Premature atrial contraction the atrioventricular (AV) node, the signal is conducted both to the ventricle and back to the SA node where the signal began. Premature atrial contraction Premature atrial contractions (PACs), also known as atrial premature complexes (APC) or atrial premature beats (APB), are a common cardiac dysrhythmia characterized by premature heartbeats originating in the atria. While the sinoatrial node typically regulates the heartbeat during normal sinus rhythm, PACs occur when another region of the atria depolarizes before the sinoatrial node and thus triggers a premature heartbeat. The exact cause of PACs is unclear; while several predisposing conditions exist, PACs commonly occur
Diskless node as thin clients. Moreover, thin client computers are increasing in power to the point where they are becoming suitable as fully-fledged diskless workstations for some applications. Both thin client and diskless node architectures employ diskless clients which have advantages over fat clients (see above), but differ with regard to the location of processing. Diskless node A diskless node (or diskless workstation) is a workstation or personal computer without disk drives, which employs network booting to load its operating system from a server. (A computer may also be said to "act as a diskless node", if its disks are unused and