Which rhythm typically has a wide QRS complex due to ventricular origin?

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Multiple Choice

Which rhythm typically has a wide QRS complex due to ventricular origin?

The key idea is that a wide QRS during a tachycardia points to ventricular origin. When the impulse starts in the ventricles, it doesn’t follow the fast His-Purkinje system, so activation spreads cell-to-cell through the ventricular myocardium. This slows conduction and widens the QRS complex, a hallmark of ventricular tachycardia. Ventricular tachycardia therefore shows broad, often bizarre-appearing QRS complexes. In contrast, atrial flutter starts in the atria and typically conducts to the ventricles through the AV node, producing a narrow QRS unless there’s aberrant conduction. Junctional tachycardia originates near the AV junction and usually uses the ventricles’ normal conduction pathway, keeping QRS width narrow. Supraventricular tachycardias also generally have narrow QRS unless there is preexisting bundle-branch block or rate-related aberrancy.

The key idea is that a wide QRS during a tachycardia points to ventricular origin. When the impulse starts in the ventricles, it doesn’t follow the fast His-Purkinje system, so activation spreads cell-to-cell through the ventricular myocardium. This slows conduction and widens the QRS complex, a hallmark of ventricular tachycardia. Ventricular tachycardia therefore shows broad, often bizarre-appearing QRS complexes.

In contrast, atrial flutter starts in the atria and typically conducts to the ventricles through the AV node, producing a narrow QRS unless there’s aberrant conduction. Junctional tachycardia originates near the AV junction and usually uses the ventricles’ normal conduction pathway, keeping QRS width narrow. Supraventricular tachycardias also generally have narrow QRS unless there is preexisting bundle-branch block or rate-related aberrancy.

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