Investigation Of Tpeak-Tend Interval And Related Repolarization Wave In The Communities Of Population And The Patients With Coronary Heart Disease

PartⅠStudy on different lead of Tpeak-Tend interval in healthy peopleObjective Tpeak-Tend interval of ECG is a recently proposed to the quantitative indicator for reflecting the ventricular transmural dispersion of repolarization, and a new index for predicting malignant ventricular arrhythmia. Measuring different lead Tpeak-Tend interval of standard electrocardiogram in healthy pepole, to provide methodological basis for further study of Tpeak-Tend interval.Methods 100 healthy people were randomly selected from 2163 healthy subjects ranged from 35 to 75 years old in the maturated communities of Taiyuan city and 12-lead ECG was recorded. Q-T interval and Q-Tpeak interval (time interval from QRS-wave starting to T-wave peak) were measured on electrocardiogram in 100 healthy people, rectrospectively. Then, Tpeak-Tend interval was calculated by Q-T interval substrating Q-T peak, and compared different lead of Tpeak-Tend interval and men's and women's Tpeak-Tend interval.Results In study of 100 cases healthy people of the communities, the Tpeak-Tend interval was the longest in lead V2 and the shortest in lead aVL in the 12-lead distribution (respectively 93.20±16.07ms and 58.06±13.70 ms); the Tpeak-Tend interval was the longest in lead V2 and the shortest in lead V6 in the precordial lead distribution (respectively 93.20±16.07ms and 66.90±11.95ms), and there were significant differences between the Tpeak-Tend interval of V2 lead and that of the other leads (P<0.01). The Tpeak-Tend interval ofⅡ,Ⅲ, aVR, V2～V6 in males were bigger than than females, the difference was significant (P<0.05).Conclusion The Tpeak-Tend interval as an ECG parameter was the longest in lead V2 and the shortest in lead V6 in the precordial leads distribution in healthy people. It shows V2 and V6 leads are the first choice when measuring Tp-Te interval and considering sex. Part II Investigation of the Tpeak-Tend interval in the communities of Taiyuan populationObjective Comparing Tpeak-Tend interval of ECG with the change of ST segment and J wave of ECG in the communities of Taiyuan city in order to provide basic date for evaluation of malignant arrhythmia.Methods 4041 subjects ranged from 35 to 75 years old in the maturated communities of Taiyuan city were selected and 12-lead ECG was recorded.3812 of all the subjects meet the measurement standards of Tpeak-Tend interval. J wave, ST segment and Tpeak-Tend interval of V2 and V6 leads were respectively measured and compared. The J wave was classified into small J wave (time course was 0.02-0.04s or wave amplitude was 0.05-0. lOmv) and big J wave (time course was>0.04s or wave amplitude was>0.10mv), and ST segment was devided into the rasion, depression and normal of ST segment groups. The community of population were devided into three groups including the inferior ventricular wall group (ⅡⅢaVF), the anterior ventricular wall group (V1-V4) and the lateral ventricular wall group (I aVL V5 V6) according to J waves appearing in different leads.Results In all the subjects, the Tpeak-Tend interval was the longest in chest lead V2 and the shortest in chest lead V6 (respectively 91.74±19.38ms and 73.34±15.77 ms). The Tpeak-Tend interval of V2 and V6 leads were significantly different between (692 subjects) J wave group and (3120 subjects) non-J wave group (respectively 88.20±18.53ms vs 93.47±19.48ms, P<0.01; 70.59±14.86ms vs 73.95±15.90ms, P<0.01), but both Tpeak-Tend interval of V2 and V6 leads were not different between small and big J wave group (respectively 87.99±18.43ms vs 90.65±19.70ms; 70.30±15.42 ms vs 72.03±14.43 ms, P>0.05). In the J wave group, the Tpeak-Tend interval of V2 lead was significantly different not only between the raise of ST segment group and the depression of ST segment group(95.78±17.53 vs 84.76±23.62, P<0.01), but also between the raise of ST segment group and the normal of ST segment group(95.78±17.53 vs 88.64±18.24, P<0.01).Conclusion In the community of population, the Tpeak-Tend interval of lead V2 and V6 were respectively (91.74±19.38)ms and (73.34±15.77) ms. Tpeak-Tend interval following to J wave shortened, and meanwhile Tpeak-Tend interval following to the raise of ST segment increased in chest lead V2. PartⅢClinical Study of Tpeak-Tend interval in patients with coronary heart diseaseObjective To investigate the characteristics of Tpeak-Tend interval in the patients with coronary heart disease (CHD) and explore its clinical significance.Methods The ECG data of 473 patients who were performed with coronary arteriography (CAG) in the cardiology department of the second hospital of Shanxi medical university were retrospectively analyzed.461 of all the subjects meet the measurement standards of Tpeak-Tend interval, including 312 cases patients with coronary heart disease (Average age (57.74±10.95) years,227 cases male,85 cases female) and 149cases patients without coronary heart disease(average age (54.32±11.22) years,84 cases male,65 cases female). J wave, V2 with V6 lead's Tpeak-Tend interval and QT interval were respectively measured and compared in all the subjects. According to the results of CAG and clinical diagnosis, the patients were divided into CHD and non-CHD group. While the CHD group were divided into three groups including a coronary artery stenosis, two coronary artery stenosis and multi-vessel coronary artery stenosis group according to the lesion involving the number of coronary artery, and the CHD patients were divided into J waves and non-J waves group according to the results of ECG. The differences of Tpeak-Tend interval of each group were made the quantitative analysis.Results The Tpeak-Tend interval of V2and V6 leads are significantly different between CHD group and non-CHD group (respectively 127.60±27.96ms vs 112.21±25.06ms, P<0.01; 99.90±24.48ms vs 87.92±16.94ms, P<0.01). In CHD group, the Tpeak-Tend interval of V2 and V6 leads are not significantly different between a coronary artery stenosis, two coronary artery stenosis and multi-vessel coronary artery stenosis group(P>0.05); The Tpeak-Tend interval of V2 and V6 leads were not significantly different between J wave group and non-J wave group (respectively 124.15±24.87ms vs 125.37±27.49ms; 92.46±19.21ms vs 94.13±22.31ms, P>0.05)。Conclusions Tpeak-Tend interval of V2 and V6 leads in CHD group were bigger than that in no-CHD group, and it does not change following to the number of coronary artery stenosis.