ABSTRACT
A cardiac arrhythmia or dysrhythmia is any disturbance that occurs to normal heart rhythm. Cardiac arrhythmias can vary in severity from an occasional missed beat to serious abnormalities of rate and rhythm that severely impair the pumping ability of the heart and can be rapidly life-threatening. Abnormal cardiac rhythms can arise in tissues of the atria or ventricles and often involve derangements to the normal cardiac conduction pathways described below (see Figure 13.1).
