Sinoatrial block Sinoatrial block A sinoatrial block is a disorder in the normal rhythm of the heart, known as a heart block, that is initiated in the sinoatrial node. The initial action impulse in a heart is usually formed in the sinoatrial node (SA node) and carried through the atria, down the internodal atrial pathways to the atrioventricular node (AV) node. In normal conduction, the impulse would travel across the bundle of His (AV bundle), down the bundle branches, and into the Purkinje fibers. This would depolarize the ventricles and cause them to contract. In an SA block, the electrical impulse is
Node deletion Node deletion Node deletion is the procedure of removing a node from a network, where the node is either chosen randomly or directly. Node deletion is used to test the robustness and the attack tolerance of networks. Understanding how a network changes in response to node deletion is critical in many empirical networks. Application varies across many fields, including the breakdown of the World Wide Web via router removal, elimination of epidemics or fighting against criminal organizations. Removing a node or multiple nodes randomly from a network means that the elimination of a set of nodes happens with a certain