What outcome might occur with effective atrial automaticity foci activity?

What outcome might occur with effective atrial automaticity foci activity?

• A. AV node blockage.
• B. Early depolarization of the ventricles.
• C. A normal sinus rhythm.
• D. Retained parasympathetic effects on heart rate.

Answer: (A)

Effective atrial automaticity foci can cause changes in the normal conduction pathway of the heart. When these foci are active, they can initiate an electrical impulse that may interfere with the regular signaling from the sinoatrial (SA) node, the primary pacemaker of the heart. This leads to the potential for various outcomes, one of which may be a blockage or disruption in the conduction through the atrioventricular (AV) node, as the foci can create competing impulses that disrupt the normal heart rhythm.

In this disrupted rhythm, the AV node may not effectively conduct impulses from the atria to the ventricles, potentially resulting in varying degrees of blockages or irregular rhythms. The other options do not directly relate to the primary effect of active atrial foci. For example, while early depolarization of the ventricles could occur in certain situations, it is not a guaranteed outcome of atrial foci activity. Similarly, the presence of a normal sinus rhythm would indicate a stable pacing from the SA node without interference, and retained parasympathetic effects would suggest that vagal tone is inhibiting heart rate increases, which does not result directly from the activity of atrial foci. Thus, the correct understanding of effective