Carvedilol, a Non-Selective β-with α1-Blocker is Effective in Long QT Syndrome Type 2

Abstract

Background: β-blockers offer the first line therapy in congenital long QT syndrome (LQTS), and are more effective to prevent the cardiac event in LQTS type 1 than in type 2 or 3. In contrast, left cardiac sympathetic denervation (LCS D) was shown to be highly effective in patients refractory to β-blockers. Total sympathetic ablation by LCSD indicates the addititional involvement of α-adr enoceptor-mediated pathway. In genotyped LQT2 patients, we therefore hypothesized that blockade of α-adrenoceptor in addition to α-adrenoceptor by carvedilol could reduce cardiac events more efficiently than other types of β-blockers. Methods and Results: The study population consisted of 51 genotyped LQT2 patients (18 males, 23 ± 11years old). They were divided into 2 groups (group 1: 43 patients treated with selective β-blockers, group 2: 8 patients with carvedilol) and retrospectively analyzed the efficacy of the respective β-blocker therapy in suppressing cardiac events. Cardiac events were observed in 11 patients of group 1 (26%) but none in group 2 during a follow-up period of 83 ± 80 months (P = 0.098). Conclusions: Carvedilol may be a potentially beneficial therapy for genotyped LQT2 patients who are refractory to other β selective blockers.

Keywords

• Long QT syndrome
• β-blocker therapy
• carvedilol
• α-adrenoceptor