Right Bundle Branch Block

Right Bundle Branch Block

Left Bundle Branch Block

Left Bundle Branch Block

QRS Widening

RBBB

IVCD Lead 1 looks like LBBB, Lead V1 looks like RBBB

LBBB

Systematic Approach

Axis Really -30 to -90 is Pathological. 0 to -30 is normal

2 Lead and Quadrant Approach to Axis Determination

2 Lead and Quadrant Approach to Axis Determination

Axis ?

Axis

Axis ?

Axis

Axis ?

Axis

Axis ?

Axis

Left Axis Deviation (LAD)

Systematic Approach

Atrial Enlargement

LVH

Left Ventricular Hypertrophy (LVH)

Strain / Strain Equivalent

Right Ventricular Hypertrophy

Systematic Approach

But, 50% of acute MIs and past MIs show normal ECGs  ECG not 100% predictive

Summary Reviewed basic principles of electrocardiography. Described a systematic approach to ECG interpretation. Reviewed common ECG abnormalities and discussed their significance. We will now describe and interpret practice tracings.

Rate: 80 Rhythm: Sinus Intervals: QRS normal, PR interval: 0.2, QT interval: prolonged Axis: No-man’s land, up-right quadrant  indeterminant

Rate: 60-75bpm Rhythm: Sinus Intervals: QRS normal, QTI <1/2 S-S’, PRI normal Axis: Pathological left deviation (<-30 degrees) Find infarct: Q: II, aVF, V2-V4 R: S: ST: V2-V4 elevated  Prior inferior MI b/c deep QS changes Poor R wave progression