Isolated<unk> -degree heart block has no direct clinical consequences. There are no symptoms or signs associated with it. It was originally thought of as having a benign prognosis. In the Framingham Heart Study, however, the presence of a prolonged PR interval or<unk>  degree AV block doubled the risk of developing atrial fibrillation, tripled the risk of requiring an artificial pacemaker, and was associated with a small increase in mortality. This risk was proportional to the degree of PR prolongation. A subset of individuals with the triad of<unk> -degree heart block, right bundle branch block, and either left anterior fascicular block or left posterior fascicular block (known as trifascicular block) may be at an increased risk of progression to complete heart block.
First-degree atrioventricular block
Second-degree atrioventricular block
Third-degree atrioventricular block
Ventricular escape beat
AV nodal reentrant tachycardia
Wandering atrial pacemaker
Re-entry ventricular arrhythmia
Left bundle branch block