ECG Basics: Difference between revisions
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*If up in leads 1 and AVF then normal axis | *If up in leads 1 and AVF then normal axis | ||
== | ==Waves== | ||
*[[Q Waves]] | *[[Q Waves]] | ||
*[[T Waves]] | |||
==Hypertrophy/Enlargement== | ==Hypertrophy/Enlargement== | ||
Revision as of 05:50, 5 February 2014
General
- 1 small box = 1mm = 0.04 sec = 40 miliseconds
- 5 small boxes = 1 big box = 5mm = 0.2 sec = 200 miliseconds
- Entire ECG strip is ~10 seconds
Intervals
| Interval | Time (s) | Boxes |
| PR | 0.12 - 0.20 | 3-5 |
| QRS | .06 - 0.10 | 1.5-2.5 |
| QTc | <0.44 | N/A |
Axis
- Cannot be measured if BBBs are present
- If up in leads 1 and AVF then normal axis
Waves
Hypertrophy/Enlargement
Blocks
Low Voltage
- QRS < 5 mm in limb leads, or
- QRS < 10 mm in chest leads
- From either low electrical power within the heart (e.g. hypothyroidism), or low conduction within the heart (e.g. sarcoid or scar tissue), or poor conduction from the heart to the ECG lead (e.g. obesity, COPD, pericardial effusion
- Low voltage + tachycardia = pericardial effusion until proven otherwise
See Also
Source
- Adapted from Niemann, Lampe, Pani, Donaldson, ECGpedia.org
- Journal of Electrocardiology. Vol 43 (2010). 40-42.