One of the measures of the strength of an encryption system is how long it would theoretically take an attacker to mount a successful brute-force attack against it. Brute-force attacks are an application of brute-force search, the general problem-solving technique of enumerating all candidates and checking each one.
Ventricular fibrillation is one type of arrhythmia that can be deadly. It occurs when the heart beats with rapid, erratic electrical impulses. This causes pumping chambers in your heart (the ventricles) to quiver uselessly instead of pumping blood. Without an effective heartbeat, blood pressure plummets, cutting off blood supply to your vital organs.
See a picture of the heart and its electrical system. How does the heart's electrical system work? Your heart muscle is made of tiny cells. Your heart's electrical system controls the timing of your heartbeat by sending an electrical signal through these cells. Two different types of cells in your heart enable the electrical signal to control your heartbeat: Conducting cells carry your heart's electrical signal. Muscle cells enable your heart's chambers to contract, an action triggered by your heart's electrical signal. The electrical signal travels through the network of conducting cell pathways, which stimulates your upper chambers (atria) and lower chambers (ventricles) to contract.