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

• Main Authors: Hiromi Kimura, MD, Yuka Mizusawa, MD, Hideki Itoh, MD, Akashi Miyamoto, MD, Mihoko Kawamura, MD, Tamiro Kawaguchi, MD, Nobu Naiki, MD, Yuko Oka, MD, Seiko Ohno, MD, Takeru Makiyama, MD, Makoto Ito, MD, Minoru Horie, MD
• Format: Article
• Language: English
• Published: Wiley 2011-01-01
• Series: Journal of Arrhythmia
• Subjects: Long QT syndrome; β-blocker therapy; carvedilol; α-adrenoceptor
• Online Access: http://www.sciencedirect.com/science/article/pii/S1880427611800347
• ISSN: 1880-4276

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.