2:1 AV block is a form of second-degree AV block that can be type I or type II. If the PR interval of the conducted beat is prolonged and the QRS complex is narrow, then it is most likely second ...

Note: A first-degree AV block is also part of a trifascicular block, as the AV node is sometimes considered the third fascicle. ECG Examples: First-Degree Atrioventricular (AV) Block ECG (Example 1) ...

Third-degree heart block prevents the electrical signal from the atria from reaching the ventricles. This leads to a very low escape rhythm from the ventricles, which can lead to severe complications.

Trained athletes commonly (up to 80%) show ECG changes such as sinus bradycardia, first-degree atrioventricular (AV) block and early repolarisation, which result from physiological adaptation of the ...