title: Atrial fibrillation with high degree atrioventricular block masquerading as ventricular fibrillation masquerading as asystole during cardiac arrest.
abstract: Ventricular fibrillation (VF) can masquerade as asystole. We report a 54-yr-old male in cardiac arrest who, on surface ECG, appeared to be in VF or asystole. A bedside intracardiac recording using a transmyocardial pacing wire showed the true rhythm to be atrial fibrillation (AF) with high grade atrioventricular block. AF with a high degree block can masquerade as VF, which simultaneously masquerades as asystole, and can be correctly diagnosed by bedside intracardiac monitoring. Patients who have a flat line rhythm which may represent asystole, fine ventricular fibrillation, or atrial fibrillation with a high degree atrioventricular block may warrant a trial of electrical countershock, high-dose atropine, or transthoracic pacing.
mesh_terms: D001145:Arrhythmias, Cardiac / Q000175:diagnosis*; D001281:Atrial Fibrillation / Q000150:complications / Q000175:diagnosis; D003937:Diagnosis, Differential; D004562:Electrocardiography; D006323:Heart Arrest / Q000175:diagnosis / Q000503:physiopathology*; D006327:Heart Block / Q000150:complications / Q000175:diagnosis; D006801:Humans; D008297:Male; D008875:Middle Aged; D014693:Ventricular Fibrillation / Q000175:diagnosis