3 Cardiac Cycle Flashcards
1
Q
Phase 2
A
Isovolemic Contraction -ventricular pressure rises rapidly w/o volume change
- ALL valves CLOSED
- S1 (LUB)- AV valves slam shut (M before T)
- QRS
2
Q
Phase 3
A
Rapid Ejection -1st third of ejection accounts for 70% out of LV Aortic & Pulmonic Open AV valves remain closed -atria continue to fill with blood -typically no sound
3
Q
Phase 4
A
Reduced Ejection -T wave - ventricular repolarization Aortic & Pulmonic Open AV valves remain closed -more gradual decrease in ventricular pressure -atrial pressures steadily rise **end of this phase concludes systole
4
Q
Phase 5
A
Isovolumic Relaxation
- S2 (dub) (A then P) - dicrotic notch
- ALL valves CLOSE
- aortic and pulmonic close d/t pressure gradient
- ventricular volume remains constant (ESV) (~50 ml)
- atrial pressure steadily rising
5
Q
Phase 6
A
Rapid filling
AV valves open - ventricular pressure < atrial pressure
Aortic and Pulmonic CLOSED
6
Q
Phase 7
A
Diastasis AV valves OPEN Aortic and Pulmonic CLOSED -passive ventricular filling is nearing completion - more volume = less compliance
7
Q
Phase 1
A
Atrial Systole
P wave - contraction of atria
AV valves open
Aortic & Pulmonic closed
8
Q
P wave
A
- atrial contraction
- accounts for only 10% (can increase to 40%) of ventricular filling, mostly passive filling of ventricles prior to p wave
9
Q
A wave
A
as atria contract, pressures within atrial chambers increase
10
Q
LVEDV
A
Left ventricle end diastolic volume
~120 ml
11
Q
S4
A
- vibration of noncompliant ventricular wall
- sometimes heard during atrial contraction
12
Q
QRS
A
-ventricular depolarization
13
Q
C wave
A
- atrial pressures transiently increase d/t continued venous return and possibly to bulging back into atria
- phase 2
14
Q
V waves
A
peak of atrial pressure just before AV valve opens - opening causes rapid fall in atrial pressure = y descent
15
Q
S3
A
phase 6, may occur during rapid filling- can represent tensing of chordae tendinae and AV ring
- normal in pediatrics
- adults = ventricular dilation
