| Objective: Atrial fibrillation (AF) is a common arrhythmia, current studies have identified that radio frequency catheter ablation(RFCA) basing on pulmonary veins (PVs) isolation is an effective treatment ,specially for paroxysmal atrial fibrillation (PAF), RFCA is the treatment that intervent the matrix, it also have a good therapeutic effect in persistent AF patients. The characteristics of anatomical structure of pulmonary veins and left atrium may be a vital significance in the occurrence and maintainance of the mechanism of atrial fibrillation . The purpose of this research is to reconstruct 3-dimensional(3D) structure of the pulmonary veins and the left atrium through multislice computed tomography (MSCT) ,and then compare the variation of ostia, the antrum volume of pulmonary veins and the left atrium volume in AF patients with and without recurrence. This research also discusses the relationship between the differences in AF recurrences, in order to further explain whether the left atrial anatomical structure participate in the occurrence and maintainance of the mechanism of AF.Methods: We consecutively enrolled sixty-five AF patients who accept RFCA therapy from June 2008 to January 2009, patients were followed up for one year from the day of RFCA. AF electrocardiogram recordings decided the recurrence. we got twenty-one and forty-four patients with and without recurrence. All the process are pulmonary veins antrum circum isolation and necessary linear ablation. All the patients were injected with intravenous constrast medium before being evaluated by 16-slice computed tomography (MSCT). The 3D reconstruction of PVs and left atrium was transformed into AW4.2 system, and we calculated the variation of pulmonary veins by Cardiac IQ software. Diameters of PVs ostia were measured by virtual endoscopy. The antrum volume of PVs and the left atrium volume were calculated by software volume rendering(VR). we analyzed Continuous variable by mean±standard deviation and not matching t test, and we also analyzed categorical variable by absoluter frequency and chi-square test , P<0.05 considered that they had significant differences, data analysis used SPSS16 (SPSS Inc , Chicago, Illinois, USA).Results: twenty-one patients with recurrence ,one patients (9.5%) had common ostia or trunk of PVs and two patients (4.5%) had right middle PVs, 44 patients without recurrence, two patients (4.5%) had common ostia or trunk of PVs, two patients (4.5%)had right middle PVs. We compared the maximum and minimum diameter of PVs ostia in patients with and without recurrence group as follows: the maximum diameters, left superior PVs(21.99±3.45 vs. 18. 28±3.61mm, P<0.01), left inferior PVs (18.38±2.51 vs. 15. 21±3.22mm, P <0.05), right superior PVs (20.65±3.41 vs.17.79±2.46mm, P< 0.05), right inferior PVs (20.19±4.39 vs. 16.46±3.21 mm, P <0.01); the minimum diameter, left superior PVs (18.67±2.05 vs. 15.11±2.56 mm, P<0.01), left inferior PVs (16.86±2.17 vs. 14.41±2.12mm, P <0.01), right superior PVs (19.23±2.45 vs. 15.55±2.34mm, P <0.01), right inferior PVs (16.90±1.75 vs. 14. 68±2.12mm, P<0.01). The antrum volume of the bilateral PVs in the patients with recurrence was significantly larger than that in the patients without recurrence, left (3.84±0.75 vs. 3.24±0.49cm3, P<0.05), right(4.95±1.48 vs. 4.54±1.11cm3, P<0.01). The left atrium volume in the patients with recurrence group was also significantly larger than in the patients without recurrence group (99.85±22.67 vs. 91.23±17.31,P<0.05), The antrum volume of bilateral PVs justified with left atrial volume had no significant difference between the two groups (0.385±0.035 vs. 0.355±0.047, P=0.08; 0.496±0.013 vs. 0.499±0.009,P=0.11).Conclusion: The mutation rate of groups with and without recurrence do not have obvious difference, may be there is no relationship between the mutation rate and recurrence of AF. The maximum and minimum diameter of PVs ostia in the patients with recurrence group were significantly larger than that in the patients without recurrence group,may be the broadening of PVs is one of the important factors which can initiate AF recurrence. Significant enlargement of the left atrium volume of the bilateral PVs and left atrium increased the recurrence rate,but it had no relationship with the atrium volume of bilateral PVs justified with left atrium volume , it also shows us the enlargement of left atrium may be synchronized with the broadening of PVs, and they are all the important factors for AF recurrence. |
PDF Full Text Request