Case Report:
A 7-year-old girl presented to our children hospital with exertional dyspnea and easy fatigability and frequent respiratory tract infections. The patients did not have any significant antenatal, natal, and neonatal history. She had normal intelligence and was doing well at school. The lips and fingernails were mildly cyanotic without clubbing. The oxygen saturation was 85% by pulse oximetry on room air. Arterial blood gas on room air showed hypoxia with PaO2 of 50 mmHg and SaO2of 83%. On general examination, she had short stature, narrow thorax, short fingers and toes, bilateral polydactyly of hands (Figure 1) and left foot. Fingernails and toenails were markedly hypoplastic, thin and wrinkled. In oral examination, anterior teeth were conical. Examination of the cardiovascular system revealed a 3/6 short systolic murmur at the left lower sternal border and a loud second heart sound. The electrocardiogram revealed left axis deviation, with complete right bundle branch block in leads V1,V2. The chest X-ray showed cardiomegaly with dilated main pulmonary artery and its branches. Transthoracic echocardiogram (TTE) showed common atrium and PAVSD with moderate mitral regurgitation (MR), mild tricuspid valve regurgitation, and moderate pulmonary hypertension. A clinical diagnosis of EVC syndrome was established. Based on the pre-operative findings, the patient was planned for surgical repair of PAVSD and common atrium. The operation was performed through median sternotomy. Total cardiopulmonary bypass was prepared, the aorta was cross-clamped, and the heart was arrested by antegrade cardioplegic solution. A right atrial incision was made parallel to the right atrioventricular groove, and the intracardiac anatomy was explored. There was DOMV (Figure 2), which was not diagnosed by preoperative TTE. The greater orifice of the mitral valve was similar to that in the classic PAVSD, and consisted of three leaflets (left superior leaflet (LSL), left inferior leaflet (LIL), and left lateral leaflet). This orifice (The greater one) of the mitral valve was repaired by suturing the free edges of LSL and LIL to each other by fine 6/0 Prolene sutures, thus converting it to a bileaflet valve (Figure 3). The other small orifice was left intact to avoid any possible mitral stenosis. Saline test showed excellent result with trivial residual MR. There was complete absence of the atrial septum without any remnants. A new atrial septum was constructed by an autologous fresh pericardial patch. The remainder of the operation progressed uneventfully and without any conduction disturbances. Postoperative TTE showed no residual shunt across the new atrial septum, and trivial MR. The postoperative period was uneventful, and the arterial blood gas showed normal oxygenation. The patient was discharged in stable condition, and has been on regular follow-up for last 6 months without any complains.