The electrical activity fails to die away properly, and moves around the muscle in a turbulent pattern causing an arrhythmia known as ventricularfibrillation.
Patients with persistent or permanent atrial fibrillation are also indicated for single chamber ventricular pacers unless efforts are being made to restore sinus rhythm.
Dual chamber pacing in SND is also favored over single chamber ventricular pacing (VVI), as it has been shown to reduce the risk of development of atrial fibrillation and the symptoms of pacemaker syndrome.