Desynchronised defibrillation is used in-
High-Yield Explanation
Synchronized electrical cardioversion is used to treat hemodynamically unstable supraventricular (or narrow complex) tachycardias, including atrial fibrillation and atrial flutter. Pulseless ventricular tachycardia and ventricular fibrillation are treated with unsynchronized shocks referred to as defibrillation. Ref Harrison 20th edition pg 1432