What happens to the heart during junctional dysrhythmia?

In junctional dysrhythmia, the normal electrical conduction pathway is disrupted, specifically affecting the impulse transmission from the sinoatrial (SA) node to the atrioventricular (AV) node. In a healthy heart, the SA node generates electrical impulses that initiate atrial contraction, which then travel to the AV node before stimulating the ventricles. However, when junctional dysrhythmia occurs, the SA node either fails to fire or the impulses are blocked from reaching the AV node effectively, resulting in an altered rhythm.

This disruption can lead to alternative pacing from the AV node or other junctional areas of the heart, resulting in a slower heart rate as the heart's primary pacemaker function is compromised. Therefore, option B accurately reflects the condition where the impulse pathway from the SA to AV node is impaired, leading to the characteristic features of junctional dysrhythmia seen in the heart's electrical activity.