Long-Term Follow-Up of Patients With Short QT Syndrome

• Published in: Journal of the American College of Cardiology Vol. 58; no. 6; pp. 587 - 595
• Main Authors: Giustetto, Carla, Schimpf, Rainer, Mazzanti, Andrea, Scrocco, Chiara, Maury, Philippe, Anttonen, Olli, Probst, Vincent, Blanc, Jean-Jacques, Sbragia, Pascal, Dalmasso, Paola, Borggrefe, Martin, Gaita, Fiorenzo
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 02.08.2011; Elsevier; Elsevier Limited
• Subjects: Adolescent; Adult; Age; Anti-Arrhythmia Agents - pharmacology; arrhythmias; Arrhythmias, Cardiac - therapy; Biological and medical sciences; Cardiac arrhythmia; Cardiology; Cardiology. Vascular system; Cardiovascular; channelopathies; Cohort Studies; Death, Sudden; Defibrillators, Implantable; Electrocardiography; Electrocardiography - methods; ERG1 Potassium Channel; Ether-A-Go-Go Potassium Channels - genetics; Families & family life; Female; Follow-Up Studies; Humans; hydroquinidine; implantable cardioverter defibrillator; Internal Medicine; Male; Medical sciences; Methods; Middle Aged; Mutation; Quinidine - analogs & derivatives; Quinidine - pharmacology; short-QT syndrome; Studies; sudden death; Syncope - pathology; Treatment Outcome; Variance analysis; QTc; ERP; short-QT syndrome; AF; channelopathies; ECG; EPS; HQ; ICD; QTp; VF; sudden death; SD; implantable cardioverter defibrillator; arrhythmias; hydroquinidine; SQTS; CA; corrected QT; cardiac arrest; electrocardiography; atrial fibrillation; predicted QT; short QT syndrome; implantable cardioverter-defibrillator; effective refractory period; ventricular fibrillation; electrophysiological study; Human; Short QT syndrome; Follow up study; Patient; Circulatory system; Cardiology; Conduction disorder; Long term
• ISSN: 0735-1097; 1558-3597; 1558-3597
• DOI: 10.1016/j.jacc.2011.03.038

The aim of this study was to investigate the clinical characteristics and the long-term course of a large cohort of patients with short QT syndrome (SQTS). SQTS is a rare channelopathy characterized by an increased risk of sudden death. Data on the long-term outcome of SQTS patients are not available. Fifty-three patients from the European Short QT Registry (75% males; median age: 26 years) were followed up for 64 ± 27 months. A familial or personal history of cardiac arrest was present in 89%. Sudden death was the clinical presentation in 32%. The average QTc was 314 ± 23 ms. A mutation in genes related to SQTS was found in 23% of the probands; most of them had a gain of function mutation in HERG (SQTS1). Twenty-four patients received an implantable cardioverter defibrillator, and 12 patients received long-term prophylaxis with hydroquinidine (HQ), which was effective in preventing the induction of ventricular arrhythmias. Patients with a HERG mutation had shorter QTc at baseline and a greater QTc prolongation after treatment with HQ. During follow-up, 2 already symptomatic patients received appropriate implantable cardioverter defibrillator shocks and 1 had syncope. Nonsustained polymorphic ventricular tachycardia was recorded in 3 patients. The event rate was 4.9% per year in the patients without antiarrhythmic therapy. No arrhythmic events occurred in patients receiving HQ. SQTS carries a high risk of sudden death in all age groups. Symptomatic patients have a high risk of recurrent arrhythmic events. HQ is effective in preventing ventricular tachyarrhythmia induction and arrhythmic events during long-term follow-up.