Part 1 Flashcards
normal cardiac anatomy = ________ chambers, ____ valves, ______ pulmonary arteries, and & _______ pulmonary veins
4, 4, 2, 4
which has a thicker muscle layer? (atrium or ventricle)
ventricle
pulmonary arteries carry ______________ blood to the lungs, and the pulmonary veins carry ______________ blood back to the heart
deoxygenated; oxygenated
describe the flow of blood through the heart, coming in from the body
body –> SVC/IVC –> R. atrium –> tricuspid valve –> R. ventricle –> pulmonic valve –> pulmonary artery –> lungs –> pulmonary vein –> left atrium –> mitral valve –> left ventricle –> aortic valve –> aorta –> body
the heart is located __________ between the lungs in the _________________
medially; mediastinum
the heart is separated from other mediastinal structures by the _______________, and sits in its own space called the __________________
pericardium; pericardial cavity
the _____________ side of the heart is deflected anteriorly; and the __________ side of the heart is deflected posteriorly
right; left
the ________________ surface of the heart sits deep to the sternum and costal cartilages
dorsal
the great veins (SVC/IVC) and the great arteries (aorta and pulmonary trunk) are attached to the _________________ surface of the heart, which is referred to as the ___________
superior; base
the base of the heart is located at the level of the ________________ costal cartilage
3rd
the inferior tip of the heart is called __________________
apex
the apex of the heart lies to the ____________ of the sternum between the junction of the ______&_________ ribs near their articulation with the costal cartilages
left; 4;5
the slight deviation of the apex of the heart to the left side is reflected in a depression in the medial surface of the inferior lobe of the left lung, which is called the _________________
cardiac notch
the ________________ is what divides the heart into chambers
septum
the septum of the heart are physical extensions of the ________________ lined with ____________
myocardium; endocardium
what are the 3 different septums of the heart
- interatrial
- interventricular
- atrioventricular
which cardiac septum includes the valves?
atrioventricular
which cardiac septum divides eh heart horizontally
atrioventricular septum
in a normal adult heart the interarterial septum bears an oval shaped depression known as the _________________
fossa ovalis
the fossa ovalis is a remnant of an opening in the fetal heart known as the __________________
foramen ovale
what is the purpose of the foramen ovale in the fetal heart?
allows blood to pass directly from the right atrium to the left atrium, by passing the pulmonary circuit
after birth a flap of tissue known as the ________________ (which previously acted as a valve) closes the foramen ovale establishing typical cardiac circulation patterns
septum primum
which septum of the heart is the thickest?
interventricular
why is the interventricular septum thicker than the interatrial
ventricles generate far greater pressure when they contract than the atria
T/F: The interventricular septum has an opening during fetal development, which closes after birth
false; interventricular septum once formed remains in tact
the _________________ septum is marked by the presence of four openings that allow blood to move through the chambers
atrioventricular
valves between the atria and ventricles are called _________________ valves, and those leading to the pulmonary trunk and aorta are known collectively as _____________ vavles
atrioventricular; semilunar
the valves/openings of the atrioventricular septum structurally weaken the AV septum, therefore; the remaining tissue is heavily reinforced with dense connective tissue called ____________________
cardiac skeleton
what is the cardiac skeleton
- 4 rings of dense connective tissue that surround the openings between the atria and ventricle and openings to the pulmonary trunk and aorta.
which valves are semilunar valves?
aortic and pulmonic
______________ valves operate passively with changes in pressure
semilunar (Aortic and pulmonic) - they open with RV/LV ejection
what are your AV valves
mitral and tricuspid
_______________ valves ensure unidirectional blood flow from the atria to the ventricles
AV valves (mitral and tricuspid)
all valves are ______________ leaflet, except _________________, which is __________ leaflet
tri; mitral; bi
pulmonic valve leaflets are identified by ________________
anatomic position
what are the leaflets of the pulmonic valve
right; left; anterior
aortic valve leaflets are identified r/t ____________________
coronary ostium
what are the leaflets of the aortic valve?
- right coronary cusp (attached to right coronary artery [ostium])
- left coronary cusp (attached to left coronary artery)
- non-coronary cusp (not attached to a coronary artery)
which valves are smaller and thicker?
semilunar (aortic and pulmonic)
which valves handle HIGH velocity
semilunar (aortic and pulmonary)
what is normal aortic valve area
3-4 cm^2
severe aortic stenosis is defined as a valve area < _________ cm^2
1
What is a possible congential heart defect of the aortic valve
bicuspid aortic valve defect
what are the leaflets of the tricuspid valve
- anterior
- posterior
- septal
what are the leaflets of the mitral valve
- anterior
- posterior
how are the leaflets of the mitral valve SUBdivided?
A1-3 & P1-3
on the mitral valve leaflets A1/P1 are ____________ side and A3/P3 are ___________ side
lateral; medial
with a ______________ MI you can have a chordae tendineae rupture
transmural
what are the small fibrous strings which attach from the AV valves to the papillary muscles
chordae tendineae
which valves are described as: large, thin, and filmy?
AV valves
normal valve area of the tricuspid valve
7 cm^2
tricuspid stenosis occurs when valve area is < _________ cm^2
1.5
normal valve area of the mitral valve
4-6 cm^2
mitral valve stenosis occurs when valve area is < ______________ cm^2
2
what is the function of the papillary muscle?
keeps valves from prolapsing backward into the atria
ruptured chordae tendineae (esp with mitral valve) causes what
pulmonary edema
when an AV valve is OPEN: the chordae tendineae is _____________ and the papillary muscles are _______________
slack; relaxed
when the AV valve is CLOSED: the chordae tendineae is _____________ and the papillary muscles are _______________
taut; contracted
what is the leading cause of aortic valve regurgitation in younger (peds) patients?
bicuspid aortic valve (CHD)
coronary ostia is in the ________________________
sinus of valsalva
_______________ is when valve opening narrows and restricts blood flow
stenosis
_______________ is when blood leaks backwards through a valve d/t incomplete closure
regurgitation
________________ is when valve leaflets do not close smoothly; they buldge upward into the atrium
prolapse
what are the common causes of valvular dz
- endocarditis
- rheumatic fever
- congenital defects (bicuspid AV)
if your valve is stenotic, you will have a ______________ gradient
higher
what is valve gradient
the difference in pressures on each side of the valve
severity of regurgitation is reported on a ______________ scale
0 - 4+
right dominant is when the posterior descending artery (PDA) is supplied from the __________, and “left dominant” is when the PDA is supplied from the _________________
right coronary artery; left circumflex
in reference to the posterior descending artery, what percentage of the population is “right dominant” and what percentage is “left dominant”
85% = right
if there is a left main coronary artery occlusion in a left dominant heart, you will lose circulation and oxygenation to which walls of the heart?
anterior, lateral, AND posterior
the right coronary artery orginates at the ___________________
right aortic sinus
___________ arteries arise off of the PDA
septals
the PDA supplies the:
- inferior wall of the heart
- cardiac septum
- posteriormedial papillary muscle
the anterior right ventricle is supplied by what artery?
the right ventricular branches (i.e. acute marginal) - which branch off the RCA
in 60% of people blood to the SA node is supplied via
sinus node artery which branches off the RCA
in most people, if they have an infarction of the ____________ artery; they will lose automaticity of the SA node
right coronary
the right coronary artery (RCA) supplies ________-____% of blood supply to the left ventricle
25-35
which coronary artery is described as the “widow maker”
left coronary artery
branches of the left coronary artery
- left anterior descending (LAD) - (aka anterior interventricular branch)
- left circumflex
the __________________ artery comes off the left main and travels down the interventricular groove to the apex
LAD (aka anterior interventricular branch)
____________ and ___________ arteries branch off the LAD and supply the lateral wall of the LV
septals and diagonals
30% of the population has an arterial branch off the LAD that looks like the 1st diagonal. This artery is called ____________________
ramus intermedius
the LAD provides blood supply for ______-______% of the LV
45-55
which arteries provide blood supply to the left ventricle (list from greatest supply to least)
LAD > RCA > left circumflex
which coronary artery travels downward and left through the AV groove
left circumflex artery
which artery supplies the posteriolateral portion of the left ventricle
left circumflex
in about 38% of the population the SA node blood supply originates from the ________________
left circumflex artery
the left circumflex artery (in right dominant heart) provides ___ -____% of blood supply to the left ventricle. in the left dominant heart, the left circumflex artery supplies about _______% of blood supply to the left ventricle
15; 25; 50
a left main artery occlusion would have EKG changes in what leads
V1-V6 (entire left ventricle
LAD occlusion would have EKG changes in what leads
V1-V4 (anterior LV)
circumflex occlusion would have EKG changes in what leads
I, aVL, V5, V6 (lateral)
RCA occlusion would have EKG changes in what leads
II, III, aVF (RV, posterior LV)
T/F: coronary circulation is continuous
false; it cycles
coronary circulation peaks during __________ and ceases during ____________
diastole; systole
what are the surface arteries of the heart that are most superficial and follow the sulci
epicardial arteries
there are _______ dilations in the wallof the aorta just superior to the aortic valve. 2 of these dilations give rise to the ___________________
3; 1 to the left coronary artery and 1 to the right coronary artery
what vein initially runs parallel with the LAD but eventually runs to the posterior side of the heart (with the circumflex)
great cardiac vein
what coronary vein runs parallel with the left marginal artery (branch of circumflex)
posterior cardiac vein
which coronary vein runs parallel with the PDA
middle cardiac vein
which vein parallels the right coronary artery and drains blood from the posterior surfaces of the right atrium and ventricle
small cardiac vein
what coronary vein parallels the small cardiac arteries and drains the anterior surface of the right ventricle
anterior cardiac veins
which coronary vein bypasses the coronary sinus and drains directly into the right atrium
anterior cardiac vein
coronary veins drain into the ___________, which empties directly into the right atrium
coronary sinus
describe the flow of blood through the coronary vasculature
aorta –> coronary arteries –> epicardium –> endocardium –> coronary veins –> coronary sinus –> R. atrium
there is a small amount of venous return to the heart from bronchial circulation through the ___________ veins; this acts as a physiological shunt
thesbian
what is normal coronary sinus SVO2
35% (meaning large O2 extraction with little reserve in times of ischemia
T/F: there is blood flow to the epicardium during the entire cardiac cycle (systole and diastole)
TRUE
blood flow to the _________________ layer of the heart occurs mainly during diastole making it the most vulnerable to ischemia
endocardium
which muscle layer of the heart is the most vulnerable to ischemia
endocardium
at rest, ________% of CO passes through the coronaries
4-5 (225mL/min)
what layer of the heart extracts 65-70% of the DO2 (delivered O2)?
myocardium
formula for coronary perfusion pressure
CPP = ADBP - LVEDP
what is a normal CPP
15-70 mmHg
what is a normal LVEDP
12-15 mmHg
coronary blood parallels what?
myocardial metabolic demand
hypoxia causes the coronaries to ____________
vasodilate (to increase supply of O2 to the heart)
volatile anesthetic gases cause the coronary artery ___________________
vasodilation (may enhance recovery of stunned myocardium)
according to Coronary STEAL, when SVR is low 2/2 dilation what is happening in the coronaries?
decreased flow to the coronaries
what is the chief cell type in the heart
cardiomyocyte
______________ cells are primarily involved in the contractile fuction of the heart
cardiomyocytes
each myocardial cell contains ____________ which are specialized organelles consisting of long chains of _____________
myofibrils; sarcomeres
what are the fundamental contractile units of muscle cells
sarcomeres
T/F: cardiomyocytes are highly resistant to fatigue
TRUE
a sarcomere bundle contains what?
- myosin
- tropomyosin-actin-troponin complex
- z-disc
when a cardiac action potential is generated calcium moves into the cell causing the ___________________ to release more calcium (inside the cell) –> interaction with troponin tropomyosin complex to initiate cardiac contraction
sarcoplasmic reticulum
Calcium-induced calcium release (CICR)
The movement of Ca2+ through the plasma membrane, including the membranes of the T tubules, into cardiac muscle cells stimulates the release of Ca2+ from the sarcoplasmic reticulum –> cardiac muscle contraction
for a cardiac myocyte to relax, what has to happen?
Calcium has to be actively transported back into the SR across cellular membrane (requires energy and O2)
when calcium is released from the SR how does this lead to muscle contraction of the cardiac myocyte
calcium binds to troponin –> conformational change of tropomyosin exposing the active binding site –> interaction with actin and myosin –> contraction
T/F: ATP and O2 are required for both relaxation and contraction of the cardiomyocyte
TRUE
what is the ideal sarcomere length
1.8 - 2.2 um
actual sarcomere size is dependent on ______________
preload
_____________ sarcomeres end-to-end comprise a myocyte
6
what is between myocytes to prevent overstretching and damage and allow them to move as “one”
collagen
in a cardiac myocyte cell, what is the function of the intercalated discs
they create gap junctions –> increased spread of depolarization –> cardiac muscle contracting in sync
__________% of ATP in the cardiac myocyte is used for myosin linking
75
_________________ is an internodal pathway that connects the right and left atrium allowing them to contract at the same time
Bachmann’s Bundle
Describe the normal electrical conduction flow of the heart
SA –> AV –> Bundle of His –> L/R Bundle branches –> purkinje fibers
the __________________________ prevents atrial depolarization from entering into the ventricular tissue
fibrous cardiac skeleton
depolarization rate of SA node is _________; however, ANS innervation brings it down to about ____________
90; 60-70
how is action potential of the SA node generated?
spontaneously
what is described as the pacemaker of the heart
SA node
phases of the Pacemaker (SA) action potential
- phase 4 - spontaneous depolarization to threshold (-30 mV) (K efflux and Na influx) from resting membrane potential (-60mV) - slow- Na influx
- phase 0 - slow depolarization d/t calcium influx (L-type)
- phase 3 - repolarization d/t K efflux
electrical conduction from SA to AV node rests for ________________ seconds before AV node is depolarized
0.1 - 0.13
the pause of electrical depolarization at the AV node allows for what
filling of chambers and coordinated contraction btwn atria and ventricle
AV node depolarizes at ________________
40-60 bpm
if AV node becomes primary pacemaker, what type of rhythm will you see on EKG
junctional rhythm (40-60 bpm; no p waves bc atria are not depolarizing)
His-Purkinje fibers depolarize at __________ bpm
20-40
the Fastest conduction velocity in the heart is performed by….
His-Purkinje (longest to travel but does so the fastest in sync)
what is the final backup in the event of SA and AV node failure
His-Purkinje system
what type of rhythm will you see if His-Purkinje system is the pacemaker
agonal rhythm
Anesthetic gases effect on SA nodal activity
depresses SA nodal automaticity and contractility
what is the mechanism on how volatile anesthetic gases depress contractility?
they decrease the entry of calcium into cells during deopolarization
phases of ventricular action potential
- phase 0: rapid depolarization (Na influx)
- Phase 1: intial repolarization (Na channels close)
- phase 2: plateau (calcium influx)
- phase 3: repolarization (K efflux)
- phase 4: Na-K pump restores restiming membrane potential
what is resting membrane potential of the ventricular action potential
-90 mV
phase 2 (plateau) ventricular action potential allows time for __________ contraction, and prevents _____________
ventricular; tetany
duration of Action potential in atrial muscle __________ s; duration of action potential in ventricular muscle ________ s
0.2; 0.3
________________ time is relatively fixed in duration, therefore at times of high heart rate ________________ time is sacrificed
systole; diastole
tachycardia decreases _________________ & _________________
ventricular filling and coronary filling
describe the process of excitation-contraction coupling in the cardiac cell
- Calcium from plateau phase of action potential enters the cell at the via DHP receptor
- calcium triggers the RYR receptor of the SR to release calcium (calcium induced calcium release)
- calcium binding to troponin –> conformational change of tropomyosin exposing the active site –> contraction
_________ % of ATP is used for Calcium transport into the SR at muscle relaxation
25
describe the process of when cardiac muscle completes contraction and is resting/relax
- calcium release from troponin and some is actively transported via atp back into SR ; other Calcium is actively pumped out of the cell via the Na/Ca exchanger (which requires ATP, K, Na pump)
how do PDE inhibitors (like milrinone) effect contractility of the heart?
prevents the breakdown of intracellular calcium –> increased contraction
how does digitalis affect contractility of the heart?
blocks the Na-K-ATPase which indirectly inhibits the Na/Ca exchanger, increasing intracellular calcium –> increased contraction
how does glucagon affect contractility of the heart
increases intracellular cAMP –> increases intracellular calcium –> enhances contractility
how does acidosis affect the contractility of the heart
slows calcium channels, slows contractility
how does N2O affect contractility of the heart
reduces the availability of intracellular calcium –> decreasing contractility
sympathetic innervation of the heart orginiates from _____________ and travels through the ________________
T1-T4; stellate ganglion
if you do a spinal block above T1, what cardiac effects would you expect to see
bradycardia and Hotn (block SNS innervation to heart)
B1 activation in the heart –> increased activation of ___________ –> ___________, which opens more ________ channels
cAMP; Ca; Ca
B1 activation of the heart causes positive ______________, ______________, and ____________ response
chronotropy; dromotropy; ionotropy
________________ innervation is widely distributed throughout the heart, but __________________ innervation is only present in atria and conduction tissues
SNS; PNS
muscarinic activation in the heart causes negative _______________, ____________, and ______________ response
chronotropic; dromotropic; ionotropic
T/F: parasympathetic innervation can decrease CO to nearly zero (esp in peds)
TRUE
SNS and PNS effects ________________ time between action potentials
latency (does not actually change the action potential)
SNS response on the heart increases _____________ via ________________
automaticity; NE
PNS response on the heart decreases _______________ via ____________
automaticity; Ach
SNS/PNS innervation on cardiac action potential is primarily d/t effects on ____________ and ___________ INFLUX
sodium; calcium
________________ from closure of mitral valve to closure of aortic valve
systole
isovolumic contraction occurs during ________________, and isovolumic relaxation occurs during _______________
systole; diastole
T/F: diastole is an energy requiring process
TRUE
during an isovolumetric contraction, how does pressure differ between atria, ventricle, and Ao (place from highest pressure to lowest)
AoP > LVP > LAP
describe the process of systolic ejection
LVP > AoP –> rapid ejection, then slow ejection
diastasis = _______________
passive filling
rapid filling =
suction of blood through open MV
atrial systole provides _______% of ventricular filling in normal pt; and ____% of filling in htn/AS pts
20; 40
EDPVR (end diastolic pressure volume relationship) refers to _____________, which is also ______________
compliance (stiffness); preload
ESPVR (end systolic pressure volume relationship) gives you ________________
contractility
if the EDPVR line is increased from baseline (higher on graph) what does this mean?
decreased compliance; decreased preload (i.e. filling) - diastolic HF
if your slope of your ESPVR is steeper than baseline; what does this mean
contractility is increased
how do you calculate stroke volume from a pressure volume loop
EDV - ESV
how do you calculate EF from a pressure volume loop?
SV / EDV
- S1 and S2 heart sounds
refer to hand out for checking answers
if your preload is increased, what parts of your pressure volume loop would also be effected?
increased EDV, LVEDP, SBP/DBP, and SV
independent effects on pressure volume loop of increase afterload
- isovolumic contraction is prolonged (d/t increased aortic pressure)
- smaller SV
- increased ESV
- increased SBP/DBP
independent effects of increased inotropy on the pressure volume loop
- increased SV and EF
- decreased ESV
- increased slope of ESPVR
CO = ____________x _________
HR; SV
ventricular systolic function is equated with ________________
CO
what is normal CO
4-6 L/min
what is the formula for CI
CO/BSA
what is normal CI
2.5- 4.2 L/min/m2
manipulation of HR will directly affect ____________
CO
__________ is an intrinsic fx of the SA node, but is affected by ANS, humoral and local factors
HR
T/F: HR decreases with age
true (r/t sns outflow
what are the main determinants of SV
preload, afterload, and contractility
________________ IS end diastolic volume (EDV) which is dependent on ________________
preload; ventricular filling
T/F: typically the heart pumps all the blood returned to it
TRUE
what is the primary determinant of preload
venous return
if you the heart more volume (preload) you _____________ the blood returned to the heart
increase
if you have too much preload (i.e. overdistension) what is the consequence
the heart cannot deliver a contraction that is strong enough (d/t sarcomeres being pulled too far apart)
when HR is constant ____________ is directly proportional to preload in both the right and left heart
CO
increase HR causes ___________ in diastolic time and impairs ______________
decrease; filling
T/F: LV output is higher than RV output over time
false; RV and LV outputs should be equal
venous compliance is _______x higher than arteriole
10
75% of blood resides in the ___________ (arteries or veins?)
veins - why venous compliance is 10x higher than arteriole
what is the bainbridge reflex
rise in atrial volume (gives increase in atrial pressure) causes the HR to increase by 10-20%
T/F: an empty heart cannot pump blood
TRUE
factors that can affect preload
- intrathoracic pressure (PPV, thoracotomy)
- positioning during surgery (t-burg)
- pericardial pressure (pericardial dz/tamponade)
- loss of atrial systole
_______________ establishes the length of each myocyte immediately before isovolumic contraction
preload
_____________ is what pulls the sarcomeres apart
preload
the steep part of the EDPVR line on a pressure volume loop represents what
preload reserve
as preload reserve increases ______________ increases but at slower rate for any given increase in pressure
SV
once preload reserve (steepest slope of EDPVR) - is steep ____________ cannot increase anymore to compensate; this means _______________ is exhausted
SV; preload reserve
_______________ is the load opposing the shortening of muscle fibers (i.e. what the heart is pumping against)
afterload
what are the factors that influence afterload
- ventricular wall tension (law of laplace: T (tension) = pressure x radius)
- Arterial impedance to rejection: HTN, arteriosclerosis, SVR, PVR
- physical properties of blood vessels and/or blood viscosity
formula for SVR
80 x (MAP-CVP)/CO
what is a normal SVR
900 - 1500 dynes/sec/cm-5
formula for PVR
80 x (mPAP - PWAP/CO)
normal PVR
50-150 dyn · s cm-5
formula for compliance
change in volume/change in pressure
CO and SV are ________________ related to afterload
inversely
which ventricle is more sensitive to afterload? why?
RV more sensitive; bc LV has 6x muscle mass than RV allowing it to withstand changes in afterload
Failing hearts are sensitive to changes in _________________
afterload
with LVF _______________ can greatly improve stroke volume
vasodilators
T/F: contractility is independent of preload and afterload
TRUE
what is the most important factor that can alter contractility
calcium concentration
formula for contractility (i.e. elastance) =
pressure/volume
contractility is dependent on the ______________ environment
chemical
factors that affect contractility
- calcium concentration (primary)
- Mg
- O2
- acidosis
methods to assess ventricular function
- frank starling curves (SV/EDV)
- pressure volume curves
- systolic fx (change in pressure/change in time)
- EF = (EDV-ESV)/EDV
- diastolic function via TEE measuring flow over MV during diastole
what is a normal EF
68%
what is the most accurate method to assess cardiac function?
TEE
what is the most commonly used monitoring method to assess the CV system
blood pressure
what is the gold standard for CV pressure monitoring
intra-arterial BP
what is the vessel of choice for placing an arterial line
Radial artery
why is the right radial artery the site of choice for Aline placement in cases of chest trauma
cross clamping of descending aorta can occlude l-subclavian artery
which artery provides the majority of blood flow to the hand in 90% of humans
ulnar, why it is not the preferred choice for ABP
using the allens test, you know the artery is sufficient to cannulate for ABP if the refill is ________________s
5-10
when doing an allens test, if refill is greater than _________ s you know that site is NOT appropriate to cannulate for ABP
15
_____________ is the change in the amount of blood ejected from the heart each beat
Stroke volume variation (SVV)
_____________ is a number that can be obtained from a vigileo, and helps guide fluid resusitation
SVV
if your SVV is > ________% it is appropriate to fluid challenge your pt
13
Factors that influence your site choice for ABP monitoring
- site of surgery
- position of patient (decreased flow to certain areas)
- hx of ischemia in limb prior to surgery
- previous cutdowns or arterial harvests
- dz processes (DM, PVD, raynauds)
contraindications to Aline placement
- infection
- coagulopathy
- proximal occlusion
- Raynauds (for certain sites)
if a patient has raynauds what site would be appropriate of aline placement
femoral or axillary; larger and have less risk for spasm/ischemia
considerations with brachial artery for ABP placement
- large artery, more proximal
- decreased chance for compromised circulation
- catheter easily kinked with patient movement
considerations of axillary artery for ABP placement
- nerves are close in proximity and risk for damage
- increased risk of hematoma (decreased ability to compress area)
if the axillary artery is used for a line placement what side should it be placed on to reduce risk of cerebral emboli
left
considerations for femoral a line placement
- high risk of infection
- risk of pseudoaneurysm formation
- not desirable site if pt has PVD
T/F: collateral circulation exists in the foot with the dorsalis pedis artery just like with the hand
TRUE
if use the dorsalis pedis for a line placement, the SBP will be ____________ mmHg higher, and the DBP will be _____________ mmHg lower
10-20 mmHg; 15-20 mmHg
which arterial cannulation site for aline placement has a high incidence of failure
dorsalis pedis
complications with aline placement
- infection
- thrombosis and distal ischemia
- hemorrhage
- skin necrosis
- emboli
- hematoma
- nerve injury
- inaccurate pressure measurements
_________________ measures filling pressures of the right ventricle and gives assessment of intravascular volume and RV fx
CVP
where does the distal tip of a CVP sit?
either in one of the large intrathoracic veins or in the RV
what can increase CVP?
- heart failure
- blood volume increase
- venoconstriction
sites for CVP
- IJ
- EJ
- Subclavian
- Antecubital vein
- femoral
indication for measuring CVP
assessing fluid volume status
accuracy and reliability of CVP is dependent on what factors?
LV and RV fx
the A wave on a CVP waveform represents what
atrial contraction (causes rise in atrial pressure)
when would you expect to lose your A wave on your CVP tracing
afib/aflutter
what does the C wave on your CVP tracing represent
tricuspid valve closure (and bulge into right atrium causing increased atrial pressure)
T/F: C wave should always be present on your CVP tracing
FALSE
what does the x descent on a CVP waveform represent
atrial relaxation
what does the v wave on the CVP waveform represent
refilling of atrium (increasing atrial pressure) during ventricular contraction
what does the Y wave represent on the CVP waveform tracing
atrial emptying/early ventricular filling d/t tricuspid opening in early ventricular diastole
what are some absolute contraindications to CVP
- superior vena cava syndrome
- obstruction in the SVC
what are some relative contraindications to CVP (not absolute, weight pros and cons)
- infection
- coagulopathy
- newly inserted pacer wires (wait 4-8 wks)
- past carotid endarectomy or needed carotid endarectomy
complications with inserting CVC
- arterial puncture
- hemothorax
- pneumothorax
- pericardial effusion/tamponade
- embolism
- nerve injury
- arrhythmias
what nerves are at risk for injury during CVC placement
- brachial plexus
- stellate ganglion
- phrenic
pneumothorax 2/2 CVC placement occurs most commonly with what stie
subclavian
what is the purpose of pulmonary arterial pressure monitoring
estimate the pressures on the left side of the heart
what is normal PCWP
10-12 mmHg
normal CVP
8-10 mmHg
normal PAP
15-30/5-15
PAP systolic and diastolic numbers reflect the pressures where?
inside the lungs
low PAP most likely indicates ______________; high most likely indicates ___________________
hypovolemia; hypervolemia
if your PAP numbers are 50-60/30s what would you suspect?
pulmonary HTN
with cardiogenic shock; SVR is ______________ and CO is _____________
high; low
PCWP estimates _____________ and ____________
left atrial pressures (LAP); LVEDP
what are some factors that alter the accuracy of PCWP numbers
- PVD
- MV dz
- PEEP
ideal placement of the PA catheter when measuring PCWP is in __________________
west lung zone III
if your PA catheter is in lung zone 1 or 2 when shooting a PCWP, what does this represent?
reflects the alveolar pressures instead of the LAP
distance to the right atrium from:
1. Subclavian vein = __________
2. right EJ = ______________
3. right IJ = _____________
4. Femoral = _______________
- 10 cm
- 10-15 cm
- 15-20 cm
- 25-40 cm
absolute contraindications to placing a PA catheter
- tricuspid or pulmonic valvular stenosis
- RA/RV mass (tumor)
- tetralogy of Fallot
what are some relative (not absolute) contraindications to placing a PA catheter (weight risk vs benefit)
- severe arrhythmias (LBBB, heart block)
- coagulopathy
- newly inserted pacer wires
if you place a PA catheter in a pt with a LBBB, this could lead to ____________; so you should have _____________ readily available
RBBB (ultimately causing a now complete heart block) ; external pacer
complications of placing a PA catheter
- arrhythmias
- endobronchial hemorrhage
- pulmonary infarction
- catheter knotting/entrapment
- valvular dammage
- thrombocytopenia
- thrombus formation
- balloon rupture
risk factors for endobronchial hemorrhage with PA catheter placement
- elderly
- female
- pulmonary HTN
- mitral stenosis
- coagulopathy
- distal placement of catheter
- balloon hyperinflation
if you have a PA catheter in, and your patient is about to undergo hypothermic cardiopulmonary bypass, what should you do?
pull the catheter back, for hypothermia can cause stiffening and migration of catheter
if you inflate your balloon to shoot a PCWP, and you start to see bright red blood in the ETT what do you suspect has happened
endobronchial hemorrhage 2/2 inflating the balloon inside the distal Pulmonary artery
inflating the balloon (to shoot PCWP) inside the distal PA has a mortality risk of _____________
50-70%
what is the normal range of SVO2
60-80%
formula for cardiac resting energy expenditure (REE) =
CO x hgb x (SaO2 - SVO2) x 95.18
how is SvO2 calculated
from differential absorptionof various wavelengths of light by saturated and desaturated Hgb
according to Ficks equation, changes in SvO2 should reflect changes in ______________
CO
causes of decreased SvO2
- anemia
- hypoxemia
- decreased CO
causes of increased SvO2
- shunting
- intracardiac VSD
- left shift of oxyhbg curve
- cell death
- sepsis
SvO2 < _____________ is treated
50%
use of an intraaortic balloon pump
- perfuse coronary arteries with ischemia
2.tx of shock (at least one of the following malfx: contractility, preload, afterload)
how does an IABP aid in decreasing afterload
when you deflate balloon at beginning of systole –> lower pressure in aorta –> blood being sucked out of LV (aids LV emptying)
with an IABP balloon is inflated at ____________ and deflated at ____________
diastole; end-diastole (beginning of systole)
how do you know your IABP is working in reducing your afterload?
blood pressure (systolic) is coming up and are able to wean gtts (like dobutamine)
inflation of IABP at beginning diastole causes what
back pressure along aortic arch (bc the aortic valve is closed) which causes filling of the coronaries and diastolic pressure to increase
how do you know your intra-aortic balloon pump is working in tx ischemic coronary arteries
when chest pain goes away
with IABP the balloon is filled with _______________
helium
why is the IABP filled with helium
it has lower density and is easier to push and pull in and out of the balloon
the IABP is typically filled to what inflation volume ________ cc
40
IABP decreases workload of the heart, ____________ ventricular performance (SV), and ______________ myocardial perfusion
increases; increases
contraindications to IABP
- aortic aneurysm
- aortic insufficiency
- PVD (unable to cannulate the femoral artery without ischemia to limbs)
- non-viable myocardium and non-transplantable pt
the IABP is distal to the ________________ and superior to the __________________
left subclavian artery; renal arteries
the IABP uses the __________________ to trigger and is inflated following closure of the _____________ and deflated just prior to _____________
R wave ECG; aortic valve; systole
with inflation of a 40 mL IABP, __________ mL of blood is dispaced to cerebral and coronary perfusion
10-30
T/F: IABP forward displacment of blood improves renal, mesenteric and systemic blood flow
TRUE
________________ is a pacer where a pacing wire is threaded down the jugular vein with an introducer where it makes contact with the RV, and wire is attached to generator box
transvenous
_______________ pacers use external pacing pads connected to device
transcutaneous
_______________ pacers use epicardial wires inserted during surgery and the leads go outside of the chest to a control box
transthoracic
pacers essentially do 2 things, what are they?
- sense (the electrical activity of the heart)
- send out electrical signals
what is pacer signal amplitude
how much “juice” the box puts through the wire with every pulse (measured in mA)
what is pacer pulse width
how long each pulse lastws
what is pacer capture threshold
minimum amount of electricity (mA) the box has to emit to pace the heart
a _____________ pacemaker is a control box and a single output wire that leads to the inner wall (v wire)
temporary
which pacer providers simple rate control by pacing the ventricles
temporary pacer
describe permanent pacers
- some have 1 wire leading ot RV
- some have 2 wires leading to RA and RV
indications for a pacemaker
- complete heart block
- symptomatic bradycardia
- CHF
- Asystole > 3 s
- arrhythmia suppression
- CAD
- valvular heart disease
- cacification of conduction system
- 2nd Degree AVB
- MI
- Sick sinus syndrome
pacers are identified by three letter acronyms:
1st letter = _______________
2nd letter = _______________
3rd letter = __________________
chamber paced; chamber sensed; response pacer makes to a sensed intrinsic beat
what is a DDD pacer
dual paced (A + V); Dual sensed (A + V); Dual pacing response (trigger and inhibited)
permanent pacemakers also have 4th and 5th letters, what do these represent?
4th = programmability
5th = arrhythmia control
AOO pacer
atrium paced, no chamber sensed; no chamber pacer response to sensed intrinsic beat
Asynchronous pacing mode ______________ sensitivity of the box; synchronous pacing mode _____________ sensitivity of the box
decreases; increases
which type of pacing mode has no sensing to detect intrinsic R waves, but can compete with pt HR and cause VT/VF
asynchronous
which type of pacing mode detects the intrinsic heart depolarization causing the pacer to be either activated or inhibited
synchronous
if your pacer is failing to capture, what should you do
increase the mA
ventricular pacing increases ______________ by increasing ____________, but does not preserve _________________
CO; HR; atrial kick
Atrial pacing CV effect
preserves atrial kick which can be very impt with heart failure pts
when is AV sequential pacing tupically used?
- when atrium is not contracting but can with electrial stimulation
- when atria and ventricular contractions are dissociated
anesthesia considerations for pt coming into surgery with pacer
- know what kind of pacer
- call rep and tell them pt is going to surgery
- have magnet in OR
- have external pacer unit on standby
T/F: AICD can act as a pacer and defibrillator
TRUE
if using a bovie in the OR and pt has a AICD what should you do
place magnet on pts chest to shut off cardioverter - still allows pacer to fx but will not pick up interference from bovie, thus will not give un-needed shock to pt
how do you know if a temporary pacer is capturing
- check pulse
- check a line
- do not assume activity of the pacer on the monitor is generating a pulse
with spontaneous breathing LV filling and SV is reduced during ______________; but with mechanical ventilation LV filling and SV is lower during _______________; (this is 2ndary to increase in intrathoracic pressure)
inspiration; expiration
systolic blood pressure typically fluctuates with spontaneous breathing by about ______________ mmHg
5-10
pulsus paradoxus is when systolic BP fluctuates with breathing by > ___________ mmHg
10
___________________ occurs during controlled mechanical ventilation when arterial pressure rises during inspriation and falls during expiration 2/2 changes in intrathoracic pressure 2/2 PPV
reverse pulsus paradoxus
with pulsus paradoxus (spontaneous breathing) SBP increases during _______________
expriation
with reverse pulsus paradoxus (mechanical ventilation) SBP increases during __________________
inspiration
formula for SVV
(SVmax - SVmin)/ SVmean over a respiratory cycle
SVV > _______% suggests that the pt is fluid responsive as it indicates the SV is sensitive to fluctuations in preload 2/2 respiratory cycle
10
formula for pulse pressure
SV / arterial compliance
causes of increased SVV
- hypovolemia
- tamponade
- constrictive pericarditis
- LV dysfx
- massive PE
- bronchospasm
- dynamic hyperinflation
- pneumothorax
- raised intrathoracic pressure &/or intraabdominal pressure
SVV > 10-13% what should you do?
fluid challenge
SVV < 10% but SV is normal, what should your intervention be
pressors
SVV < 10%, but SV is low, what is your intervention
inodilator
SVV < 10% but SV is high what is your intervention
diuretic
T/F: Swan and CVP monitors have been proven to improve outcomes
FALSE
limitations to arterial based monitoring (flotrac, vigelio)
- pt must be intubated, sedated, paralyzed
- severe arrhythmias (do not get adequate information)
- have to have a pulse rate (IABP, ventricular assist device)
cerebral oximetry is based on ____________ technology
near infared spectroscopy (NIRS)
NIRS should be kept at least ____________% of baseline saturation
70-75
NIRS should be placed ________________ forehead
midline
what is rSO2
regional oxygen saturation; what the NIRS will typically be set to monitor
if doing a “body” NIRS in peds, what type of O2 monitoring will you set the monitor to
regional cerebral tissue oxygen saturation (SctO2)
healthy rSO2 on NIRS
58-82%
intervention threshold for rSO2 number with NIRS monitoring
~20% from baselin
Critical threshold for rSO2 number with NIRS monitoring
~25% from baseline
interventions to improve Cerebral rSO2 (NIRS)
- rule out mechanical cause (head position, cannula position)
- increase supply (O2 delivery): increase CO, BP, DO2, PaCO2, Hgb/Hct
- decrease demand: increase anesthetic, decrease temperature
_________________ is the leading cause of death in the US
coronary artery disease
risk factors for CAD
- obese
- sedentary life style
- smoking
- HTN
- DM
______________ is the most stressful event for the CV system
exercise
during exercise CO can be increased by______________x 2/2 increased HR and contractility
2.5-7
at rest the coronary sinus Po2 is __________
27%
ischemia of the myocardium occurs when __________________ exceeds ______________
O2 demand; supply
formula for O2 content of blood
hgb x 1.34 x SpO2 + (0.003 x PAO2)
what is the normal O2 content of blood
20 mL / 100 mL
what is the primary determinant of O2 content of blood
hgb
coronary perfusion pressure is “autoregulated” btw ____________ - _______ mmHg
50-150
CPP is completely dependent on ___________, if it is outside of the autoregulation pressure (50-150mmHg)
HR
ways to optimize coronary perfusion pressure (CPP)
- normal to high ADBP
- Low LVEDP
- Low HR
formula for Coronary blood flow
CBF = coronary perfusion pressure (CPP)/Coronary vascular resistance (CVR)
normal Coronary blood flow value?
225-250
what influences Coronary vascular resistance (CVR)
- metabolic factors
- ANS
- hormonal
- endothelial factors
- anatomic factors
- blood viscosity
how does ANS influence coronary vascular resistance
- alpha-1 constriction, mainly epicardial arteries
- beta-1 dilation, mainly intramuscular arteries
what metabolic factors influence coronary vascular resistance
- pH
- CO2
- lactate
- O2
- adenosine
what hormones influence coronary vascular resistance
- vasopressin
- angiotensin
- prostacyclin
- TXA
what anatomic factors influence coronary vascular resistance
- capillary recruitment
- collateral artery development.
what increases Coronary vascular resistance
- increased O2
- decreased CO2
- increased pH
- increased alpha-adrenergic tone
- increased cholinergic tone
- increased vasopressin
- increased angiotensni
- increased TXA
what decreases coronary vascular resistance
- decreased O2
- increased CO2
- decreased pH
- lactate
- adenosine
- increased Beta-adrenergic tone
- increased prostacyclin
- increased nitric oxide
- increased endothelium derived hyperpolarizing factor
- increased prostaglandin I2
___________________ vessesl are already maximally dilated; therefore they cannot respond to increase in demand (and are most susceptible to ischemia)
subendocardial
_______________ is the MOST susceptible to ischemia
subendocardium
coronary stenosis ___________ CVR and __________ CBF
increase; decrease
T/F: sequential lesions/plaques in the coronaries are additive
true; LAD + circ occlusion is a left main equivalency
coronary blood flow is reduced with coronary stenosis based on ______________ law
poiseuilles
if you have a 50% decrease in coronary diameter 2/2 stenotic lesion, that area of the heart is now only receiving _______________ of flow
1/16
why do young individuals with an MI have worse outcomes than older individuals with MI
younger individuals have not developed collateral flow
what are the 3 main determinants of myocardial oxygen consumption (MVO2)
- HR
- contractility
- wall stress
formula for myocardial oxygen consumption (MVO2)
MVO2 = CBF - (CaO2 - CvO2)
what is the MOST important determinant of myocardial oxygen demand
HR
doubling the heart rate ___________________ the myocardial oxygen demand
more than doubles
increased contractility causes ______________ myocardial oxygen demand
increased (d/t needing more energy and more O2)
clinical measurement of contractility
- visually during open heart
- briskness of upstroke on arterial waveform tracing
- echocardiogram (*most accurate)
cardiac wall stress is dependent on ________________, ________________, and ________________
afterload; chamber size (preload), and thickness
what law helps explain wall stress
law of laplace: tension(wall stress) = (P x radius)/(2x wall thickness)
MAP = _______________
MVO2
doubling MAP, ________________ myocardial oxygen demand (MVO2)
doubles
clinically to decrease myocardial O2 demand, what do you want to decrease?
SVR
MVO2 is increased by an increase in…
- HR
- preload
- contractility
- afterload
- temperature
- hgb
T/F: ECG is the least sensitive method for monitoring for myocardial ischmeia
TRUE
ST depression = ______________, elevation = _________________
ischemia; infarction
flattening or inversions of T waves indicate __________________
ischemia
ST changes will occur on ECG ____________ after ischemia occurs
1-2 min
what leads are the most sensitive for ischemia monitoring?
an inferior lead (II, III, or aVF) + V5
_____________% of ischemic events are captured if an inferior lead (II, III, aVF) + V5 are used to monitor
90
Sudden increase in PAP indicates what
decrease in cardiac function
if there is a new onset of prominent V wave on PCWP waveform, this indicates what
papillary muscle dysfunction
____________________ precedes ECG and PAP changes with myocardial ischemia
regional wall motion abnormalitiy (detected with TEE)
gold standard for myocardial ischemia montioring
TEE
_________________ monitoring assess preload, contractility, Reigonal wall motion abnormality, valvular fx, antatomy, and presence of pericardial effusion
TEE
on TEE you see lack of movement of wall, this is called _________________
akinesis
on TEE you see decreased regional wall movement, this is called _______________
hypokinesis
on TEE you see paradoxical movement during systole this is called ____________________
dyskinesis
dyskinesis is typically d/t __________________, and this is an emergency situation
ventricular aneurysm
ideal induction agent for cardiac patients
etomidate
ketamine effects on CV
- increase SVR
- increase preload
- increase contractility
- increase HR
what is the perfect induction agent for a pt with cardiac tamponade
ketamine
__________________ is not an ideal induction agent for pts with cardiac ischemia
ketamine; d/t increased MVO2
propofol CV effects
- decrease BP
- Decrease SVR
- decrease contractility
BZ effect on CV
minimal HD effects
opioids effect on CV
decrease myocardial demand, without decreasing contractility
CV effects of precedex
hypotension and bradycardia
volatile anesthetics effects on MVO2
- all decrease contracility
- all decrease afterload
- minimal change in preload
- HR increase (esp with des)
- vasodilation of normal coronary vasculature decrease perfusion to ischemic areas
which anesthetic gas is a very poor choice for pts in RV failure or pts with pulmonary HTN
nitrous oxide
effects of nitrous oxide on MVO2
decreases contractility and increases PVR
___________ HR, _______________ contractility, ________________ SVR, ______________Preload, & _____________ SNS stimulation
decrease; minimal effect, decrease, decrease, decrease
succinylcholine effect on MVO2
bradycardia especially with repeated doses
pancuronium effect on MVO2
increases HR by 20%
how can you attenuate the increased HR (and thus increased MVO2) with pancuronium administration
high dose narcotics
vecuronium and rocuronium effect on MVO2
minimal CV effect (thus minimal MVO2 effect)
cisatracurium effect on MVO2
no CV effect (thus no MVO2 effect)
what muscle relaxants are the best choice for cardiac cases
vec, roc, or nimbex
treatments for CAD (surgical)
- angioplasty
- stents
- CABG
what is “fast track” cardiac anesthesia
- driven by desire to reduce cost
- accomplished by better drug selection/dose, new surgical techniques, warmer bypass temps
- early extubation and hemostatic control = essential
anesthetic approach for myocardial revascularization procedures
- fast track anesthesia
- ERAS cardiac
- off bypass revascularization
- MIDCAB, port access, redo CABG
which heart failure is more common (systolic or diastolic)?
systolic
systolic HF is more common in _____________________, where diastolic HF is more common in ________________
middle aged men (2/2 CAD); elderly women (2/2 obesity, htn, DM postmenopause)
T/F: heart failure is primarily a disease of the elderly
TRUE
T/F: HF spends more healthcare dollars than any other dz
TRUE
most common cause of RV failure?
LV failure
causes of systolic HF
- CAD
- Dilated CM
- chronic pressure overload (AS, HTN)
- chronic volume overload (valve insuff, high output failure)
sx of systolic HF
- decreased EF
- ventricular dysrhythmias are common (risk of sudden death)
- S3 heart sound
s/sx of diastolic HF
- normal EF, but sx of failure
- S4 heart sound
- increased LVEDP (classic sign)
hallmark sign of systolic HF
decreased EF
classic sign of diastolic HF
increased LVEDP
which HF is age dependent? increased incidence in 50+; > 50% in those > 70 years of age
diastolic
______________ HF is an inability to pump; where ______________ HF is an inability to fill
systolic; diastolic
causes of diastolic HF
- ischemic heart disease
- chronic HTN
- progressive aortic stenosis
- age
T/F: diastolic HF may coexist with Systolic HF
TRUE
inotropes effect on PV loops
shift loop left
diuretics and vasodilators effect on PV loops
decrease LVEDP
vasopressors effect on the PV loop
*shift loop up
_________________ = acute or worsening imbalance of myocardial oxygen supply to demand
acute coronary syndrome
most common cause of ACS
focal disruption of atheromatous plaque –> partial/complete occlusion of coronary
3 categories of ACS
- STEMI
- NSTEMI
- Unstable angina
ST segment depression/nonspecific ECG changes with elevated cardiac biomarkers = _______________
NSTEMI
ST depression/nonspecific ECG changes with normal cardiac biomarkers = __________________
unstable angina
________________ occurs when coronary blood flow decreases abruptly
STEMI
5 common pathophysiologic process that causes NSTEMI
- rupture/erosion of coronary plaque that leads to non-occlusive thrombosis
- dynamic obstruction d/t VC
- worsening coronary luminal narrowing due to progressive atherosclerosis, instent restenosis, or narrowing of CABG
- inflammation
- myocardial ischemia due to demand increase
Basic set up for CABG
- std monitors + ABP/PAP/CVP, cerebral oximetry, BIS, TEE
- emergency meds: inotrope (epi), vasopressor (neo), vasodilator (cardene)
- routine induction meds: etomidate, paralytic, narcotics, heparin
- at least 2 units blood ready
- temporary pacer checked, and battery is working
- infusions are set up and ready
what is the purpose of giving versed and fentanyl prior to CABG
decrease unwanted SNS response 2/2 anxiety
pt coming in for CABG who should you caution premedication of versed and fentanyl with ?
CHF, low CO, and pulmonary HTN pts
pre-bypass goals
- keep pt at baseline
- do not start correcting numbers until surgical correction has been made
- do no harm
periods of increased stimulation (pre-bypass CABG)
- incision
- sternotomy & retraction
- sympathetic nerve dissection (at LIMA)
- pericardiotomy
- aortic cannulation
inadequate anesthesia during times of increased stimulation with CABG (prebypass) can result in…
increased circulating catecholamines –>
1. HTN
2. dyrhythmias
3. tachycardia
4. ischemia
5. HF
pre-bypass CABG, periods of decreased stimulation (“slump”)
- preincision
- peripheral graft harvest (from leg)
- IMA dissection
- venous cannulation
periods of decreased stimulation (“slump”) with prebypass CABG - what are the risks?
- Hotn
- bradycardia
- dysrhythmias
- ischemia
what is teh most stimulating part of the induction period for CABG pt?
laryngoscopy
what is your first line tx for hypotension for the pt on pump
neosynephrine (not fluids, need to avoid hemodilution)
autologous blood removal for CABG
taking 1 unit of blood prior induction via gravity.
risks with autologous blood removal
- Hotn 2/2 hovolemia
- decreased O2 carrying capacity (will be reflected through mixed venous sat)
- infection
autologous blood is stored in a bag with _________________ (similarly to banked blood)
citrate phosphate dextrose solution
relative c/i to autologous blood removal
- left main dz
- LV dysfx (cannot handle hovol with losing 1 unit blood
- anemia with hgb < 12
- emergent surgery
when would you expect there to be a high risk of major structure accidently being cut during CABG?
redo sternotomy 2/2 adhesions and scar tissue
if a major structure is accidently cut during CABG (specifically with sternotomy) what do you do
- put on bypass immediately
- have blood products checked and ready for administration
prolonged sternotomy dissection for CABG increases the risk of _______________ redo surgery
dysrhythmias
what are the vessels that could be used for coronary bypass
- LIMA/RIMA
- saphenous vein
- radial artery
endoscopic vein harvest for CABG is typically done if which vein is used
saphenous
what is the preferred agent for anticoagulation with CPB
unfractionized heparin
initial dose of unfractionized heparin for anticoagulation prior to CPB
300 units/kg
retrograde autologous priming
draining blood out of pt through aortic cannula to prime CPB circuit
what is the most common arterial access site for aortic cannulation
distal ascending aorta
before aortic cannulation, ACT must be greater than ___________
400 s
if the distal ascending aorta is not an arterial access option for aortic cannulation, what are the other arterial access sites that can be used?
femoral artery
what is the number one complication from aortic cannulation (CABG)
embolic phenomena 2/2 air or atherosclerotic plaque dislodgement
