What is ventricular parasystole?

What is ventricular parasystole?

• A. A condition with no ectopic beats
• B. A dominant pacemaker with independent ventricular foci
• C. A rapid and irregular heartbeat
• D. A normal rhythm with frequent PVCs

Answer: (B)

Ventricular parasystole is characterized by the presence of a dominant pacemaker in the atria or AV node, coupled with independent ectopic foci in the ventricles that fire autonomously. This results in an organized yet irregular rhythm where the ventricular ectopic beats occur without influence from the normal conduction system. The ectopic foci fire at their own intrinsic rates, and while the dominant pacemaker is still present, it does not inhibit or coordinate the responses of the ventricular foci.

This mechanism distinguishes ventricular parasystole from other conditions, such as those with rapid and irregular heartbeats, which may include atrial fibrillation or other types of arrhythmias where there is no defined ectopic ventricular focus independence seen. In summary, option B accurately describes the scenario where both a dominant pacemaker exists and independent ectopic ventricular activity is present, leading to a unique rhythm pattern indicative of ventricular parasystole.