| Objective To investigate the effects of CPVI on atrial electrical remodeling in patients with paroxysmal atrial fibrillation, the effective refractory period(ERP), the effective refractory period dispersion(d ERP) of atrium and the atrial activation conduction time changes before and after circumferential pulmonary vein isolation(CPVI) are compared.Methods 30 patients who underwent radiofrequency catheter ablation for paroxysmal AF were enrolled in this study. Using FAM mode, the RA and LA anatomical models were achieved in the CARTO 3 system. SVC, MRA, RAA, LA-A, LA-R, LA-P, LAA, LSPV, LIPV, RSPV, RIPV, CSp, CSd, were respectively located in the RA or LA anatomical model. Before and after CPVI, ERPs were measured in different parts of the atrium using programmed stimulation. The ERPs and d ERPs of the RA(SVC, MRA, RAA, CSp), LA(LA-A, LA-R, LA-P, LAA, CSd), PVs(LSPV, RSPV, LIPV, RIPV), and A(the whole atrium) were compared. Bilateral CPVIs were completed in all patients, and PV-LA bidirectional conduction block was achieved. Left atrial conduction time(CSp ~ CSd conduction time), and interatrial conduction time(RAA ~ LAA conduction time) were measured before and after CPVI. The occurrence of atrial arrhythmias induced by programmed stimulation and vagal response to the operation were recorded. The changes of electrophysiological characteristics of atrium before and after CPVI were observed.Results(1) ERP and d ERP of different parts in the atrium comparison before CPVI: Comparisons of ERPs in different parts of atrium: RAA(197.4 ± 28.6) ms was the minimum(P < 0.01); secondly for PVs, respectively, LSPV(213.0 ± 47.5) ms, LIPV(208.9 ± 45.9) ms, RSPV(209.3 ± 43.6) ms, RIPV(213.5 ± 48.1) ms, and LAA(218.1 ± 28.3) ms. Comparisons of ERPs and d ERPs in RA, LA, and PVs: PVs ERP(211.2 ± 35.2) ms was the shortest, RA ERP(226.7 ± 24.0) ms, LA ERP(241.2 ± 21.8) ms, the difference between them were statistically significant(P < 0.05); RA d ERP(62.4 ± 23.5) ms, LA d ERP(54.0 ± 26.5) ms, PVs d ERP(57.2 + 36.0) ms, there were no statistical difference(P > 0.05). Compares of ERPs and d ERPs according history of AF, and LA diameter: Group A(history of AF<12 months), Group B(history of AF?12 months): the ERPs of LA, LA-PV, and A in Group B were shortened, the difference was statistically significant; the d ERPs were not significantly different. Group A(LA diameter?40 mm), Group B(LA diameter<40 mm): the ERPs of LA, LA-PV, and A in Group A were prolonged, the difference was statistically significant; the d ERPs were not significantly different.(2) Comparisons of ERPs and d ERPs before and after CPVI: Comparisons of ERPs in different parts of atrium: RAA(197.4 ± 28.6 ms VS 208.6 ± 32.2 ms, P<0.01), CSp(234.7 ± 29.1 ms VS 246.9 ± 29.7 ms, P<0.01), LA-R(242.9 ± 28.9 ms VS 258.3 ± 26.9 ms, P<0.01), LA-P(252.2 ± 28.5 ms VS 261.1 ± 30.2 ms, P<0.05), CSd(238.6 ± 28.3 ms VS 250.3 ± 23.6 ms, P<0.01), they were statistically prolonged after CPVI. Comparisons of ERPs in RA, LA, and PVs: RA(227.0 ± 23.7 ms VS 235.9 ± 21.7 ms, P<0.01), LA(241.0 ± 21.5 ms VS 249.7 ± 19.9 ms, P <0.01), LA-PV(228.5 ± 24.0 ms VS 249.8 ± 20.3 ms, P <0.001), A(228.0 ± 21.9 ms VS 243.4 ± 19.0 ms, P <0.001), they were statistically increased after CPVI. Comparisons of d ERPs in RA, LA, and PVs: RA(62.1 ± 23.0 ms VS 64.1 ± 20.7 ms,P>0.05), LA(54.1 ± 25.5 ms VS 54.9 ± 20.4 ms, P>0.05), LA-PV(88.7 ± 34.1 ms VS 54.3 ± 20.5 ms, P <0.001), A(107.6 ± 32.9 ms VS 80.9 ± 21.2 ms, P<0.001), d ERPs of LA-PV and A were reduced after CPVI, the difference between them were statistically significant. Comparisons of atrial conduction time: CSp ~ CSd conduction time(28.7 ± 7.2 ms VS 32.4 ± 10.0 ms, P<0.05), the left atrial conduction time was prolonged, and the difference was statistically significant after CPVI. RAA ~ LAA conduction time(51.3 ± 15.7 ms VS 51.6 ± 14.4 ms, P>0.05), there was no statistical difference. Atrial arrhythmias were induced by 90 times before CPVI, RAA(17), LAA(12), and PVs(36), whose ERPs were short; and after CPVI were induced by 8 times, RAA(4), LAA(3), and SVC(1).(3)Vagal reaction occurred in 15 cases(50%); vagal response group(15 cases), and no-vagal response group(15 cases). The ERP of LA, RA in the vagal response group were longer than before operation(P < 0.05), but there was no difference in the no-vagal response group. There wasn't significant difference in d ERP before and after CPVI.Conclusions(1) Compared with other parts of atrium, ERPs of PVs, LAA and RAA are significantly short in patients with paroxysmal AF; In PVs, LAA, and RAA atrial arrhythmias are easily to induce by programmed stimulation.(2) Comparision of ERPs in paroxysmal AF: PVs ERPs is the shortest, followed by RAs, LA ERPs is the longest; and there is a large ERP gradient change between PVs and LA.(3) ERPs of RAs, LAs, As, and LA-PV are increased after CPVI; d ERPs of LA-PV and A are decreased after CPVI.(4) After CPVI, the left atrial conduction time is prolonged.(5) Atrial arrhythmia is less likely to be induced after CPVI. |
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