Local reentry within the atria or ventricles causes which type of tachycardia?

• A. Atrial or ventricular tachycardia
• B. SVT
• C. AF
• D. Asystole

Answer: (A)

Local reentry in the atrial or ventricular tissue creates a self-sustaining circuit that keeps circulating the impulse within that chamber. When this reentrant circuit resides in the atria, the resulting fast rhythm is an atrial tachycardia; when it resides in the ventricles, it is a ventricular tachycardia. Supraventricular tachycardia refers more broadly to rapid rhythms arising above the ventricles (often from the AV node or an accessory pathway) and isn’t defined by a single intrachamber reentry circuit. Atrial fibrillation is due to multiple rapidly firing wavelets in the atria rather than a single reentrant loop, and asystole is the absence of electrical activity.