The document provides information about ECG patterns and abnormalities. It defines a normal ECG and discusses how to calculate heart rates from the P-P and R-R intervals. It also describes how to identify left ventricular hypertrophy and patterns of ischemia in different leads. Common arrhythmias like atrial fibrillation, ventricular tachycardia, and ventricular fibrillation are outlined. How to distinguish right versus left bundle branch block is explained. Clinical teaching fellow Mark Hall maintains a blog with more information at markmeded.blogspot.com.

1. ECGs
Mark Hall
Clinical Teaching Fellow

4. Normal ECG

5. P-Q-R-S-T Complex
Atrial rate = 300 / P-P interval (large squares)
Ventricular rate = 300 / R-R interval
Paper rate = 25 mm/sec (Five large squares)
Note – may be increased to 50 mm/sec.

6. Axis Deviation

9. LV Hypertrophy
Count the small squares in the V lead with max
S wave
Count the small squares in the V lead with the
max R wave
If the sum is >35 - LVH

12. Patterns of Ischaemia
 Anterior V1 – V4
 Inferior II, III, aVF
 Lateral I, aVL, V5, V6
 Septal V3,V4
 Posterior
Mirror image of acute injury in
leads V1 - 3
Tall R wave, tall upright T wave
in leads V1 -3 usually
associated with inferior and/or
lateral STEMI

16. Arrythmias
Narrow QRS Broad QRS
Supra Ventricular
Tachycardia (SVT) Ventricular
Regular Usually can’t see P wave Tachycardia
Rate >150 (VT)
Atrial Fibrillation (AF) Ventricular
Irregular No P wave – wavy baseline
Fibrillation (VF)

21. Bundle Branch Block
 MaRRow RIGHT Bundle Branch Block
 WiLLiaM LEFT Bundle Branch Block

22. Bundle Branch Block

24. Random Assortment

28. Blog
markmeded.blogspot.com