V tach is a rapid heart rhythm originating in which part of the heart?

• A. Atria
• B. Atrioventricular node
• C. Ventricles
• D. Sinoatrial node

Answer: (C)

Ventricular tachycardia is a rapid rhythm that begins in the ventricular myocardium, not in the atria or above the ventricles. When the ventricle tissue takes over, the impulse spreads through the ventricles in a way that is slower and abnormal compared to the normal His-Purkinje conduction, so the ECG shows a wide, abnormal QRS complex during the tachycardia. This ventricular origin distinguishes VT from tachycardias that start in the atria or the AV node, which typically produce narrower QRS complexes and different P-wave relationships. Because the impulse is generated in the ventricles, VT can more readily compromise cardiac output and hemodynamics, making it the correct origin.