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Objective We sought to evaluate the efficacy of bipolar radiofrequency ablation of atrial fibrillation (AF) in patients undergoing cardiac surgery,and to determine independent factors affecting the recurrence.Methods From June 2007 through February 2010,81 patients with atrial fibrillation underwent a modified Cox-Maze Ⅳ procedure using a biopolar radiofrequency device( Medtronic in 32 cases,Atricure in 49 cases).There were 45 males and 36 females,aged (48.2 ± 11.0)years,including 26 cases of permanent AF,44 cases of persistent AF and 11 cases of paroxysmal AF.The mean duration time of AF was (7.56 ± 7.47 ) years.The left atrial diameter were 36 ～ 72 mm.In conjunction with cardiac surgery including:mitral valve replacement (MVR) (or add tricuspid valve plasty (TVP) in 33 cases,mitral and aortic valve replacement (DVR)( or add TVP) in 18 cases,off-pump coronary artery bypass surgery (OPCAB) in 16 cases,aortic valve replacement (AVR) in 4 cases,MVR and coronary artery bypass grafting (CABG) in 1 case,mitral valve plasty (MVP) in 1 case,and others in 8 cases.Among them,22 patients were undergoing electrophysiological mapping by high-frequency bipolar stimulation from June 2009 to February 2010.A follow-up of 12 to 44 months was completed.Recurrences were evaluated by 12-lead ECG or 24 hour Holter recording every clinic visit-1,3,6,9,and 12 months after the procedure and yearly thereafter,or if symptoms developed.Multivariate regression analysis was performed to determine independent factors affecting the recurrence.Results Hospital mortality was 1.23％.The successful ablation of AF were 100％,82.5％,and 84.8％ immediately after operation,at discharge,and at 2(6.1 ± 13.6) months after operation respectively.Multinomial regression analysis showed small left atrium ( ＜ 60 mm),and electrophysiological mapping might contribute better sinus rhythm restoration ( P ＜ 0.05 ).Conclusion Bipolar radiofrequency ablation of atrial fibrillation in patients undergoing cardiac surgery is safe and effective.Small left atrium ( ＜ 60mm) and electrophysiological mapping should be considered to improve results in selected patients.
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Objective To evaluate left atrial (LA) function by real-time three-dimensional echocardiography (RT-3D) and speckle tracking imaging (STI) after circumferential ablation of pulmonay vein ostia for atrial fibrillation guided by carto mapping system. Methods Thirty patients who had ablation procedure for paroxysmal atrial fibillation were accepted echocardiography to estimate the LA function at pre-operation,3 days and 3 months of post-operation. The LA maximal, minimal and pre-systolic volume (LAVmax, LAVmin and LAVp), LA passive ejection fraction (LAPEF), LA active ejection fraction (LAAEF) were measured by RT-3DE respectively. The strain rate curve was acquired in each LA segment (anterior, posterior, lateral, inferior and septal) by STI. Systolic strain rate (SRs), early diastolic strain (SRe) and late diastolic strain rate(SRa) of each left atrial segments were measured. Results Comparing with preoperative,3 days post-ablation SRs,SRe and SRa decreased significantly in each wall of LA. After 3 months,SRa and SRe in anterior, inferior and septal were significantly improved, however, SRs showed no significant difference. LAVmax and LAVpre were significantly decreased. LAPEF and LAAEF were significantly improved. Conclusions The patients with circumferential pulmonary vein ablation were in a deterioration after three days. The pump function and conduit functions of left atrial were increased after 3 months.
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BACKGROUND: Lone atrial fibrillation(LAF) is defined by the presence of atrial fibrillation(AF) in the absence of any other clinical evidence to suggest a primary cardiac disease. In general, it has been accepted that LAF is a benign from of AF, but there is some evidence that LAF may induce atrial enlargement and left ventricular dysfunction. Atrial enlargement has also been reported to reduce the success rate of cardioversion to sinus rhythm, and in addition thrombus formation is more likely to occur in larger atria. Therefore this study was designed to detect any structural characteristics or functional abnormality in patients with LAF. METHOD: Twenty six patients with LAF(19 men and 7 women ; age 52±12 years) were studied by echocardiography and compared with 12 normal persons(2 men and 10 women ; age 47±7 years). Patients were divided into recurrent paroxysmal group(11 patients) and chronic group(15 patients) according to the character of LAF. Three orthogonal dimensions of both left atrium(LA) and right atrium(RA) were measured echocardiographically, and atrial volume was calculated. Peak early diastolic transmitral inflow velocity(E), peak velocity during atrial contraction(A), and deceleration time(DT) of E wave measured by Doppler echocardiography. RESULTS: Cardiac abnormalities in patients include trivial mitral regurgitation(12 cases), trivial tricuspid regurgitation(8 cases), senile aortic valve sclerosis(7 cases), and mild senile calcification of mitral annulus(1 case) and papillary moscle(1 case). LA volume(65.1±32.8 vs 38.3±10.4cm2, p < 0.01), RA volume(65.6±23.0 vs 38.7± 10.3cm2, p < 0.01), and DT(216±32 vs 194±19msec, p < 0.05) were significantly increased in patients with LAF as compared with the cotrol group. RA volume(54.2±16.6 vs 38.7±10.3cm2, p < 0.05) and DT(231±23 vs 194±19msec) were significantly increased, and E/A(1.1±0.4 vs 1.4±0.3 p < 0.05) was signficantly decreased in the parxysmal group as compared with the control group. LA volume(78.4±33.9 vs 46.9±21.3cm2, p < 0.01) and RA volume(74.0±23.9 vs 54.2±16.6cm2, p < 0.05) were significantly increased and left ventricular ejection fraction(60±7 vs 68±6%, p < 0.01) tended to be decreased in the chronic group as compared with the paroxysmal group. CONCLUSION: Atrial enlargement and left ventricular diastolic dysfunction were noted in patients with LAF. The degree of atrial enlargement in the chronic group was much more than that in the paroxysmal group. We conclude that LAF per se is associated with both atrial enlargement. Left ventricular diastolic dysfunction in these patients needs to be further investigated.