The Study Of Correlation Between Left Atrium Scar Area With Radiofrequency Ablation Destination And Prognosis In Persistent Atrial Fibrillation Patient

Objective : persistent atrial fibrillation is complicated due to its sustaining factors and recur factors. The aim of this study is to investigate defferent left atrium low voltage areas by Carto mapping system, which is used for guiding ridiofrequncy ablation therapy.Methods:A total of 20 persistent atrial fibrillation patients who underwent the ridiofrequncy ablation from 2007 to 2010.They were divided into two groups by ablition destination, one is re-sinus rhythm group( meam age58.4±8.8Y,mean case history9.0±7.4M),the other one is un-sinus rhythm group( meam age 50.8±12.9Y,mean case history10.4±5.78M), and we divid left atrium into different departments by Carto mapping syetem and CTmerge.ROOF:It's an area which between the line of left superior to right superior pulmonary vein and a line which is upside tangent line of left atrial appendage. POST: The area among the four tangent lines of four pulmonaries veins.from the normaposterior of pulmonary veins.BASE(coronary sinus that endocardial surface):area between left inferior-right inferior pulmonary veins line and tangent line that below mitral valve annulus . ANTERIOR:the area between tangent line that upside the mitral valve annulus and upside tangent line of left atrial appendage .MVdepartment: Area between left inferior pulmonary vein and side wall of mitral valve ,which include mitral valve. LAseptal: Area between mitral valve and right inferior pulmonary vein. LAA:The area of left atrial appendage.Four plumonary veins(plumonary veins vestibule):(LSPV,LIPV,RSPV,RIPV) areas of four plumonary veins porch that connected left atrium. Define the low voltage area that bipolar voltage<0.5mv as scar areas. Compute left atrium volume ,scar areas of different department by off-line software. Define recur as the patients were followed-up, atrial fibrillation can be certain found from ECG or Holter that 3 monthes after ablation。Deal with SPSS17.0 statistical software, measurement data to the mean±standard deviation(±s), comparison between groups using independent sample t test, non-normal distribution with rank sum test between two groups. P <0.05 was considered statistically significant.Results:1. Persistent atrial fibrillation patients who underwent the ridiofrequncy ablation were divided into two groups by ablition destination, one is un-sinus rhythm group which has 10 cases, the other is re-sinus rhythm group which has 10 cases. Compare two groups the minimum voltage difference significantly (0.038±0.01vs0.073±0.03 p=0.028) , Left atrium internal diameter and left atrium volume's comparison in the two groups are both enlargement (43.5±4.9 vs 39.2±3.2 p=0.013 , 133.7±23.2 vs 95.5±27.8 p=0.018).2. To compare the different scar areas of left atrium in the two groups of re-sinus rhythm group and un-sinus rhythm group. The two groups are not seen significant difference in the whole scar area (p=0.280). In the contrast of two groups of different departments scar areas it seems statistics difference in LAA, ANTERIOR( P = 0.004, 0.026, respectively) are statistically significant. It means the scar areas of LAA, and ANTERIOR can affect ablition destination.3. The relationship between scar areas and prognosis Follow-up after ablition (average follow up time is19.3±6.19 months ),there are 5 patients recurrent, including 1 case in re-sinus rhythm group and 4 cases in un-sinus rhythm group. the recurrence rate is 25%.Comparison of two groups, that the scar areas of whole left atrial and LAA,ANTERIOR,LAseptal,Mitral isthmic have a certain statistically significant (p=0.013,0.025,<0.001,0.034,0.014),it promt that the persistent atrial fibrillation patient who have more scar areas of the four department and the whole left atrial that the more possibility recurrence after ablation .Conclusion:1,Persistent atrial fibrillation with less left atrium internal diameter and left atrium volume will easier to end the radiofrequency ablition. The larger scar area of LAA or ANTERIOR that <0.5mv ,the more possibility of in vitro electrical conversion .2. The lower left atrium minimum voltage is, the lower possibility of re-sinus -rhythm intraoperative is.3. These patients who have larger scar area may be recur.At the same time ,changes in low voltage areas of LAA,ANTERIOR,LAseptal and Mitral isthmus also could affect the recurrence.