Cardiac Flashcards
Ejection fraction
percentage of blood ejected on each ventricular beat
normal is 67%
stroke volume
volume of blood ejected on each stroke
70 ml is normal
factors affecting stroke volume
preload (venous return)
cardiac contractility (inotropy, dromotropy)
afterload (systemic vascular resistance)
cardiac output
amount of blood heart pumps in 1 min
hr x sv
layers of heart
endocardium- innermost layer
myocardium- mid layer
pericardium- outer layer
pericardium
protective sac that surrounds the heart
layers of pericardium
visceral- innermost lining of the sac
25 ml of pericardial fluid
parietal-second or middle lining of the sac
fibrous- outermost lining
what separates right and left atria, ventricles
interatrial septum
intraventricular septum
blood flow through heart
1: superior and inferior vena cava returns blood to heart
2: right atrium-> tricuspid valve
3: right ventricle-> pulmonic valve->pulmonic artery
4: Lungs-> pulmonary vein
5:Left atrium-> Mitral valve
6:Left ventricle -> Aortic valve
7: Aorta (largest artery in body)
7A: aorta feeds heart muscle by way of coronary arteries
when are coronary arteries perfused
diastole
Left Coronary artery supplies what
Left ventricle, inter-ventricular septum, part of right ventricle, hearts conduction system
Left coronary artery branches
Left anterior descending
left circumflex
Right coronary artery supplies what
portion of right atrium, portion of right ventricle, part of conduction system
branches of RCA
posterior descending
marginal branch
Collateral circulation
protective mechanism providing alternative path for blood to flow in event of blockage
Layers of blood vessles
tunica intima- innermost
tunica media- middle layer, elastic fibers, gives vessels strength and allows for recoil
tunica adventitia- outermost lining, fibrous, gives strenght
vessles of circulatory system
oxygenated blood -> aorta -> arteries -> arterioles ->capillaries
deoxygenated
capillaries-> Venules -> veins ->Vena cava
what does cardiac axis mean
portion of heart is requiring more energy to depolarize
Extreme right
right
left
extreme left
right atrium
right ventricle
left atrium
left ventricle
normal axis deviation
-30-+90
causes of Extreme right axis deviation
vtac
severe hyper k
pvc
severe rvh
causes of right axis deviation
right ventricular hypertrophy
copd
pulmonary embolism
lateral MI
hyperk
wpw
Left axis deviation causes
Left ventricular hypertropy
left bbb
rbbb
inferior MI
wpw
parasympathetic (cholinergic) function
neurotransmitter
major nerve
feed and breed
acetylcholine
vagus nerve
sympathetic nervous system (adrenergic)
function
neurotransmitter
fight or flight
norepi
parasympatholytic
blocks parasympathetic nervous system
sympathomimetic
mimics sympathetic nervous system
epi
alpha 1 receptor jobs
vasoconstriction
pupil dilation
decreased renin secretion
beta 1
hr chronotropy
contractilty ino
conduction dromo
beta blocker ending
olol
renin function
released by kidneys in response to low blood pressure and decreased perfusion
explain renin angiotensin aldosteron system
angiotensinogen is secreted by liver and put into circulation
renin is released by kidneys
angiotensin is converted by renin to angiotensin 1 which is then converted by lungs to using ACE to angiotensin 2
this takes 20 min and causes vasoconstriction
baroreceptors function
detect low bp
baroreceptors location
carotid sinus and aortic arch
most prevalent extracellular cation
sodium
sodium function
plays role in depolarization
calcium function
myocardial depolarization and contraction
potassium function
influences repolarization
most prevalent intracellular cation
potassium
what does atp do
fuel for cell
explain cardiac action cycle
resting potential -> polarization-> K in Na out
action potential-> depolarization -> influx of Na
recovery -> repolarization-> k returns into cell, Na exits
intercalated disc function
allow simultaneous contraction
s1 sound
lub closure of AV valves
s2
dub closure of semilunar valve
s3
chf or fluid sounds like kentuky
s4
sounds like tenesse, increased atrial contraction
SA intrinsic rate
60-100
AV intrinsic rate
40-60
purkinje intrinsic rate
15-40
what is coronary artery disease
diseases that affect arteries of heart
thrombus
clot formed of blood and plaque
embolus
blockage of vessle by clot
atherosclerosis
calcium and cholesterol build up inside walls of blood vessels leading to ischemia
arteriosclerosis
hardening of arterial walls preventing adequate vasocaonstriction and dilation
what is angina
“pain in the chest” from hearts demand for o2 exceeding supply.
commonly caused by atherosclerosis and cad
stable angina time of onset, length, persistence
sudden onset with activity
lasts 3-5 min, subsides with nitro and rest
unstable angina, time of onset, duration, persistnece
sudden onset during rest, lasts more than 20 min, wont resolve with nitro
variant angina (prinzmetal)
caused by coronary vessle vasospasm, can occur at rest, may go away with rest or meds
Subendocardial MI
mi extends partially through thickness of myocardium. may or may not produce pathological q wave
transmural MI
MI goes through full thickness of myocardium
Stemi requirements
1mm or more of elevation in contigous or consecutive
atypical MI can present in who
elderly, female, chronic hypertensive, diabetics
causes of right heart failue
1 left heart failure
cor pulmonale (right ventricular hypertrophy)
right ventricualr infarct, tricuspid or pulmonic valve damage, PE
causes of left heart failure
pulmonary edema
htn
left ventricular infarct
mitral valve damage
aortic valve damage
cardiomyopathy
MI #1 cause
ss of R heart failure
JVD
peripheral edema
ascites
sacral/scrotal edema
orthopnea
hepato jugular reflex
ss of left heart failure
anxiety
tachycardia
htn
pale sweaty skin
paroxysmal nocturnal dyspnea orhtopnea
rales/crackles
pink frothy sputum
pulsus paradoxus
pulsus alterans
right heart failure treatment
o2, 12 lead, fluid administration
left heart failure treatment
o2 , 12 lead, nitro, cpap, furosemide
becks triad
jvd
muffled heart sounds
hypotension
what type of shock is cardiac tamponade
obstructive and cardiac
ss of cardiac tamponade
becks triad
cp
dyspnea
orthopnea
narrowing pulse pressure
electrical alternaans
pulsus paradoxus
cardiac tamponade managemnt
o2 fluid bolus 20 ml/kg
pressor
cardiogenic shock causes
impaired contractility due to mi
impared ventricular emptying (left sided heart failure)
tension pneumothorax
cardiac tamponade
trauma
cardiogenic shock ss
sbp less than 80
respiratory distress
cp
weakness
altered mental status
hypotension
tachycardia
cardiogenic shock treatment
o2, identify underlying problems, fluid, vasopressor
1-200 ml fluid boluses
dissecting aortic aneurysm signs and symptoms
syncope
absent or reduced pulses
unequal bp
heart failure
tearing sensation in back
flank pain
scapular pain
pain radiating in legs
hypertensive crisis definiton
uncontrolled htn that flucuates and is above 180/120
1 small box on ekg
.04 seconds
1 big box
.2 seconds
how fast does paper move
25 mm/ second
lead 1 shows what axis
0
lead 2 shows what axis
60
lead 3 shows what axis
120
avr shows what view
right arm
avl shows what view
left arm
afv shows what view
left foot
p wave means what
atrial depolarization
pr interval shows what
time it takes for impulse to travel from sa node to ventricles
normal is .12-.20
measured from beginning of p wave
qrs complex shows what
depolarization of ventricles normal is .04-.12
t wave means what
repolarization of ventricles
Lateral Leads artery
LCX
Inferior leads artery
RCA
septal and anterior leads artery
LAD
digitalis effect on 12 lead
st segment “sag”
WPW wave
delta wave, slurred upstroke
osborne wave
J wave, Hump on back of qrs
