The silent patent ductus arteriosus.

Objectives: To describe the characteristics and outcome of children with an isolated silent patent ductus arteriosus (SPDA), with comparison to non-silent ducts.

Patients And Methods: Between 1999 and 2004, all consecutive cases of isolated silent and non-silent-patent ductus were recorded at the National Register of Pediatric and Congenital Heart Disease, Lebanese Society of Cardiology. Patients with a SPDA were followed clinically and by Doppler echocardiography while all non-SPDA were percutaneously or surgically closed.

Results: Twenty-four cases of isolated SPDA and 50 cases of isolated non-SPDA ducts were recorded. Male sex was significantly predominant in the silent group (70%). First-cousin consanguinity rates were not different between both groups, with 20.4% for the silent group versus 22% for the non-silent group. Down's syndrome was associated in three cases of SPDA. No cases of endocarditis were noted during a mean follow-up of 33.3 months. Four patients with a SPDA experienced spontaneous closure at the age of 25, 30, 36 and 58 months.

Conclusion: SPDA is a relatively benign disease. The risk of endocarditis cannot be totally ignored, but the systematic closure of the SPDA is not warranted. Larger series and longer follow-up are needed in order to draw conclusions. Spontaneous closure occurred in four patients with SPDA.