Coarse Ventricular Fibrillation (Coarse v fib)

Coarse Ventricular Fibrillation, shortly coarse v fib is the first phase of ventricular fibrillation and characterized by bigger waveform in the ECG. Coarse ventricular fibrillation is still some effective contractions before going into fine ventricular fibrillation and eventually into asystole.

Pathophysiology of Coarse Ventricular Fibrillation: If we look into the pathophysiology of development of ventricular fibrillation, it will become clear. Ventricular fibrillation happens because of severe electrical disturbance in the heart in the form of abnormal automaticity and reentry. The ventricular musculature becomes hyper excitable and contracts asynchronously due to multiple focus electrical activity leading to rather quiver than coordinated  effective contraction. This results in-efficient cardiac output and resulting symptoms, ultimately leading to death. The most common causes of ventricular fibrillation are:

  • Myocardial infarction
  • Cardiac tamponade
  • Cardiomyopathy (dilated, hypertrophic, restrictive)
  • Long QT (acquired / congenital)
  • Brugada syndrome
  • Drugs
  • Electrical shocks Drowning Hypothermia
  • Pulmonary embolism
  • Blunt trauma (Commotio Cordis)
  • Electrolyte abnormalities

In most cases the initial contractions in Ventricular Fibrillation are somewhat bigger and more resultant. The ECG here shows coarse ventricular fibrillation waves. Thus some amount of Cardiac Output may be maintained. However, as time progress and if untreated, the condition worsens and heart contractions turn into smaller ineffective ‘contractions. At this stage these changes on ECG appear as fine ventricular fibrillation. If untreated the next stage is complete asystole, when heart musculature stops completely the contraction efforts.

Coarse Ventricular Fibrillation ECG:

Following are the examples of Coarse Ventricular fibrillation ECG

coarse v fib


coarse ventricular fibrillation



Fine Ventricular Fibrillation ECG:

Here is a comparison with Fine Ventricular Fibrillation:-

v fib



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