Experimental Studies Of Effects Of Extracorporeal Skock Wave On Canine Hearts

PURPOSES: Purposes extracorporeal shock wave(ESW) discharged on canine hearts in the study is: to study effects of ESW on canine cardioelectrophysiology and to study mechanisms of arrhythmia induced by ESW; to study effects of ESW on canine hemodynamics; to study effects of ESW on plasma levels of enzymes and morphology of myocardium; to stuy effects of ESW on blood cells and cllotting funtion. MATERIALS AND MTHODS: The ends of electrode catheters were taken as the markers of localization by X ray fluoroscopy. Areas of canine hearts ESW discharged respectively at were the right atrium, atrioventricle junction area and apex of the right ventricle. ESW was discharged by JT ESWL桰II extraeorporeal shock wave lithotriptor. Effects of ESW on canine hearts were studied from the following four parts: Determining cardioelectrophsiological parameters and recording arrhythmia Three 6F Cordis electrode catheters of four lectrode were respectively inserted into left and right femoral vein and cervical vein, and then they were put respectively at the atrium, atrioventricle junction area and apex of the right ventricle. Endrocardiac electrogram and el ectro cardiogram were recorded, cardioelectrophsiological parameters were determined after and before discharges of ESW, which were relative refractory p en od(RRP), effective refractory period(ERP) and their 4 dispersion, diastolic threshold and Q-T dispersion(Q-Td), Wenckebach抯 period point and 2:1 blocking point of atroventricular conduction, sinoatrial conduction time(SACT), sinoatrial node recovery time (SNRT) and corrected sinoatrial node recovery time(SNRTc). Categories and their counts of arrhythmias were recored for 4 hours before and after discharges of ESW and in the course of discharges of ESW. Monitoring parameters of hemodynamics Femoral arterial pressure was monitored by cannulas placed right femoral artery. Swan- Gans catheters were respectively put into the right atrial, right ventricle and the pulmonary artery through right femoral vein and inferior vena cava. Their pressures were monitored respectively before and after discharges of ESW. Cardiac output was determined by themodilution method before and after discharges of ESW. Determinating plasma levels of enzymes of myocardium and examinating morphology of myocardium 2m1 Venous blood was taken out before discharges and 0-2-4 hours after discharges. plasma levels of enzymes of myoeardium were determined by automatic biochemistry analyst. The enzymes determined were ereatine phosphokinase(CK) and its isoenzyme(CK-MB), alanine-glusate trans-aminase(AST), lactate dehydrogenase(LDH). Canine hearts were taken out from their pectoral cavities at the end of experiments. Morphologic examination of hearts based on observetion of light microscope and electron microscopy was performed after specimen were formed. blood cells count and Determination of PT and APTT Venous blood was taken out before and after discharges of ESW, blood cell count and test of PT and APTT were performed. RESULTS: Effects of ESW on cardioelectrophysiology of canine hearts After discharges of ESW. RRP, ERP and their dispersion, diastolic threshold of atrium and ventricle, Q-Td, all of them remained unchanged (P>O.05). Wenckebach抯 period point and 2:1 blocking point of...