Mohamed A. Seliem

Background: Familial aggregation of congenital heart disease (CHD) has been well described in different populations, in particular those with a high consanguinity rate. Extensive genetic study of affected families has improved the understanding of basic genetics of different cardiac lesions. Objective: To identify the role of consanguinity as a risk factor among familial cases of CHD in a stable outpatient population of a tertiary care center in the Eastern Province of Saudi Arabia. Methods: All familial cases of CHD seen over 5 years (1996–2000) in the Division of Pediatric Cardiology were identified. The presence or absence of parental consanguinity (first cousin marriage) was defined in each of these families. Results: Ninety-three cases were identified in 37 families. Twenty-three (62%) families resulted from consanguineous marriages. In 4 families where there were 2 marriages, the affected children came from the consanguineous marriage in 3 of these families. Discordant lesions occur only among non-consanguineous cases, while all consanguineous cases were concordant. Five sets of twins of the same sex (one set are monozygotic by DNA analysis) occurred among consanguineous marriages, in 3 of these both twins were affected with the same disease. Affected parents were seen in 2 families with consanguineous marriage and none in the non-consanguineous marriages. The prevalence of dilated cardiomyopathy was much higher among consanguineous cases (26 vs. 2). Conclusions: Familial aggregation of congenital heart disease is common in our population. Consanguinity is common in these families, and the distribution of congenital heart disease differs in this subgroup compared to the rest of the familial cases. Further genetic studies of these families may help to shed more light on basic genetics and the specific pathogenetic mechanisms involved.

We present 4 cases of cor triatriatum in whom the diagnosis was correctly made by 2-dimensional transthoracic echocardiography, which showed the supravalvular left atrial membrane that divides the left atrium into 2 chambers. The pulmonary veins were connected normally to the proximal left atrial chamber and the left atrial appendage was connected to the distal left atrial chamber. In 1 patient there was evidence of severe pulmonary venous obstruction to the mitral valve by Doppler examination, while in the other three, there was no venous obstruction. Patients were then examined by real-time 3-dimensional echocardiography (RT3DE, using x4 matrix array transducer connected to Sonos 7500 echocardiographic system Phillips, Andover, Mass, USA). This showed the exact morphology of the membrane and led to cancellation of planed surgical intervention in 1 case in which the membrane was only a broad band crossing the left atrial cavity. In addition to delineating the exact morphology of the intracavitary anomaly, this novel echocardiographic imaging modality should be an additive tool to better understand the natural history of these nonobstructive left atrial membranes via longitudinal follow-up of these patients.