Chapter 9 - The P-wave Flashcards
P-waves are (+) in what leads?
I, II, V4-V6
P-waves are negative in what leads?
AVR
Criteria for right atria enlargement diagnosis
- p-wave greater than 0.-2 S
- P-wave “notching” with the NOTCH more wide than 0.04s
Explain the ECG changes with right atrial enlargement
1) widening of the p-wave occurs due to enlarged right atria
2) More tissue (RAE) requires greater time for the AP to be conducted down intermodal pathways.
3) L atria conduction time remains the same.
4) the increased RA conduction widens the p-wave and adds the “notch”
Explain the criteria for diagnosing p-pulmonale.
What does p-pulmonale indicate?
- Found in leads I and II
- p-wave greater than 2.5 mm
- Right atrial enlargement
Explain the criteria for diagnosing p-mitrale.
What does p-mitrale indicate?
- p wave longer than 0.12 s (3 boxes)
- a “notched” p-wave with a notch > 0.04 s (1 box)
- Left atrial enlargement
Explain the criteria for diagnosing intraatrial conduction delay.
- It indicates a “non-specific delay”
- Any criteria for diagnosing RAE or LAE can be used to determine which specific type of delay it is.