This document outlines the objectives and modules of an ECG rhythm interpretation course. It begins by defining normal sinus rhythm as the normal heart rhythm originating from the sinoatrial node and conducted through the normal pathway. It then describes potential problems that can cause arrhythmias in the sinoatrial node, atrial cells, atrioventricular junction, or ventricular cells, such as firing too slowly, too quickly, occasionally, continuously from foci or reentrant circuits. Common arrhythmias that may result from these problems are also identified.

1. ECG Rhythm Interpretation Module III Normal Sinus Rhythm

10. Atrial Cell Problems Atrial cells can also: • fire continuously from multiple foci or fire continuously due to multiple micro re-entrant “wavelets” Atrial Fibrillation Atrial Fibrillation

11. Teaching Moment Multiple micro re-entrant “wavelets” refers to wandering small areas of activation which generate fine chaotic impulses. Colliding wavelets can, in turn, generate new foci of activation. Atrial tissue