Chapter 9 - The P Wave Flashcards
The P wave represents depolarization of the ____.
Atria
The P wave is the ______ wave in the complex.
First
The electrical impulse travels from the ___ node, through the atria, to the ___ node.
SA, AV
The P wave is usually upright in which leads.
I, II, V4, V5, V6
The P wave is usually negative in which lead.
AVR
What is a compensatory pause?
A pause where the SA node is not reset, and so fires its next beat on schedule.
What is a non-compensatory pause?
A pause where the SA node is reset, and so the next beat arrives earlier than normal schedule.
Are most APCs compensatory or non-compensatory?
Non compensatory.
P-mitrale is associated with ____ atrial enlargement.
Left
The width of the notched P wave in P-mitrale must be at least ___ seconds.
0.12
Are P-mitrales commonly found in ECGs?
No
The notching of the P wave in P-mitrale is due to slower conduction through the ___ atrium.
Left
P-pulmonale is a sign of ____ atrial enlargement.
Right
The P wave in P-pulmonale must be at least ___ mm high.
2.5
In which leads is P-pulmonale found?
Limb leads
In which leads is P-pulmonale best seen?
II and III
Biphasic P waves in which lead are consistent with an intraatrial conduction delay?
V1
When the first half of the P wave in V1 is ____ than the first half of the P wave in V6, right atrial enlargement is likely.
greater
If the product of the height times the width of the last half of the P wave is greater than or equal to ___, the probability of LAE is over 95%
0.3
All biphasic P waves in V1 are examples of ____.
Intraatrial conduction delay
Biphasic P waves in lead I which do not quite meet LAE or RAE criteria can be labelled as _____.
IACD
In LAE, the product of width x depth must be above ____.
0.3
____ enlargement occurs when you have evidence of both left and right atrial enlargement.
Biatrial
The P wave represents:
a) atrial repolarization
b) atrial depolarization
c) ventricular repolarization
d) ventricular depolarization
e) none of the above
b) atrial depolarization