Cardio PT 1 Flashcards
Easy way to remember beta-1 vs beta-2:
1 heart vs 2 lungs.
Beta blockers _______ cardiac contractility (negative inotropes), so a beta agonist ______ cardiac contractility.
Beta blockers REDUCE cardiac contractility (negative inotropes), so a beta agonist BOOSTS cardiac contractility.
Differences between cardiac muscle
and skeletal muscle
Duration of contraction (cardiac is longer)
Functional syncytium: cells all connected via gap junctions. (still separate cells)
Syncytia (Atrial and Ventricular) separated by fibrous tissue around AV openings.
Additional channel: Ca-Na (slower but longer)
(Skeletal muscle and cardiac muscle both have fast sodium channels)
Primary pace maker?
controlled by?
SA node
Autonomic NS
a class III antiarrythmic agent that prolongs phase 3 of the cardiac action potential, the REPOLARIZATION phase where there is normally decreased calcium permeability and increased potassium permeability
Amnioderone
Slows down the conduction of electrical activity within the heart by blocking the calcium channel during the PLATEAU phase of the action potential of the heart
CCB
reduces HR (parasympathetic)
used to treat a fast HR called SVT
Vagal stimulation
Vagus nerve = parasympathetic = rest & digest
During isovolumic, only thing changing is
PRESSURE (volume does not change)
The purpose of valves is to prevent
BACKFLOW
The purpose of chordae tendineae is to
prevent over bulging/prolapse
Pressures during diastole:
Ventricles
Atria
Ventricles have LOWER pressure.
Atria have HIGHER pressure.
A-V Valve opening
Once pressure in the _______ builds up enough, we open the valve.
Once the valve is open, we fill up our _______
A-V Valve opening
Once pressure in the ATRIA builds up enough, we open the valve.
Once the valve is open, we fill up our LV
Period of rapid filling what valve opens?
Systole or Diastole?
A-V Valve opening
Diastole
Pressures during Systole:
Ventricles
Atria
Ventricles have HIGHER pressure.
Atria have LOWER pressure.
Once pressure in the LV builds up enough (____________), we open the __________
Semilunar Valve opening
Once pressure in the LV builds up enough (ISOVOLUMIC CONTRACTION), we open the SEMILUNAR VALVE.
Once we hit right above ________mmHg in the LV then the ______________
Majority of your blood (_____%) is ejected QUICKLY (_____ time), which is the period of rapid ejection.
Rest takes _____ time for the period of slow ejection.
Once we hit right above 80 in the LV, semilunar valves open.
Majority of your blood (70%) is ejected QUICKLY (⅓ time), which is the period of rapid ejection.
Rest takes ⅔ time for the period of slow ejection.
Once your LV is done squeezing, it ________, so LV pressure _______ and the semilunar valve closes. (_____________)
Closing of the Semilunar Valves
Once your LV is done squeezing, it relaxes, so LV pressure DROPS and the semilunar valve closes. (Isovolumic relaxation)
What is the pressure of the LV and LA during Systole
LV = high, LA = low
Average Cardiac Output =
Cardiac output equation =
5L/min
Cardiac output = Stroke Volume x Heart Rate
Average Stroke Volume =
70 mL/beat
Ejection Fraction (EF) =
((EDV - ESV) / EDV) x 100 = EF
How much blood did you pump out compared to what you started with.
End systolic volume/ESV =
the volume at the END of systole (50 mL)
Stroke volume/SV =
the volume EJECTED out of the LV during systole (70 mL)
End Diastolic Volume - End Systolic Volume = SV
End diastolic volume/EDV =
the volume at the END of diastole (120 mL)
EDV = SV + ESV?
Distinction between Ejection Fraction and Stroke Volume
you can have a small Stroke Volume, but Ejection Fraction normal if your End Diastolic Volume was low to start with.
End Diastolic Volume - End Systolic Volume =
Stroke Volume
((End Diastolic Volume - End Systolic Volume) / End Diastolic Volume) x 100 =
((120ml - 50ml) /120) x 100 =
Ejection Fraction (usually = about 60%)
58% EF
Ejection Fraction
((End Diastolic Volume - End Systolic Volume) / End Diastolic Volume) x 100 = EF
EDV of 150 mL
ESV of 50 mL
What is the SV?
What is the EF?
SV = EDV - ESV = 150 - 50 = 100 mL
EF = (EDV-ESV)/EDV x 100
EF = (150-50)/150 x 100 = 66%
Fick equation
FICK = VO2 = CO x (aO2-vO2)
Orrrrr
CO = VO2 / (Ca -Cv)
Cardiac output = O2 consumption in milliliters of pure gaseous oxygen per minute / (O2 content of arterial blood - O2 content of mixed Venus blood)
250 ml/min = 5000ml/min x 5 ml O2/100ml bid (.05ml)
Fick
Starling’s Law, Preload, & Afterload
the more blood that flows into the heart, the more it will pump out.
increasing preload or EDV means increaseing how much blood _______ the heart.
If you increase preload, then your stroke volume should _________.
increasing preload or EDV means increasing how much blood ENTERS the heart.
If you increase preload, then your stroke volume should increase.
EDV and Venous return is ___________
increasing EDV and Venous return is (increasing or decreasing) ___________
Preload
Increases Preload
Things that increase preload
Muscle pump (standing up)
Respiratory pump (inspiration = negative pressure) (lungs like vacuum for blood (pressure goes down, volume increases))
Venoconstriction (Increased venous return) (hose squeezing)
Dynamic work (Running) (relaxed)
Systemic Blood Pressure is
Afterload
Things that increase Afterload
SBP
Aortic stenosis (or HTN)
Arteriosclerosis
Static work (Weight lifting) (tensed up)
Anything that increase venous return to the heart = increases afterload or preload
preload
Anything that increases your BP, aka the resistance you must overcome during systole = increases afterload or preload
afterload
Concentric = ______ biceps
Eccentric = ______ biceps
Concentric = Curling biceps,
Eccentric = Extending biceps
Do these increase preload or afterload primarily
Shoveling Snow
Running
Standing up
Taking a deep breath in
Lifting weights at the gym
Shoveling Snow = Increases Afterload
Running = Increases Preload
Standing up = Increases Preload
Taking a deep breath in = Increases Preload
Lifting weights at the gym = Increases Afterload
Preload is increased by things that increase ______.
Afterload is increased by things that increase _____________.
Venous Return
resistance after the aorta.
HR, SV, CO is increased by sympathetic or parasympathetics
sympathetics
STOKE VOLUME is highlighted bc __________ mainly affect the
SV is highlighted bc SYMPATHETICS mainly affect the VENTRICLES
Parasympathetics mainly affect the ______
Parasympathetics mainly affect the ATRIA
Ex: Slowing HR
