Effect of endocardiac pacing by steel wire electrode cardial puncture on living dog myocardium with normal heart beat / 中国中西医结合急救杂志

ABSTRACT

Objective To observe the parameters and effect of endocardial pacing by steel wire electrode cardiac puncture on heart with normal beat in living animal, and evaluate its safety.Methods After anaesthesia and thoracotomy in 6 living dogs with normal heart beat, the pericardia were excised. Steel wire electrodes with annular or hook tips were used respectively at right ventricular 4 corresponding spots to perform cardiac puncture endocardiac pacing (each dog experienced 8 times of puncture); the time from puncture to effective pacing, pacing parameter and puncture complication (time and quantity of bleeding) of each electrode at each spot were recorded. Finally, the two types of electrode completed 24 times of manipulation respectively; the data collected of the two types were compared. Results The cardiac pacing successful rates in the two groups were 100%; the time taken from the beginning of heart puncture to effective pacing in annular tip group was less than that in hook tip group, but the time difference between the two groups showed no statistical significance (s 18.4±2.3 vs. 19.6±4.1,P > 0.05). The parameters of pacing in the annular tip group, such as operation time (s 18.4±2.3 vs. 19.6±4.1), the threshold value of pacing (V 2.1±0.2 vs. 2.2±0.8), the amplitude of R wave sensed (mV 11.3±3.2 vs. 12.6±4.1) and the impedance of electrode (Ω 674.2±89.7 vs. 668.5±101.3) were not significantly different compared with those in the hook tip group (allP > 0.05). Either after puncture or after the electrodes were taken out, the time of bleeding [after puncture (minutes) 4.4±2.3 vs. 4.5±3.1, after the electrodes taken out (minutes) 4.1±2.2 vs. 4.8±2.5] and the volume of bleeding [after puncture (mL) 2.8±2.4 vs. 3.2±3.5, after the electrodes taken out (mL) 3.3±1.7 vs. 3.5±2.6] were not significantly different between the two groups (allP > 0.05).Conclusions In living dogs with normal heart beat, the manipulation and function of endocardiac pacing by cardiac puncture with either steel wire annular or hook tip electrode are well and effective, and the performance is simple and safe without any serious myocardial injury and complication. Thus, it is helpful to quickly establish efficient endocardiac pacing in emergency cases.