Graph Paper - Cardiac Rhythms.
- The value of time and voltage just discussed is very important to understand, but it must be combined with an understanding of the grid or graph paper the tracing is printing upon that you are analyzing.
- The grid is broken down in small boxes (1 X 1 millimeter) and heavier darkened lined boxes.
- There are five small boxes going from left to right and bottom to top of each large box (5 X 5 mm).
- Voltage is important when measuring the height or depth of a waveform.
- The height or depth provides an indication of the amount of electrical activity occurring within the heart.
- Voltage can be affected by a number of different factors to include the amount of viable muscle mass in the heart.
- When analyzing cardiac tracings, the question always comes up “where do I measure from”?
Authors and ReviewersAuthored by Thomas O'Brien
Medically reviewed by Dr. Jonathan Keroes, MD, Cardiology
Last Update: 11/8/2020