Basic - Cardiology/Heme Flashcards
1
Q
How do diuretics (ie. furosemide) affect the frank starling curve (Cardiac output vs EDV)?
A
reduces cardiac filling pressures along the same ventricular function curve
2
Q
What does the frank-starling curve represent?
A
how the contractile force of the myocardium (stroke volume or cardiac output) is dependent on the sarcomere length (diastolic filling volume or preload) immediately before contraction
3
Q
Summary of cardiovascular system changes with aging: (4)
A
- Decreased ventricular compliance
- Decreased beta-receptor responsiveness
- Increased SNS activity
- Increased stiffness of large arteries
4
Q
In pts with reduced diastolic function, LVEDP is (increased/decreased), and preload is more dependent on _____
A
Increased (elevated)
Atrial kick
5
Q
Complete heart block (aka third degree heart block) is associated with ischemia involving the ______artery and typically involves the ________
A
RCA
PDA supplying the Inferior wall of the LV
*ischemia of LAD will damage the distal conducting system (bundles branches, purkinje system)
6
Q
in 85% of patients, the ____ branches off the Right Coronary artery and supplies the _____
A
posterior descending artery (PDA)
posterior 1/3 of the interventricular septum and posteromedial papillary muscle
7
Q
The supply of the SA node does not depend on coronary dominance (like the PDA is), the SA node is supplied by the RCA in __% of patients, and LCA in __%
A
RCA 60%
LCA 40%
8
Q
The L main artery gives rise to ____.
Does it supply the AV node?
A
L circumflex
LAD
No
9
Q
What does the LAD supply?
A
- Anterior wall of the heart
- Interventricular septum
- Bundle branches
- Purkinje system
*blockage of the LAD will not cause complete heart block
10
Q
What does the L circumflex artery supply?
A
The posterior and lateral walls of the LV
- in 15% it also supplies the PDA (L dominant)
11
Q
Treatment for hemophilia A?
A
Factor VIII
Desmopressin
*FFP not recommended bc it poses infxn risk and lg volumes are needed
12
Q
Factor VIII levels have to decrease < __% to alter hemostasis.
A
30%.
- During surgery, pts with hemophilia A are advised to have factor VIII activity lvl of 30-40% for mild hemorrhages and 50% for severe hemorrhages
13
Q
what blood products contain factor VIII?
A
FFP and cryoprecipitate
14
Q
Treatment for hemophilia B?
A
Recombinant factor IX
15
Q
Treatment for hemophilia C?
A
supportive
- Deficiency is from Factor XI, but there is a high risk of thrombotic events
16
Q
Nitroglycerin MOA
A
direct acting venodilator via activation of cGMP production
- added benefit of coronary vasodilation
17
Q
How do carvedilol and nicardipine affect preload?
A
minimal effect on preload
18
Q
Carvedilol MOA
A
nonselective BB
- acts on SNS to slow heart
alpha blocking
- modest vasodilation
- minimal effect on preload
19
Q
Nicardipine MOA
A
CCB
- ARTERIOLOAR vasodilation -> decreases afterload and SVR
- minimal effect on preload
20
Q
Sodium nitroprusside MOA
A
direct acting vasodilator via conversion to nitric oxide in vascular smooth muscle -> increase cGMP levels
21
Q
How does hyperventilation increase the risk of citrate toxicity?
A
It decreases ionized calcium ions (think perioral tingliness when people hyperventilate)
- Citrate toxicty is actually d/t HYPOcalcemia (citrate binding with calcium)
22
Q
Signs of citrate toxicity?
A
Same as hypocalcemia
23
Q
Citrate toxicity is highest when which blood product is given?
A
FFP
24
Q
What does FFP contain?
A
- All clotting factors,
- fibrinogen
- plasma proteins (albumin),
- electrolytes,
- physiologic anticoagulants (C, S, antithrombin)
- added anticoagulants (citrate)
25
What is the primary mech behind delayed hemolytic transfusion reaction (DHTR)?
Donor red cell antigens
- Typically the recipient was already exposed to antigens through prior transfusion or pregnancy
- Recipient antibody and complement attack on donor cells
26
What is the primary mech behind acute hemolytic transfusion reactions?
ABO incompatibility
- (recipient antibody and complement attack on donor cells)
- Fatal
- Most often d/t clerical error
27
Signs of acute hemolytic transfusion reactions when pts are awake vs under GA?
Awake
- Fever, chills, CP, N/V
GA
- Hemoglobinuria, bleeding diathesis, hypotension
28
What is the primary mech behind febrile transfusion reactions?
Donor cytokines and antibodies reacting to recipient leukocyte antigens
29
What is the primary mech behind Graft vs host disease (GVHD)?
lymphocytes in donor blood reacting against recipient tissues
- recipient is unable to reject the donor lymphocyte bc of immunodeficiency or immunosuppression
- irradiated blood can decrease risk
30
Leading cause of death related to blood transfusions
1) transfusion related acute lung injury (TRALI) 55%
- noncardiogenic pulmonary edema
2) Hemolytic transfusion reaction (22%)
- Non-ABO > ABO
3) Infection
31
Diagnostic criteria for TRALI (4)
1. Sudden onset hypoxemia (< 6 hours from last blood product)
2. B/l "fluffy" infiltrates on CXR
3. No appreciable change in cardiac filling pressures or increased L atrial pressures
4. All other etiologies for ALI r.o
32
What is NOT a good treatment for TRALI
1. diuretics
- this is a noncardigenic pulmonary edema: will worsen hypotension
2. Corticosteroids
- avoid just like in ARDS
*Lung protective ventilation strategies are safe. Most pts require ventilatory support, IV fluids, and vasopressors.
33
What is the primary mech behind TRALI?
anti-granulocyte antibodies from donor -> attack activated recipient leukocytes sequestered in lungs -> pulmonary inflammatory response
*P:F ratio typically 200-300mmHg
34
Hyperkalemia EKG findings
1. Widening of QRS complex
| 2. Peak T waves
35
The R wave should be small in lead V1. Throughout the precordial leads (V1-V6), the R wave becomes larger — to the point that the R wave is larger than the S wave in lead V4.
Name Disorders associated with large R wave in lead V1
1. right bundle branch block
2. Wolff-Parkinson-White syndrome
3. Posterior wall MI
4. R atrial enlargement/RVH
5. Duchenne muscular dystrophy
- isolated posterior wall hypertrophy
36
What does cryoprecipitate contain?
1. vWF
2. Fibrinogen
3. Fibronectin
4. Factor VIII
5. Factor XIII
6. Factor C
*does NOT contain VII
37
According to ACC/AHA guidelines for pts undergoing PCI for ischemic heart disease, what is the rule for perioperative dual antiplatelet therapy?
BMS:
- DAPT for 1 month after stent placement
- only ASA in periop period
DES:
- DAPT for 6 months
* think des for 6
38
Normal pulmonary artery pressure? What is it elevated in?
6-12mmHg
| CHF
39
When should perioperative beta blockers be started on patients preoperatively (but not the day of surgery)?
If they have 3/more risk factors for CAD
- h.o ischemic Heart disease
- CHF
- stroke
- DM
- CKD
40
Most sensitive lead for detecting MI?
V5, when used alone
41
Why is lead II generally looked at on continuous ECG monitoring?
It gives the largest P wave
| - good for rhythm change
42
What is the most sensitive combination for detecting ischemia on continuous ECG monitoring?
II + V4 (82%)
II + V5 (80%)
II + V4 + V5 = 90%
43
Ischemia criteria on ECG
ST segment depression (>1 mm)
1. Slope of the segment must be horizontal or downsloping
2. Commonly indicates endocardial ischemia
ST segment elevation (>0.1 mV in > 2 contiguous leads)
1. Indicates transmural ischemia or reciprocal change in a lead oriented opposite to the primary vector with subendocardial ischemia
2. Typically seen in cardiac surgery during wean from CPBG d/t disruption of coronary blood flow
44
Pts with prolonged K value (slope of angle) on TEG, would probably benefit from:
Cryoprecipitate
- remember it contains fibrinogen
1. vWF
2. Fibrinogen
3. Fibronectin
4. Factor VIII
5. Factor XIII
45
Cryoprecipitate contains ____ mg/unit of fibrinogen. 10 units of cryo contains ____ mg of fibrinogen.
200mg/u
10u cryo = 2000mg
46
What is the benefit if receiving leukoreduced blood transfusions (eliminate donor leukocyte in blood)?
avoids transfusion-related immunomodulation (TRIM)
- proinflammatory and immunosuppressive effects in allogenic blood
Decreases risk of febrile transfusion reaction
*neg effects are almost all speculative
47
The only established clinical effect of transfusion-related immunomodulation (TRIM)
Enhanced survival of renal allografts
| - found before potent immunosuppressive regimens were done
48
Most common complication following autologous blood transfusion?
Infection d/t improperly stored blood
49
Why can autologous blood be beneficial?
does not contain non-self antigens to trigger allogenic hemolytic/nonhemolytic reactions
50
Storage of pRBCsis associated with what changes in:
- 2,3 DPG
- pH
- CO2
- K
during storage, erythocytes remain metabolically active (anaerobic)
Decrease in:
- 2,3 DPG
- pH
Increase in:
- CO2
- K (moves out of pRBC to maintain electroneutrality w. H+ generated during anaerobic metabolism)
51
Normal Central venous pressure (CVP)
4-6
- BP in the vena cava, near the RA
* if CVP is high = overhydration
52
Formula for oxygen delivery (DO2)
CO * CaO2 * 10
CaO2 = arterial oxygen content
*notice that peripheral vasoconstriction does not increase DO2 bc it does not increase CO or CaO2
53
Formula for CaO2 (arterial oxygen content)
1. 34 * hgb * SaO2 + (0.003 * PaO2)
| * notice that PaO2 contributes relatively less to overall arterial oxygen content than CO, hgb, or SaO2
54
What does it mean when a blood is "screened"?
1. Screen for unexpected antibody status mixing of pt red cells w/ commercial reagents that contain most clinically important RBC antigens implicated in hemolytic transfusion reactions
2. Determine pt ABO status:
- Mixing pt red cells with commercial type O RBCs for anti-A, anti-B, anti-AB, anti-D antibodies
- if negative = pt can be safely transfused with ABO and Rh compatible blood
55
What does it mean when blood is "crossmatched"?
pts plasma and donor RBCs are mixed to determine compatibility and ensure no serious transfusion reaction
56
Why is giving type O blood in a pt who has a positive antibody screen significant??
bc type O blood has both anti-A and anti-B ANTIBODIES
*it has no antigens
57
Type AB blood has what antigens and antibodies?
A and B antigens
No antibodies
- can receive AB, A, B, and O blood
*universal recipient
58
What type blood is the universal recipient and donor?
Universal recipient: AB blood
Universal donor: O blood
59
Pts with IgA deficiency who receive blood transfusions are at increased risk of ____
allergic reaction to antigens in donor blood
| - can be severe anaphylaxis or mild urticaria
60
Thrombotic thrombocytopenic purpura (TTP) is a disorder of _____. And can benefit from which blood product?
platelet destruction
FFP
1. All clotting factors,
2. fibrinogen
3. plasma proteins (albumin),
4. electrolytes,
5. physiologic anticoagulants (C, S, antithrombin)
6. added anticoagulants (citrate)
61
Which blood product is at substantially higher risk of contamination and transfusion associated sepsis?
Platelets
62
Simple febrile reactions to blood products are usually d/t ____
antibodies that the host has formed against HLAs present on donor leukocytes
- febrile period is mild, short lived, tx with acetaminophen
63
Which mechanism of epinephrine makes it a med of choice in Vfib?
ALPHA receptor mediated vasoconstriction
- increases coronary and cerebral perfusion pressure
*note that the beta response can increase myocardial work
64
How does metformin cause lactic acidosis, which can be associated with a 50% mortality rate?
Metformin reduces the activity of pyruvate dehydrogenase and the transport of mitochondrial reducing agents
->
Increase anaerobic metabolism as pyruvate accumulates
-> gets converted to lactate
65
Should metformin be continued in the periop period?
yes
66
Lab test to monitor enoxaparin response
factor Xa activity
67
LMWH is cleared by the ____.
kidney
68
Unfractionated Heparin MOA
| - Monitored by tracking ___
binds and enhances antithrombin III
- inactivates thrombin (factor II), Xa, other factors in intrinsic pathway
- monitor PTT
69
Enoxaparin MOA
| - Monitored by tracking ___
binds and enhances effects of AT3 through conformational change
- factor Xa
70
Treatment of AT3 deficiency
Administer AT3 or FFP
71
How does positive lusitropy affect LVEDP?
reduces it
72
How does phenylephrine affect preload and afterload?
increases both
| -alpha 1 receptor agonist
73
How does phenylephrine affect stroke volume?
Depends
- if pts are on steep portion of frank starling curve (volume dependent), they will have increase in SV d/t increase in preload
- if pts are on flat portion of curve (volume independent), they will not have any increase in stroke volume from increase in preload, and the increase in afterload reduces further cardiac output
74
Which blood products are stored frozen and are only thawed on demand?
FFP and cryoppt
| - low risk of infxn
75
```
What the the normal values for:
Cardiac output
Cardiac index
Stroke volume
Stroke volume index
```
Cardiac output: 4-8 L/min
Cardiac index: 2.5 - 4.0
Stroke volume: 60-100mL/beat
Stroke volume index: 33-47
76
The _____ reflex helps maintain arterial blood pressure through a negative feedback loop
baroreceptor reflex
77
Which BB is metabolized by RBC esterases?
Esmolol
78
Cardioselective BB mneumonic
BEAM
- Bisoprolol
- Esmolol
- Atenolol
- Metoprolol
79
Carvedilol, Propanolol and labetalol targets which receptors since they are nonselective?
Carvedilol
- B1
- B2
- A1
Propanolol
- B1
- B2
Labetalol
- B1
- B2
- A1
80
Which BB has minimal effects on pts with reactive airway disease? Where are they metabolized?
atenolol
- kidneys
- (ATNolol - ATN also affects kidneys)
metoprolol
- liver
81
Nicardipine MOA
ARTERIOLAR vasodilator
| - decreases BP primarily by afterload reduction (minimal effect on preload)
82
Fenoldopam MOA
short acting dopamine receptor agonist
- profound peripheral vasodilation via cAMP stimulation
- reduces preload and afterload
- stimulates diuresis and natriuresis (useful in stimulating kidney perfusion while simultaneously treating HTN)
83
Nitroglycerin MOA
direct acting VENOUS vasodilator by activating cGMP
| - added benefit of coronary vasodilation
84
Sodium Nitroprusside MOA
direct acting ARTERIOLAR AND VENOUS vasodilator by increaing cGMP
85
Nesiritide MOA
recombinant form of brain natriuretic peptide (BNP)
- vasodilation
- diuresis
- natriuresis
*BNP is counter-regulatory to angiotensin II, norepi, and endothelin
86
Nesiritide only current indication for treatment
acutely decompensated CHF
87
What is defined as an "old" vs acute vs recent MI?
Old: occurred > 30 d ago
Acute: 7-30 d ago
Recent < 7 days ago
88
What constitute active cardiac conditions?
1. Unstable coronary syndrome
- acute/recent MIs
- unstable angina
2. Decompensated HF
3. Significant arrhythmias
- high grade AV block (II/III)
- uncontrolled supraventricular tachy (ie:afib) > 100bpm
- symptomatic bradycardia
4. Severe valvular disease
89
Severe aortic stenosis:
- peak vel
- mean PG
- AVA (cm2)
- Indexed AVA
- Vel ratio (DI)
- peak vel: >4
- mean PG: >40
- AVA (cm2): <1
- Indexed AVA: <0.6
- Vel ratio (DI): < 0.25
90
When do you use infective endocarditis abx prophylaxis in pts undergoing dental procedure?
Dental procedure must involve mucosal or gingival procedures
Pt has high risk cardiac condition:
1. Prosthetic heart valve
2. Previous endocarditis
3. Congenital heart disease
- only if its unrepaired, recently repaired, or repaired with residual defects
4. Cardiac transplant recipient w/ valvular disease
91
When do you use infective endocarditis abx prophylaxis in pts undergoing Respiratory tract procedures?
Respiratory procedures must be invasive and involve incision and biopsy of resp mucosa (ie: T+A, NOT bronchoscopy)
Pt has high risk cardiac condition:
1. Prosthetic heart valve
2. Previous endocarditis
3. Congenital heart disease
- only if its unrepaired, recently repaired, or repaired with residual defects
4. Cardiac transplant recipient w/ valvular disease
92
Milrinone MOA
- how does it affect inotropy and vasculature?
- How does it affect the frank starling curve?
PDE 3 inhibitor
- improved inotropy
- vasodilation
- Leftward (Decreased EDV)
- Upward (increased CO)
93
Nicardipine and hydralazine
| - How does it affect the frank starling curve?
They are vasodilators
| - improved ventricular function (CO), while reducing cardiac filling pressures
94
Factors that improve defibrillation
1. Electrode gel
2. Biphasic defibrillation
- Low energy (200J)
3. Larger electrodes
95
Defibrillation vs cardioversion?
Defib: unsynchronized shock
- depolarizes entire myocardium
Cardioversion
- Synchronized with QRS complex to deliver shock on R wave.
- Avoids R on T phenomenon
96
If a pts major adverse cardiac event (MACE) is >1%, what do you do next?
Check functional capacity
| - if < 4 METS, obtain further study
97
On the wiggers diagram, CVP tracing includes 3 waves (a, c, v) and 2 descents (x, y), what do they represent?
3 waves (a, c, v)
- a: RA contraction
- c: RV contraction
- v: Filling of RA
2 descents (x, y)
- x: emptying RV
- y: passive emptying of RA
98
On CVP tracing:
Cannon a wave is seen with _____.
Large cv-wave is seen with ____.
Large a-wave_____.
Cannon a wave is seen with AV dissociation.
Large cv-wave is seen with TR.
Large a-wave tricuspid stenosis.
________
- a: RA contraction
- c: RV contraction
- v: Filling of RA
- x: emptying RV
- y: passive emptying of RA
99
Ventricular hypertrophy (increases/decreases) wall tension
decreases
- increase in pressure or radius of the ventricle increases wall tension, so it compensates that increasing wall thickness, to decrease wall tension
*decreases wall tension, but becomes less compliant
100
____ is the most imporatnt parameter regulating the myocardial oxygen supply demand relationship?
Heart rate
101
Vasopressin acts on V1 receptors, which stimulates what?
water retention, peripheral vasoconstriction
- -> increases SVR and afterload
- -> improve MAP and cerebral and coronary perfusion
102
Can vasopressin cause pulmonary vasoconstriction?
no, there are no V1 receptors in lungs
*epi and alpha-1 agonists can though
103
The right ventricle is perfused during (diastole/systole)
both
- but receives greatest perfusion during peak/late systole, early diastole
*diff from LV that is perfused only during diastole
104
_______ potentiates the effects and toxicity of digoxin.
Hypokalemia
| - monitor K in pts receiving loop diuretics
105
digoxin MOA
Inhibits Na-K ATPase
- increases intracellular Na [ ] --> inc intracellular Ca [ ]
Positive inotrope
106
First line vasopressor in pts with a TBI, inc urine output, and hypotension
Vasopressin
| - vasoconstrictor and ANTI-diuretic
107
Why does ABO incompatible blood cause increase in bilirubin levels?
Incompatible transfused erythrocytes are rapidly destroyed -> hemolysis -> free hgb is metabolized to bilirubin (both indirect and direct bilirubin) will be elevated.
108
During acute hemolytic transfusion reactions, what happens to PT/INR and PTT? Fibrinogen?
Both increase
*fibrinogen decreases
109
Why is FFP generally transfused with pRBCs during MTPs?
in order to prevent development of dilutional coagulopathy
110
What is myasthenia gravis d/t?
antibodies destroying post-synaptic ACh receptors
111
Factors that decrease the release of ACh?
1. Antibiotics (clindamycin, polymixin)
2. Magnesium (antagonizes Ca2+)
3. Hypocalcemia
4. Anticonvulsants
5. DIuretics (furosemide)
6. Eaton-Lambert syndrome: inhibits P-type calcium channels
7. Botulinum toxin: inhibits SNARE poteins
112
Can Calcium channel blockers interfere with ACh release?
no
- it blocks L-type channels, not P-type calcium channels
*Lambert eaton inhibits P-type CC
113
Both botulinum and tetanus toxin inhibits _____. Whats the difference?
SNARE proteins
Botulinum: affects peripheral nerves
Tetanus: affects CNS
114
How much FFP do you need for warfarin reversal?
10-15mL/kg
115
Warfarin MOA
inhibits vit K dependent coag factor synthesis in the liver (II, VII, IX, X)
1972
116
What is warfarin induced skin necrosis d/t?
after warfarin initiation, there is an initial shift towards clotting
- protein C: half life of 6 hours
117
What is P50?
Hgb molecule is 50% saturated with oxygen
| - normally 27mmHg
118
An increase and decrease in P50 affects hgb affinity for O2 how?
Increase P50:
- decreases hgb affinity for O2, release O2 to tissues
- Right shift
Decrease P50:
- increases hgb affinity for O2
- Left shift
119
What is hetastarch (HES) made of?
6% hydroxyethyl starch
electrolytes
glucose
lactate
120
How does hetastarch (HES) cause platelet dysfunction?
reduces availability of glycoprotein IIb-IIIa on platelets
121
St. John's wort is used to treat depression and
| PMS. What are some negative side effects?
CYP3A4 inducer ->increased metabolism (decreased efficiacy) of digoxin, warfarin, cyclosporine, anticonvulsants
122
What herbal supplements are linked to platelet dysfunction?
1. Ginger
2. GInko
3. Garlic
4. Vit E
123
(FFP/PCC) is preferred to rapidly reverse warfarin?
PCC > FFP
* PCC contains Vit K dep coag factors (II, VII, IX, and X)
- more [ ], lower INR, rapid onset
124
what are the physiological effects of acute normovolemic hemodilution (giving pt fluid, then take their blood and save for later)?
1. decrease blood viscosity
2. decrease peripheral vascular resistance
3. increased cardiac output
4. inc regional blood flow
125
Timeframe for anaphylactic transfusion reaction vs TRALI (both manifest after blood products and can have increased pulmonary pressures)?
anaphylactic transfusion reaction: w/in 1 hr
TRALI: w/in 6 hours
126
How does the content of dissolved gases (O2 and CO2) change with temperature?
It doesn't, the partial pressure changes
| - Ie: PO2 and PCO2 can change with temp, but O2 and CO2 content has not
127
As pt temperature drops, what happens to pH, PaO2m PCO2?
pH will be higher
pCO2 will be lower
paO2 will be lower
128
Maximum allowable blood loss equation
MABL = [EBV * kg * (starting Hct - target Hct)] / starting Hct
129
```
Estimated blood volume (mL/kg) for:
Premature infant:
Full term newborn:
Infant (3 mo-1yr):
Child (1-12 yr):
Adult Female:
Male:
```
```
Premature infant: 100
Full term newborn: 85
Infant (3 mo-1yr): 75
Child (1-12 yr): 70
Adult Female: 60
Male: 70
```
130
What is the only factor in FFP that is easily degraded (unstable) above 4C?
Factor VIII
- Factor V is next
*this is why FFP needs to be frozen for storage
131
______ is the carrier molecule for factor VIII, which is ultimately activated by ___
vWF
IIa
132
Why doesn't FFP have a high risk for GvH or CMV transmission?
It doesn't carry a sig quantity of viable leukocytes
133
Laboratory evidence of Acute hemolytic transfusion rxn?
Hemolysis +
| + direct antiglobulin test
134
What does a positive direct antiglobulin (Coombs) test confirm?
the presence of antibodies to the RBC components
| - does not prove or disprove acute hemolytic rxn
135
Diff betwn direct and indirect coombs test?
Direct:
- antibodies present against on RBC surface
Indirect:
- free antibodies in blood against RBC
- used in testing samples prior to blood transfusion and prenatal testing of pregnant women
136
What is coronary steal phenomenon?
When meds that cause coronary vasodilation causes redirection of blood flow away from stenotic lesions (that are already maximally dilated), thus worsening ischemia
137
What are surrogates for LVEDP?
PCWP
PAOP
LAP
