Objective To evaluate the effect of modified Maze lines plus pulmonary vein (PV) isolation created by radiofrequency catheter ablation (RFCA) on atrial wall guided by a novel geometry mapping system in the treatment of elderly patients with paroxysmal atrial fibrillation (PAF). Methods After regular electrophysiological study, transseptal punctures were achieved twice with Swartz L1 and R1 sheaths. PV angiographics were conducted to evaluate their orifices and branches. A balloon electrode array catheter with 64 electrodes was put in the middle of the left atrium. Atrium geometry was constructed using Ensite 3000 Navx system. Two RFCA lesion loops and three lines (modified Maze) were created on left and right atrial walls. Each lesion point was ablated for 30 seconds with preset temperature 50 (?)and energy 30W. The disappearance or 80% decrease of the amplitude of target atrial potential and 10 to 20. decrease of ablation impedance were used as an index of effective ablation. Results A total of 11 patients (7 male and 4 female, mean age, 68.7±5.1 years) were enrolled. PAF history was 7.9±4.5 years. PAF could not be prevented by mean 3.1±1.6 antiarrhythmic agents in 6.3±3.4 years. None of the patients had complications with structural heart disease or stroke. Left atrial diameter was 41.3±3.6 mm and LVEF was 59.2±3.7 % on echocardiography. Two loops and three lines were completed with 67.8±13.1 (73-167) lesion points. Altogether 76-168 (89.4±15.3) lesion points were created in each patient. PAF could not be provoked by rapid burst pacing up to 600 beat per minute delivered from paroxysmal coronary sinus electrode pair. Complete PV electrical isolation was confirmed by three-dimensional activation mapping. Mean procedure time was 2.7±0.6 hours and fluoroscopy time was 17.8±9.4 minutes. Patients were discharged with oral aspirin and without antiarrhythmic agents. During follow up of 6.5±1.8 months, seven patients were PAF symptom free (63.6%). PAF attacks were decreased more than 70% in two patients (18.2%). PAF frequency did not change in another two patients (18.2%). Conclusions Ensile 3000 Navx guided modified Maze lines plus PV isolation on the atrial wall is safe and feasible in the elderly palienls. It has the advanlages of exact procedural endpoint, shorter X-ray exposure, fewer complications and salisfied long-term effect PAF control. (J Geriatr Cardiol 2005;2(2): 95-100). Objective To evaluate the effect of modified Maze lines plus pulmonary vein (PV) isolation created by radiofrequency catheter ablation (RFCA) on atrial wall guided by a novel geometry mapping system in the treatment of elderly patients with paroxysmal atrial fibrillation (PAF). Methods After regular electrophysiological study, transseptal punctures were achieved twice with Swartz L1 and R1 sheaths. A balloon electrode array conducted with evaluate their orifices and branches. A balloon geometry array built with 64 electrodes was put in the middle of the left atrium. Both lesion loops and three lines (modified Maze) were created on left and right atrial walls. Each lesion point was ablated for 30 seconds with preset temperature 50 (?) And energy 30W. The disappearance or 80% decrease of the amplitude of target atrial potential and 10 to 20. decrease of ablation impedance were used as an index of effective ablation. Results PAF could was be prevented by mean 3.1 ± 1.6 antiarrhythmic agents in 6.3 ± 3.4 years. None. A total of 11 patients (7 male and 4 female, mean age, 68.7 ± 5.1 years) were enrolled. of the patients had complications with structural heart disease or stroke. Left atrial diameter was 41.3 ± 3.6 mm and LVEF was 59.2 ± 3.7% on echocardiography. Two loops and three lines were completed with 67.8 ± 13.1 (73-167) lesion points. Altogether 76-168 (89.4 ± 15.3) lesion points were created in each patient. PAF could not be provoked by rapid burst pacing up to 600 beat per minute delivered from paroxysmal coronary sinus electrode pair. Complete PV electrical isolation was confirmed by three-dimensional activation The mean procedure time was 2.7 ± 0.6 hours and fluoroscopy time was 17.8 ± 9.4 minutes. Patients were discharged with oral aspirin and without antiarrhythmic agents. During follow-up of 6.5 ± 1.8 months, seven patients were PAF symptom free (63.6%). PAF attacks w ere decreased more than 70% in two patients (18.2%). PAF frequency did not change in another two patients (18.2%). Conclusions Ensile 3000 Navx guided modified Maze lines plus PV isolation on the atrial wall is safe and feasible in the elderly palienls . It has the advanlages of exact procedural endpoint, shorter X-ray exposure, fewer complications and salived long-term effect PAF control. (J Geriatr Cardiol 2005; 2 (2): 95-100).