Influence Of Complete Atrioventricular Block On Levels Of SerumB-type Natriuretic Peptide And Cardiac Structure In Canine

Objective: To establish a experimental model of complete atrioventricular block (CAVB) by radiofrequency catheter ablation to investigate the variation in serum B-type natriuretic peptide(BNP),Left ventricle at the end of diastolic diameter (LVEDD),Left ventricle Ejection fraction(LVEF),The diameter of right ventricular (RAD) and The diameter of left atrium (LAD) levels .Following,to evaluate the effects of complete atrioventricular block (CAVB)on cardiac function.Methods:Canine models of complete eatrioventricular block were established by radiofrequency catheter ablation (RFCA) in experimental group,with other dogs as control group,serum BNP was measured before ablation,immediately after ablation,one week after ablation and one month after ablation,and echocardiography was acquired in the same time.Measurement data was expressed by means of x±s,SPSS17.0 software was used for comparison,ANOVA to test interclass difference,and correlation analysis was acquired,p<0.05 was significant.Results: 1 Before ablation ,serum BNP levels of experimental group was(1.42±0.41)μg/L, immediately after ablation was(1.70±0.41)μg/L,one week after ablation was(2.31±0.40)μg/L and the concentration reached(8.46±0.65)μg/L at one month after ablation;the serum BNP level of before ablation group is increased significantly compared to one week after ablation group and one month after ablation group,immediately after ablation group is increased significantly compared to one week after ablation group and one month after ablation group,the BNP level of one week after ablation group is increased significantly compared to one month after ablation group,P<0.05;there is no significant differences between other groups,P>0.05Before ablation,LVEDD levels of experimental group was(23.33±3.56)mm,immediately after ablation was(26.67±3.01)mm, one week after ablation was(30.17±2.40)mm and reached(35.83±5.38)mm at one month after ablation,the LVEDD level of before ablation group is increased significantly compared to one week after ablation group and one month after ablation group,the LVEDD level of immediately after ablation group is increased significantly compared to one month after ablation group, the LVEDD level of one week after ablation group is increased significantly compared to one month after ablation group,P<0.05,there is no significant differences between other groups,P>0.05.Before ablation,LVEF levels of experimental group was(0.84±0.05)%,immediately after ablation was(0.73±0.05)%,one week after ablation was(0.65±0.05)% and reached (0.57±0.07)% at one month after ablation,there is significant differences between four groups,P<0.05 .Before ablation,RVD levels of control group was(15.00±4.69)mm immediately after ablation was(15.00±5.37)mm,one week after ablation was(19.17±4.54)mm and one month after ablation was(16.50±3.39)mm,there is no significant differences between four groups,P>0.05.Before ablation,LAD levels of control group was(17.17±2.14)mm,immediately after ablation was(19.17±1.60)mm,one week after ablation was(21.00±3.29)mm and one month after ablation was(20.83±4.96)mm,there is no significant differences between four groups,P>0.05.2 Before ablation,serum BNP levels of control group was(1.39±0.41)μg/L,immediately after ablation was(1.29±0.42)μg/L,one week after ablation was(1.34±0.44)μg/L and the concentration at one month after ablation was (1.33±0.37)μg/L,there is no significant differences between four groups,P>0.05Before ablation,LVEDD levels of control group was(26.67±1.53)mm,immediately after ablation was(28.00±1.00)mm,one week after ablation was(31.67±4.16)mm and one month after ablation was(29.33±2.89)mm,there is no significant differences between four groups,P>0.05.Before ablation,LVEF levels of control group was( 0.80±0.01)%,immediately after ablation was(0.78±0.02)% , one week after ablation was(0.77±0.02)% and one month after ablation was(0.79±0.01)%,there is no significant differences between four groups,P>0.05Before ablation,RVD levels of control group was(15.00±1.73)mm,immediately after ablation was(15.00±2.00)mm, one week after ablation was(15.33±2.52)mm and one month after ablation was(14.33±2.08)mm,there is no significant differences between four groups,P>0.05Before ablation,LAD levels of control group was (18.67±3.06)mm,immediately after ablation was(18.33±3.21)mm,one week after ablation was(20.67±2.31)mm and one month after ablation was(18.67±2.52)mm,there is no significant differences between four groups,P>0.05 3 Experimental group with the serum BNP level was positively correlated to the LVEDD level (r =0.742,P<0.05)and was negatively correlated to the LVEF level (r= -0.736,P<0.05).Conclusions: The experimental model of complete atrioventricular block can set up quickly and safely with radiofrequency catheter ablation.;complete atrioventricular block can lead the levels of serum BNP and LVEDD increased and the levels of LVEF decreased...