cardiovascular disorders
Long QT Interval Syndromes
Key Points
Congenital long QT interval syndromes may cause torsades de pointes ventricular tachycardia, ventricular fibrillation and sudden death. Numerous factors, particularly use of certain drugs, increase the risk of ventricular arrhythmias. Diagnosis is based on a combination of clinical and electrocardiographic criteria, including exercise and sometimes provocative testing. Genetic testing is done on selected patients. Family members should be screened. Long-term management includes avoidance of triggers, use of beta-blockers, and often permanent pacing or an implantable cardioverter-defibrillator. 