Outline the approach to interpreting an ECG
- "An ECG does Not Really Require A Woman's Input"
How is the heart rate measured and rhythm determined using an ECG?
- 300 divided by the number of large boxes between each R spike. (0.6-1.2 seconds)
- Mark a strip of paper at every R spike; abnormal/repetitive pattern?
How is heart axis determined on an ECG?
- Examine lead I and II
- If the QRS complex of both are mostly positive = normal axis
- If I-QRS positive and II-QRS negative, then posterior deviation
- If opposite; I-negative, II positive then anterior deviation
How are the waves of an ECG examined?
- P: One per QRS, no bifidity [except v1]
- ST: Elevation?
- T: Inversion in V3-6 or I/II?
What are the important intervals to note when examining an ECG?
- PR: 1/2 - 1 full large box
- QRS: 1/2 a large box
- QT: 2 large boxes in II
What are the common ECG findings in an acute MI?
- ST segment elevation (>80ms)
- Prominent, symmetrical, pointed T waves
What are the ECG findings of 1st and 3rd degree heart block?
- 1st degree: Prolonged PR interval (>0.2 secs); delayed conduction from atria-ventricles
- 3rd: No relation between P and QRS; complete block of conduction