Cardiac Cycle Flashcards
1st step in cardiac cycle:
atrial systole
analagous part on ECG
occurs after P wave (atrial contraction)
1st step in cardiac cycle:
atrial systole
part on venous pulse curve
incr in atrial pressure (venous pressure) by atrial systole = A WAVE
1st step in cardiac cycle:
atrial systole
auscultation
atrial systole –> ventricular filling –> 4TH HEART SOUND (not audible in normal)
2nd step in cardiac cycle:
isovolumetric ventricular contraction
analagous part on ECG
begins during QRS complex (ventricular activation)
2nd step in cardiac cycle:
isovolumetric ventricular contraction
part on venous pulse curve
rapid rise in ventricular pressure due to ventricular contraction and no blood leaving ventricle (aortic valve is closed)
2nd step in cardiac cycle:
isovolumetric ventricular contraction
auscultation
when ventricular pressure > atrial pressure, AV valve close
(first heart sound)
can be split b/c mitral valve closes before tricuspid valve
3rd step in cardiac cycle:
rapid ventricular ejection
what reaches max value?
ventricular pressure
3rd step in cardiac cycle:
rapid ventricular ejection
part on venous pulse curve
C wave because of bulging of tricuspid valve into RA during RV contraction
when ventricular pressure > aortic pressure, aortic valve opens –> rapid ejection of blood due to downward P gradient
3rd step in cardiac cycle:
rapid ventricular ejection
what happens after RV ejects blood
most of stroke volume ejected
atrial filling begins
3rd step in cardiac cycle:
rapid ventricular ejection
part on ecg
onset of T wave (repol of ventricles)
end of both ventricular contraction and rapid ventricular ejection
4th step in cardiac cycle:
reduced ventricular ejection
what happens
RV continues to eject blood but SLOWER
atrial filling continues
4th step in cardiac cycle:
reduced ventricular ejection
what happens to ventricular and aortic pressure
ventricular pressure DECREASES
aortic pressure also DECREASES because large arteries empty into smaller arteries
4th step in cardiac cycle:
reduced ventricular ejection
part on venous pulse curve
V wave because blood flow into RA (rising phase of wave) and then from RA into RV (falling part)
5th step in cardiac cycle:
isovolumetric venticular relaxation
part on ECG
end of T wave (repol of ventricles complete)
5th step in cardiac cycle:
isovolumetric venticular relaxation
auscultation
aortic valve closes –> then pulmonic valve closes
(both are semilunar valves) –> 2nd heart sound
Inspiration can delay closing pulmonic (splitting of S2)
5th step in cardiac cycle:
isovolumetric venticular relaxation
what valve is still closed during this phase
AV valves
5th step in cardiac cycle:
isovolumetric venticular relaxation
what happens to ventricular pressure
decr rapidly because ventricle now relaxed
5th step in cardiac cycle:
isovolumetric venticular relaxation
what happens to ventricular VOLUME
constant because all valves are closed
5th step in cardiac cycle:
isovolumetric venticular relaxation
what unique happens with the aortic pressure tracing?
“blip” rise due to dicrotic notch (INCISURA)
6th step in cardiac cycle:
Rapid ventricular filling
what happens
ventricular pressure < atrial pressure –> mitral valve opens to fill LV
6th step in cardiac cycle:
Rapid ventricular filling
what happens to aortic pressure
keeps decreasing because blood continue to run off into smaller arteries
6th step in cardiac cycle:
Rapid ventricular filling
auscultation
rapid flow of blood from atria into ventricles –> S3 (normal in children, pathologic in adults)
7th step in cardiac cycle:
Reduced ventricular filling (diastasis)
is the ____ phase of the cardiac cycle
longest
7th step in cardiac cycle:
Reduced ventricular filling (diastasis)
what happens
ventricular filling continues but at slower rate
7th step in cardiac cycle:
Reduced ventricular filling (diastasis)
how does heart rate affect time for diastesis/ventricular filling
incr HR, decr time for ventricular filling, decr EDV, decr SV
