Which are the two most common treatable abnormal rhythms associated with sudden cardiac arrest?

The two most common treatable abnormal rhythm associated with sudden cardiac arrest are ventricular fibrillation and ventricular tachycardia. Ventricular fibrillation occurs when the ventricles fibrillate without organized rhythm while ventricular tachycardia occur when an abnormal electrical impulse control the heart, making it impossible for the heart to pump the blood around the body effectively.