Malignant familial long QT syndrome

Authors

• Raghavan Subramanyan, Department of Pediatric Cardiology, Royal Hospital, PO Box 1331, PC 111, Muscat, Sultanate of Oman. Tel. +968 596689. Fax. +968 591027. E-mail: ragusha{at}omantel.net.om
• Poothirikovil Venugopalan, Department of Pediatrics, Sultan Qaboos University Hospital, Muscat, Sultanate of Oman.

Abstract

We report a family with congenital long QT syndrome, an inherited disorder of myocardial repolarization in which affected individuals have prolongation of corrected QT interval on the electrocardiogram and a tendency to develop ventricular arrhythmia, leading to syncope, convulsion or sudden death. Our family is characterized by several affected members (11/16), early onset of symptoms, malignant course prior to diagnosis and good response to beta-blocker therapy. The genetic basis of long QT syndrome has been traced to defective proteins encoding cardiac ion channels. Diagnosis is based on an unexplained prolongation of QT interval >0.45 second in the presence of suggestive symptoms or evidence, or both of a familial pattern. Beta-adrenergic blocker therapy gives symptomatic relief in 80%-85% of patients. Precipitating factors like vigorous exercise especially swimming and exposure to significant emotional or auditory stimuli should be avoided. Occasional patients require in addition, a demand cardiac pacemaker, left cardiac sympathectomy or an implantable cardioverter-defibrillator, or both. Regular follow up is mandatory even after subsidence of symptoms.

Article Type

Case Report

First Page

738

Last Page

742

Recommended Citation

Subramanyan, Raghavan and Venugopalan, Poothirikovil (2002) "Malignant familial long QT syndrome," Saudi Medical Journal: Vol. 23: Iss. 6, Article 24.
DOI: https://doi.org/10.15537/1658-3175.1743