ECG - Blocks
by Naomi Rumrill
1. 2nd Degree AV Block - Mobitz I (Wenkebach)
1.1. Block at AV junction
1.1.1. progressive
1.2. PR becomes progressively longer until QRS is dropped
1.3. P - P = regular
1.4. R - R = irregular
2. 3rd Degree AV Block
2.1. Block between atria and ventricles
2.2. P waves: no relationship to QRS
2.3. No true PR interval
2.4. QRS: same shape and size
2.4.1. Usually wide, bizarre and > 0.12
2.5. Ventricular rate usually 20 - 40
2.6. Atrial rate usually 60 - 100
3. 1st Degree AV Block
3.1. From the Atria
3.1.1. Delay between the atria and bundle of his
3.2. PR > 0.20
4. Mobitz II
4.1. Block at AV junction
4.1.1. intermittent block
4.2. More P waves then QRS complexes
4.3. Usually a pattern
4.3.1. 2:1, 3:1, 4:1
5. Bundle Branch Block
5.1. Block in bundle branch (left, right or both)
5.2. QRS usually same size and shape, notched appearance
5.2.1. Usually > 0.12
5.3. Looks like PVC except:
5.3.1. Has P wave
5.3.2. t wave going in same direction
5.3.3. Initiated by SA node, not ventricle