ABSTRACT
AIM: To evaluate the effect of cardiac pacing with a His bundle lead on cardiac electrophysiological and haemodynamical action in dogs and the experience of location technique with His bundle pacing lead. METHODS: With opening chest operation in general-anesthetized dogs, a special lead was located at His bundle based on a typical "H" wave and narrow duration of the QRS wave recorded in ECG; Platinum leads were fixed at the epicardium of the right ventricular apex (RVA) respectively, forming HisB- VVI pacing,RVA- VVI pacing. Cardiac electrophysiological and haemodynamical parameters were compared in sinus rhythm and the different pacing models. RESULTS: The threshold of HisB pacing is similar to that of RVA pacing. Cardiac output(CO)is increased about 18.81% in HisB- VVI pacing than self. It is decreased about 5.41% in RVA- VVI pacing. SV is similar to self,but it is 25.59% higher in HisB- VVI than RVA- VVI . LVSW and RVSW in His B- VVI pacing is superior to that in RVA- VVI . CONCLUSION: His bundle pacing significantly improves cardiac function compared with the RVA- VVI pacing because it can maintain normal physiological electronic activation sequence and systolic synchrony and have a better haemodynamics effect.neral-anesthetizeddogs,as