Objective To discusse the mechanism and clinical significance of bradycardia -hypotension phenomenon which is caused by vagal reflex during and after the RFCA and present the experience of using appropriate measures to decrease the incidence of this situation. Methods The patients who were suffering from tachyarrhythmias and treated by RFCA were divided into two groups. The groups were as follows:148 patients who were not taken special measures in the early stage were selected in control group;1 540 patients who were taken measures to prevent vasovagal reflex were selected in observation group. Result During the RFCA, the incidence of bradycardia -hypotension phenomenon in control group was 13.5% (20/148), the incidence of bradycardia-hypotension phenomenon in observation group was 5.0%(77/1540) (<0.01) .Conclusions The incidence of bradycardia-hypotension phenomenon caused by vagal reflex during the RFCA is related to catheter irritation to the heart,pressure on the vessels and hypovolemia. The incidence of this phenomenon can be decreased obviously by some measures,such as non-restricted diet before RFCA,discretion rehydration during and after the RFCA and hemostasis with appropriate force after extubation. The key to rescue patients successfully are early detection and timely processing.

Objective To evaluate the feasibility of catheter ablation of Para-Hisian Atrial Tachycardia guide by CARTO. Method Catheter ablation guided by CARTO was performed after activation map in three patients with Para-Hisian Atrial Tachycardia. Result Successful ablation was got at right atrial in two patients and at non-coronary in one patient. Conclusion Catheter ablation guided by CARTO is safe and efficient for Para-Hisian Atrial Tachycardia.

Objective To test synchronization of cardiac mechanical contraction by means of advanced echocardiography and investigate the correlation of left ventricular ejection fraction (LVEF) and the indexes of mechanical dyssynchrony, and the relationship between DTI, STI and RT-3DE.Methods Control group (20 cases), chronic heart failure with a widened QRS complex (12 cases) and chronic heart failure with a shortened QRS duration (10 cases) were selected. We evaluated mechanical dyssynchrony with the DTI, the STI and the RT-3DE, and analyzed the correlation between the improvement degree of cardiac function and indexes of mechanical dyssynchrony, and the correlation between DTI, STI and RT-3DE. Results (1) In CHF groups (including shortened QRS group and widened QRS group), the indexes of synchronization of cardiac mechanical contraction were higher than control group ( <0.05) . (2) However, the indexes of mechanical dyssynchrony before operation showed no statistically significant difference between the widened QRS group and the shortened QRS group (>0.05) . (3) In CHF groups (including shortened QRS group and widened QRS group), the indexes of mechanical dyssynchrony before operation were higher more than after operation ( <0.05) . (4) In postoperation, the indexes of mechanical dyssynchrony showed no statistically significant difference between the widened QRS group and the shortened QRS group ( >0.05) . (5) There was a significant negative correlation between the LVEF and the indexes of mechanical dyssynchrony (<0.01) . (6) .In the indexes of synchronization of cardiac mechanical contractions, there are significant positive correlations between the DTI, the STI and the RT-3DE ( <0.01) . Conclusion Echocardiography can be used to screen CHF patients,and patients with left ventricular synchronous (including shortened QRS duration) can also be benefited from CRT.

Objective This study was purposed to analyze and summarize the vein temporary cardiac pacing therapy in patients with acute inferior wall myocardial infarction complicated by high degree atrioventricular block (AVB) . Methods One hundred and twelve patients with acute inferior wall myocardial infarction complicated by high degree AVB were selected as observation and research subjects, and they were treated by vein temporary cardiac pacing therapy. The safety, availability of different kinds of this surgical methods and the relationship between these surgical methods and complication were observed. Results Three out of 60 patients who were treated by ordinary temporary pacing electrode catheter were suffering from cardiac tamponade. No serious complications occurred when 52 patients were treated by floating temporary pacing electrode catheter. Conclusion Floating temporary pacing electrode catheter have already proved safe and effective in the treatment of acute inferior wall myocardial infarction complicated by AVB, and it could decrease the incidence of serious complications such as myocardial perforation.