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Abstract

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. in particular pulmonary vein isolation (PVI), can be considered as an early option in the management of patients with AF [5]. Success rates of the initial ablation procedure depend on the definition of success; they vary between 60 and 85% for AFparox and are lower for persistent AF (AFpers) [3,[6][7][8][9].The initiation of AF requires both a trigger and a susceptible substrate. In recurrent AFparox ectopic focal activity is thought to be local and limited to one or a few sites. On the contrary in AFpers there tend to be multiple ectopic sites throughout the atria and advanced damage of atrial myocardium (more susceptible substrate) [10][11][12][13]. Large left atrial (LA) size was found to be a predictor of recurrence of AF after electrical or pharmacological cardio-version as well as after ablative treatment [14][15][16][17]. The prognostic value of volume seems to be absent in AFparox, however [18].LA function comprises three phases: reservoir, conduit and active contraction phase [19]. LA-active function increases with slight volume load as long as LA structural dilatation is limited [19,20]. Thus, in early LA dysfunction as expected in AFparox systolic LA dimensions are ambiguous, because an increased systolic volume may reflect increased loading and/or size (history of dilatation).Recent studies suggest that preserved atrial reservoir function related to preload is a predictor of success [21]. Impairment of atrial reservoir function and poor long-term success of PVI in small left atria was related to enhanced fibrosis [22]. Whereas conduit function related to after-load may become increasingly important for PVI success in large atria with poor emptying.Thus, we tested the hypothesis that in AFparox atrial reservoir function and in AFpers residual conduit function is crucial for success of PVI by an analysis in the function-size plane in a retrospective study in our PVI data-base. As second end points we wanted to identify echocardiographic parameters potentially predicting recurrence of AF after PVI and elucidate the impact of body mass index (BMI) in this context.