Evaluation of Tp-e interval and Tp-e/QT ratio in patients with ankylosing spondylitis

Abstract

Objectives. Ankylosing spondylitis (AS) is a chronic multi-systemic inflammatory rheumatic disorder. Several studies have suggested that the interval from the peak to the end of the electrocardiographic T wave (Tp-e) may correspond to the transmural dispersion of repolarization and that increased Tp-e interval and Tp-e/QT ratio are associated with malignant ventricular arrhythmias. The aim of this study was to evaluate ventricular repolarization by using Tp-e interval and Tp-e/QT ratio in patients with AS, and to assess the relation with inflammation.

Methods. Sixty-two patients with AS and 50 controls were included. Tp-e interval and Tp-e/QT ratio were measured from a 12-lead electrocardiogram, and the Tp-e interval corrected for heart rate. The plasma level of high sensitive C-reactive protein (hsCRP) was measured. These parameters were compared between groups.

Results. In electrocardiographic parameters analysis, QT dispersion (QTd) and corrected QTd were significantly increased in AS patients compared to the controls (31.7 ± 9.6 vs 28.2 ± 7.4 and 35.8 ± 11.5 vs 30.6 ± 7.9 ms, P = 0.03 and P = 0.007, respectively). cTp-e interval and Tp-e/QT ratio were also significantly higher in AS patients (92.1 ± 10.2 vs 75.8 ± 8.4 and 0.22 ± 0.02 vs 0.19 ± 0.02 ms, all P values <0.001). cTp-e interval and Tp-e/QT ratio were significantly correlated with hsCRP (r = 0.63, P < 0.001 and r = 0.49, P < 0.001, respectively).

Conclusions. Our study revealed that Tp-e interval and Tp-e/QT ratio were increased in AS patients. These electrocardiographic ventricular repolarization indexes were significantly correlated with the plasma level of hsCRP.     

The effect of moderate altitude on Tp-e interval,Tp-e/QT,QT, cQT and P-wave dispersion

Introduction

Long-time exposure to high altitude leads to changing at the respiratory, cardiovascular and hematological systems. There is no sufficient study about cardiovascular changes in moderate altitude. The distance between the peak and the end of the T wave (Tp-e) is a measure of transmyocardial distribution of repolarization and may be associated to dangerous rhythm disorders and ventricular arrhythmias. Again, P-wave dispersion (PWD) described as the extension of interatrial and intraatrial conduction time and inhomogeneous spread of sinus pulses are well recognized electrophysiologic features in patients with atrial fibrillation. We aimed to compare repolarization parameters (Tp-e interval, Tp-e/QT ratio, QT, cQT) and P wave dispersion between healthy people living at moderate altitude and sea level.

Evaluation of ventricular repolarization features with Tp-e,Tp-e/QTc,JTc and JTd during electroconvulsive therapy

Objective

The purpose of this study was to investigate the influence of electrical stimulation transmitted through the body during electroconvulsive therapy on traditional and relatively new ventricular repolarization parameters (Rate corrected QT interval (QTc), QT dispersion (QTd), rate corrected JT interval (JTc), JT dispersion (JTd), T-peak to T-end interval (Tp-e) and Tp-e/QTc ratio) under propofol anaesthesia.

Assessment of Tp-e interval and Tp-e/QT ratio in patients with human immunodeficiency virus

ObjectiveSudden cardiac death (SCD) plays an important part in all-cause mortality in patients infected with human immunodeficiency virus (HIV). The T-peak to T-end (Tp-e) interval, corrected Tp-e (Tp-ec) interval, and Tp-e/QT ratio on the ECG are parameters used to stratify risk for SCD. The objective of this study was to investigate the differences between HIV-infected patients and healthy individuals in terms of Tp-e interval, Tp-ec interval, and Tp-e/QT ratio, as well as other influencing factors.MethodsNinety-eight HIV-infected patients and 62 healthy controls were included in this prospective case-control study. Tp-e interval, Tp-ec interval, and Tp-e/QT ratio were measured in all participants. Echocardiographic examination and routine laboratory analysis were performed. In addition, CD4 T-cell count and HIV RNA levels were assessed in HIV-infected patients.ResultsAll baseline characteristics were comparable in both groups. The median survival of those living with HIV was 20.63 months; 53% of them had controlled viral load, and 74% were receiving antiretroviral therapy. Mean baseline CD4 T-cell count was 409. In HIV-infected patients, the Tp-e interval and Tp-ec interval were prolonged, and the Tp-e/QT ratio was higher (p<0.001, p<0.001 and p=0.021, respectively). In bivariate and partial correlation analyses, there was a negative correlation between CD4 T-cell level and Tp-e interval, Tp-ec interval, and Tp-e/QT ratio.ConclusionTp-e interval, Tp-ec interval, and Tp-e/QT ratio were greater in HIV-infected patients compared with healthy individuals. HIV-infected patients, particularly those with low baseline CD4 T-cell counts, should be closely monitored due to risk of SCD.     

Neutrophil to lymphocyte and platelet to lymphocyte ratio in patients with dipper versus non-dipper hypertension

Background: Neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) are associated with worse outcome in various diseases. Non-dipping blood pressure pattern is associated with higher cardiovascular mortality. The aim of this study was to explore the association between NLR and PLR in patients with dipper versus non-dipper hypertension.

Methods: The study included 166 patients with hypertension. Eighty-three patients (40 male, mean age: 49.1?±?10.5 years) had dipper hypertension, while 83 patients (41 male, mean age: 52.3?±?12.7 years) had non-dipper hypertension.

Results: Baseline demographic characteristics were similar in both groups. Patients with non-dipper hypertension had significantly higher NLR compared to dipper hypertension (2.3?±?0.9 versus 1.8?±?0.5, p?p?=?0.001). In univariate analysis, hyperlipidemia, smoking, presence of diabetes, PLR more than 107 and NLR more than 1.89 were among predictors of dipper and non-dipper status. In logistic regression analyses, only hyperlipidemia (odds ratio: 2.96, CI: 1.22–7.13) and PLR more than 107 (odds ratio: 2.62, CI: 1.13–6.06) were independent predictors of dipper and non-dipper status. A PLR of 107 or higher predicted non-dipper status with a sensitivity of 66.3% and specificity of 68.7%.

Conclusion: We demonstrated that patients with non-dipper hypertension had significantly higher NLR and PLR compared to dipper hypertension, which has not been reported previously. Moreover PLR more than 107 but not NLR was independent predictor of non-dipper status.     

慢性心力衰竭患者Tp-e/QT比值变化及其临床意义

<正>近年来,国内外研究证实心脏室壁心肌具有电异质性,心室肌跨壁复极离散度产生的一个正常存在的电生理现象,并且发现异常增大的跨壁复极离散度是多种室性心律失常(室性心动过速、心室颤动、心源性猝死)发生的主要基质,也是预测室性心律失常的重要指标[1]。T波峰-末间期(Tp-e)已证实可作为反映心室跨壁复极离散度的量化指标[2]。慢性心力衰竭     

Tp-e间期的研究进展及其在冠心病中的临床应用

Tp-e间期和Tp-e/QT比值是新近提出的可以反映心室跨壁复极离散度(myocardial transmural dispersion of repolarization,TDR)的心电指标,其与恶性室性心律失常发生密切相关.冠心病是导致恶性室性心律失常甚至心源性猝死(sudden cardiac death,SCD)的最常见心脏结构异常,寻找冠心病患者恶性室性心律失常以及SCD的有效预测指标成为近些年临床上的研究重点.     

长QT综合征患者心电图T波峰-末间期及其与QT比值的特征

目的探讨长QT综合征(LQTS)患者T波峰-末(Tp-e)间期及Tp-e/QT与室性心律失常发作的相关性。方法回顾性分析确诊为LQTS的14个家系,对家系成员的临床情况进行综合分析。记录先证者(包括发作期和稳定期)、无症状者及家族中正常者共149例成员的同步12导联心电图,测量计算心电图校正QT(QTc)间期、Tp-e间期以及Tp-e/QT,并进行比较。结果先症者发病年龄19.2岁。在20岁以前发病者占57.1%。患者以女性居多,均以晕厥为主要发病表现。运动及情绪激动诱发12例,休息或睡眠时发生2例。先证者和无症状患者的QTc间期、Tp-e间期及Tp-e/QT显著大于家系其他正常成员(P≤0.05)。先证者发作期的Tp-e间期及Tp-e/QT大于稳定期(P≤0.05)。结论伴有晕厥的长QT综合征患者Tp-e间期延长,Tp-e/QT增大提示增加跨壁复极离散度与恶性室性心律失常发生相关,动态观察LQTS患者心电图改变可能成为预测LQTS恶性心律失常发生危险的临床指标。     

Effects of azithromycin on ventricular repolarization in children with COVID-19

IntroductionAzithromycin is used to treat pediatric COVID-19 patients. It can also prolong the QT interval in adults. This study assessed the effects of azithromycin on ventricular repolarization in children with COVID-19.MethodThe study prospectively enrolled children with COVID-19 who received azithromycin between July and August 2020. An electrocardiogram was performed before, one, three, and five days post-treatment. Using ImageJ®, the following parameters were measured: QT max, QT min, Tp-e max, and Tp-e min. The parameters QTc max, QTc min, Tp-ec max, Tp-ec min, QTcd, Tp-ecd, and the QTc/Tp-ec ratio were calculated using Bazett's formula.ResultsThe study included 105 pediatric patients (mean age 9.8±5.3 years). The pretreatment heart rate was higher than after treatment (before 92 [79–108]/min vs. Day 1 82 [69–108)]/min vs. Day 3 80 [68–92.2]/min vs. Day 5 81 [70–92]/min; p=0.05).ConclusionAzithromycin does not affect the ventricular repolarization parameters on ECG in pediatric COVID-19 cases.     

Dispersion of the QT Interval in Subjects with Frequent Nonsustained Ventricular Arrhythmias and No Underlying Heart Disease: Arrhythmogenic Substrate or Mechanoelectrical Feedback of Arrhythmias?

Background: QT dispersion (QTd) on the ECG is thought to reflect the temporal and spatial inhomogeneity of repolarization in the underlying myocardium. In myocardial infarction, ischemia, and long QT syndromes, an increased QTd is associated with a propensity for malignant ventricular arrhythmias and sudden cardiac death. We investigated this feature of the repolarization process in subjects with frequent ventricular arrhythmias and structurally normal hearts. Methods: Forty‐nine patients referred for frequent, nonsustained ventricular arrhythmias (45 ± 14 years, ×± SD, 61% female) had normal ventricular dimensions and function, no late potentials, and normal ECG. They were compared with 30 controls (42 ± 13 years, 50% female). QTd was measured as the difference between the longest and the shortest QT in the six precordial leads at a paper speed of 50 mm/s. Results: In patients, QTc was similar to that of controls: 395 ± 21 versus 386 ± 20. However, QTd was greater: 49 ± 20 ms versus 32 ± 14 ms, P < 001. Moreover, 18 patients (36%) had QTd exceeding 60 ms—a value superior to the mean normal value of 2 SD—compared to only 1 control (3%) (P < 0.01). Finally, patients with more frequent ventricular arrhythmias had larger QTd. Conclusions: In patients with frequent nonsustained ventricular arrhythmias and otherwise normal hearts, QT interval dispersion is increased. We speculate that, instead of representing a specific electrophysiological substrate of arrhythmias, QT dispersion in this specific population could result from arrhythmias themselves through a possible mechanoelectrical feedback.     

ST段抬高型急性心肌梗死合并J波的临床特征分析

目的分析ST段抬高型急性心肌梗死合并J波的临床特征。方法对近年住院治疗的470例sT段抬高型急性心肌梗死患者进行回顾性研究,观察J波的形态、出现和消失的时间及最明显的部位,同时统计QT离散度、Tp-e、Tp—e／QT、心律失常以及住院期间病死率等。结果根据诊断标准确定92例ST段抬高型急性心肌梗死患者合并J波,发现J波形态多变,J波出现的时间为发病后（3．9±2．6）h,消失的时间为（26．5±17．9）h。与不伴J波的ST段抬高型急性心肌梗死患者相比,合并J波的患者QTd、Tp—e和Tp—e／QT明显增大（P〈0．05）;合并J波的急性心肌梗死患者室性心律失常的发生率明显升高（P〈0．05）,合并J波的急性心肌梗死患者住院病死率明显高于不伴J波的急性心肌梗死患者（P〈0．05）。ST段抬高型急性下壁和／或右心室心肌梗死的J波发生率明显高于前壁心肌梗死（P〈0．05）。结论ST段抬高型急性心肌梗死合并J波多累及下壁或右心室,该类患者的QTd、Tp—e和Tp—e／QT增大,易发生室性心律失常,病死率高。     

Effect of balloon inflation-induced acute ischemia on QT dispersion during percutaneous transluminal coronary angioplasty

Background: QT dispersion (QTd = QT_max - QT_min) measured as interlead variability of QT interval reflects the spatial inhomogeneity of ventricular repolarization times, and increased QTd may provide a substrate for malignant ventricular arrhythmias. Ischemia is associated with regional abnormalities of conduction and repolarization. Hypothesis: This study aimed to investigate the effect of acute ischemia on QTd during successful percutaneous transluminal coronary angioplasty (PTCA). Methods: Forty-three patients (10 women, 33 men, mean age 56 years) were enrolled in the study. Electrocardiogram (ECG) recordings were taken before PTCA and during balloon inflation period. QT maximum (QT_max), QT minimum (QT_min), and QTd (QT_max - QT_min) values were calculated from the surface ECG. Results: There was no difference among QT_max values (p = 0.6). Mean QT_min during balloon inflation was lower than before PTCA (368 ± 45 vs. 380 ± 41 ms, p = 0.002). The difference between QTd values before and during balloon inflation was statistically important (65 ± 9 vs. 76 ± 10 ms, p = 0.001). This difference is caused by a decrease in QT_min during balloon inflation. Conclusion: Acute reversible myocardial ischemia induced by balloon inflation causes an increase in QTd value, and this increment is the result of a decrease in QT_min interval. Therefore, QTd may be a marker of reversible myocardial ischemia.     

Diabetic microvascular complications associated with myocardial repolarization heterogeneity evaluated by Tp-e interval and Tp-e/QTc ratio

IntroductionThe heterogeneity in myocardial repolarization increases the risk of ventricular arrhythmias and sudden death in patients with diabetes mellitus (DM). The Tp-e interval and Tp-e/QTc ratio are found to be useful in the prediction of ventricular arrhythmias. In this study, we aimed to investigate the Tp-e interval and Tp-e/QTc ratio in diabetic patients with and without microvascular complications.Materials and methodsThis cross-sectional observational study included patients with type 2 DM who presented to the endocrinology outpatient clinic. Diabetic microvascular complications were evaluated. The Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio were also calculated.ResultsA total of 240 patients with type 2 DM (148 patients had microvascular complications) were included in the study. Diabetic neuropathy rate was 30.4%, diabetic nephropathy rate was 38.4%, and diabetic retinopathy rate was 21.7%. Upon comparing patients according to Tp-e/QTc ratio, the median Tp-e/QTc interval of the group of patients with complications was 0.21 (0.19–0.23) and the median Tp-e/QTc ratio of the group of patients without complications was 0.19 (0.18–0.20) (p < 0.001). When patients were grouped according to the presence and severity of retinopathy, the Tp-e/QTc ratio was more prolonged in the proliferative retinopathy group [0.27 (0.23–0.30)] than the non-proliferative retinopathy group [0.20 (0.19–0.22), p < 0.001]. When patients were grouped according to the presence and severity of nephropathy, the Tp-e/QTc ratio was more prolonged in the macroalbuminuria and microalbuminuria group than the normoalbuminuric group [0.25 (0.21–0.30), 0.23 (0.19–0.24), and 0.19 (0.20–0.22), respectively, p = 0.002].ConclusionsOur study is the first to demonstrate the association of the Tp-e interval and Tp-e/QTc ratio with the presence and severity of microvascular complications in patients with type 2 DM.     

跨壁复极离散在多形性折返性室性心动过速发生中的作用

目的探讨跨壁复极离散与室性心律失常发生的关系。方法以冠状动脉灌注兔左室楔形组织块为研究对象,对标本施加刺激基础周长分别为500,1000,2000ms的S1刺激,记录内、外膜侧心肌细胞动作电位和跨壁心电图,测量QT间期、时间易损窗及Tp-e/QT值。每10个S1刺激后施加期前S2刺激,S1S2耦联间期以1ms递增,以测量引起单向传导阻滞的时间易损窗。结果时间易损窗与QT间期呈正相关;Tp-e/QT比值在0.10～0.14之间无多形性室性心动过速(PVT)发生,当Tp-e/QT比值大于0.15,可引起PVT发生,而该比值在0.18～0.21时,无论S2刺激施加于内膜侧还是外膜侧,均可引起PVT。结论随着QT间期的延长时间易损窗增大;Tp-e/QT比值越大,室性心律失常越易发生。     

Detection of atrial electrical and mechanical dysfunction in non-dipper pre-hypertensive subjects

Introduction: A relationship between atrial conduction time and hypertension was shown in previous studies. Increased atrial electromechanical intervals used to predict atrial fibrillation by measured tissue Doppler imaging (TDI). So we aimed to search if there was any association between the non-dipping status and atrial electromechanical intervals in pre-hypertensive patients.

Methods: Forty-one non-dipper and 33 dipper pre-hypertensive subjects enrolled in the study. Systolic and diastolic blood pressures were measured with a mercury sphygmomanometer. Twenty-four hours blood pressure was measured with cuff-oscillometric method. All patients were evaluated by transthoracic echocardiography. Using tissue Doppler imaging (TDI), atrial electromechanical coupling (PA) was measured from the lateral mitral annulus (PA lateral), septal mitral annulus (PA septum) and right ventricular tricuspid annulus (PA tricuspid).

Results: Systolic and diastolic blood pressures were significantly higher in subjects with non-dipper phenomenon than dipper ones at night. Twenty-four hours average systolic and diastolic blood pressures were higher in non-dipper pre-hypertensive subjects, but this elevation was not significant. Left and right intraatrial (PA lateral-PA septum and PA septum-PA tricuspid) and interatrial (PA lateral-PA tricuspid) electromechanical coupling intervals were measured significantly higher in non-dipper pre-hypertensive patients (31.3?±?3.9 versus 24.1?±?2.3, p?=?0.001; 19.5?±?4.3 versus 13.8?±?2.1, p?=?0.001; and 11.4?±?2.8 versus 8.8?±?1.5, p?=?0.001). Also, interatrial electromechanical delay was negatively correlated with dipping levels.

Conclusion: This study showed that prolonged atrial electromechanical intervals were related non-dipper pattern in pre-hypertensive patients. Prolonged electromechanical intervals may be an early sign of subclinical atrial dysfunction and arrhythmias’ in non-dipper pre-hypertensive patients.     

Immediate and short term effects of percutaneous atrial septal defect device closure on cardiac electrical remodeling in children

Background

The beneficial effects of atrial septal defect (ASD) device closure on electrical cardiac remodeling are well established. The timing at which these effects starts to take place has yet to be determined.

尖端扭转型室性心动过速与TP—TE时间及Q—T间期比值关系的研究

目的探讨长Q—T间期患者T波峰末时间（TP-TE时间）、TP-TE／Q—T与尖端扭转型室性心动过速（TdP）发生的相关性。方法选择长Q—T间期患者29例,将其分为伴TdP组（发作期或稳定期）和不伴TdP组两组,通过常规心电图和动态心电图分析测量并比较Q—T间期、校正的Q—T间期（Q—Tc间期）、TP-TE时间和TP-TE／Q—Tc结果伴TdP组稳定期患者TP-TE时间、TP—TE／Q—T（14157±37．33ms、0．27±0．05）和发作期（154．29±42ms、0．29±0．06）均较不伴TdP组（97．60±5．51ms、0．19±0．13）延长或增大。差异均有统计学意义（均P〈0．05）;在预测TdP发生风险时,伴TdP组稳定期和发作期TP-TE时间、TP-TE／Q—T均较Q—T间期更敏感（Wald值分别为1247、15．77和5．77、6．23）,差异均有统计学意义（P〈O．05）。结论TP-TE时间TP-TE／Q—T比值有助于预测长Q—T间期患者发生TdP的风险。     

Impact of cardiac rehabilitation on ventricular repolarization indexes in patients with rheumatid arthritis

Objective

Abnormalities in ventricular repolarization (VR) parameters have been associated with sudden cardiac death (SCD) in patients with rheumatoid arthritis (RA). The benefits of cardiac rehabilitation (CR) in patients with RA are well recognized. We aimed to assess its impact on VR indexes in patients with RA.

心肌梗死患者经皮冠状动脉介入治疗术后ST段回落与Tp-ec间期变化相关性与预测价值

目的 急性ST段抬高的心肌梗死(STEMI)患者动作电位2相折返引起ST段抬高和复极离散度变化,通过对STEMI患者经皮冠状动脉介入治疗(PCI)前后抬高的ST段回落(STR)、Tp-ec(校正的T波顶点到T波终点的时间)和Tp-e/QT的测算,分析其相关性,并评价这些指标对恶性心律失常事件(MAE)的预后价值.方法 ...     

First Evaluation of P Dispersion and Tp-e Parameters in Electrocardiograms of Children with Diabetic Ketoacidosis

Objective:Diabetic ketoacidosis (DKA) is an important complication of type 1 diabetes mellitus. We aimed to evaluate the effect of metabolic disorders of DKA on electrocardiography (ECG) parameters in children.Methods:This study was performed between December 2018 and March 2020 and included 39 children with DKA and 40 healthy children. Three ECGs (one before and two after treatment) were obtained from the patient group. P-wave dispersion (Pd), QT dispersion (QTd), QTc dispersion (QTcd), Tp-e intervals, and the ratios of Tp-e/QT and Tp-e/QTc were measured electrocardiographically. ECG parameters from children with DKA and healthy controls were compared statistically.Results:The mean age of the patient group was 10.50±4.12 years. There was no significant difference in terms of age, gender, weight, height and body mass index between patients and controls. In the patient group, a statistically significant increase was found in Pd, QTd and QTcd in the initial ECG compared to the second and third ECGs. Also, when the first and third ECGs were compared, a significant increase in Tp-e and Tp-e/QT was evident in the first ECG. There was a significant difference in the values of Pd, QTd, QTcd, Tp-e and Tp-e/QT in the first ECGs, obtained before DKA treatment, and those values obtained from the control group.Conclusion:This is the first article evaluating Pd and Tp-e parameters in children with DKA. Cardiac arrhythmia risk markers were increased in children with DKA compared to controls. Therefore, clinicians should be aware of the possibility of developing new arrhythmias during DKA treatment.