Cardiac Cycle Flashcards
Pulmonary wedge pressure
Indicator of left atrial pressure
Ventricular contraction and ejection of blood
Systole
Ventricular relaxation and filling with blood
Diastole
Wiggers diagram part a = atrial systole:
- Triggered by
- Small pressure rise as
- Tops of ventricle- already ______ full of blood
- Triggered by P wave
- Small pressure rise as atrium squeezes blood into ventricle
- Tops off ventricle- already 90-95% full of blood
Wiggers diagram part b-c= isovolumetric contraction:
- Triggered by
- Mitral valve _______ creating the
- Aortic valve is ________
- Pressure
- Volume is ______
- Aortic pressure is ________
- Triggered by GRS complex
- Mitral valve closes— creates the c wave atrium
- Aortic valve is closed
- Pressure rises rapidly
- Volume is constant
- Aortic pressure is ~ 80 mmH
Wiggers diagram= part c: opening of aortic valve
- Ventricular pressure ________ aortic
- Begins _______ phase
- Ejection is initially
- Aortic pressure _______
- Ventricular pressure exceeds aortic
- Begins ejection phase
- Ejection initially rapid
- Aortic pressure rises
Wiggers diagram- part d: reduction in ejection rate
- Ventricle approaches the end of _______— _____ wave occurring
- Outward flow declines as kinetic energy of blood ______
- Ventricular and aortic pressures begin to _______
- Ventricle approaches the end of contraction — T wave occurring
- Outward flow declines as kinetic energy of blood decreases
- Ventricular and aortic pressures begin to fall
Wiggers diagram= part e-f:isovolumetric relaxation
- forward movement of blood reverses ______ aortic valve
- Incisura (dichroic notch) indicates
- Ventricular pressure
- Atrial pressure ______ as venous inflow fills the atrium
- Aortic pressure ________ as ejected blood drains away from heart
- Forward movement of blood reverses, closing aortic valve
- Incisura indicated aortic valve closure
- Ventricular pressure falls
- Atrial pressure rises as venous inflow fills the atrium
- Aortic pressure falls as ejected blood drains away from heart
Wiggers diagram= part f: opening of mitral valve
- Begins ________ of ventricle from accumulated blood in atrium
- Rapid filling followed by _______ filling from pulmonary veins
- Begins rapid filling of ventricle from accumulated blood in atrium
- Rapid filling followed by reduced filling from pulmonary veins
Ventricular systole begins when the mitral valve ______ and ends when the aortic valve ________
Mitral valve closes and aortic valve closes
Atrial systole fills the ventricular to the
End diastolic volume (EDV)
Volume stays constant during ____________, then _______ as blood is ejected into the aorta
Volume stays constant during isovolumetric contraction, then decreases as blood is ejected into the aorta
At the end of ejection, the volume remaining in the ventricle is the
End systolic volume (ESV)
EDV- ESV =
Stroke volume
Closure of mitral (and tricuspid) valves with the sudden rise in ventricular pressure causes turbulence of blood ventricles
S1
Closure of aortic and pulmonic valves causes vibrations of blood in the high pressures vessels
S2
During rapid filling in some individuals- normal in children— Kentucky
S3
Vibration of ventricular walls during atrial systole in some individuals— Tennessee
S4
Murmurs (4)
- Stenosis- partial obstruction of flow
- Regurgitation- regurgitate flow across and incompetent valve
- Ventricular septal defect- abn shunting of blood from one vascular chamber to another lower pressure chamber
- High flow rate associated with anemia- increased flow through normal structures
Systolic (ejection) murmurs
- Aortic or pulmonic stenosis
Pansystolic murmurs
- Regurgitate flow through incompetent mitral or tricuspid valve
- From left to right ventricle through a ventricular septal defect
Diastolic murmurs
- Regurgitate flow through incompetent aortic or pulmonic valve
- Mitral or tricuspid stenosis
Continuous murmurs— heard throughout the cardiac cycle
- Patent ductus arteriosus— pressure gradient between aorta and pulmonary artery persists in both systole and diastole
Right ventricle develops pressure of only
25/0-4
Pulmonary arterial blood pressures are
25/10
Gives the maximal pressure that can be developed under any given left ventricular volume
ESPVR curve
Duration of systole is about _____ of the cycle while diastole is ____
Systole- 1/3 and diastole is 2/3
Emptying occurs at ____ pressures while filling is mostly _______ pressure
Emptying occurs at high pressure while filling is mostly passive at low pressure
Systemic and pulmonary blood flow are equal although SVs can vary from beat to beat
True
Volume and pressures do not change in exercise or disease
FALSE
All valves are _______ during isovolumetric contraction and relaxation
Closed
Events that occur almost simultaneously with onset of systole:
- GRS complex
- S1
- C wave
- Closure of mitral valve
- Rise in ventricular pressure
Events that occur almost simultaneously with onset of diastole
- S2
- Closure of aortic valve
- Incisura
- Drop in ventricular pressure
Heart pumps its stroke volume in the time between
S1 and S2
pressure volume loops:
phases:
a
b
c
d
a-ventricular filling from ESV when mitral valve opens to EDV at its closing
b- isovolumetric contraction
c- ejection of SV from when the aortic valve opens until it closes
d- isovolumetric relaxation
left ventricular pressure is plotted against left ventricular volume during a single cardiac cycel
pressure-volume loops
the width of the loop in a pressure- volume loop is the difference between EDV and ESV
SV
the are within a pressure-volume loop is the ________- the work done by the ventricle to eject a volume of blood into the aorta
ventricular stroke work
