Different Role of Left Atrial Size and Function in Patients with Paroxysmal versus Persistent Atrial Fibrillation. Wellnhofer: LA Size & Function in Atrial Fibrillation

Purpose: Pulmonary vein isolation (PVI) is established as interventional treatment in atrial fibrillation (AF). Recent studies suggest that atrial reservoir function (preload) is involved in initiation of paroxysmal AF (AFparox) and conduit function (after-load) may be crucial in persistent AF (AFpers). Methods: We enrolled 336 consecutive patients scheduled for PVI (age 60±10 years). Point-to-point radiofrequency ablation was used in the majority of cases. Success was defined as a minimum of 3 months (median 12 months) follow-up as absence of recurrence of AF in any Holter ECG since PVI. Results: Patients with recurrent AFparox demonstrated a significantly better outcome (64% success) than patients with AFpers (41% success). AFparox patients were 5 years younger and had smaller atria, a better emptying index, higher systolic pulmonary venous velocity, and only borderline impaired diastolic left ventricular function. LA size per se was not related to success in AFparox. Left ventricular filling times (Tfill) and the ratio of systolic to diastolic tissue Doppler (TDI) velocity (S'/E') were found to be potential risk predictors. Increased LA-size, reduced LA-emptying and impaired diastolic left ventricular function were found in AFpers patients. S'/E' and isovolumic relaxation time stratify risk in AFpers patients. Conclusions: In AFparox long term failure of primary PVI is associated with restrictive reservoir function but not LA enlargement. Whereas in AFpers a combination of severely reduced LA emptying, increased LA size and severely impaired diastolic LV function result in a high rate of recurrent AF. TDI (Tfill, S'/E') may help to improve risk stratification.