6th March 2024

Ventricular Fibrillation (VF)

This describes a chaotic irregular ventricular tachyarrhythmia, with no discernibility of any wave formation. It is the most common cause of death within a few hours of a myocardial infarction, as this can precipitate an R on T phenomenon. This describes a ventricular ectopic depolarisation i.e., the R wave being superimposed on the prior repolarisation i.e., the T wave. Other than ischaemia, other causes of VF include:

• Structural disease with impaired ventricular function or severe LV hypertrophy
• Preceding VT can rapidly deteriorate to VF
• AF with aberrancy, especially in the presence AV blocking agents (adenosine, digoxin, verapamil, b-blockers)
• Metabolic states such as hypoxia and acidosis can precipitate VF 
• It is important to note that genetic syndromes can also precipitate VF, such as patients with Brugada and long-QT syndrome, such patients may subsequently receive ICD implantation

VF is not compatible with life and so requires urgent electrical cardioversion.