient remained symptom-free and with the same echo findings in the routine follow-up after 2 months. Discussion This report illustrates several features of a rare variant of AV septal defect, with three AV valve orifices. The patient had AVSD with totally closed atrial component dividing the common AV valve into a right and left components. Misalignment between the atrial septum and muscular ventricular septum caused overriding

and straddling of the right component of the common AV valve. The ventricular component of the AVSD has also totally closed causing the crest of the ventricular septum to divide the right AV valve into a valve connecting the right atrium to the right ventricle and another smaller valve connecting the right atrium to the left ventricle. Thus although the atrioventricular connections were seemingly concordant, at the same time there was double outlet right atrium and double inlet left ventricle with two balanced ventricles (Figure 8). Figure 8. Diagram showing the atrioventricular (AV) connections. The malalignment of the atrial and ventricular septae caused overriding and straddling of the right AV valve, resulting in double outlet right atrium and double inlet left ventricle with two adequate … The tiny systolic flow, detected pre-operatively, that was thought to be a leak in the aneurysmal tissue closing the ventricular septal defect,

was actually trivial regurgitation in the small orifice of the right AV valve connecting the right atrium to the left ventricle (Figure 2). Although there was a communication between the right atrium and the left ventricle, the patient did Anacetrapib not give history of cyanosis and her resting oxygen saturation was 98%. This can be explained by the fact that the blood preferentially flowed from the right atrium to the right ventricle because the AV valve connecting them was significantly bigger than the other small orifice opening to the left ventricle, in addition the left ventricular compliance was much less than that of the right ventricle, which is secondary to the coexisting left ventricular Hypertrophy due to the subaortic membrane.