A wide complex tachycardia on ECG is most likely which rhythm?

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Multiple Choice

A wide complex tachycardia on ECG is most likely which rhythm?

A wide complex tachycardia can still arise from a supraventricular source if there is aberrant conduction, such as a preexisting bundle branch block. AV nodal reentrant tachycardia is a supraventricular tachycardia that, when conducted with abnormal ventricular conduction, can display a wide QRS. The rapid, regular rhythm originates in or near the AV node, but if the ventricles are activated through a blocked or delayed pathway, the QRS broadens. This is why AV nodal reentrant tachycardia can present as a wide complex tachycardia, especially in a patient with baseline conduction abnormalities. In contrast, sinus tachycardia is typically a narrow-complex rhythm, atrial fibrillation is usually irregular and often shows narrow QRS unless aberrant conduction is present, and true ventricular tachycardia is a ventricular-origin rhythm that classically maintains a wide QRS with distinct AV dissociation or capture/fusion phenomena.

A wide complex tachycardia can still arise from a supraventricular source if there is aberrant conduction, such as a preexisting bundle branch block. AV nodal reentrant tachycardia is a supraventricular tachycardia that, when conducted with abnormal ventricular conduction, can display a wide QRS. The rapid, regular rhythm originates in or near the AV node, but if the ventricles are activated through a blocked or delayed pathway, the QRS broadens. This is why AV nodal reentrant tachycardia can present as a wide complex tachycardia, especially in a patient with baseline conduction abnormalities.

In contrast, sinus tachycardia is typically a narrow-complex rhythm, atrial fibrillation is usually irregular and often shows narrow QRS unless aberrant conduction is present, and true ventricular tachycardia is a ventricular-origin rhythm that classically maintains a wide QRS with distinct AV dissociation or capture/fusion phenomena.

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