Dr.S.Venkatesan MD

Ventricular fibrillation is invariably fatal if not treated . When can atrial fibrillation be fatal ? 

                                     Atrial fibrillation is relatively a benign arrhythmia especially when it occurs in isolation with  structurally normal heart.This is sometimes referred to lone atrial fibrillation . Even otherwise, atrial fibrillation is rarely fatal except in few situations.But AF commonly destabilises the patient  who have baseline valvular or myocardial disease.(Post MI, dilated cardiomyopathy etc)

There are few situations where AF can be life threatening

• In patients  with WPW syndrome*where , AF  enters into a electrical short  circuit , downhill to enter the ventricle and make it fire at the same rate as that of atria . ( ie 400-600) and result in ventricular  fibrillation.Note , even here it is the VF that kills  not , AF per se.
• AF in acute MI  often precipitates LVF , but rarely fatal.
• In patients with critical aortic stenosis, or hypertrophic cardiomyopathy, sudden onset of AF can result in acute cardiac failure.
• AF is often a terminal event in primary pulmonary hypertension

While atrial fibrillation is  less likely to cause  death , it is  a highly morbid arrhythmia .It is one of important cause of stroke in elderly as well as young !