Abstract Introduction: Catheter ablation is an increasingly utilized procedure to manage symptoms of atrial fibrillation (AF). However, early incident acute heart failure (HF) can lead to increased resource utilization postablation. Methods: In the Multicenter prospective C ohort study examining L eft A trial P ressure and the risk of early incident H eart failure after catheter ablation of A trial F ibrillation (CLAPHAF) study, we examined risk factors for HF after AF ablation. Results: Of the 286 subjects enrolled, 11.8% of subjects experienced incident HF a median 14 (12, 31) days from ablation. Risk factors for incident HF were persistent AF, recurrent post ablation AF, procedural IV fluid administration, longer case duration, and lower procedural blood pressures. A threshold of 1400mL fluid administration had 2.21 odds ratio increase in incident HF (1.03-4.70, p = 0.04). The secondary endpoint of AF-free HF correlated with chronic kidney disease, lack of class 3 antiarrhythmic drug use, longer procedure duration, and increased IV fluid administration. Administration of ≥1400mL corresponded with a 3.00 odds ratio for incident AF-free HF (1.03-8.72, p = 0.04). Multivariable analysis revealed no independent risk factors for HF or AF-free HF. Conclusions: In this prospective, multicenter cohort study, greater procedural IV fluid administration was a consistent risk factor for early incident HF after AF ablation, independent of recurrent AF. Low blood pressure during the case should perhaps trigger more pressor use and less fluid use in this population with impaired atrial function. A threshold of 1400mL IV fluid administration is reasonable to consider periprocedural diuretic titration.