Evaluation The Effect Of Circumferential Pulmonary Vein Ablation In Atrial Fibrillation

Objective: To investigate and evaluate the efficacy of circumferential pulmonary veinablation(CPVA) in atrial fibrillation (AF).Methods: From January2010to September2011,56patients with complaint ofrepeated attacks of AF were admitted to the cardiovascular department of the FirstAffiliated Hospital of Soochow University and received CPVA. They all had been treatedwith anti-arrhythmic drugs. But there were no effect. Amony them there were36males and20females. The average age was59.7±8.3years old. Average atrial fibrillation durationwas6.8±5.9years. There were52cases with paroxysmal AF,4cases with persistent AF.There were29cases with hypertension,2cases with hypertrophic cardiomyopathy,2caseswith coronary heart disease,1case with congenital ventricular septal defect,3cases withdiabetes mellitus. Twenty patients received pulmonary vein pacing during oberation beforeand after CPVA. The pulmonary vein pacing thresholds were measured in order to verifythe exit block between pulmonary vein and left atrium. After ablation patients werefollowed up for1~24months with routine electrocardiogram(ECG),24hourselectrocardiogram and echocardiography. If the patients had symptoms of palpitationduring follow-up, we recorded the ECG. According to the follow-up result patients weredivided into2groups: group A (success group) and group B (recurrence group). Patients ingroup A didn’t has episodes of AF,atrial flutter or atrial tachycardia without usinganti-arrhythmic drugs or using preoperative ineffective anti-arrhythmic drugs during3months after ablation,and AF episodes load was significantly reduced. Patients in group Bhad recurrence of AF, atrial flutter or atrial tachycardia,and the duration was greater than orequal to30seconds. We analysed the effect of CPVA on AF and the relationship betweenrecurrence and clinical variables including sex, age, type of AF, duration of AF, episodes of AF duration, presence hypertension, Left atrial anteroposterior dimension (LAAPD),leftventricular end diastolic diameter(LVEDD), left ventricular ejection fraction (LVEF)andbody mass index(BMI).Results: All cases were followed up for6~26(14.1±5.1) months, the success ratewas71.4%(40/56). The recurrence rate was28.6%(16/56). Four cases with persistent atrialfibrillation were followed up for9~15months, the success and recurrence rate was75%and25%, respectively. Six cases whose heart rhythm were converted to sinus rhythm werefollowed up for6~24months, the success and recurrence rate was both50%.Among12cases with early recurrence4cases had no episodes of AF3months later. Ten casesreceiving secondary ablation were followed up for4~18months. their success andrecurrence rate was80%and20%, respectively.Univariate analysis revealed that longerepisodes of AF duration, larger LAAPD, higher BMI were significantly related to therecurrence of AF after ablation(P<0.05). Logistic regression analysis revealed the episodesof AF duration was the only independent risk factor of recurrence(OR=1.002, P=0.016).Before CPVA, left superior, left inferior, right superior, right inferior pulmonary veinpacing threshold of20cases was2.3±0.3V,1.9±0.3V,2.0±0.4V,1.8±0.3V; after CPVA,the value was26.1±4.9V,23.8±7.3V,24.4±7.9V,22.7±8.3V; There was significantdifference between values before and after CPVA. The difference between four pulmonaryveins pacing threshold were not statistically significant(P>0.05) before CPVA or afterCPVA. Before CPVA, the average pulmonary vein pacing threshold was2.0±0.3V. AfterCPVA, the average pulmonary vein pacing threshold was24.8±6.0V. Operationcomplications included pericardial tamponade(2cases), right lower limb deep venousthrombosis(1case) and femoral artery-vein fistula(1case).Conclusions:1. CPVA is an effective treatment of AF. But there are somecomplications and recurrence rates.2. AF patients with longer episodes of AF duration,larger LAAPD, higher BMI are susceptible to recurrence of AF after CPVA. Episodes ofAF duration is the independent risk factor of recurrence.3. Pulmonary vein pacingthreshold (24.8±6.0V,10ms) suggest that CPVA can isolate pulmonary vein successfully.