Arrhythmogenesis

Arrhythmogenesis is the process by which cardiac tissue generates or propagates an abnormal impulse. A rapid rhythm may come from an irritable focus, a beat-triggered discharge, or a self-sustaining electrical loop; those mechanisms predict both the ECG pattern and the treatment that can work. A regular narrow-complex tachycardia may terminate when transient AV-nodal block interrupts AVNRT or orthodromic AVRT. An irregular wide-complex rhythm in a patient with an accessory pathway may deteriorate if the AV node is blocked. Polymorphic ventricular tachycardia on a prolonged QT interval requires removal of the repolarization trigger, electrolyte correction, magnesium, and often heart-rate acceleration rather than repeated AV-nodal blockade. At the bedside, assess perfusion before naming the rhythm. Once immediate danger is addressed, use the ECG to decide whether the problem is impulse formation, conduction, or both, and search for a reversible substrate. Medication selection and prescribing must follow the NP’s provincial authority, local protocol, and the current Health Canada product monograph; US and Canadian labels are not interchangeable.