What is atrioventricular heart block?

Atrioventricular heart block refers specifically to a condition where there is an interruption or delay in the electrical signals that travel from the atria to the ventricles of the heart. In a healthy heart, electrical impulses originate in the sinoatrial (SA) node, spreading through the atria to prompt contraction, and then travel to the ventricles via the atrioventricular (AV) node. In the case of AV block, this conduction pathway is compromised, which can lead to an irregular heartbeat, varying in severity depending on the degree of the block.

For instance, first-degree AV block may show a simple delay, while second-degree can result in missed beats, and third-degree block (complete heart block) can cause a complete dissociation between atrial and ventricular rhythms. This abnormal conduction impacts the heart's ability to pump blood efficiently, potentially leading to various symptoms or even more serious complications.

The other choices describe different cardiac conditions that do not accurately represent the nature of atrioventricular heart block. Rapid electrical impulses above the atria suggest a different rhythm disturbance, increased heart rate pertains to a different clinical scenario, and the absence of impulses from the atria could indicate other pathologies rather than a block in conduction through