What is ventricular fibrillation and what would it look like on an ECG?

As a medical professional with expertise in cardiology, I can provide you with an explanation of ventricular fibrillation and its appearance on an ECG. Ventricular fibrillation (VF) is a life-threatening cardiac emergency characterized by rapid, irregular, and ineffective contractions of the heart's lower chambers (ventricles). This condition prevents the heart from pumping blood effectively, leading to a lack of blood flow to the body and brain. It is often caused by underlying heart disease, but can also be triggered by other factors such as electrolyte imbalances, certain medications, or trauma. On an ECG, ventricular fibrillation is identified by a chaotic pattern of irregular, rapid, and unsynchronized electrical activity. The ECG will show no organized QRS complexes, P waves, or T waves. Instead, there will be a series of rapid, irregular, and varying amplitude waveforms, often referred to as "fibrillatory waves" or "coarse waves." This pattern indicates that the ventricles are not contracting in a coordinated manner, which is critical for effective blood circulation. Timely treatment is crucial for survival, and it typically involves defibrillation, which is the delivery of an electric shock to the heart to try to restore a normal rhythm. The treatment approach for VF is outlined in the advanced cardiac life support (ACLS) protocol, specifically the left branch of the cardiac arrest algorithm.

The two images above show what ventricular fibrillation will look like on a EKG rhythm strip. VF can rapidly lead to heart muscle ischemia and there is a high likelihood that it will deteriorate into asystole. Ventricular fibrillation is treated using the left branch of the cardiac arrest arrest algorithm.