Definition Synchronized cardioversion is employed for hemodynamically unstable supraventricular tachycardias (atrial fibrillation / atrial flutter, AV junctional tachycardia, multifocal atrial tachycardia, and paroxysmal reentrant tachycardia). New onset atrial flutter often requires only 50 J (monophasic or biphasic). For atrial fibrillation and PSVT in adults start with 100-120 J for biphasic waveforms (100-200 J with monophasic). […]