<unk>  is a cause of cardiac arrest. The ventricular muscle twitches randomly rather than contracting in a co-ordinated fashion (from the apex of the heart to the outflow of the ventricles), and so the ventricles fail to pump blood around the body – because of this, it is classified as a cardiac arrest rhythm, and patients in<unk>  should be treated with cardiopulmonary resuscitation (CPR) and prompt defibrillation. Left untreated,<unk>  is rapidly fatal as the vital organs of the body, including the heart, are starved of oxygen, and as a result patients in this rhythm will not be conscious or responsive to stimuli. Prior to cardiac arrest, patients may complain of varying symptoms depending on the underlying cause. Patients may exhibit signs of agonal breathing, which to a layperson can look like normal spontaneous breathing, but is a sign of hypoperfusion of the brainstem. It has an appearance on electrocardiography of irregular electrical activity with no discernable pattern. It may be described as 'coarse' or 'fine' depending on its amplitude, or as progressing from coarse to fine<unk> . Coarse<unk>  may be more responsive to defibrillation, while fine<unk>  can mimic the appearance of asystole on a defibrillator or cardiac monitor set to a low gain. Some clinicians may attempt to defibrillate fine<unk>  in the hope that it can be reverted to a cardiac rhythm compatible with life, whereas others will deliver CPR and sometimes drugs as described in the advanced cardiac life support protocols in an attempt to increase its amplitude and the odds of successful defibrillation.
Ventricular fibrillation
Torsades de pointes
Ventricular flutter
Sinus arrhythmia
Sinoatrial arrest
Ventricular tachycardia
Pre-excitation syndrome
Primary ventricular fibrillation