The Study Of Acute Electrical Remodeling Of Canine Pulmonary Vein

Atrial fibrillation is one of the common arrhythmia in clinic. Its morbility is about 1% every year in our country.AF can damage the function of heart and induce artery embolism.To clarify the mechanism of AF has crucial meaning for mankind to conquer the serious disease. Most paroxysm AF originate from pulmonary vein. The fact has been confirmed that pulmonary vein muscle sleeve extends from atrium muscle.Atrial electricaL remodeling (AER)is very important to the occurrence and the maintaining of AF.So,it is necessary to research the pulmonary electrical remodeling and the effect on the occurrence and maintaining of AF.Most experiment about the electrical remodeling related to the atrium remodeling. Some experiments about pulmonary electrical remodeling were completed by means of stimulating atrium.We adopted the method that stimulating pulmonary directly.The datum are more exact because of avoiding the conducting block or slow conduction between left atrium and pulmonary vein.The prevalent operation of pulmonary vein electricityisolation can cut off the conduction between the left and pulmonary,but may be that don not eliminate the focus of AF located in pulmonary vein.Fast electricity activity can exist in pulmonary some time.We anticipate this kind of electricity activity will lead pulmonary vein effective refractory period to shorten.There will be effect on AF begetted from pulmonary vein.In addition,we observed the effect of veripamil and atropine on pulmonary vein effective refractory period.Objective:To investigate the alteration of (PV-ERP)and PV-ERP rate adaptability and the inducible rate of AF after ten minutes rapid PV stimulation;To observe the changing of conduction duration between PV and left atrium after 10 minutes rapid PV stimulation.To investigate the effect of veripamil and atropine on PV-ERP and PV-ERP rate adaptability after ten minutes rapid PV stimulation.Method:Annular electrode was placed on ostia pulmonary veins of 24 healthy canines.Stimulating electrode was placed on distal pulmonary vein.The first step experiment:Basic PV-ERP(PCL400ms, 300ms) was measured firstly. After Stimulating to distal pulmonary vein for ten minutes by maximum frequency that 1:1 pacing pulmonary vein,PV-ERP was remeasured immediately,at 5min and at 10min, respectively. Next,AF inducible rate and AF duration before and after rapid PV stimulation for ten minutes was observed.S1S1 burst stimulus and S1S2 programmed stimulus method was adopted.Finally,the veripamil was gived in 10 canines and the atropine was gived in 6 canines respectively when above experiment had been completed for 15 minute.Then the first step experiment was repeated.Result:After rapid pulmonary vein stimulation for 10 mins PV-ERP shortened and PV-ERP rate adaptability decreased at...