Do you know if ventricular fibrillation is the most common rhythm during cardiac arrest?

No. The initial rhythm causing a cardiac arrest is most usually monomorphic ventricular tachycardia (62%), followed by bradycardia (17%), then polymorphic VT (13%) and finally primary vf (8%). Most of these rhythms will eventually degenerate into vf, however.

Related Questions

Why is ventricular fibrillation the most common rhythm of cardiac arrest?

Why not. Basically we are talking about cardiac arrest. This means the heart ceases to pump. The two options are asystole or no heart beats or ventricular fibrillation...Rapid chaotic ineffective quivering of the heart. Vf is a common consequence of heart attacks. It is also a common consequence of enlarged weakened heart (cardiomyopathy). Two common causes of death. Read more...
Final pathway. Ventricular fibrillation is the final step before a heart stops beating. Any heart that has not gotten enough blood flow or oxygen for a prolonged period of time will begin fibrillating followed shortly by asystole (no beating at all). In a sense, ventricular fibrillation is the final step every heart likely goes through before it stops beating. Read more...

Is ventricular fibrillation the cause of cardiac arrest?

One of them. It is the most common heart arrhythmia associated with cardiac arrest. It is not exact to call it the cause, since ventricular fibrillation itself has an underlying cause, most commonly coronary artery disease, but there are others. Read more...
Sometimes... Ventricular fibrillation is a cardiac arrhythmia that results in the heart being unable to circulate blood. Thus, there is no pulse with this rhythmn. However, there are other cardiac rhythmns that also result in cardiac arrest. Read more...

What are the chances of cardiac arrest (ventricular fibrillation) occuring twice?

Very likely. Very likely especially if the first one was not treated. Somewhat less likely if the first one was treated and predisposing factors were identified and eliminated, but still possible e.g. Unidentified additional predisposing factors or just heart tissue being more sensitive. Read more...