Reversal of left ventricular dysfunction following ablation of atrial fibrillation

Evaluation of ventricular rate control in atrial fibrillation (AF) can be difficult, and the presence of an AF-induced ventricular cardiomyopathy due to intermittent poor rate control or other causes may be underestimated. The outcome with AF ablation in patients with a decreased left ventricular ejection fraction (LVEF) may provide insight into this important clinical issue.

To determine the effect of pulmonary vein isolation on LVEF in patients with AF and decreased LVEF (< or = 50%).

Ablation consisted of proximal isolation of arrhythmogenic pulmonary veins (PVs) and elimination of non-PV triggers. LVEF was determined within 24 hours after ablation and again at up to 6 months follow-up. Transtelephonic monitoring was performed routinely for 2-3 weeks prior to ablation, at 6 weeks, and 6 months post and with symptoms following ablation. AF control was defined as freedom from AF or marked (>90%) reduction in AF burden on or off previously ineffective antiarrhythmic medication.

AF ablation was performed in 366 patients and 67 (18%) patients had decreased LV function with a mean LVEF of 42 +/- 9%. An average of 3.4 +/- 0.9 PVs were isolated. AF control in the depressed LVEF group compared favorably with the normal EF group (86% vs. 87% P = NS), although more redo procedures were required (1.6 +/- 0.8 vs 1.3 +/- 0.6 procedures; P < or = 0.05). Only 15 of 67 patients (22%) with decreased LVEF had shown tachycardia (>100 bpm) on repeated preablation ECG recordings during AF. In the decreased LVEF group, the LVEF increased from 42 +/- 9% to 56 +/- 8% (P < 0.001) after ablation.

Patients with AF and decreased LVEF undergoing AF ablation have similar success to patients with normal LVEF and have improvement in LVEF after ablation. These results suggest the presence of a reversible AF-induced ventricular cardiomyopathy in many patients with AF and depressed LV function. The presence of under-recognized and reversible cardiomyopathy even when tachycardia is not persistent is important to recognize.