Malignant Ventricular Arrhythmias Resulting From Drug-Induced QTc Prolongation: A Retrospective Study

Abstract

BackgroundSeveral 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.MethodsThe 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).ResultsA 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.ConclusionsIn 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.

Cardiovascular side effects of neuropsychiatric medication: an update

“…QT interval on the ECG means the depolarization and repolarization of the ventricles and it is measured from the beginning of the QRS complex to the end of the T wave. For the QT correction there have been developed many formulae, but Bazett formula (QTc = QT/RR1/2) is the most frequently used in clinical practice 12 . American Guidelines recommend to use Hodges formula (QTc = QT + 1.75 (HR-60)) and in cases of bundle branch block and paced rhythms, JT interval (JT = QT duration-QRS duration).…”

Elective lung resection increases spatial QRS-T angle and QTc interval

“…Pathologically prolonged QTc has been noted in patients with electrolyte disturbances such as hypokalemia, hypomagnesemia and/or hypocalcemia, myocardial ischemia, heart failure and severe bradycardia [19,20,31]. Many medications can also result in asymptomatic or symptomatic QTc interval prolongation, their administration sometimes being associated with an increased risk for cardiac arrhythmias [22].…”

“…It should be noted that volatile anaesthetics and some opioids, including fentanyl, significantly prolong QTc. However, there is controversy as to whether propofol has an effect [22,[40][41][42]. Chang et al [41] documented a prolongation of QTc following propofol anesthesia.…”

“…Its prolongation has been observed in patients with electrolyte disorders and coronary diseases who are treated with antiarrhythmics or subjected to general anaesthesia with a volatile anesthetic [19][20][21]. A prolonged QTc interval has been well recognized as a parameter indicating an increased risk of malignant ventricular arrhythmias [22,23]. Although a prolonged QTc has been noted in patients undergoing surgery with pneumoperitoneum [24,25] and cardiac surgery [26], changes in QTc have not been recognised in patients undergoing lobectomy or pneumonectomy.…”

Avaliação dos Efeitos Cardíacos de Lectina Solúvel em Água (WSMoL) de Sementes de Moringa Oleifera

“…15,16 Entre os eventos adversos no sistema cardiovascular, estão a ocorrência de insuficiência cardíaca com disfunção ventricular sistólica, arritmias e isquemia miocárdica. 17 Classicamente, como uma consequência de cardiotoxicidade, podem ser observadas alterações no eletrocardiograma (ECG), tais como o prolongamento do intervalo QT, o qual tem sido observado em pacientes que usaram várias classes de drogas antimicrobianas, incluindo macrólidos e fluoroquinolonas. [18][19][20] Entre os macrólidos, a administração intravenosa de eritromicina apresenta o risco maior de aumento do intervalo QT, e arritmias fatais têm sido relatadas quando foi usada isoladamente ou em combinação com outras drogas que prolongam o intervalo QT.…”