Effects Of Estradiol Combined With Progesterone On Experimental Arrhythmia In Rabbits

Objective: To investigate the effects and mechanism of estradiol combined with progesterone on experimental arrhythmia in rabbits in toto. Methods: Thirty-two New Zea . land female rabbits were randomly divided into four groups: control group, lidocaine group, estradiol group and estradiol combined with progesterone group. After abdominal anesthesia, supination fixation and tracheal intubation, the surface electrocardiogram (ECG), mean artery pressure (MAP) and cardiac function which was measured by inserting pipes into rabbits' left ventricle were simultaneously recorded in each group after infusion of 0.1% adrenaline with the dose of 75μg /kg. The effect of adrenaline on ECG, MAP, cardiac function as well as arrhythmogenesis was analyzed and compared between each group. Results: Adrenaline can induced ventricular arrhythmia because of augmentation of excitability and autorhythmicity, at the same time, the cardiac function [Left Ventricle Systolic Pressure(LVSP), Maximum Positive Left Ventricle Pressure Change(+dp/dtmax), Maximum Negative Left Ventricle Pressure Change (-dp/dtmax)] significantly elevate while Left Ventricle End-Diastolic Pressure (LVEDP) decrease, MAP apparently rise, heart rate markedly accelerate, QRS time prolong after quick infusion of adrenaline. Estradiol combined with progesterone may evidently prolong the latency of Ventricular Premature Beats (VP) and shorten the duration of Ventricular...