Clinical History 254

Seventy-seven year old woman status post an acute left middle cerebral artery occlusion and urokinase administration who is now experiencing recurrent atrial arrhythmias. Medications at the time of this electrocardiogram included diltiazem, topical nitroglycerin and isosorbide mononitrate. An echocardiogram performed during this hospitalization demonstrated moderate left atrial enlargement and normal left ventricular systolic function without evidence of a prior myocardial infarction.
Comment on this ECG ?