Sinoatrial exit block occurs when the action potential initiated by the sinoatrial node is inhibited or completely blocked before it is able to leave the SA node and reach the atrium, and thus no ...

A premature atrial contraction occurs when a focus in the atrium (not the sinoatrial node ... to as “atrial bigeminy” as seen in this strip above. If a PAC occurs when the AV node has not ...