Introduction: The precise role of irregular ventricular response in atrial fibrillation (AF) has not been fully elucidated. This study examined the independent effects of rhythm regularity in patients with chronic AF.
Methods and results: This study included 50 patients who had chronic lone AF and a normal ventricular rate. Among these patients, 21 who underwent AV junction ablation and implantation of a VVIR pacemaker constituted the ablation group; the other 29 patients were the medical group. Acute hemodynamic findings were measured in 21 ablation patients before ablation (during AF, baseline) and 15 minutes after ablation (during right ventricular pacing). Compared with baseline data, ablation and pacing therapy increased cardiac output (4.7 +/- 0.8 vs 5.2 +/- 0.9 L/min; P = 0.05), decreased pulmonary capillary wedge pressure (16 +/- 5 vs 13 +/- 4 mmHg; P = 0.001), and decreased left ventricular end-diastolic pressure (14 +/- 4 vs 11 +/- 3 mmHg; P < 0.05). After 12 months, the ablation group patients showed lower scores in general quality of life (-20%; P < 0.001), overall symptoms (-24%; P < 0.001), overall activity scale (-23%; P = 0.004), and significant increase of left ventricular ejection fraction (44% +/- 6% vs 49% +/- 5%; P = 0.02) by echocardiographic examination.
Conclusion: AV junction ablation and pacing in patients with chronic AF and normal ventricular response may confer acute and long-term benefits beyond rate control by eliminating rhythm irregularity.