Introduction Pulmonary vein isolation is an effective therapy for curing symptomatic atrial fibrillation (AF). While it is known the severity of left atrial (LA) enlargement affect the success of AF ablation, little is known the impact of intracardiac pressure on the ablation outcome.
Methods This prospective study consisted of 63 patients (mean age 57±9 years, 73% male) who underwent catheter-based pulmonary vein isolation for drug refractor symptomatic AF (48% paroxysmal, 52% persistent). All patients underwent simultaneous echocardiography and haemodynamic measurements including left ventricular end systolic pressure (LVEDP), mean left atrial pressure (LAP) and dP/dtmax using Millar catheter at the time of procedure during AF. Left atrial volume (LAV) was measure by biplane area length method. Recurrence of AF was defined as episodes of AF more than 5 min documented in 24h ambulatory ECG or event monitor.
Results After a mean follow-up duration of 16±7 months, AF elimination off anti-arrhythmic drugs was achieved in 70 % (44/63) of patients. Among the echographic and haemodynamic measurements, the baseline LAV and mean LAP were 57.62±25.39 ml and 12.19±4.57 mm Hg in AF free patients compared to 81.20±40.88 ml (p=0.02) and 16.46±4.14 mm Hg (p=0.01) in AF recurrence groups. Univariate and multivariate analysis showed LAP was the only independent predictor of the recurrence with an adjusted odd ratio of 1.27 (95% CI 1.04 to 1.54, p=0.03, table).
Conclusion LAP is a determinant of AF recurrence after AF ablation. Therapies towards reduction of LA filling pressure, especially in patients with elevated LAP, may improve the outcome of ablation.