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.
1 Rhythm problems also can occur because of a blockage of your heart's electrical pathways. 2  The artificial pacemaker's pulse generator sends electrical impulses to the heart to help it pump properly. 3  An electrode is placed next to the heart wall and small electrical charges travel through the wire to the heart. Your heartbeat is sometimes normal and sometimes too fast or too slow. 2  The sinoatrial (SA) node or sinus node is the heart's natural pacemaker. 3  It's a small mass of specialized cells in the top of the right atrium (upper chamber of the heart).