Kawasaki R, Machado C, Reinoehl J, Fromm B, Baga J J, Steinman R T, Lehmann M H
Department of Medicine/Division of Cardiology, Sinai Hospital, Detroit, Michigan, USA.
J Cardiovasc Electrophysiol. 1995 Nov;6(11):1032-8. doi: 10.1111/j.1540-8167.1995.tb00380.x.
To determine whether an increased female gender susceptibility to torsades de pointes (TdP) may exist in a clinical model of bradycardia-induced long QT syndrome, we investigated reported cases of TdP associated with acquired complete heart block.
Seventy-two cases reported in the medical literature dating from 1941 through 1993 were identified, all describing TdP or "transient ventricular tachycardia/fibrillation" (to include those cases reported prior to the use of TdP terminology) in the setting of acquired complete heart block unassociated with QT prolonging drugs. Expected female prevalence in complete heart block was estimated at 52%, based on projections derived from 206,016 hospital discharges in the National Inpatient Profile (Commission on Professional and Hospital Activities, Ann Arbor, MI), over the years 1985 through 1992. During complete heart block, mean heart rate was 37 beats/min in both sexes (combined n = 43), and absolute QT interval ranged from 0.52 to 0.88 seconds, with a mean of 0.68 seconds (n = 25). Female prevalence among patients with TdP during complete heart block was greater than expected: 72% for all studied cases (P < 0.001); 70% (P < 0.04) and 74% (P < 0.02) among those reported prior to (n = 35) and during or after (n = 37) 1980, respectively; 73% (P < 0.03) among those with documented normokalemia (n = 26); and 68% (P = 0.2) among those with a prolonged QT interval and known polymorphic VT (i.e., unequivocal TdP; n = 25).
Despite inherent limitations of this retrospective study, the data are consistent in suggesting a greater than expected female prevalence among patients with TdP related to complete heart block. This finding lends support to a broadening concept of increased susceptibility of women to the development of TdP in various settings of QT prolongation.
为了确定在心动过缓诱发的长QT综合征临床模型中女性是否更易患尖端扭转型室性心动过速（TdP），我们调查了与获得性完全性心脏传导阻滞相关的TdP报告病例。
确定了1941年至1993年医学文献中报告的72例病例，所有病例均描述了在未使用延长QT药物的获得性完全性心脏传导阻滞情况下的TdP或“短暂性室性心动过速/心室颤动”（包括在使用TdP术语之前报告的病例）。根据1985年至1992年期间《国家住院患者概况》（专业与医院活动委员会，密歇根州安阿伯）中206,016例出院病例的预测，预计完全性心脏传导阻滞中女性患病率为52%。在完全性心脏传导阻滞期间，两性平均心率均为37次/分钟（共43例），绝对QT间期范围为0.52至0.88秒，平均为0.68秒（25例）。完全性心脏传导阻滞期间发生TdP的患者中女性患病率高于预期：所有研究病例中为72%（P<0.001）；1980年之前报告的病例中为70%（P<0.04），1980年期间或之后报告的病例中为74%（P<0.02）；血钾正常的病例中为73%（P<0.03）（26例）；QT间期延长且已知多形性室性心动过速（即明确的TdP；25例）的病例中为68%（P=0.2）。
尽管这项回顾性研究存在固有局限性，但数据一致表明，与完全性心脏传导阻滞相关的TdP患者中女性患病率高于预期。这一发现支持了一个不断拓宽的概念，即女性在各种QT延长情况下更易患TdP。
