The Cardiac Cycle Flashcards
Draw the WIgger’s Diagram for the left atrium, ventricle, and aorta.
left atrial a wave
contraction of the atrium (atrial kick) during atrial systole
left atrial c wave
valve leaflets are moving back up into the left atrium when the ventricle contracts, leading to a rise in pressure in the atrium
left atrial v wave
during ventricular ejection, blood continues to flow into the atria from the systemic and pulmonary veins while the AV valves are closed
this distends the atrial walls and causes a gradual rise in atrial pressure
a sharp fall occurs when the AV valves open at the onset of rapid ventricular filling
normal human end diastolic volume
130 mL
normal human end systolic volume
60 mL
Draw the waveform of the jugular venous pulse.
What is the normal stroke volume for a 70kg person?
75 mL
What is the normal cardiac output?
5L/min
incisura (dicrotic notch)
the result of the elastic recoil of aortic diameter back down from its temporarily expanded diameter caused by ventricular ejection
diastasis (quiet period)
the period in late diastole where very little additional blood fills the ventricles
jugular a wave
rise in pressure caused by atrial contraction
priminent a wave signifies right ventricular hypertrophy or tricuspid stenosis
jugular c wave
rise in pressure caused by right ventricular contraction and movement of tricuspid valve into the right atrium
jugular v wave
filling of the right atrium against a closed tricuspid valve
prominent v wave signifies tricuspid regurgitation
jugular x descent
fall in atrial pressure that occurs as the ventricle ejects volume into the pulmonary artery
jugular y descent
caused by the opening of the tricuspid valve
prominent y descent signifies constrictive pericarditis
first heart sound S1
vibration caused by closing of the AV valves, mitral first then tricuspid
best heard at the apex “lub”
Where is the mitral valve closing best heard?
to the left of the sternum (4th intercostal space)
Where is the closing of the tricuspid valve best heard?
over the sternum
second heart sound S2
closure o the aortic and then pulmonary valves
“dub”
Where is the aortic component of S2 best heard?
to the left of the sternum at the first intercostal space
Where is the pulmonic component of S2 best heard?
to the right if the sternum at the first intercostal space
third heart sound S3
when the blood flows passively from the atria into the ventricles, it creates some turbulence, which if excessive, causes S3
this is not normally heard
fourth heart sound S4
the additional spurt that can cause some turbulence when the atria contract
this is not normally heard
Describe the timing of contraction, valve movements, and heart sounds.
cadicac index (liters/min/sq m)
mean at rest: 3.1
range at rest: 2.5-4.0
venous pressure (mmHg)
mean at rest: 5
range at rest: 3-8
right atrial pressure (mean; mmHg)
mean at rest: 2
range at rest: -2 - +5
right ventricular pressure (systolic; mmHg)
mean at rest: 25
range at rest: 18-30
right ventricular pressure (end-diastolic; mmHg)
mean at rest: 2
range at rest: -5 - +5
pulmonary artery pressure (systolic; mmHg)
mean at rest: 25
range at rest: 18-30
pulmonary artery pressure (diastolic; mmHg)
mean at rest: 10
range at rest: 6-12
pumonary artery pressure (mean; mmHg)
mean at rest: 15
range at rest: 10-20
pulmonary wedge (mean; mmHg)
mean at rest: 6
range at rest: 0-12
left atrial pressure (mean; mmHg)
mean at rest: 6
range at rest: 0-12
left ventricular pressure (systolic; mmHg)
mean at rest: 120
range at rest: 100-140
left ventricular pressure (diastolic; mmHg)
mean at rest: 6 mmHg
range at rest: 0-12
brachial artery pressure (mean; mmHg)
mean at rest: 95
range at rest: 85-105
right ventricular contraction
free wall shortens
free wall moves towards septum
septum moves towards free wall
left ventricular contraction
chamber constricts
chamber shortens
