Association of secundum atrial septal defect with abnormalities of atrioventricular conduction or left axis deviation. Genetic study of 10 families.

Abstract

A genetic analysis was made of rofamilies in which the propositi had a secundum atrial septal defect associated with abnowrmal atrioventricular conduction (first, second, or third degree heart block) or unexplained left axis deviation or a combination of these conduction disturbances. Diagnostic information was available on 51 (8I%) of the first degree relatives. Three of the families appeared to be examples of a new syndrome which, with variable expression, was inherited as a non-sex-linked autosomal dominant. The main features were a secundum atrial septal defect; disease of the conducting tissue, which in some cases was progressive; unexplained left axis deviation; and unexpected death. These families did not seem to be examples of the Holt-Oram syndrome,for the upper limbs were clinically and radiologically normal in the I9 members examined.The importance of recognizing this syndrome is the occurrence ofprogressive disease of the conducting tissue and the risk ofsudden death. When, therefore, unexplained left axis deviation or prolonged atrioventricular conduction is found in association with a secundum atrial septal defect all available relatives should be examined.In the remaining seven families there was only one affectedfirst degree relative out of 39 examined. He was the son of one of the propositi and had paroxysmal coronary sinus rhythm with an intact atrial septum.

Clinical Use of Electrocardiography in Adults With Congenital Heart Disease

“…Criteria for right atrial enlargement are fulfilled in 35% of patients. 21 In inferior leads, a notch near the apex of the R wave, coined "crochetage," has been correlated with ASD. 23 In 1560 adults and adolescents, 73.1% of patients with ASDs displayed this pattern, with a specificity of 92% when present in all inferior limb leads.…”

“…PR prolongation is seen in 6% to 19% of patients and uncommonly progresses toward higher-degree AV block, 20 with complete block rarely reported. 21 The QRS axis is usually between 0°and 180°and is often vertical (60°to 90°). Right-axis deviation is common in adults with associated pulmonary vascular disease.…”

Double Intervention in Single Sitting: Percutaneous Device Closure and Permanent Pacemaker Implantation in a Patient with Atrial Septal Defect

“…Earlier, Emanuel et al had proposed a genetic connection to rationalize left axis deviation and prolonged AV conduction in patients with secundum ASD [5]. Mutations in the transcription factors of NKX2.5 and GATA4 genes are found to be associated with nonsyndromic ASDs.…”

“…It is suggested that all available relatives should also be examined when unexplained left axis deviation or prolonged AV conduction is observed in a patient with a secundum ASD [5]. Earlier, Emanuel et al had proposed a genetic connection to rationalize left axis deviation and prolonged AV conduction in patients with secundum ASD [5].…”

“…Genetic analyses have shown that mutations in NKX2. 5 and GATA4 genes are responsible for familial forms of secundum ASD [1]. Although the defect remains asymptomatic, it may contribute to significant morbidity and premature mortality, if not corrected [2].…”