Effect of reperfusion strategy on QT dispersion in patients with acute myocardial infarction:Impact on in-hospital arrhythmia

BACKGROUND Myocardial ischemia and ST-elevation myocardial infarction(STEMI)increase QT dispersion(QTD)and corrected QT dispersion(QTcD),and are also associated with ventricular arrhythmia.AIM To evaluate the effects of reperfusion strategy[primary percutaneous coronary intervention(PPCI)or fibrinolytic therapy]on QTD and QTcD in STEMI patients and assess the impact of the chosen strategy on the occurrence of in-hospital arrhythmia.METHODS This prospective,observational,multicenter study included 240 patients admitted with STEMI who were treated with either PPCI(group I)or fibrinolytic therapy(group II).QTD and QTcD were measured on admission and 24 hr after reperfusion,and patients were observed to detect in-hospital arrhythmia.RESULTS There were significant reductions in QTD and QTcD from admission to 24 hr in both group I and group II patients.QTD and QTcD were found to be shorter in group I patients at 24 hr than those in group II(53±19 msec vs 60±18 msec,P=0.005 and 60±21 msec vs 69+22 msec,P=0.003,respectively).The occurrence of in-hospital arrhythmia was significantly more frequent in group II than in group I(25 patients,20.8%vs 8 patients,6.7%,P=0.001).Furthermore,QTD and QTcD were higher in patients with in-hospital arrhythmia than those without(P=0.001 and P=0.02,respectively).CONCLUSION In STEMI patients,PPCI and fibrinolytic therapy effectively reduced QTD and QTcD,with a higher observed reduction using PPCI.PPCI was associated with a lower incidence of in-hospital arrhythmia than fibrinolytic therapy.In addition,QTD and QTcD were shorter in patients not experiencing in-hospital arrhythmia than those with arrhythmia.

Subclinical impairment of left ventricular myocardium function in type 2 diabetes mellitus patients with or without hypertension

BACKGROUND Cardiovascular disease has been the leading cause of morbidity and mortality for type 2 diabetes mellitus(T2DM)patients over the last decade.AIM To determine whether layer-specific global longitudinal strain(GLS)combined with peak strain dispersion(PSD)can be used to assess left ventricle(LV)myocardium systolic dysfunction in T2DM patients or without hypertension(HP).METHODS We enrolled 97 T2DM patients,70 T2DM+HP patients and 101 healthy subjects.Layer-specific GLS and PSD were calculated by EchoPAC software in apical three-,four-and two-chamber views.GLS of the epimyocardial,middle-layer and endomyocardial(GLSepi,GLSmid,and GLSendo)were measured and recorded.Receiver operating characteristic analysis was performed to detect LV myocardium systolic dysfunction in T2DM patients.RESULTS There were significant differences in GLSepi,GLSmid,GLSendo,and PSD between healthy subjects,T2DM patients and T2DM patients with HP(P<0.001).Trend tests yielded the ranking of healthy subjects>T2DM patients>T2DM with HP patients in the absolute values of GLSepi,GLSmid and GLSendo(P<0.001),while PSD was ranked healthy subjects<T2DM<T2DM with HP(P<0.001).Layer-specific GLS and PSD had high diagnostic efficiency for detecting LV myocardium systolic dysfunction in T2DM patients,however,the area under the curve(AUC)for layer-specific GLS and PSD combined was significantly higher than the AUCs for the individual indices(P<0.05).CONCLUSION Layer-specific GLS and PSD were associated with LV myocardium systolic dysfunction in T2DM patients,T2DM patients with HP.T2DM patients with HP have more severe LV myocardium systolic dysfunction than T2DM patients without HP and normal control patients.The combination of layer-specific GLS and PSD may provide additional prognostic information for T2DM patients with or without HP.

Effect of transcatheter aortic valve implantation on QT dispersion in patients with aortic stenosis

Background QT dispersion （QTd） is a predictor of ventricular arrhythmia. Ventricular arrhythmia is an important factor influencing morbidity and mortality in patients with aortic stenosis. Surgical aortic valve replacement reduced the QTd in this patients group. However, the effect of transcatheter aortic valve implantation （TAVI） on QTd in patients with aortic stenosis is unknown. The aim of this study was to investigate the effect of TAVI on QTd in patients with aortic stenosis. Methods Patients with severe aortic stenosis, who were not candi-dates for surgical aortic valve replacement due to contraindications or high surgical risk, were included in the study. All patients underwent electrocardiographic and echocardiographic evaluation before, and at the 6th month after TAVI, computed QTd and left ventricular mass index （LVMI）. Results A total 30 patients were admitted to the study （mean age 83.2 ± 1.0 years, female 21 and male 9, mean valve area 0.7 ± 3 mm2）. Edwards SAPIEN heart valves, 23 mm （21 patients） and 26 mm （9 patients）, by the transfemoral approach were used in the TAVI procedures. All TAVI procedures were successful. Both QTd and LVMI at the 6th month after TAVI were significantly reduced com-pared with baseline values of QTd and LVMI before TAVI （73.8 ± 4 ms vs. 68 ± 2 ms, P=0.001 and 198 ± 51 g/m2 vs. 184 ± 40 g/m2, P=0.04, respectively）. There was a significant correlation between QTd and LVMI （r=0.646, P〈0.001）. Conclusions QTd, which malign ventricular arrhythmia marker, and LVMI were significantly reduced after TAVI procedure. TAVI may decrease the possibility of ventricu-lar arrhythmia in patients with aortic stenosis.

Defective recovery of QT dispersion following transcatheter aortic valve implantation： frequency, predictors and prognosis

Background Corrected QT dispersion （cQTD） has been correlated with non-uniform ventricular repolarisation and increased mortality. In patients with aortic stenosis, cQTD has been shown improved after surgical valve replacement, but the effects of transcatheter aortic valve implantation （TAVI） are unknown. Therefore, we sought to explore the frequency, predictors and prognostic effects of defective cQTD recovery at 6 months after TAVI. Methods A total of 222 patients underwent TAVI with the Medtronic-CoreValve System between November 2005 and January 2012. Patients who were on class Ⅰ or Ⅲ antiarrhythmics or on chronic haemodialysis or who developed atrial fibrillation, a new bundle branch block or became pacemaker dependent after TAVI were excluded. As a result, pre-, post- and follow-up ECG （median： 6 months） analysis was available in 45 eligible patients. Defective cQTD recovery was defined as any progression beyond the baseline cQTD at 6 months. Results In the 45 patients, the mean cQTD was 47 ± 23 ms at baseline, 45 ±17 ms immediately after TAVI and 40 ± 16 ms at 6 months （15% reduction, P = 0.049）. Compared to baseline, cQTD at 6 months was improved in 60% of the patients whereas defective cQTD recovery was present in 40%. cQTD increase immediately after TAVI was an independent predictor of defective cQTD recovery at 6 months （per 10 ms increase; OR： 1.89, 95% CI： 1.15-3.12）. By univariable analysis, defective cQTD recovery was associated with late mortality （HR： 1.52, 95% CI： 1.05-2.17）. Conclusions Despite a gradual reduction ofcQTD after TAVI, 40% of the patients had defective recovery at 6 months which was associated with late mortality. More detailed ECG analysis after TAVI may help to avoid late death.

Effects of 6-minute walk test on the QT dispersion in patients with congestive heart failure

Objective: To investigate the clinical value of QT dispersion (QTd) and the effects of 6-minute walk test (6-MWT) mimicking the patients' daily activities on QTd in patients with congestive heart failure (CHF).Methods: Twenty-eight CHF patients and 22 normal subjects participated these study, who all completed 6-MWT without developing severe arrhythmias.Before and after 6-MWT, standardized 12-lead surface ECGs were obtained to measure QTd and corrected QTd (QTcd).Results: Both before and after 6-MWT, the QTd and QTcd in CHF patients were longer than those in the controls (P<0.001), and QTd and QTcd after 6-MWT were significantly shorter than those before 6-MWT in CHF patients (P=0.007, and 0.018).There was no significant difference in the measurement in the control group.Conclusion: QTd and QTcd are longer in CHF patients than in normal subjects.Moderate exercise may improve the inhomogeneity of ventricular repolarization dispersion in CHF patients.

QT Dispersion Level and Its Clinical Significance in Dilated Cardiomyopathy

Objective To evaluate the clinical significance of QT dispersion (QTd, QTcd) in dilated cardiomyopathy (DCM). Methods QTd and QTcd were measured on simultaneously recording 12 lead electrocardiograms (ECGs) in 60 DCM patients and compared with 60 healthy subjects. Results The values of QTd and QTcd in DCM were significantly higher than those in control group (P<0 01). With subgroup analysis, QTd and QTcd in patients with cardiac sudden death (CSD) were longer than those in survivors and those died of progressive heart failure (P<0 05), patients with ventricular tachycardia (VT) or with severe heart failure than those without (compared with patients with ventricular premature beats [VPB], P<0 05, compared with patients without ventricular arrhythmia [VA], P<0 01) or with mild heart failure (P<0 01). The values of QTd and QTcd in patients with VPB were greater than those in patients without VA(P<0 05). There were significant differences in the rates of VT, CSD and heart failure between the groups of QTd>110 ms and QTd≤110 ms(P<0 01 or P<0 05), in contrast to ejection fraction(EF) and fractional shortening (FS)(P>0 05). Conclusion The values of QTd and QTcd increased in DCM patients were susceptive index for monitoring maligant VA in DCM, also important prognostic markers of CSD. QTd was correlated with NYHA functional class but not with EF and FS.

Prolonged QT dispersion in inflammatory bowel disease

AIM:To investigate the frequency and factors of prolonged QT dispersion that may lead to severe ventricular arrhythmias in patients with inflammatory bowel disease(IBD).METHODS:This study included 63 ulcerative colitis(UC) and 41 Crohn's disease(CD) patients.Forty-seven healthy patients were included as the control group.Heart rate was calculated using electrocardiography,corrected QT dispersion(QTcd) and the Bazett's formula.Homeostasis model assessment(HOMA) was used to determine insulin resistance(IR).HOMA values < 1 were considered normal and values > 2.5 indicated a high probability of IR.RESULTS:Prolonged QTcd was found in 12.2% of UC patients,and in 14.5% of CD patients compared with the control group(P < 0.05).A significant difference was found between the insulin values(CD:10.95 ± 6.10 vs 6.44 ± 3.28,P < 0.05;UC:10.88 ± 7.19 vs 7.20 ± 4.54,P < 0.05) and HOMA(CD:2.56 ± 1.43 vs 1.42 ± 0.75,P < 0.05;UC:2.94 ± 1.88 vs 1.90 ± 1.09,P < 0.05) in UC and CD patients with and without prolonged QTcd.Disease behavior types were determined in CD patients with prolonged QTcd.Increased systolic arterial pressure(125 ± 13.81 vs 114.09 ± 8.73,P < 0.01) and age(48.67 ± 13.93 vs 39.57 ± 11.58,P < 0.05) in UC patients were significantly associated with prolonged QTcd.CONCLUSION:Our data show that IBD patients have prolonged QTcd in relation to controls.The routine followup of IBD patients should include determination of HOMA,insulin values and electrocardiogram examination.

QT Dispersion and QTc Interval in Patients with Adult Sickle Cell Disease: Electrocardiographic (EKG) and Echocardiographic Evaluation

Background: QT dispersion (QTd) varies according to heterogeneity of recovery time in the myocardium, and the impact of iron overload on the QTd in adult patients with Sickle Cell Disease (SCD) is not clear. Aim: This cross-sectional study was designed to evaluate corrected QTc interval and QTd on 12 leads ECG in patients with SCD, and assess the LV systolic and diastolic function using Pulsed Doppler Echocardiogram. Method: All patients were evaluated clinically with pulse Doppler echocardiography. Twelve leads ECG were taken to measure QTd and QTc. Blood samples withdrawn to assess the blood level of ferritin and hemoglobin. Pearson correlation coefficient was used to measure the linear relationship between serum ferritin and QTd. Results: The study included patients with SCD (n = 70, age 15.7 ± 8.9 years), compared with age-matched healthy control group (n = 70, age 15.9 ± 8.9 years). In patients with SCD compared with healthy control group the QTc (msec) 416 ± 23.21 ms vs. 401 ± 24.12 (p = 0.75), and the QTd were slightly longer in SCD compared with the control of 43 ± 22.1 vs. 38 ± 20.16 msec, (p = 0.071) with no significant difference. M mode echo showed that SCD patients compared with control had higher LVMI gm/M2 of 105 ± 10.3 vs. 83 ± 7.1, P = 0.001, larger LV end diastolic dimension (cm) of 5.5 ± 0.32 vs. 4.72 ± 0.35, p = 0.03, RV diameter (cm) of 2.8 ± 0.42 vs. 2.4 ± 0.31, (p = 0.041) and RV wall thickness (mm) of 0.31 ± 0.06 vs. 0.28 ± 0.03, (p = 0.024). Pulsed Doppler showed high LV transmitral E wave velocity of 85.23 ± 1.92 vs. 62.43 ± 1.67 m/s (p = 0.001), A wave (msec) 46.26 ± 4.7 vs. 56.24 ± 3.2 m/s, p = 0.032, with E/A ratio of 1.86 ± 0.01 vs. 1.10 ± 0.03, (p = 0.024) and DT of E wave (msec) of 156.43 ± 23.5 vs. 189.87 ± 19.5, (p = 0.031). Left ventricle ejection fraction percentage was similar between both groups, but SCD had significantly higher right ventricle tricuspid annular plane systolic excursion TAPSE (cm) of 1.23 ± 0.21 vs. 1.11 ± 0.23 cm (p = 0.02), and the tricuspid valve velocity showed significant higher velocity (m/s) in the SCD patients of 2.9 ± 0.14 vs. 1.7 ± 0.09, p = 0.004 indicating higher pulmonary artery pressure with calculated right ventricle systolic pressure of 38.64 vs. 16.56 mmHg. Conclusion: SCD patients compared with control have higher but not significant QT dispersion and corrected QT interval with a significantly larger LV mass and LV diastolic filling indices suggestive of restrictive diastolic pattern. These data indicate that LV diastolic abnormalities compromised initially in patients with SCD.

EFFECTS OF AMIODARONE AND SOME CLASS ⅠAGENTS ON QT DISPERSION

Objective To investigate the elfects of some class Ⅰ antiarrhythmic agents on QT dispersion and compared with those of amiodarone. Methods Group I was composed of 30 cases, they were all treated with class Ⅰ agents. The drugs used include: mexiletine (8 cases), moricizine (9), propafenone (12) and apridine (1). GrouP Ⅱ was composed of other 30 patients, and were all treated with amiodarone. The ddlerences of QT intervals between ECG leads (QTd and QTcd) were measured belore and aler medication. Results Before medication, the QTmax and QTcmax in group Ⅱ were signilicantly longer than those of group Ⅰ, resulting in greater QTd and QTcd in grouP Ⅱ (QTd:66± 14ms vs 31± 16ms, P<0.01; QTcd:71±36ms vs 44± 18ms, P<0.01). Alter medication, QTmax and QTcmax of group Ⅰ were prolonged, leading to the lengthening of QTd (from 31±16ms to 45±17ms, P<0.01) and QTcd (from 44± 18 ms to 58± 21ms, P<0.05), indicating the increase of inhomogeneity of myocardial repolarization after the treatment of class Ⅰ agents. Alter amiodarone treatment, QTmin and QTmax in grouP Ⅱ were both prolonged, with a greater amplitude of QTmin prolongation, resulting in decreased QTd and QTcd in group Ⅱ (QTd /rom 66± 14ms to 36±22ms, P<0.01, QTcd from 71±36ms to 45±27ms, P<0.01). The signifcant dofference of QTd and QTcd between two groups disappeared aler medication. Conclusion The results of the present study may relect the opposite effects of amiodarone and these class Ⅰ agents on myocardial repolarization.

Ventricular Repolarization: Epidemiology and Clinical Correlates among Type-2 Diabetics with Uncontrolled Arterial Hypertension in Western Region of the Republic of Macedonia

This study aimed to describe the epidemiology of repolarization dispersion (QT dispersion and Tpeak-Tend dispersion) and further describe their associated clinical correlates among uncontrolled arterial hypertension in type-2 Diabetics patient, in western region of the Republic of Macedonia. Abnormal ventricular repolarization is associated with increased cardiovascular risk. Data relating to the frequency of increased repolarization dispersion, among uncontrolled arterial hypertension in type-2 Diabetics patient in western region of the Republic of Macedonia, are scarce. A total of 600 patients were enrolled into this observation study. Study participans were selected among primary care patient, who were receiving ongoing care for diabetes mellitus and hypertension during 1 calendar year. Twelve lead resting electrocardiography, QT, QTc, Tpeak-Tend-intervals and dispersions, were determined manually, and were compared between groups. Patients with uncontrolled BP have greater frequency of: prolonged QTc.max.interval, (61.3% vs.33.6%;p = 0.0005), prolonged Tpeak-Tend interval (65.3% vs. 34.7%;p = 0.005), increased dispersion of QTc. interval (65.9% vs. 34.1%;p = 0.00), increased disperion of Tpeak-Tend interval (65.5% vs. 34.5%;p = 0.002). Females with uncontrolled BP have greater frequency of: increased dispersion of QTc. interval (61.2% vs. 38%;p = 0.02), increased dispersion of Tpeak-Tend interval (63.1% vs. 31.5%;p = 0.008). Hypertensive diabetic patients with uncontrolled BP and abnormal ventricular repolarization have greater BMI (p = 0.000;95%CI 3.849 - 7.871), longer duration of D.M (p = 0.000;95%CI 1.600 - 1.981), longer duration of arterial hypertension (p = 0.000;95%CI 1.468 - 1.850) and less controlled glycemia (p = 0.000;95%CI 1.556 - 3.004). Frequency of increased set of electrophysiological parameters that indicate a prolonged and more heterogeneous repolarization among diabetic patients with uncontrolled BP, is considerable high and seems to be significantly associated with demographic and clinical parameters: gender, BMI, duration of diabetes, duration of BP and glycemic control.

外周血25-(OH)-D、D-二聚体及QT离散度与支气管肺炎患儿心肌损伤标志物的相关性

目的 探究外周血25-羟维生素D[25-(OH)-D]、D-二聚体及QT离散度与支气管肺炎患儿心肌损伤标志物的相关性。方法 前瞻性选取2020年1月至2022年1月池州市第二人民医院收治的45例支气管肺炎伴心肌损伤患儿纳入研究组,另按照1∶1的比例随机抽取45例在本院接受治疗的支气管肺炎未发生心肌损伤患儿纳入对照组。对两组患儿的心肌损伤标志物[肌酸激酶(CK)、肌酸激酶同工酶(CK-MB)、肌钙蛋白T(cTnT)及N-末端脑钠肽前体(NT-proBNP)]水平进行记录,采用Pearson相关性分析探究患儿心肌损伤标志物水平与外周血25-(OH)-D、D-二聚体及QT离散度的相关性;采用受试者操作特征(ROC)曲线探究上述指标对支气管肺炎患儿发生心肌损伤的诊断价值。结果 研究组患儿的CK、CK-MB、cTnT及NT-proBNP水平分别为(185.46±18.33) U/L、(62.45±8.44) U/L、(1.89±0.36)μg/mL、(287.65±45.12) ng/L,均高于对照组患儿[(82.22±11.02) U/L、(20.58±4.15) U/L、(0.44±0.12)μg/mL、(122.45±25.15) ng/L],差异均有统计学意义(P<0.05)。研究组患儿25-(OH)-D水平为(53.45±6.11) nmol/L,低于对照组[(74.45±5.15) nmol/L],D-二聚体、QT离散度水平分别为(3.98±1.18)μg/mL、(33.18±1.98) ms,均高于对照组[(2.11±0.54)μg/mL、(25.15±2.16) ms],差异均有统计学意义(P<0.05)。经Pearson相关性分析可知,患儿的CK、cTnT、CK-MB及NT-proBNP水平均与25-(OH)-D水平呈负相关(P<0.05),与D-二聚体、QT离散度水平呈正相关(P<0.05)。经ROC曲线分析可知,外周血25-(OH)-D、D-二聚体、QT离散度均对支气管肺炎患儿心肌损伤具有一定诊断价值,其曲线下面积值分别为0.854、0.843、0.894、0.827(P<0.05)。结论 支气管肺炎患儿25-(OH)-D、D-二聚体、QT离散度与其心肌损伤存在显著相关性,且各指标对支气管肺炎并发心肌损伤均存在一定诊断价值。

活血化瘀汤辅助常规疗法治疗心肌梗死伴心房颤动的疗效及对QT校正离散度的影响

目的:探讨活血化瘀汤辅助常规疗法治疗心肌梗死(Myocardial infarction, MI)伴心房颤动(Atrial fibrillation, AF)的疗效及对QT校正离散度的影响。方法:前瞻性选取我院2020年8月—2023年3月收治的94例MI伴AF患者,按随机数表法分为观察组(n=47)、对照组(n=47)。对照组采用常规疗法治疗,观察组采用活血化瘀汤辅助常规疗法治疗。比较两组疗效,治疗前、治疗1个月后心功能指标(心排血量、左心室收缩末内径、舒张末内径、射血分数)、QT间期离散度[QT离散度(QTd)、校正的QT离散度(QTcd)]、炎症及氧化应激反应[超氧化物歧化酶(SOD)、NADPH氧化酶(NOX)、肿瘤坏死因子(TNF-α)]水平及不良反应发生情况。结果:观察组总有效率(95.74%,45/47)显著高于对照组(76.60%,36/47)(P<0.05);治疗1个月后观察组心排血量、左心室射血分数高于对照组,左心室收缩末内径、舒张末内径低于对照组(P<0.05);治疗1个月后观察组QTcd、QTd改善幅度大于对照组(P<0.05);治疗1个月后观察组SOD水平高于对照组,NOX、TNF-α水平均低于对照组(P<0.05);观察组不良反应总发生率为6.38%(3/47),与对照组的12.77%(6/47)相比,差异无统计学意义(P>0.05)。结论:采用活血化瘀汤辅助常规疗法治疗MI伴AF疗效显著,能有效抑制炎症、氧化应激反应,促进心功能、QT离散度改善,并能保障安全,利于预后病情转归。

Nifekalant hydrochloride terminating sustained ventricular tachycardia accompanied with QT dispersion prolongation

Background Ventricular tachycardia （VT） and ventricular fibrillation are the main reasons causing sudden cardiac death.This study aimed to investigate the effects of nifekalant hydrochloride （NIF） on QT dispersion （QTd） in treating VT.Methods A total of 16 consecutive patients suffered sustained VT was included and then randomly divided into two groups according to the administration duration of NIF.In long-time group （group L）, patients were injected with NIF continuously for at least 12 hours after a bolus dose.The patients in short-time group （group S） were injected with NIF just for 1 hour.Results There were 7 of all 10 episodes of VT which were terminated by NIF, including 4 episodes in group L were stopped over 1 hour after continuous infusion of NIF.One patient suffered from torsade de pointes.Electrocardiography analysis indicated that QTd was significantly decreased 12 hours after stopping of infusing NIF compared with that when VT stopped （（45.4±22.1） ms vs.（73.4±33.2） ms, P 〈0.01）, and the corrected QTd （QTcd） decreased too （（47.8±22.9） ms vs.（78.3±36.5） ms, P 〈0.01 ）.There was a positive correlation between the increase in QTd and dose of administrating NIF （P 〈0.01）, so was QTcd （P 〈0.01）.Conclusions More administration of NIF indicates higher terminating rate of VT and more QTd prolongation.However,the safety is acceptable if several important issues were noticed in using NIF, such as serum potassium concentration,stopping side-effect related agents, and carefully observing clinical responses.

Both transmural dispersion of repolarization and of refractoriness are poor predictors of arrhythmogenicity： a role for iCEB （QT/QRS）？

We read the original article by Nuis, et al. and the reply by Dogan, et al. with great interest. Nuis, et al. examined whether transcatheter aortic valve implantation （TAVI） in patients suffering from severe aortic stenosis led to changes in corrected QT dispersion （cQTD）, previously used to predict arrhythmic risk. Dogan, et al. proposed that a different marker, transmural dispersion of repolariza- tion （TDR）, has better accuracy in risk prediction.

Changes of QT Dispersion in Hemodialysis Patients after Administrating Zhigancao Decoction(炙甘草汤)

Objective： To observe the alteration of QT dispersion（QTd） and QTc dispersion（QTcd） in hemodialysis patients after oral administration of Zhigancao Decoction（炙甘草汤,Roasted Licorice Decoction,RLD）.Methods： To investigate the alteration of QTd and QTcd in 68 routine hemodialysis patients before and after hemodialysis with 12-lead electrocardiogram（ECG） after orally administrated RLD for 4 weeks.Blood was also taken for measurement of plasma electrolytes,liver function,renal function,hemoglobin（Hgb） and hematocrit（HCT）.Results： After hemodialysis,QTd and QTcd were prolonged evidently; the difference was significant between before and after hemodialysis（P〈0.05）.After RLD orally administrated for 4 weeks,QTd and QTcd only slightly increased after dialysis compared with pre-dialysis（P〉0.05）.The QTd and QTcd of the post-therapy-post-dialysis decreased significantly compared with the pre-therapy-post-dialysis（P〈0.05）.There were no other significant changes in other variables（post-therapy-pre-dialysis vs.pre-therapy-pre-dialysis,or post-therapy-post-dialysis vs.pre-therapy-post-dialysis; P〉0.05）.After therapy,the number of patients with supraventricular arrhythmia,occasional ventricular premature beat and multiple ventricular premature beat were decreased from 15 to 4,10 to 2 and 7 to 1,respectively.Conclusion： RLD therapy not only lowered the increased QTd and QTcd after hemodialysis,but also displayed a safety profile.

QT DISPERSION: A RISK INDICATOR FOR SEVERE VENTRICULAR ARRHYTHMIA IN PATIENTS WITH ISCHEMIC AND IDIOPATHIC CARDIOMYOPATHY

Increased QT dispersion in the surface ECG (QTd = QTmax minus QTmin) is considered as an indicator of electrical inhomogeneitv and a useful predictor for severe ventricular arrhythmia and sudden cardiac death in patients with different heart diseases. Patients with ischemic and idiopathic cardiomyopathy have a very high incidence of severe ventricular arrhythmia and sudden cardiac death. We compared QT, QTc. JT and JTc dispersion in ischemic (ICMP) and idopathic (CCMP) cardiomyopathy patients with and without severe ventricular arrhythmia and normal controls.

QT interval dispersion in the patients with central serous chorioretinopathy

AIM: To evaluate QT dispersion(QTD) in patients with central serous chorioretinopathy(CSC).METHODS: This clinical, comperative, case-control study included 30 patients with CSC at acute phase(Group 1) and 30 age- and sex-matched healthy subjects(Group 2, the control group). From all subjects, a 12-lead surface electrocardiography was obtained. The heart rate(HR), QT maximum(QT max), QT minimum(QT min), QT corrected(QT c), QTD and T mean were manually measured and analyzed. Student’s t-test and Pearson’s method of correlation were used for statistical analysis.· RESULTS: The patient and control groups were matched for age, smoking status(rate and duration) and gender. There were no significant differences with regard to these among the groups(P 】0.05). The participants included 19 men(63.3%) and 11 women(36.7%) in Group1, 20 men(66.7%) and 10 women(33.3%) in Group 2.QT max, QTD and QT c were significantly higher than those of healthy controls(P 【0.001 for QT max, P =0.01 for QTD and P =0.001 for QT c). QT min, T mean and HR did not differ significantly between the study groups(P =0.28 for QT min,P =0.56 for T mean and P 】0.05 for HR). No significant correlation was found between duration of the disorder and QTD values(r =0.13, P 】0.05).CONCLUSION: These findings suggest that CSC may be associated with an increase in QTD and that the patients might be at risk for ventricular arrhythmia.

ST段抬高型心肌梗死合并完全性右束支传导阻滞急诊PCI后心率变异性、QTcd和心电QRS电压影响的研究

目的探讨急性ST段抬高型心肌梗死(STEMI)合并完全性右束支传导阻滞行急诊经皮冠状动脉介入治疗(PCI)后,对患者心率变异性(HRV),QT校正离散度(QTcd)和心电QRS电压的影响。方法选择2019年12月至2021年12月梅州市人民医院诊断为STEMI并行急诊PCI或延期PCI患者150例,将急性STEMI合并完全性右束支传导阻滞行急诊PCI设定为观察组,急性STEMI合并完全性右束支传导阻滞行延期PCI设定为对照一组,急性STEMI无完全性右束支传导阻滞行急诊PCI设定为对照二组,每组各50例,评估其对HRV、QTcd和心电QRS电压的影响。结果治疗后,观察组QRS波群电压(aVF导联)及QTcd短于对照一组与对照二组,差异有统计学意义(P<0.05)。结论STEMI合并完全性右束支传导阻滞行PCI后,对HRV,QTcd和心电QRS电压的观测有助于临床筛选高危患者,利于远期预后。

血府逐瘀汤联合双联抗血小板药物对冠心病心绞痛患者QT间期离散度、左室舒张功能的影响

目的分析血府逐瘀汤联合双联抗血小板药物对冠心病心绞痛患者QT间期离散度(QTd)、左室舒张功能的影响。方法选取该院2020年4月至2022年4月收治的136例冠心病心绞痛患者为研究对象,使用随机数字表法将其分为观察组与对照组,每组各68例。对照组给予氯吡格雷及阿司匹林双联抗血小板药物治疗,观察组在对照组基础上给予血府逐瘀汤。比较两组疗效,记录比较两组治疗前后中医症状积分,比较两组治疗前后QTd,并计算校正QTd(QTcd),比较两组治疗前后左室舒张功能[舒张早期二尖瓣血流峰值(E)、舒张晚期二尖瓣血流峰值(A)、E/A、E峰减速度时间(DT)、等容舒张时间(IVRT)],比较两组不良反应发生率。结果观察组总有效率高于对照组,差异有统计学意义(P<0.05)。治疗后,两组胸痛、胸闷、心悸、面色青白、唇舌紫暗积分均较治疗前明显下降,且观察组各项症状积分明显低于对照组,差异均有统计学意义(P<0.05)。治疗后,两组QTd、QTcd水平均较治疗前明显下降,且观察组QTd、QTcd水平明显低于对照组,差异有统计学意义(P<0.05)。治疗后,观察组与对照组E、E/A较治疗前均有明显上升,A、DT、IVRT均较治疗前明显下降,且观察组E、E/A明显高于对照组,A、DT、IVRT明显低于对照组,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(P>0.05)。结论血府逐瘀汤联合双联抗血小板药物对冠心病心绞痛有较好疗效,能够有效缓解患者临床症状,调节QTd并改善左室舒张功能,且安全性较高,具有临床应用价值。

QT离散度对川崎病患儿发生冠状动脉损伤及其预后的预测价值

目的 探讨心电图QT离散度(QTd)对川崎病患儿冠状动脉损伤和预后的预测价值。方法 回顾性分析2018年1月至2021年7月中国医科大学附属盛京医院收治的1 743例川崎病患儿的临床资料。根据心电图QTd预测冠状动脉损伤和主要不良心脏事件的最佳截断值分别将患儿分为2组。分析QTd对川崎病患儿发生冠状动脉损伤和远期预后的影响。结果 QTd预测川崎病患儿冠状动脉损伤的受试者操作特征(ROC)曲线结果显示,曲线下面积(AUC)为0.940 (95%CI:0.893~0.986,P <0.001),QTd最佳截断值为38.5 ms,敏感度为88.64%,特异度为77.12%。QTd预测主要不良心脏事件的最佳截断值为39.5 ms (AUC=0.867,95%CI:0.792~0.934,P <0.001),灵敏度为78.57%,特异度83.71%。logistic多因素回归分析结果显示,QTd≥38.5 ms是冠状动脉损伤的独立预测因子。Kaplan-Meier生存分析发现QTd≥39.5组患者心律失常、川崎病复发发生率高于QTd<39.5组。Cox回归分析也证实QTd≥39.5 ms可以独立预测主要不良心脏事件的发生。结论 QTd对川崎病患儿是否发生冠状动脉损伤具有一定预测价值。对于QTd≥38.5 ms患儿应警惕冠状动脉损伤的发生;对于QTd≥39.5 ms患儿应警惕主要不良心脏事件的发生。