Figure 2.

Time course of 12-lead electrocardiogram (ECG). The heart rhythm at the start of the procedure was sinus rhythm. After completion of the third cryoballoon application at upper site of the left pulmonary vein, ST segment elevation in inferior leads and QRS width prolongation in all leads occurred, accompanied by atrial fibrillation bradycardia. These ECG changes were eliminated after the resolution of coronary spastic occlusion with intracoronary administration of isosorbide dinitrate. AF = atrial fibrillation.