Conduction Defects

https://lifeinthefastlane.com/ecg-library/basics/conduction-blocks/

Atrioventricular (AV) Block

First Degree AV Block

Def: prolonged PR interval > 0.20 sec (200ms) at a heart rate of 70 bpm

Causes:

1. Degenerative changes in AV conduction system

Aging

Digitalis

Exaggerated vagal tone

Ischemia (diaphragmatic infarct)

Inflammation (myocarditis, rheumatic fever)

2. Cardiomyopathies

Second Degree Heart Block

Mobitz type I

Characters:

1. Constant P-P interval
2. Increasing PR interval