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
目的观察氨磺必利与齐拉西酮治疗精神分裂症的临床疗效及对心电图QTC间期的影响。方法选取2020年5月至2022年8月吉安市第三人民医院收治的76例精神分裂症患者作为研究对象,采用随机数字表法分为常规组与研究组,各38例。常规组服用盐酸...目的观察氨磺必利与齐拉西酮治疗精神分裂症的临床疗效及对心电图QTC间期的影响。方法选取2020年5月至2022年8月吉安市第三人民医院收治的76例精神分裂症患者作为研究对象,采用随机数字表法分为常规组与研究组,各38例。常规组服用盐酸齐拉西酮胶囊,研究组服用氨磺必利。比较两组临床疗效、阳性和阴性症状量表(positive and negative syndrome scale,PANSS)评分、记忆功能[韦氏记忆量表中国修订版(Wechsler memory scale-revised Chinese version,WMS-RC)评分]、认知功能[简易智能精神状态检查量表(mini-mental state examination,MMSE)评分]、QTC间期及不良反应发生情况。结果两组治疗总有效率比较差异无统计学意义。用药后,两组一般精神病理、阳性症状、阴性症状评分及总分均低于用药前,差异有统计学意义(P<0.05),但组间比较差异无统计学意义。用药后,两组WMS-RC、MMSE评分均高于用药前,差异有统计学意义(P<0.05),但组间比较差异无统计学意义。用药后2、4、8周,研究组QTC间期均短于常规组,差异有统计学意义(P<0.05)。两组不良反应发生率比较差异无统计学意义。结论氨磺必利、齐拉西酮治疗精神分裂症临床疗效及安全性相当,均可减轻患者阳性及阴性症状,改善患者记忆功能与认知功能,但氨磺必利对心电图QTC间期的影响更小,值得临床推广应用。展开更多
Objective： To evaluate the changes in Tp-e interval （an interval from the peak to the end of the T wave）, QT interval and Tp-e/QT ratio of the body surface ECG in patients with left ventricular hypertrophy （LVH）....Objective： To evaluate the changes in Tp-e interval （an interval from the peak to the end of the T wave）, QT interval and Tp-e/QT ratio of the body surface ECG in patients with left ventricular hypertrophy （LVH）. Methods： The Tp-e interval and QT interval were measured on body surface ECGs in 42 patients without either hypertension or LVH （control group）, 41 patients having hypertension but not LVH （non-LVH group）, and 38 patients with both hypertension and LVH （LVH group）. Results： The mean corrected QT （QTc） interval, and mean corrected Tp-e[T（p-e）c] interval were significantly longer in the LVH group （0.430±0.021s vs. 0.409±0.019s, p 〈 0.01; 0.098±0.013s vs. 0.088±0.011s, respectively） than those in the control group. The Tp-e/QT ratio was also amplified in LVH group （0.232± 0.028 vs.0.218± 0.027） （p 〈 0.05）. Conclusion： LVH increased the QT interval, Tp-e interval and Tp-e/QT ratio of the body surface ECG.展开更多
Background PD(PD)is associated with a twofold increase in the risk of death especially sudden death.A predisposing factor for cardiac sudden death is prolongation of the QT interval.This study evaluated the potential ...Background PD(PD)is associated with a twofold increase in the risk of death especially sudden death.A predisposing factor for cardiac sudden death is prolongation of the QT interval.This study evaluated the potential association between QT interval and PD.Methods A systematic search was conducted of Medline and EMBASE using the search terms“PD”AND“QT interval”OR“Cardiac Repolarization”to identify articles.Results Seven studies with persons with PD(n=981)and control groups were identified.There was a significant difference in QT interval comparing patients with PD and persons without PD.The odds ratio showed a significant(P<0.001)2.6-fold(random effect)greater QTc prolongation in PD compared to control.Overall,there was a significantly longer QT in patients with PD than controls of 10.7±2.8 ms.Data analysis did not show much publication bias.Focusing only on studies that related the QT interval to the severity of PD as assessed by Hoehn–Yahr classification(n=6),there was a significant(P=0.004)overall correlation between QT interval and the severity of PD.There was little publication bias.The data directly examining patients with PD taking any drug than might prolong QT do not support an association between these mediations and QT prolongation.Conclusion Individuals with PD have a longer QT interval than individuals without PD.The QT interval is associated with a greater severity of PD and a greater probability of developing more severe PD.The QT interval should be considered in assessment of PD and possibly as a target for the treatment of PD.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: Cirrhotic Cardiomyopathy is a relatively ill-characterized condition, which is often under-diagnosed due to absence of defined diagnostic criteria. ECG showing corrected QT Interval prolongation is the mos...BACKGROUND: Cirrhotic Cardiomyopathy is a relatively ill-characterized condition, which is often under-diagnosed due to absence of defined diagnostic criteria. ECG showing corrected QT Interval prolongation is the most suitable available option for diagnosis of this condition. OBJECTIVE: To determine the frequency of corrected QT interval prolongation in patients with liver cirrhosis. METHODOLOGY: Patients (n = 166) with confirmed cirrhosis, 30 years or older, presented in the outpatient and emergency department of medicine at Capital Hospital Islamabad between 1 October 2011 and 30 September 2012, were enrolled in this cross-sectional study after taking consent. ECG was done using calibrated ECG machine, and the QT Interval was measured. Corrected QT was calculated using Bazett’s formula and a QTc of more than 0.44 seconds was considered as being prolonged. RESULTS: The mean age of the patients was 57.05 ± 12.03 years. The corrected QT Interval varied from 337 ms to 560 ms. The mean QTc Interval was 429.92 ms ± 45.11. QTc was prolonged in 41 out of 166 patients (24.7%). Frequency of QTc prolongation was 4.5% in Child Pugh Grade A, 23.2% in Child Pugh Grade B, and 32.0% in Child Pugh Grade C. Association of Child Pugh Scoring with QTc prolongation was determined and found to be statistically significant (P < 0.05). CONCLUSION: QTc interval was prolonged in 24.7% of cirrhotic patients in our study. There was a significant increase in frequency with worsening of Child Pugh Grade, thereby indicating an association between QTc prolongation and the severity of cirrhosis.展开更多
Background Haloperidol is the most frequently prescribed antipsycbotic for delirium symptoms. The risk of QTc prolongation often raises concerns, although the effect of haloperidol on QTc interval has not yet been inv...Background Haloperidol is the most frequently prescribed antipsycbotic for delirium symptoms. The risk of QTc prolongation often raises concerns, although the effect of haloperidol on QTc interval has not yet been investigated in a randomised placebo-controlled fixed-dose study. Methods A subanalysis of a randomised double-blind placebo-controlled study was conducted to evaluate the effect of prophylactic haloperidol 1 mg or placebo 1 mg orally twice-daily （maximum of 14 doses） on QTc interval in patients aged 70 years and over. Bedside, 12-lead ECGs were recorded before, during and after the one-week intervention period. Automatic QTc measurements were ob- tained in addition to manual measurements of QT and RR intervals, blinded for treatment status. Manual measurements were corrected （QTc） using Bazett （QTc-B）, Framingham （QTc-Fa）, Fridericia （QTc-Fi） and Hodges （QTc-H） methods. Mixed model analyses were used to test for differences in longitudinal course of QTc between patients receiving haloperidol and placebo. Results ECG recordings of 72 patients （haloperidol n = 38） were analysed, 45.8% male. Median （range） haloperidol serum concentration on day 4 was 0.71 （0.32-1.82） μg/L （n = 23）. Longitudinal course of mean QTc did not significantly differ between treatment arms for any of the automatic or manually derived QTc values. Conclusions Low dose oral haloperidol did not result in QTc prolongation in older acutely hospitalised patients. Results may not be generalizable to patients with existing ECG abnormalities such as atrial fibrillation.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.
文摘目的观察氨磺必利与齐拉西酮治疗精神分裂症的临床疗效及对心电图QTC间期的影响。方法选取2020年5月至2022年8月吉安市第三人民医院收治的76例精神分裂症患者作为研究对象,采用随机数字表法分为常规组与研究组,各38例。常规组服用盐酸齐拉西酮胶囊,研究组服用氨磺必利。比较两组临床疗效、阳性和阴性症状量表(positive and negative syndrome scale,PANSS)评分、记忆功能[韦氏记忆量表中国修订版(Wechsler memory scale-revised Chinese version,WMS-RC)评分]、认知功能[简易智能精神状态检查量表(mini-mental state examination,MMSE)评分]、QTC间期及不良反应发生情况。结果两组治疗总有效率比较差异无统计学意义。用药后,两组一般精神病理、阳性症状、阴性症状评分及总分均低于用药前,差异有统计学意义(P<0.05),但组间比较差异无统计学意义。用药后,两组WMS-RC、MMSE评分均高于用药前,差异有统计学意义(P<0.05),但组间比较差异无统计学意义。用药后2、4、8周,研究组QTC间期均短于常规组,差异有统计学意义(P<0.05)。两组不良反应发生率比较差异无统计学意义。结论氨磺必利、齐拉西酮治疗精神分裂症临床疗效及安全性相当,均可减轻患者阳性及阴性症状,改善患者记忆功能与认知功能,但氨磺必利对心电图QTC间期的影响更小,值得临床推广应用。
文摘Objective： To evaluate the changes in Tp-e interval （an interval from the peak to the end of the T wave）, QT interval and Tp-e/QT ratio of the body surface ECG in patients with left ventricular hypertrophy （LVH）. Methods： The Tp-e interval and QT interval were measured on body surface ECGs in 42 patients without either hypertension or LVH （control group）, 41 patients having hypertension but not LVH （non-LVH group）, and 38 patients with both hypertension and LVH （LVH group）. Results： The mean corrected QT （QTc） interval, and mean corrected Tp-e[T（p-e）c] interval were significantly longer in the LVH group （0.430±0.021s vs. 0.409±0.019s, p 〈 0.01; 0.098±0.013s vs. 0.088±0.011s, respectively） than those in the control group. The Tp-e/QT ratio was also amplified in LVH group （0.232± 0.028 vs.0.218± 0.027） （p 〈 0.05）. Conclusion： LVH increased the QT interval, Tp-e interval and Tp-e/QT ratio of the body surface ECG.
文摘Background PD(PD)is associated with a twofold increase in the risk of death especially sudden death.A predisposing factor for cardiac sudden death is prolongation of the QT interval.This study evaluated the potential association between QT interval and PD.Methods A systematic search was conducted of Medline and EMBASE using the search terms“PD”AND“QT interval”OR“Cardiac Repolarization”to identify articles.Results Seven studies with persons with PD(n=981)and control groups were identified.There was a significant difference in QT interval comparing patients with PD and persons without PD.The odds ratio showed a significant(P<0.001)2.6-fold(random effect)greater QTc prolongation in PD compared to control.Overall,there was a significantly longer QT in patients with PD than controls of 10.7±2.8 ms.Data analysis did not show much publication bias.Focusing only on studies that related the QT interval to the severity of PD as assessed by Hoehn–Yahr classification(n=6),there was a significant(P=0.004)overall correlation between QT interval and the severity of PD.There was little publication bias.The data directly examining patients with PD taking any drug than might prolong QT do not support an association between these mediations and QT prolongation.Conclusion Individuals with PD have a longer QT interval than individuals without PD.The QT interval is associated with a greater severity of PD and a greater probability of developing more severe PD.The QT interval should be considered in assessment of PD and possibly as a target for the treatment of PD.
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: Cirrhotic Cardiomyopathy is a relatively ill-characterized condition, which is often under-diagnosed due to absence of defined diagnostic criteria. ECG showing corrected QT Interval prolongation is the most suitable available option for diagnosis of this condition. OBJECTIVE: To determine the frequency of corrected QT interval prolongation in patients with liver cirrhosis. METHODOLOGY: Patients (n = 166) with confirmed cirrhosis, 30 years or older, presented in the outpatient and emergency department of medicine at Capital Hospital Islamabad between 1 October 2011 and 30 September 2012, were enrolled in this cross-sectional study after taking consent. ECG was done using calibrated ECG machine, and the QT Interval was measured. Corrected QT was calculated using Bazett’s formula and a QTc of more than 0.44 seconds was considered as being prolonged. RESULTS: The mean age of the patients was 57.05 ± 12.03 years. The corrected QT Interval varied from 337 ms to 560 ms. The mean QTc Interval was 429.92 ms ± 45.11. QTc was prolonged in 41 out of 166 patients (24.7%). Frequency of QTc prolongation was 4.5% in Child Pugh Grade A, 23.2% in Child Pugh Grade B, and 32.0% in Child Pugh Grade C. Association of Child Pugh Scoring with QTc prolongation was determined and found to be statistically significant (P < 0.05). CONCLUSION: QTc interval was prolonged in 24.7% of cirrhotic patients in our study. There was a significant increase in frequency with worsening of Child Pugh Grade, thereby indicating an association between QTc prolongation and the severity of cirrhosis.
文摘Background Haloperidol is the most frequently prescribed antipsycbotic for delirium symptoms. The risk of QTc prolongation often raises concerns, although the effect of haloperidol on QTc interval has not yet been investigated in a randomised placebo-controlled fixed-dose study. Methods A subanalysis of a randomised double-blind placebo-controlled study was conducted to evaluate the effect of prophylactic haloperidol 1 mg or placebo 1 mg orally twice-daily （maximum of 14 doses） on QTc interval in patients aged 70 years and over. Bedside, 12-lead ECGs were recorded before, during and after the one-week intervention period. Automatic QTc measurements were ob- tained in addition to manual measurements of QT and RR intervals, blinded for treatment status. Manual measurements were corrected （QTc） using Bazett （QTc-B）, Framingham （QTc-Fa）, Fridericia （QTc-Fi） and Hodges （QTc-H） methods. Mixed model analyses were used to test for differences in longitudinal course of QTc between patients receiving haloperidol and placebo. Results ECG recordings of 72 patients （haloperidol n = 38） were analysed, 45.8% male. Median （range） haloperidol serum concentration on day 4 was 0.71 （0.32-1.82） μg/L （n = 23）. Longitudinal course of mean QTc did not significantly differ between treatment arms for any of the automatic or manually derived QTc values. Conclusions Low dose oral haloperidol did not result in QTc prolongation in older acutely hospitalised patients. Results may not be generalizable to patients with existing ECG abnormalities such as atrial fibrillation.
