Background: The QT interval shortens in response to sympathetic stimulation. Head-up tilt-table (HUT) testing is a straightforward way to achieve brisk sympathetic stimulation. There is not enough information about th...Background: The QT interval shortens in response to sympathetic stimulation. Head-up tilt-table (HUT) testing is a straightforward way to achieve brisk sympathetic stimulation. There is not enough information about the response of the QT interval to HUT, particularly, in patients with orthostatic hypotension (OH). Objective: Analyse the response of the RR, QT and QTc intervals in patients with OH and reflex syncope (NM) during HUT and find differences between groups. Methods: We reviewed the electrocardiograms and compare the RR and QT/QTc intervals during 1) baseline;2) HUT plus hyperventilation;3) positive test. Results: We studied 137 patients, 62 control group (no syncope and negative HUT). On average, the RR HUT interval was shorter than the resting RR by −171 ± 110.4 ms in controls;−228.6 ± 119.4 ms (NM) and −194 ± (OH) (P Conclusion: Significant differences between the reflex group and the OH during a positive test, the QTc decreased in the NM group, but in the OH population increased. This observation has not been described. We hypothesize that QTc prolongation could reflect autonomic nervous system downregulation and could explain to a degree, the increased mortality in this group.展开更多
许多广泛使用的药物都可能导致QT间期/QTc延长,继而引起尖端扭转型室性心动过速(torsade de pointes,TdP)等心律失常,后者可能会进一步恶化为心室颤动,甚至造成心脏性猝死。因此,为了预防和降低药源性QT间期延长和TdP的风险,对危险因素...许多广泛使用的药物都可能导致QT间期/QTc延长,继而引起尖端扭转型室性心动过速(torsade de pointes,TdP)等心律失常,后者可能会进一步恶化为心室颤动,甚至造成心脏性猝死。因此,为了预防和降低药源性QT间期延长和TdP的风险,对危险因素的发现、预警和纠正至关重要。近年来,临床已开始应用决策支持系统等预警策略,通过识别多种风险因素预测QT间期/QTc延长和警示TdP高风险人群。本文总结了可引起长QT间期和TdP风险的药物及相关危险因素,并归纳现有的预警措施,期望为暴露于相关风险的患者管理提供参考。展开更多
BACKGROUND QTc interval prolongation with an increased risk of torsade de pointes(Tsd)has been described in coronavirus disease 2019(COVID-19)patients treated with hydroxychloroquine(HCQ)and azithromycin(AZI)in Wester...BACKGROUND QTc interval prolongation with an increased risk of torsade de pointes(Tsd)has been described in coronavirus disease 2019(COVID-19)patients treated with hydroxychloroquine(HCQ)and azithromycin(AZI)in Western countries.In the DR Congo,few studies have evaluated the safety of this association or proposed new molecules.AIM To determine the incidence of QTc prolongation and Tsd in COVID-19 patients treated with HCQ-AZIs vs doubase C(new molecule).METHODS In present randomized clinical trial,we have included patients with mild or moderate COVID-19 treated with either HCQ-AZI or doubase C.Electrocardiogram(ECG)changes on day 14 of randomization were determined based on pretreatment tracing.Prolonged QTc was defined as≥500 ms on day 14 or an increase of≥80 ms compared to pretreatment tracing.Patients with cardiac disease,those undergoing other treatments likely to prolong QTc,and those with disturbed ECG tracings were excluded from the study.RESULTS The study included 258 patients(mean age 41±15 years;52%men;3.4%diabetics,11.1%hypertensive).Mild and moderate COVID-19 were found in 93.5%and 6.5%of patients,respectively.At baseline,all patients had normal sinus rhythm,a mean heart rate 78±13/min,mean PR space 170±28 ms,mean QRS 76±13 ms,and mean QTc 405±30 ms.No complaints suggesting cardiac involvement were reported during or after treatment.Only four patients(1.5%)experienced QTc interval prolongation beyond 500 ms.Similarly,only five patients(1.9%)had an increase in the QTc interval of more than 80 ms.QTc prolongation was more significant in younger patients,those with high viral load at baseline,and those receiving HCQ-AZI(P<0.05).None of the patients developed Tsd.CONCLUSION QTc prolongation without Tsd was observed at a lower frequency in patients treated with HCQ-AZI vs doubase C.The absence of comorbidities and concurrent use of other products that are likely to cause arrhythmia may explain our results.展开更多
文摘Background: The QT interval shortens in response to sympathetic stimulation. Head-up tilt-table (HUT) testing is a straightforward way to achieve brisk sympathetic stimulation. There is not enough information about the response of the QT interval to HUT, particularly, in patients with orthostatic hypotension (OH). Objective: Analyse the response of the RR, QT and QTc intervals in patients with OH and reflex syncope (NM) during HUT and find differences between groups. Methods: We reviewed the electrocardiograms and compare the RR and QT/QTc intervals during 1) baseline;2) HUT plus hyperventilation;3) positive test. Results: We studied 137 patients, 62 control group (no syncope and negative HUT). On average, the RR HUT interval was shorter than the resting RR by −171 ± 110.4 ms in controls;−228.6 ± 119.4 ms (NM) and −194 ± (OH) (P Conclusion: Significant differences between the reflex group and the OH during a positive test, the QTc decreased in the NM group, but in the OH population increased. This observation has not been described. We hypothesize that QTc prolongation could reflect autonomic nervous system downregulation and could explain to a degree, the increased mortality in this group.
文摘许多广泛使用的药物都可能导致QT间期/QTc延长,继而引起尖端扭转型室性心动过速(torsade de pointes,TdP)等心律失常,后者可能会进一步恶化为心室颤动,甚至造成心脏性猝死。因此,为了预防和降低药源性QT间期延长和TdP的风险,对危险因素的发现、预警和纠正至关重要。近年来,临床已开始应用决策支持系统等预警策略,通过识别多种风险因素预测QT间期/QTc延长和警示TdP高风险人群。本文总结了可引起长QT间期和TdP风险的药物及相关危险因素,并归纳现有的预警措施,期望为暴露于相关风险的患者管理提供参考。
文摘BACKGROUND QTc interval prolongation with an increased risk of torsade de pointes(Tsd)has been described in coronavirus disease 2019(COVID-19)patients treated with hydroxychloroquine(HCQ)and azithromycin(AZI)in Western countries.In the DR Congo,few studies have evaluated the safety of this association or proposed new molecules.AIM To determine the incidence of QTc prolongation and Tsd in COVID-19 patients treated with HCQ-AZIs vs doubase C(new molecule).METHODS In present randomized clinical trial,we have included patients with mild or moderate COVID-19 treated with either HCQ-AZI or doubase C.Electrocardiogram(ECG)changes on day 14 of randomization were determined based on pretreatment tracing.Prolonged QTc was defined as≥500 ms on day 14 or an increase of≥80 ms compared to pretreatment tracing.Patients with cardiac disease,those undergoing other treatments likely to prolong QTc,and those with disturbed ECG tracings were excluded from the study.RESULTS The study included 258 patients(mean age 41±15 years;52%men;3.4%diabetics,11.1%hypertensive).Mild and moderate COVID-19 were found in 93.5%and 6.5%of patients,respectively.At baseline,all patients had normal sinus rhythm,a mean heart rate 78±13/min,mean PR space 170±28 ms,mean QRS 76±13 ms,and mean QTc 405±30 ms.No complaints suggesting cardiac involvement were reported during or after treatment.Only four patients(1.5%)experienced QTc interval prolongation beyond 500 ms.Similarly,only five patients(1.9%)had an increase in the QTc interval of more than 80 ms.QTc prolongation was more significant in younger patients,those with high viral load at baseline,and those receiving HCQ-AZI(P<0.05).None of the patients developed Tsd.CONCLUSION QTc prolongation without Tsd was observed at a lower frequency in patients treated with HCQ-AZI vs doubase C.The absence of comorbidities and concurrent use of other products that are likely to cause arrhythmia may explain our results.
