Clinical features and management of congenital long QT syndrome: a report on 54 patients from a national registry

To assess the clinical features and the management of congenital long QT syndrome (LQTS) in China, we collected the clinical data of 54 LQTS patients (14 males and 40 females) from our newly established national registry. All patients were symptomatic, with syncope being the most common symptom. The average age when the first symptoms occurred was 17.9+/-15.6 (range, 0.5-62) years; 55.6% of them had the first symptoms before the age of 20. The most common triggers of the symptoms were physical exercise or emotional stress. The average corrected QT interval was 0.55+/-0.08 s. Using ECG criteria, there were 14 (25.9%) LQT1 patients, 28 (51.9%) LQT2, and 2 (3.7%) LQT3. Thirty (55.6%) patients were treated with beta-blockers at the time of enrollment, with propranolol being the most commonly used drug, with an average daily dose of 57.5+/-39.1 mg. Four patients underwent left cardiac sympathectomy. After an average follow-up of 24.9+/-13.2 months, 3.1% (1/32) of patients with antiadrenergic therapy and 9.1% (2/22) without antiadrengergic therapy died of sudden cardiac death (P<0.05). We concluded that LQT2 might be the most common subtype in these patients. Antiadrenergic treatment was underused, raising the urgent need for educating both physicians and patients on the nature of the disease and its optimal antiadrenergic therapy.