Cardiac Pacing And The Level Changes Of Brain Natriuretic Peptide And Cardiac Troponin As Well As Their Clinical Significance

Objective: Implanting permanent cardiac pacing of antibradycardia is an important method to the therapy of cardiac brandycardia. With the development of the type and capability of the pacemaker, the skilled technology of operator, more and more patients accepted the therapy of implanting permanent cardiac pacemaker. At the same time, with such reports due to the implantation of pacemakers the patients caused negative impact of cardiac function, myocardial injury. People in order to find a more reasonable cardiac pacing reseach furtherly using different pacing system such as physiological pacing and non-physiological pacing, right ventricular different pacing sites, active leads and passive leads in patients to find the impact to cardiac function and myocardial injury. Brain natriuretic peptide and cardiac troponin I as sensitive biochemical makers for hemodynamic and myocardial injury after pacemaker implantation, they are payed more and more attention. Plasma brain natriuretic peptide is a sensitive biochemical marker for atrioventricular sequence in patients with pacemakers and a screening tool for heart failure in the pacemaker population. cTnI represents useful markers for myocardial injury. It's reported that about 1/3 of patients were observed with an increase in cTnI over the usual cutoff for the laboratory diagnosis of myocardial infarction after the implantation of a pacing system. Because of the cardiac pacing, the ECG loses its sensitivity or specificity, so when chest pain and myocardial ischemia symptoms accured in the early time of postoperation, the relation between cTnI levels and pacing systems is really important.The purpose of this study is to understand how the different cardiac pacing mode and pacing site, the application of different leads impact the patient'heart function and myocardial injury by many test patients'brain natriuretic peptide and cardiac Troponin levels in different periods of before and after operation. Furthermore,we discuss which type of cardiac pacing can benefit more patients. We recognize further comprehensive understanding of postoperative patients'cardiac Troponin level changes and positive incidence which benefit for us to have more comprehensive and accurate understanding between the patients who have chest pain in the early period of postoperation, especially for the differential diagnosis with acute coronary syndrome.Methods: From August 2008 to October 2009 we enrolled 43 cases with permanent pacemaker implantation in the Department of Cardiology, The Second Hospital of Hebei Medical University. 25 cases were male, female 18 cases; age (66.30±1.39) years of age. Type of arrhythmia were 23 cases of sick sinus syndrome,Ⅲdegree atrioventricular block in 19 cases,ⅡTypeⅠdegree atrioventricular block in 1 case. By implanted pacemaker types are divided into 11 cases of dual-chamber pacemakers, single-chamber pacemaker in 32 cases (right ventricular apical pacing in 27 cases, right ventricular outflow tract pacing in 5 cases). Selected 43 patients in 40 cases according to type of wire electrodes implanted electrodes in 22 cases were divided into passive, active electrode in 18 cases. Enzyme-linked immunosorbent kit of 43 cases were determined to install a permanent anti-slow arrhythmia pacemaker patients before, after 1 day, 1 week, 3 months, 6 months of BNP level. Determination of 43 patients, of which 40 patients (before surgery to exclude ACS) patients before and after 1, after 1 week of cTnI levels. Measurement data with the mean value±standard deviation (SD) indicated. Of BNP, cTnI levels over time, changes in repeated measures design analysis of variance was used to compare between the two groups 22 of two independent samples t test. Count data using fourfold table Chi-square test.P <0. 05 was considered statistically significant.Results: For patients with heart function classⅠor with normal heart function before operations, BNP 1evels were not significantly changed in difeerent pacing and the following periods. cTnI levels were not significantly changed before pacing operation and 1 week postoperatively in the patients without ACS(4.08±0.21 ng/ml vs 3.81±0.22 ng/ml,P=0.302>0.05), but postoperation 1 day it's significantly increased (5.48±0.31 ng/ml vs 4.08±0.21 ng/ml,P<0.05). For further observation, we found that cTnI levels of 1 day postopratively were not significantly changed between single and dual pacemaker(5.95±1.40 ng/ml vs 5.01±1.79 ng/ml,P =0.140>0.05), but it's significantly changed between passive and active fixation pacemaker. The cTnI level of 1 day postopratively of active fixation was more than the passive fixation pacemakers that impalanted(6.33±1.42 ng/ml vs 4.36±1.45 ng/ml,p<0.05). After operation 1 day, there were 13 of 40 patients's cTnI levels over the usual cutoff for the laboratory diagnosis of myocardial infarction in about 32.5% of patients. To observe the incidence of cTnI increased above the upper limit of the normal range on 1 day postopratively, we found that there weren't significantly changed between single/dual(26.667% vs 50.000%;χ2 = 1.861, P = 0.172) and active/passive(44.444% vs 22.727%;χ2=2.128, P = 0.145)groups.Conclusion: For patients of preoperation with heart function classⅠor normal heart function, the BNP levels were not significantly changed in the following 6 months in different pacing. The pacemaker implantation would cause damege to the myocardial and the damege looked more severely in the active fixation group than passive fixation group, but the cTnI levels all were down to normal on 1 week postoperation. Furthermore, there were't differences between single/dual and active/passive groups that the incidence of cTnI increased above the upper limit of the normal range on 1 day postoperatively.