The ECG Rhythms content is currently under development and is being updated by medical professionals.
Ventricular fibrillation (VFib) is a critical and life-threatening cardiac arrhythmia characterized by chaotic and disorganized electrical activity within the ventricles. This erratic electrical activity causes the ventricles to quiver or twitch in a rapid and uncoordinated manner, rendering them unable to pump blood effectively to the rest of the body.
Analogy: “A complete breakdown of the orchestra, with all instruments playing randomly and without coordination.”
On an ECG, ventricular fibrillation presents as chaotic, irregular fibrillatory waves with varying amplitude and morphology. There are no identifiable P waves, QRS complexes, or T waves. The ventricular rate is very rapid, typically ranging from 150 to 500 beats per minute. The amplitude of the fibrillatory waves may decrease over time, a progression from coarse ventricular fibrillation to fine ventricular fibrillation. This rhythm signifies a complete electrical disorganization of the ventricles.
The most common and immediate symptom of ventricular fibrillation is sudden collapse, followed by loss of consciousness. Individuals in ventricular fibrillation have no palpable pulse and are not breathing. This condition leads to sudden cardiac arrest and is the most frequent cause of sudden cardiac death if not treated immediately. Prior to the onset of ventricular fibrillation, some individuals may experience symptoms of an irregularly fast or erratic heartbeat, such as chest pain, very fast heartbeat (tachycardia), dizziness, nausea, or shortness of breath. Ventricular fibrillation is often preceded by conditions such as myocardial ischemia or ventricular tachycardia.
“Like a washing machine violently shaking and unable to perform its function, the ventricles are quivering and unable to pump blood.”