What is a defining characteristic of heart block?

Heart block is primarily characterized by an interference with the normal transmission of electrical impulses within the heart. This disruption can occur at various levels within the electrical conduction system, such as the atrioventricular (AV) node, leading to delayed or blocked impulses that affect how the heart beats. In heart block, the signals that coordinate the heart's contractions are not able to pass through as they normally would, which can result in a slower heart rate or skipped beats.

This distinguishing feature of impaired impulse transmission is what differentiates heart block from other cardiac conditions. Regular conduction of electrical impulses is not seen in heart block, as this condition specifically involves abnormalities in how impulses travel. Additionally, heart block does not typically present as a consistent heart rate with varying rhythms, nor does it lead to rapid ventricular responses, which are commonly associated with other arrhythmias such as atrial fibrillation or tachycardia. Understanding that heart block fundamentally involves disruption of the conduction pathway helps clarify its implications on heart function and overall health.