RA pressure waves Flashcards
1
Q
a wave
A
Atrial contraction
2
Q
v wave
A
Ventricular contraction/systole, systolic filling of atrium.
3
Q
c wave
A
Isovolumic contraction, bulging of the closed AV valve into the atrium (mid-systole, peak ao pressure)
4
Q
y descent
A
Early ventricular filling (diastole), fall in ventricular pressure after opening oft valve.
5
Q
x descent
A
Atrial relaxation and (emptying during ventricular filling?).
6
Q
x’ descent
A
Descent of the base (apex does not move so base gets closer to apex which causes the pressure in the atrial to decrease.)
7
Q
Changes with inspiration and expiration
A
Decreases with inspiration (intrathoracic pressure becomes more negative), increases with expiration.
- Opposite with mechanical ventilation
- End-expiration is best time for measurement
8
Q
ECG timing a wave
A
PR interval
9
Q
ECG timing v wave
A
End of t wave
