The predictors of successful cardioversion are: age < 50 (OR = 12.5; p = 0.002); the duration of atrial fibrillation < 2 years (OR = 5.6; p = 0.003); cardiothoracic index < 65% (OR = 6.8; p = 0.002); Diameter of left atrial < 45 mm (OR = 9.1; p = 0.018); Area of left atrial in the 4 chambers < 45 cm2 (OR = 4.2; p = 0.014), heart rhythm in the operation room is sinus (OR = 9.3; p = 0.0001).