De Vecchis Renato, Ariano Carmelina, Di Biase Giuseppina, Noutsias Michel
Preventive Cardiology and Rehabilitation Unit, DSB 29 "S. Gennaro dei Poveri Hospital", via S.Gennaro dei Poveri 25, 80136 Napoli, Italy.
Division of Geriatrics, "Casa Sollievo della Sofferenza" Hospital, viale Cappuccini 2, 71013 San Giovanni Rotondo, Italy.
J Clin Med Res. 2018 Jul;10(7):593-600. doi: 10.14740/jocmr3470w. Epub 2018 Jun 4.
Several drug classes (antiarrhythmics, antimicrobials, antidepressants, phenothiazines, opiates, prokinetics of digestive tract, etc.) have been related to ventricular hyperkinetic arrhythmias such as torsade de pointes (TdP). TdPs are usually heralded by an abnormal prolongation of heart rate-corrected QT interval on the electrocardiogram, so-called drug-induced long heart rate-corrected QT (diLQTc). We don't know to what extent the drug-induced QTc prolongation is able to predict malignant arrhythmias. Thus we have retrospectively examined the clinical history of patients with diLQTc.
The case-record, concerning the period from January 2008 to December 2017, was collected from two hospitals. The diLQTc was defined as drug- induced heart rate-corrected QT of ≥ 450 ms or ≥ 470 ms, respectively in male or female patients. The primary purpose was to verify whether in diLQTc patients the length of this electrocardiographic segment was associated with the risk of symptoms or events (TdP, ventricular fibrillation).
A total of 73 validated cases of diLQTc were gathered. Among them, the QTc duration was not able to predict the occurrence of symptoms or events (odds ratio: 0.998; 95% CI: 0.984 to 1.013; P = 0.8821). Likewise, a diQTc lasting longer than 500 ms compared to diQTc comprised between 450 and 500 ms was not associated with an increased risk of arrhythmic events.
In some probably genetically predisposed subjects, the occurrence of symptoms (dizziness, lipothymia, syncope ) and/or documented arrhythmic events (TdP), is related to intake of certain drugs (antiarrhythmics, antimicrobials such as quinolones and macrolides, etc.). Nevertheless, in our diLQTc patients, QTc duration didn't predict occurrence of symptoms, or arrhythmic events. Thus, other determinants should be postulated to clarify why sometimes diQTc prolongation propitiates ventricular malignant arrhythmias whereas in other cases this arrhythmogenic effect is lacking.
几类药物（抗心律失常药、抗菌药、抗抑郁药、吩噻嗪类、阿片类、消化道促动力药等）已被证实与室性心动过速性心律失常有关，如尖端扭转型室速（TdP）。TdP通常在心电图上表现为心率校正QT间期异常延长，即所谓的药物性长QT间期（diLQTc）。我们尚不清楚药物诱导的QTc延长在多大程度上能够预测恶性心律失常。因此，我们对diLQTc患者的临床病史进行了回顾性研究。
收集了2008年1月至2017年12月期间两家医院的病例记录。diLQTc定义为男性或女性患者药物诱导的心率校正QT分别≥450 ms或≥470 ms。主要目的是验证在diLQTc患者中，该心电图段的长度是否与症状或事件（TdP、室颤）风险相关。
共收集到73例确诊的diLQTc病例。其中，QTc持续时间无法预测症状或事件的发生（优势比：0.99；95%置信区间：0.984至1.013；P = 0.8821）。同样，与450至500 ms的diQTc相比，持续时间超过500 ms 的diQTc与心律失常事件风险增加无关。
在一些可能具有遗传易感性的个体中，症状（头晕、晕厥前期、晕厥）的出现和/或记录到的心律失常事件（TdP）与某些药物（抗心律失常药、喹诺酮类和大环内酯类等抗菌药等）的摄入有关。然而，在我们的diLQTc患者中，QTc持续时间并不能预测症状或心律失常事件的发生。因此，应假设其他决定因素来阐明为什么有时diQTc延长会引发室性恶性心律失常，而在其他情况下则缺乏这种致心律失常作用。
