The Clinical Study Of Tp-Te Interval When Pacing At Different Site

Since the first fully implanted permanent pacemaker employed in October15,1958in a Swedish hospital, it has become an important treatment procedurefor bradyarrhythmia, malignant arrhythmia (such as atrial fibrillation,ventricular tachycardia, ventricular fibrillation), heart failure and so on.Initially used was a single chamber pacemaker(SCP) with its electrodefixed in the right ventricular apical. Then single atrial, ventricle and atrium ofdual chamber, biventricular and right atrial or double atrium and right ventriclethree chamber and four chamber pacemaking were developed and applied,making pacing therapy in a more physiological mode.Dated from the nineteen eighties, dual chamber pacemaker(DCP) has beenincreasingly used. Compared with single chamber one, it significantlyincreased ventricular ejection fraction and gave an impression of improvingpatients’ life quality and reducing mortality. However, some studies haveconfirmed, in terms of life quality, stroke, atrial fibrillation incidence andmortality, the two showed no significant difference.However, there is no uniform standard for electrode fixed sites of theS/DCP as well as right ventricular.Object: This study intends to measure and compare the Tp-Te intervals ofpatients with different pacing sites and probe its clinical significance andapplication value, taking the healthy as the control.Methods:61patients, of which29are male, with cardiac pacemakers weresampled from Cardiovascular Medicine of Sino-Japanese Joint Hospital,2010March to2011December, and30cases of healthy adult were taken as thecontrol. Single chamber ventricular pacemaker(SCVP)25cases with13theRight ventricular electrode (RVE) fixed in apical and12in Ventricular septal; dual chamber pacing（DCP）30cases, among which biventricular pacemakergroup6cases; the control group: male14and female16. ECG-9130P twelvelead electrocardiogram instrument (Japanese Optoelectronic Industry Co Ltd)was adopted to record synchronously12lead ECG: paper speed50mm/s,Calibration voltage10m/V; groups V2, V3, and V4’s ECG Tp-Te intervalswere measured manually, then their ECG Tp-Te intervals were compared withthe control. Groups with RVE in the ventricular septum or in the apical groupare compared while single chamber pacemaker(SCP) group are compared withDCP group in terms of ECG Tp-Te intervals. SPSS17.0software was used forstatistical analysis, x±S was represent for measurement data (consistent withnormal distribution) with and t test was employed, P <0.05was for thestatistically significant difference.Results: the tested group showed remarkable longer ECG Tp-Te intervalsthan the control (P <0.001), while there had no significant differences betweenthe two groups with RVE in the chamber or in apical (P>0.05); no significantdifference can be seen between single cavity right ventricular group and DCPgroup (P>0.05). However, the Tp-Te intervals of biventricular pacing groupwere obviously prolonged compared with the single chamber ventricular group(P <0.05).Conclusions:1.The group with pacemaker fixed showed a significant longer ECGTp-Te interval than the control, indicating that a pacemaker may increase therisk of ventricular arrhythmia.2.Tp-Te intervals cannot be used as selection factors for whether theventricular electrode is fixed in the interventricular septum or apex.3.Tp-Te interval cannot be taken as a reference for the selection of SCP ora dual one.4.Biventricular pacing may increase the transmural dispersion of repolarization and enhance the risk of malignant arrhythmia.