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From Flashcardlet > Cardio > Flashcards

Cardio Flashcards

Memorize cardio physiology, ddx, and cardiovascular drugs

1
Q

List 12 causes of sinus bradycardia

A
  1. Hypothermia
  2. Hypothyroidism
  3. Cardiac arrest (before or after arrest)
  4. Drugs (tranquilizers, anesthetics, beta-blockers, calcium- channel blockers, digoxin)
  5. Increased ICP
  6. Brainstem lesion
  7. Severe metabolic disease (uremia, hyperkalemia)
  8. Ocular pressure
  9. Carotid sinus pressure
  10. High vagal tone (eg, lower airway dz, pharyngeal dz, GI obstruction)
  11. Sinus node disease
  12. Normal variation (athletic dog)
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2
Q

List 15 causes of sinus tachycardia

A
  1. Hyperthermia/fever
  2. Hyperthyroidism
  3. Anemia/hypoxia
  4. Heart failure
  5. Shock
  6. Hypotension
  7. Sepsis
  8. Anxiety/fear
  9. Excitement
  10. Exercise
  11. Pain
  12. Drugs (anticholinergics, sympathomimetics)
  13. Toxicities (chocolate, hexachorophene)
  14. Electrical shock
  15. Other causes of high sympathetic tone
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3
Q

What percentage of total blood volume is in the systemic circulation and how is it distributed between the veins, arteries, and capillaries?

A

75% of TBV

80% veins
15% arteries
5% capillaries

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4
Q

What percentage of total blood volume is in the pulmonary circulation?

A

25%

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5
Q

Where do the left and right coronary arteries arise from?

A

sinuses of Valsalva (behind aortic valve leaflets to myocardium)

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6
Q

The RV wall is usually ____ the LV wall.

A

1/3 as thick as..

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7
Q

What are the normal pressures (mm Hg) in the heart?

A

RA: 0-5 (mean)
RV: 15-30 (systolic), 0-5 (end-diastolic)
PA: 15-30 (systolic), 5-15 (diastolic), 10-20 (mean)
LA: 4-12 (mean)
LV: 90-120 (systolic), 4-12 (end-diastolic)
Aortic: 90-150 (systolic), 60-100 (diastolic), 70-100 (mean)

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8
Q

List 10 cardiac causes of supraventricular arrythmias

A 
Mitral or triscuspid insufficiency
DCM
HCM
Restrictive cardiomyopathy
Cardiac neoplaia
Congenital malformation
Accessory AV nodal bypass tract (s)
Myocardial fibrosis
High sympathetic tone
Digitalis glycosides
Other drugs (anesthetics, bronchodilators)
Ischemia
Intraatrial catheter placement
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9
Q

List 5 extracardiac causes of supraventricular arrhythmias

A 
catecholamines
electrolyte abnormalities
acidosis/alkalosis
hypoxia
thyrotoxicosis
severe anemia
electric shock
thoracic surgery
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10
Q

List 10 cardiac causes of ventricular arrhythmias

A 
CHF
Cardiomyopathy (Doberman/Boxer)
Myocarditis
Pericarditis
Degenerative valve dz with myocardial fibrosis
Ischemia
Trauma
Cardiac neoplasia
Heartworm disease
Congenital heart disease
Ventricular dilation
Mechanical stimulation (catheter/wire)
Drugs (digitalis, sympathomimetics, anesthetics, tranquilizers, anticholinergics, antiarrhythmics)
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11
Q

List 15 extracardiac causes of ventricular arrhythmia

A 
Hypoxia
Electrolyte imbalances (especially K+)
Acidosis/alkalosis
Thyrotoxicosis
Hypothermia
Fever
Sepsis/toxemia
Trauma (abdominal or thoracic)
GDV
Splenic mass or splenectomy
HSA
Lung dz
Uremia
Pancreatitis
Pheochromocytoma
Endocrine (Addison's, DM, hypothyroidism
High sympathetic tone (pain, anxiety, fever)
Central nervous system disease (increases in symp or vagal stimulation)
Electric shock
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12
Q

List 7 effects of angiotensin 2

A
  1. vasoconstriction
  2. increased peripheral resistance
  3. increased mean circulatory filling pressure
  4. decreased Na and H2O secretion via direct renal effects
  5. increased aldosterone release
  6. stimulates thirst
  7. myocardial hypertrophy
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13
Q

Angiotensinogen is converveted to angiotensin I by what?

A

renin

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14
Q

Angiotensin I is converted to AT2 by what

A

ACE, in lungs

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15
Q

What is the main effect of ANP?

A

Diuresis and vasodilation, antagonizes the effects of ATII

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16
Q

How much desaturated hemoglobin is needed for cyanotic mucous membranes?

A

> 5 g/dl (50 g/L)

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17
Q

What is the normal vertebral heart score in dogs?

A

8.5-10.5

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18
Q

How do you determine if the cranial lobar vessels are enlarged on a thoracic lateral radiograph?

A

Compare the vessel diameter to where it crosses the 4th rib. The vessels should be no wider than 0.5-1X the diameter of the proximal 1/3rd of the rib

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19
Q

How do you determine if the caudal lobar vessels are enlarged on a thoracic VD radiograph?

A

Compare caudal lobar vessel to where they cross the 9th rib (dog) or 10th rib (cat). Normal is 0.5-1 x width of rib where they cross.

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20
Q

List 5 causes of a pulmonary undercirculation pattern.

A
  1. severe dehydration
  2. hypovolemia
  3. obstruction to RV inflow
  4. right sided CHF
  5. tetrology of Fallot
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21
Q

List 3 ways to determine caudal vena cava enlargement in dogs with radiographs.

A
  1. CaVC/aorta diameter at same ICS > 1.5
  2. CaVC/length thoracic vertebrae directly above tracheal bifurcation >1.3
  3. CaVC/width right 4th rib > 3.5
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22
Q

List the standard bipolar leads.

A

I: RA (-) –> LA (+)
II: RA (-) –> LL (+)
III: LA (-) –> LL (+)

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23
Q

How do you determine HR on ECG?

A

3000/# small boxes R-R (50 mm/s)

1500/# small boxes R-R (25 mm/s)

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24
Q

What is a wandering pacemaker?

A

Cyclic change in p wave configuration related to a shift in pacemaker location.

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25
Q

What is a sinus arrhythmia?

A

Faster HR during insp, slower during exp, normal d/t vagal tone.

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26
Q

What is the definition of sinus arrest?

A

Pause in sinus activity lasting at least twice the duration of the normal R-R interval.

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27
Q

What is a Mobitz I second degree AV block?

A

Progressive PR prolongation before a dropped beat. Ddx: AV node dysfxn, high vagal tone

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28
Q

What is a Mobitz II second degree AV block:

A

Uniform PR intervals before blocked impulses, lower AV dz (bundle of His or major BB)

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29
Q

What is the normal rate for ventricular escape rhythm?

A

40-50 bpm (dog), < 100 (cat)

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30
Q

What is the normal rate for a junctional escape rhythm?

A

40-60 (dog)

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31
Q

How do you estimate the MEA?

A
  1. Lead with the largest R wave (+ direction is the est MEA)

2. Isoelectric, then perpendicular, + or - = MEA

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32
Q

What is normal MEA?

A

+40 to +100 (dog), 0 to +120 (cat)

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33
Q

What is p mitrale?

A

Wide, notched p waves = LA enlargement

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34
Q

What is p pulmonale?

A

Tall p waves = RA enlargement

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35
Q

List 5 differentials for small voltage QRS.

A
  1. Pleural or pericardial effusion
  2. Obeisty
  3. Intrathorcic mass
  4. Hypovolemia
  5. Hypothyroidism
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36
Q

What are the ECG expectations with hyperkalemia?

A
  1. Tented +/- large t waves
  2. Abbreviated QT
  3. Flat/absent p wave
  4. Widened QRS
  5. ST depression
  6. Asystole, sinoventricular rhythm
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37
Q

Hyperkalemia is accentuated by the following:

A

Hypocalcemia, Hyponatremia, Acidosis

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38
Q

Hyperkalemia is counteracted by:

A

Hypercalcemia, Hypernatremia

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39
Q

Which organ in the body always receives the most blood flow?

A

Lungs

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40
Q

Whevever skeletal muscle blood flow increases, blood flow to other organs must decrease. T/F

A

F

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41
Q

A leaky aortic valve will cause what kind of murmur?

A

Diastolic

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42
Q

Slowing of action potential condunctino through the AV node will slow the heart rate. T/F

A

F

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43
Q

How are cardiac muscle cell action potentials different from skeletal muscle cells?

A
  1. They can be self-generating
  2. They can be conducted directly from cell to cell
  3. They have long durtion, which precludes fusion of individual twitch contractions
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44
Q

What is the effect of hyperkalemia and hypokalemia on the RMP?

A

Hyperkalemia decreases (less negative) the RMP, Hypokalemia increases (more negative) the RMP.

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45
Q

What are the effects of sodium channel blockers on the PR interval of the ECG? Duration of QRS complex?

A

Prolongs both

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46
Q

What are the effects of calcium channel blockers on the rate of firing of the SA nodal cells? Rate of conduction of the AP through the AV node? Myocardial contractility?

A

Decreases all

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47
Q

What are the effects of potassium channel blockers on action potential duration? On refractory periods?

A

Increases AP duration and refractor period

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48
Q

An increase in which of the following (with others held constant) will result in an increase in amout of active shortening of a cardiac muscle cell?

a. preload
b. afterload
c. contractility

A

preload and afterload

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49
Q

What happens when an intervention promotes early activation of the “delayed rectifier” K channel in cardiac muscle?

A

AP duration is decreased b/c activation of Ik initiates repolarization

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50
Q

Action potential conduction velocity in cardiac muscle tissue is influenced by all of the following except:

a. cell diameter
b. RMP
c. Extracellular K concentration
d. Rate of rise (phase 0) of the AP
e. Duration of the plateau phase (phase 2) of the AP

A

e

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51
Q

The primary route of removal of calcium fromt eh sarcoplasm during relaxation of a cardiac muscle cell is by:

A

Active transport into the SR

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52
Q

What cardiovascular factors increase NT-proBNP?

A
  1. Heart failure
  2. Ischemia
  3. Arrhythmia
  4. Valvular heart disease
  5. Hypertension with LVH
  6. Asymptomatic LV dysfxn
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53
Q

List 10 noncardiac factors that can increase NT-proBNP.

A
  1. PTE
  2. Cor pulmonale
  3. Sepsis
  4. Pulmonary hypertension
  5. Hyperthyroidism
  6. Kidney failure
  7. Lung tumors
  8. Intracerebral hemorrhage
  9. Advanced liver disease
  10. Excessive cortisol levels
  11. Sleep apnea
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54
Q

What is the definition of a biomarker?

A

A characteristic that is objectively measured and evaluated as an indicator of normal biologic processes, pathogenic processes, or pharmacologic responses to therapeutic intervention.

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55
Q

What are some examples of biomarkers of myocyte injury?

A

Troponin I, troponin T, creatinine kinase isoenzymes

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56
Q

What are some examples of biomarkers of myocyte stress?

A

Natriuretic peptides, adrenomedullin, mid-regional proadrenomedullin, ST2

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57
Q

What are some biomarkers of cardiac remodeling?

A

MMPs 1, 2, 7, 8, 9
Tissue inhibitors of metalloproteinases
Procollagen type III amino terminal peptide

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58
Q

What are some biomarkers of endothelial dysfunction?

A

Flow mediated dilation (FMD), p-selectin, soluble ICAM-1, vascular adhesion protein 1, asymmetric and symmetric dimethylarginine, vWF, l-arginine, NO metabolites

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59
Q

What are some biomarkers of inflammation?

A

CRP
IL -1, 6, 10
TNF alpha

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60
Q

What are some neurohormonal biomarkers?

A

natriuretic peptides, endothelin-1, big endothelin-1

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61
Q

BNP is released in response to what? from where?

A

volume expansion and pressure overload, from ventricular myocytes

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62
Q

List at least 6 physiological functions of BNP

A

Natriuresis, diuresis, vasodilation, inhibition of sympathetic tone, inhibition of the RAAS, inhibition of endothelin-1, inhibition of myocardial hypertrophy, inhibition of smooth muscle proliferation, altered vasosympathetic balance, inhibition of bronchoconstriction, lusitropy, gastric emptying and absorption, potential central effects (thirst inhibition, decreased salt appetite, inhibtion of ACTH and vasopressin)

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63
Q

From the pilot study by Prosek et al on azotemia and serum NTproBNP, their findings showed BNP is not affected by renal dysfunction. T/F

A

False. Renal dz increased NTproBNP. With indexed with BUN or creatinine (NTproBNP:BUN or :creat), the effect of renal dysfxn removed.

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64
Q

Which of the following was associated with higher cTnI in patients undergoing cardiac catheterization procedures (Shih, 2009)?

a. difficulty of procedure
b. amount of contract injected
c. length of procedure
d. difficulty of anesthesia

A

c. length of procedure

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65
Q

Which of the following cardiac cath procedures led to the largest increase in cTnI (Shih, 2009)?

a. Balloon valvuloplasty
b. Pacemaker implantation
c. PDA coil embolization

A

b. pacemaker (* increased at 4, 240, and 10 d after procedure)

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66
Q

Brady, JVECC, 2004, Na and Glucose CHF found which three things statistically different in survivors vs. nonsurvivors.

A
  1. NS had lower sodium
  2. NS had higher glucose
  3. NS had lower medial rectal temp
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67
Q

What are the 3 theories for hyperglycemia in CHF?

A
  1. Impaired insulin-mediated glucose uptake
  2. Defects in insulin signal transduction
  3. Insulin receptor antagonism
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68
Q

What is normal DO2 in a dog?

A

823 ml/min/m2

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69
Q

What is normal VO2 in a dog?

A

166 ml/min/m2

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70
Q

What is normal oxygen extraction ratio in a dog?

A

20.5%

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71
Q

What is normal venous admixture in a dog?

A

2.8-4.4%

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72
Q

Prognosis is less than 50% if cats present with a rectal temperature less than ___ on presentation with ATE.

A

37.2 C (98.9 F)

72% cats with ATE fit this category on presentation

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73
Q

What percentage of cats with HCM will develop ATE.

A

21%

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74
Q

What is the median age of cats with ATE.

A

8-9 y

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75
Q

What percentage of cats have history of heart disease on presentation with ATE?

A

<12%

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76
Q

What percentage of cats will have normal thoracic auscultation on presentation with ATE?

A

40%

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77
Q

Reported avg survival in ATE cats is?

A

51-350 d

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78
Q

What percentage of cats treated for ATE will have recurrence?

A

17-50%

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79
Q

List 5 antithrombotic factors of normal endothelium.

A
  1. antithrombin
  2. thrombomodulin
  3. tPA
  4. prostacyclin (PGI2)
  5. nitric oxide
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80
Q

From the MacDonald et al paper on echocardiographic pericardial effusion paper, what is the sensitivity and specificity of echo for detection of a RA mass?

A

82% sensitivity, 99% specificity

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81
Q

What were the most common ECG abnormalites from the MacDonald pericardial effusion paper?

A
  1. electrical alternans (28%)
  2. Dampened QRS (24%)
  3. Ventricular arrhythmia (13%)
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82
Q

What echo view gives the best view of the right atrium?

A

Left cranial parasternal long-axis view

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83
Q

What is the difference in MST for neoplastic vs. nonneoplastic causes of pericardial effusion?

A

cancer 26-56 d

no cancer 790-1068 d

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84
Q

From the MacDonald paper on pericaridal effusion, all of the following are true except:

a. 30% of dogs with cardiac HSA had splenic HSA
b. All dogs with LSA had metastatic disease
c. Dogs with masses were significantly older than dogs w/o masses (9.7 y vs 7.9 y)
d. A globoid heart was seen on radiogaphs in 90% of cases

A

d. A globoid heart was only seen in 52.3% of dogs, making this a poorly sensitive diagnostic test for pericardial effusion

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85
Q

Pericardial fluid analysis identified the cause of pericardial effusion in 80% of cases (MacDonald, 2009). T/F

A

F - 12.8%, only those with infective pericarditis and lymphoma

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86
Q

The rate of bicavitary effusion, pleural effusion, or ascites did not differ between neoplastic causes and idiopathic pericaridits (MacDonald, 2009). T/F

A

T

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87
Q

What percentage of cats were hypercoagulable (based on factor excess, inhibitor deficiency, or thrombin generation) in cats with smoke vs. ATE (Stokol, 2008, JVIM)?

A

50% smoke, 56% ATE

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88
Q

Which of the following was significantly higher in ATE cats (Stokol, 2008, JVIM)?

a. fibrinogen
b. vWF:Ag
c. thrombin-antithrombin complex
d. d-dimers

A

b. vWF:Ag - reflective of endothelial damage from occlusive thrombus

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89
Q

What makes up Virchow’s triad?

A
  1. Endothelial injury
  2. Blood flow abnormalities
  3. Hypercoagulability
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90
Q

Left atrial size was found to be a risk factor for ATE in the Stokol, JVIM, 2009 paper. T/F

A

F

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91
Q

Left atrial size was found to be a risk factor for hypercoagulability in the Stokol, JVIM, 2009 paper. T/F

A

F - left atrial size not associated with hypercoagulability or increased risk of ATE

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92
Q 
Rank the following in most common to least commonly documented with hyperkalemia in the JVECC, 2008 paper, Tag, et al.
hyponatremia
hypochloridemia
hypermagnesemia
hypocalcemia
venous acidemia
A
  1. venous acidemia (94%)
  2. hypermagnesemia (67%)
  3. hyponatremia (49%)
  4. hypochloridemia (40%)
  5. hypocalcemia (20%)
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93
Q

How does hypocalcemia affect the action potential?

A

Prolongs phase 2 and is postulated to down-regulate myocardial B-receptors causing weakness of the cardiac muscle.

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94
Q

What is the effect of hypocalcemia on the ECG?

A

Prolongation of the the S-T segment and Q-T interval.

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95
Q

How does hypocalcemia enhance cardiotoxicity of hyperkalemia?

A

Lowers the cell’s threshold potential, the resting membrane potential is elevated during hyperkalemia, further exacerbating the cell’s hyperexcitability.

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96
Q

What are the ECG abnormalities associated with hypermagnesemia?

A

Prolonged QRS, shortened QT, prolonged PR

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97
Q

List 5 causes of peaked T waves.

A
  1. Bradycardia
  2. Cerebrovascular accidents
  3. LV diastolic overload
  4. Subendocaridal ischemia
  5. Hypothermia
  6. Death
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98
Q

List 5 causes of wide QRS complexes:

A
  1. Increased parasympathetic tone
  2. Hypoglycemia
  3. Hypothermia
  4. Hypothyroidism
  5. Drugs (digoxin, propranolol)
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99
Q

List 5 factors that influence the difference between ScvO2 and SvO2. (Vincent, Crit Care, 2011)

A
  1. Sampling site of central venous blood
  2. L–> R shunts
  3. Incomplete mixing of venous blood
  4. Oxygen extraction in renal and splanchnic beds
  5. Redistributino of blood flow through upper and lower body
  6. Level of consciousness
  7. Myocardial VO2
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100
Q

What is the Bernolli equation derivation to convert velocity to pressure gradient?

A

Pressure gradient = 4 x velocity squared

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101
Q

What is the formula for fractional shortening?

A

(LVIDd-LVIDs)/LVIDd x 100%

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102
Q

Pro-BNP is cleaved to cBNP and NT-proBNP by….

A

corin

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103
Q

cBNP binds to what receptor

A

NPRa

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104
Q

cBNP was sinificantly increased in all dogs with CHF compared to other groups with a mean value of? (Lee, JVECC, 2011)

A

4.2 pg/mL

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105
Q

What percentage of dogs w/o CHF had cBNP value over 4.2 pg/mL (Lee, JVECC, 2011)

A

21%

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106
Q

What was the interassay and intraassay coefficient of variation for the cBNP test (Lee, JVECC, 2011)?

A

9.41% and 7.79%, respectivly

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107
Q

Spontaneous echocardiographic contrast (“smoke”) is thought to be directly proportional to ___ and ___ and inversely related to ____.

A

HCT and fibrinogen, shear rate (flow)

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108
Q

What is the best echo view to assess for heart based tumor?

A

Long and short axis RIGHT cranial position

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109
Q

What is the best echo view to valuate the right auricle?

A

tilted LEFT cranial view

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110
Q

List the bradyarrhythmias requiring emergency intervention.

A 
High-grade 2nd degree AV block
Complete (3rd degree) block
Sinus arrest (SSS)
Persistent atrial standstill
Asystole
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111
Q

List 3 indications for a temporary pacemaker.

A
  1. Not stable enough to transfer
  2. Intoxications (short term pacing)
  3. To assess end organ dysfxn before perm pacemaker
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112
Q

Which side should a temporary pacemaker be placed on?

A

left jugular

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113
Q

What is output on PACE generator?

A

strength of pacing impulse (mA)

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114
Q

What should the output be set at?

A

2-3X the lowest output determined to capture the heart

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115
Q

What is sensitivity on PACE generator?

A

how well the pacemaker senses the intrinsic electrical activity (mV); higher mV means lower sensitivity

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116
Q

What is the most common complication of temporary pacemaker?

A

Loss of capture

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117
Q

List complications of long term pacemaker.

A 
Lead dislodgement
Arrhythmia during placement
Seroma over generator
Infection
Programming difficulties
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118
Q

CC CPR results in ___ % normal blood flow to heart, and ____% normal flow to brain.

A

10-20%, 20-30%

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119
Q

What is the theory behind use of ITD during CPR?

A

Impedance of gas on INSPIRATION during the DECOMPRESSION phase of CPR would result in increased negative intrathoracic pressure and improve venous return to heart

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120
Q

What maneuver is the ITD based on?

A

Mueller maneuver

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121
Q

What is the cracking pressure of the ITD?

A

Pressure at which air flow is no longer impeded by the ITD (10-15 cm H20)

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122
Q

What are advantages to using ITD during CPR.

A 
Improve preload
Improve myocardial perfusion
Decrease ICP
Increase CPP
Higher ROSC
Better neuro outcome (humans)
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123
Q

What are contraindications of ITD?

A

pulm edema, CHF, < 10 kg

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124
Q

What do each of the subunits (C, T, I) of troponin bind?

A

C - calcium, T - tropomyosin, I - thin actin filaments

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125
Q

What are the sizes of cTnT vs. cTnI?

A

T - 37 kDa, I - 24 kDa (T elimination decreased in kidneys)

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126
Q

What breed possibly has higher cTnI than other breeds?

A

Greyhounds

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127
Q

What can falsely increase cTnI (according to manufacturer) - 3 things.

A
  1. severe hemolysis
  2. hemoconcentration >65%
  3. hyperglobulinemia
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128
Q

What was the main findings from Payne, JVECC, 2011 on cTnI in dogs presenting in resp distress to differentiate cardiogenic vs. non-cardiogenic?

A

Sign diff between normal, resp, and cardio. cTnI > 1.5 ng/ml sens 78%, spec 52%, so not recommended on its own

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129
Q

What was the main finding from Valverde, JVECC, 2011, comparing art pulse pressure waveform analysis to LiDCCO in dogs?

A

FloTrac/Vigileo (pulse pressure) OVERESTIMATED CO values compared to LiDCCO. Relative error was high (48 +/- 14%), so unreliable. Correlation acceptable (r=0.7). CO estimates throughout experiment 48-73% (avg 62%) higher than LidCCO

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130
Q

What is the difference between PiCCO and PulseCO?

A

Both are pulse contour CO monitors. PiCCO uses cold saline transpulm thermodilution to calibrate whereas PulseCO uses LiDCO as calibration

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131
Q

Arterial waveform is a product of:

A

stroke volume force (arterial peak before dichrotic notch) and elastic component of arteries, or Windkessel effect (area after the dicrotic notch)

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132
Q

Pulse pressure is proportional to ____ and inversely related to ______.

A

Stroke volume, aortic compliance

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133
Q

The Fick principle for CO is based on….

A

Flow is proportional to the rate of indicator uptake and the difference between the inflow indicator concentration and that of the outflow. (EX: NICO, LiDCO)

134
Q

What is the reported CI (kg) in normal vs. anesthetized dogs?

A

165+/- 43 ml/min/kg awake vs. 125-150 ml/min/kg anesth

135
Q

What was the main finding in Shih, JVECC, 2011 paper on PiCCOmet vs PiCCOfem vs. LidCO?

A

PiCCOfem compared reasonably well to LiDCCO. PiCCOmet terrible, overest CO at low CO states and underestimated CO at high CO states. Unable to calibrate PiCCOmet in 60% experiments.

136
Q

Which of the following is not true regarding Vigani, JVECC, 2011 paper on use of ITD during hypovolemic hemorrhagic shock?

a) No CV changes detected between groups w/ or w/o use of ITD during euvolemia
b) During acute hypo hem shock, CI and DO2 were higher with ITD than w/o (2.9 vs 1.8 ml/min/m2 and 330 ml/min vs 192 ml/min)
c) ITD increased SAP and MAP
d) ITD decreased ResR and increaed RC during hypovolemia and euvolemia

A

d) - ITD increased respiratory resistance and decreased respiratory compliance during both hypovolemia and euvolemia

137
Q

ITDs for CPR and for spontaneous breathing differ in _______.

A

Cracking pressure (higher, -12 cm H20 ,for CPR; lower, -7 cm H20, for spontaneous breathing)

138
Q

What is the definition of cardiogenic shock?

A

Inadequate cellular metabolism secondary to cardiac dysfunction, despite adequate intravascular volume

139
Q

What are the four classifications of shock?

A

distributive, metabolic, hypoxic, cardiogenic

140
Q

What determines stroke volume?

A

Preload, afterload, contractility

141
Q

Causes of quiet heart sounds?

A

Pericardial effusion, severe hypovolemia, obesity

142
Q

How is cardiogenic shock diagnosed?

A

Evidence of systolic dysfunction in the presence of adequate end diastolic volume

143
Q

What is the most common cause of cardiogenic shock resulting from systolic dysfunction?

A

DCM

144
Q

What breeds are predisposed to DCM?

A

Doberman Pinscher, Boxer, Great Dane, Lab, Cocker, Irish Wolfhounds

145
Q

DCM in cats is usually associated with what?

A

Taurine deficiency

146
Q

What are 3 preload parameters obtained from PAC?

A

CVP, pulmonary arterial pressure, pulmonary arterial occlusion (wedge) pressure

147
Q

What are the theories for decreased EF during the hyperdynamic phase of sepsis?

A
  1. reduced ventricular compliance
  2. biventricular dilation
  3. decreased contractile fxn
148
Q

Diastolic failure can occur due to: (list 4)

A

Inadequate filling (hypovolemia), physical restriction (tamponade), inability to relax (HCM), inadequate filling time (tachycardia)

149
Q

What is pseudo-hypoadrenocorticism related to chronic pericardial effusion?

A

Hyponatremia and hyperkalemia from reduced effective circulating volume

150
Q

What is lusitropy?

A

myocardial relaxation

151
Q

Escape rate from bundle branches or distal Purkinje fibers is….

A

20-40 beats/min

152
Q

What test is always indicated with high grade 2nd degree AV block?

A

Atropine response test - can differentiate if vagally mediated or not; if not then beta-agonist like isoproteronol or dobutamine can sometimes increase HR and treat cardiogenic shock, if not, needs temp pacemaker

153
Q

Define circulatory failure.

A

Delivery of oxygenated blood is insufficient to meet metabolic demands of tissues. (Can be due to heart, vasuclar bed, blood volume, concentration of oxygenated hemoglobin)

154
Q

Define heart failure.

A

Pathophysiologic state that results when teh heart is unable to pump blood at a rate that will meet the metaboilc demands of the tissues and maintain normal arterial or venous pressures at rest of with exercise.

155
Q

Define myocaridal failure.

A

Heart failure caused by defect in myocardial contractility (systolic pump failure)

156
Q

Causes of systolic pump failure.

A

DCM, pericardial effusion, contrictive pericarditis, acute PTE

157
Q

Define CHF

A

Clinical syndrome - accumulation and retention of sodium and water with the resulting signs of congestion and edema

158
Q

What is the critical factor that determines oxygen delivery to mitochondria?

A

Oxygen tension at the end of the capillary bed (normal is higher than 30 mm Hg)

159
Q

What is the critical level of oxygen tension at the end of the capillary bed?

A

20-24 mm Hg - oxygen delivery to mitochondria becomes inadequate, cells must start relying on anaerobic metabolism, lactic acid produced

160
Q

Normal LV interventricular septum or LV free wall in cats is less than…

A

6 mm

161
Q

What is the MOA of nitroprusside?

A

venodilation and dilation of specific arteriolar beds (coronary); preload reducing intervention

162
Q

What kind of drug is diltiazem?

A

Benzothiazepine CCB, class 4, decreases slow inward calcium flux

163
Q

Which breed is associated with onset of juvenile DCM?

A

Portugese Water Dog, die from CHF at 13 w (avg)

164
Q

Which breed with DCM is commonly associated with low taurine levels +/- low carnitine (dog)?

A

Cocker spaniel…I love CanTon:)

165
Q

What percentage of Dobermans have ventricular arrhythmias without the classic ventricular dilation seen with DCM and CHF?

A

25-30%

166
Q

What is the most common initial finding in Great Danes and Irish Wolfhounds with DCM?

A

Atrial fibrillation

167
Q

A heritable form of HoCM has been described in what breed?

A

Pointers

168
Q

What is Duchenne cardiomyopathy and what breed is affected?

A

Inherited NM disorder with an X-lined pattern of inheritance; absent dystrophin (cytoskeletal protein of plasma membrane); Golden Retrievers; Dante is a douche:)

169
Q

What breeds are associated with atrioventricular myopathy?

A

English Springer Spaniel; Old English Sheepdog; persistent atrial standstill

170
Q

What is the most common cause of toxic myocardial disease and what is dose causing cardiotoxicity and what drug protects against cardiomyopathy?

A
  1. Doxorubicin (anthracycyline antibiotic)
  2. Cumulative dose 200-300 mg/m2
  3. Dexrazoxane (cyclic derivative of ethylenediaminetetraacetic acid)
171
Q

Normal LA/Ao is:

A

> 1.5

172
Q

What is considered severe LA enlargement?

A

LA/Ao >2

173
Q

What valves are most commonly involved with infective endocarditis?

A

Aortic and mitral

174
Q

What are the most common causitive agents of endocarditis?

A

Staph, Strept, E.coli, +/- Bartonella

175
Q

What are the most frequently reported arrhythmias secondary to canine myocardial injury?

A

VPCs, v tach, nonspecific ST segment elevation or detression

176
Q

Echocardiographic features of myocardial injuries in dogs:

A
  1. Increased end-diastolic wall thickness
  2. Impaired contractility
  3. Increased echogenecity
  4. Localized areas of echolucency consistent with intramural hematoma
177
Q

List some serious adverse effects of beta blockers.

A

AV block, hypotension, bronchoconstriction, decreased cardiac contractility

178
Q

Lidocaine adverse effects:

A

vomiting, seizures

179
Q

How does myocardial ischemia differ from myocardial hypoxemia?

A

Ischemia results from stais of waste products of cellular metabolism and lack of oxygen delivery - so worse than hypoxemia

180
Q

What two endocrine diseases have been associated with artherosclerosis in dogs?

A

Hypothyroidism and DM

181
Q

What is the isovolemic contraction phase?

A

Period between mitral valve closure and aortic valve opening - ventricle is closed with a fixed voluem

182
Q

What is the dicrotic notch?

A

A dip (incisura) that occurs in the aortic pressure tracing because a small volume of aortic blood must flow backward to fill the space behind the aortic valve leaflets as they close.

183
Q

What is the isovolemic relaxation phase?

A

The time period when the aortic valve closes and the mitral valve is also closed before the intraventricular pressure falls below atrial pressure and the AV valve opens, beginning another cardiac cycle

184
Q

Under normal circumstances, the heart ejects about ___% of its end-diastolic volume.

A

60%

185
Q

At normal resting heart rate, what portion of the time is spent in diastole vs. systole?

A

2/3 diastole, 1/3 systole

186
Q

When do cannon a waves occur?

A

Atria contract against closed valves due to AV dissociation

187
Q

What are the waves and descents on a right atrial pressure tracing?

A

a wave = atrial contraction (occurs after p wave on ECG)
x descent = atrial relaxation
c wave = beginning of ventricular contraction with tricuspid valve bulges into RA
x’ descent = descent of AV ring during ventricular contraction and continued atrial relaxaion
v wave = venous filling of atria during ventricular systole when tricuspid valve is closed
y descent = rapid atrial emptying when tricuspid opens

188
Q

What are signs of hypertensive retinopathy?

A

acute onset blindness, intraocular hemorrhage, retinal detachment, retinal vessel tortuosity, edema, and retinal degeneration

189
Q

What is the ACVIM classification for SBP in dogs and cats based on risk for further end-organ damange?

A

I (< 150) minimal
II (150-159) mild
III (160-179) moderate
IV (>180) severe

190
Q

What is the mechanism of action of hydralazine

A

Increases cGMP levels, decreasin phosphorylation of SM myosin light chains causing blood vessel relaxation; arteries and arterioles, t1/2 2-4h

191
Q

What is the MOA of amlodipine?

A

CCB, dihydropyridone calcium antagonist, inhibits transmembrane influx of calcium ions in the vascular SM and cardia muscle, vascular>heart, t1/2 33 h

192
Q

Patients with pulsus paradoxus have a reduction in arterial pressure of _____ or more during inspiration.

A

10 mm Hg

193
Q

Define cardiac tamponade.

A

Collapse of RA +/- RV during diastole due to increased intrapericardial pressure

194
Q

What is seen on ECG with large volume pericardial effusion.

A

Low-voltage QRS (most common), electrical alternans (6-37%), ST segment elevation (epicardial injury)

195
Q

How does cardiac tamponade alter the CVP waveform?

A

Markedly diminishing the y descent (during atrial emptying, ventricular diastole)

196
Q

How does restrictive pericarditis alter the CVP waveform?

A

Prominent y descent

197
Q

What are potential complications of pericardiocentesis?

A

VPCs, coronary laceration, myocardial infaction, lung laceration causing pneumo or hemothorax, dissemination of infection or cancer cells

198
Q

What are the most common pericardial diseases in dogs?

A

HSA, idiopathic pericarditis, mesothelioma, heart based tumors

199
Q

What are the most common pericardial diseases in cats?

A

LSA, FIP, CHF

200
Q

_____ is a poor prognostic indicator and _____ is a good prognostic indicator in patients presenting with pericardial effusion.

A

Collapse, ascites

201
Q

List 3 congenital pericardial diseases.

A

Pericardial cyst, PPDH, partial or total pericardial agenesis

202
Q

What is the most common organ to herniate through PPDH?

A

liver and omentum

203
Q

Ehrhart et al reported MST of ___ in dogs with with pericardial window vs. ____ w/o pericardial window related to aortic body tumors.

A

730 d vs 42 d

204
Q

Is PPDH more common in cats or dogs?

A

Cats

205
Q

What kind of drug is isoproterenol?

A

beta-adrenergic agonist

206
Q

A positive atropine response test means…

A

Bradycardia due to increased vagal stimulation

207
Q

If there is no response to an atropine response test, this means…

A

SSS most likely

208
Q

Define sinus arrest.

A

Pause in the sinus rhythm that lasts for more than two R-R intervals.

209
Q

List 4 oral anticholinergics.

A

atropine, isopropamide, prochlorperazine plus isopropamide, propantheline

210
Q

Define 1st degree AV block.

A

Prolonged PR interval (0.13 dog, 0.09 cat)

211
Q

Causes of 1st degree AV block.

A

Degenerative or inflammatory dz of conduction system, drugs (digitalis, beta blockers, CCB), hyperkalemia, high vagal tone

212
Q

Define 2nd degree AV block, type 1

A

Wenkenbach, PR progressively prolongs before blocked beat

213
Q

Define 2nd degree AV block, type 2

A

Sudden failure of conduction w/o alteration in PR interval. Labeled by # p waves : #QRS generated

214
Q

What is a high grade 2nd degree AV block?

A

Any block that is 2:1 or greater cannot be classified as type 1 or 2 b/c there is no chance to determine whether progressive prolongation is occurring or not - so called high grade

215
Q

What kind of block can be seen in puppies normally?

A

Mobitz type I (Wenkenback), 2nd degree AV block, 8-11 weeks

216
Q

ECG findings of RBB.

A

Wide QRS (longer than 0.06 dog, 0.04 cat), decreaed R wave amplitude, and large, wide S waves in leads I, II, III, and aVF

217
Q

PE findings RBB

A

Possibly split second heart sound due to delayed closure of tricuspid and pulmonic valves

218
Q

A negative dromotropic effect means:

A

Slows the conduction speed in the AV node

219
Q

Procainamide MOA

A

Na and K blocker, decreases abn ERP in atrial (and ventricular), accessory pathway, and retrograde fast AV nodal tissue; VW class Ia

220
Q

Sotalol MOA

A

Prolongs ERP or atrial myocardium and accessory pathways by blocking potassium entry, VW class III

221
Q

What are the 3 electrophysioloic mechanisms of ventricular tachycardia?

A
  1. Reentry
  2. Enhanced automaticity
  3. Triggered activity
222
Q

Define agonal breathing.

A

Preterminal form of respiration characterized by an acute deep inspiration that results from decreased oxygen delivery to the pneumotaxic and apneustic breathing centers in the pons leading to stimulation of respiratory pacemaker-like neurons in the medulla

223
Q

ITD should not be used in patients with the following:

A

Pulmonary dz, CHF, < 10 kg, compromised chest wall

224
Q

What are the negative impacts of not allowing full thoracic wall recoil during chest compressions?

A

Increased intrathoracic pressure, increased RAP, decreased CoronaryPP, decreased CI, decreased CerebralPP

225
Q

Coronary perfusion occurs during ventricular systole. T/F

A

F - diastole, reason why ITD not increasing DAP concerning

226
Q

Atropine is no longer recommended for routine use for PEA or asystole in human CPR according to 2010 AHA guidelines. T/F

A

T - Atropine use in humans with PEA assc’d with decreased 30 day survival

227
Q

What is the incidence of bradycardia associated with high vagal tone in veterinary arrest patients (dogs vs cats)?

A

23% dogs

21% cats

228
Q

PETCO2 < 15% associated with ____% dogs NOT resuscitated; whereas, PETCO2 > or = 15 mm Hg associated with ____% of dogs successfully resuscitated.

A 
94% = not if less than 15
86% = :) with > or = 15
229
Q

In cats, ___ % of cats with PETCO > or = to ____ mm Hg were successfully resuscitated.

A

90%, 20 mm Hg

230
Q

Coronary perfusion pressure equation:

A

Aortic diastolic pressure - right atrial diastolic pressure

231
Q

Coronary perfusion pressure greater or equal to ____ is thought to correlate with ROSC.

A

15 mm Hg

232
Q

Steinberg, JVECC, 2012. Main findings of retrospective study on circadian and seasonal presentations in dogs with CHF?

A

Most (57%) occured on Mondays and Tuesdays, least on Sundays. Most common between 9-11:55 AM (55%). More common during Sept-Nov

233
Q

Buckley, JVECC, 2012. ITD use in CPR, main findings?

A

Increased carotid blood flow, increased coronary perfusion pressure (d/t decreased RA diastolic pressure).

234
Q

What is deferoxamine?

A

Iron chelator, used in IR injury

235
Q

What is dimethyl sulfoxide?

A

free radical scavenger, used in IR injury

236
Q

What class is lidocaine? How does it work?

A

1b; acts on fast sodium channels during the inactive phase, inhibiting their depolarization

237
Q

How is calcium infusion cardioprotective with hyperkalemia?

A

Hyperkalemia reduces the RMP (-90 to -80ish), calcium reduces the threshold potential (-75 to -65ish); thus restoring the difference between RMP and threshold, and normal membrane excitability.

238
Q

How does insulin and glucose tx hyperkalemia?

A

Shifts K into cells by stimulating ATP-dependent potassium channels.

239
Q

How do beta-agonists tx hyperkalemia?

A

Stimulate adenylyl cyclase that converts ATP to cAMP. This results in stimulation of the Na-K ATPase pump and intracellular K uptake.

240
Q

How does sodium bicarb tx hyperkalemia?

A

Decreases concentration of hydrogen ion in the extracellular fluid compartment. This, in turn, increases intracellular sodium through Na-H exchanger and facilitates potassium shift into cells via the Na-K ATPase pump.

241
Q

Increased sympathetic tone shortens the time to reach membrane potential. T/F

A

True, which is why it increases HR

242
Q

What is ventricular afterload?

A

Determines the tension that must develop by cardiac muscle fibers before they can shorten

243
Q

S1 occurs when

A

MV and TV close - beginning of systole

244
Q

S2 occurs when

A

Aortic and pulmonic valve close - beginning of isovolumetric relaxation

245
Q

What does Starling’s law of the heart state?

A

Stroke volume increases as cardiac filling (preload) increases

246
Q

Pouiselle’s Equation

A

Q = deltaP x (pi r^4 / 8nl)

247
Q

What is the equation for resistance

A

8nl/pi r^4

248
Q

Q =

A

(delta P)/R

249
Q

Ejection fraction =

A

SV/EDV

250
Q

Determinants of SV

A

Preload, afterload, contractility

251
Q

List 5 functions of NE (SNS stimulation) on the heart

A
    • chronotrope (increases HR)
  2. Decrease cardiac action potential duration by early activation of the delayed iK current, which minimizes detrimental effect of tachycardia
    • dromotrope (Increases rate of action potential conduction) by altering conductivity of gap junctions and increasing rate of initial depolarization
    • inotrope (increases contractility) by activating iCa2+ current and increasing calcium release by SR which increases contractility at any given preload (decreases ESV)
    • lusitrope (increases rate of relaxation) by increasing calcium uptake by SR
252
Q

Fick principle

A

Xtc = Q([X]a - [X]b) - can solve for Q to get cardiac output if know Xtc (amt of substance consumed by an organ or tissue)

253
Q

Who the hell is Einthoven?

A

Einthoven’s triange - standard ECG leads (I, II, III)

254
Q

What is the normal QT interval?

A

less than half of the R-R interval

255
Q

You hear a systolic murmur on the right side of the heart and on ECG there is a right axis shift. Most likely diagnosis?

A

Pulmonic stenosis

256
Q

What alteration in jugular venous pulsations might accompany complete heart block?

A

canon a waves (atria contracting against closed tricuspid valve)

257
Q

Units of resistance?

A

mm Hg/L/min

258
Q

Aortic insufficiency causes a low systolic pressure. T/F

A

F - low diastolic pressure from blood flowing back through insufficient valve

259
Q

What four factors determine the rate of diffusion of a substance between the blood and interstitial fluid?

A
  1. concentration difference
  2. surface for exchange
  3. diffusion distance
  4. permeability of the capillary wall to the diffusing substance
260
Q

Net filtration rate?

A

K[(cap hydrostatic pressure-intersitial hydrostatic pressure) - (capillary oncotic pressure - interstitial oncotic pressure)]

K = constant expressing how readily fluid can move across capillaries (essentially the reciprocal of the resistance to fluid flow through the capillary wall)

261
Q

What part of the vascular system imparts the highest resistance to flow?

A

arterioles

262
Q

Compliance =

A

Vice President

Change in volume / change in pressure

263
Q

MAP =

A

CO x TPR

TPR = total peripheral resistance

264
Q

MAP =

A

Diastolic pressure + 1/3 (Systolic pressure - diastolic pressure)

265
Q

Pulse pressure =

A

Systolic pressure - diastolic pressure

SV/compliance

266
Q

What is the resting membrane potential for smooth muscle cells

A

-40 to -65 mV

267
Q

What specific potassium channel is predominantly responsible for the RMP in smooth muscle?

A

inward rectifying-type K+ channel

268
Q

Smooth muscle action potentials are are initiated primarily by ___

A

inward calcium current

269
Q

Repolarization of smooth muscle cells occurs primarily by…

A

Outward flux of potassium through both delayed K channels and calcium-activated K+ channels

270
Q

How does NE cause vasoconstriction?

A
  1. binds to receptor operated channels for calcium that allow more calcium to influx into cell; G protein linkage of alpha-adrenergic receptors to phospholipase C
  2. the bound activated receptor then induces formation of an intracellular second messenger, inositol triphosphate (IP3) which opens specific channels that release calcium from SR stores

In both the activated receptor first stimulates GTP binding proteins

271
Q

List 3 vasodilator substances that work through the cAMP pathway.

A

epinephrine, histamine, vasoactive intestinal peptide

272
Q

List an vasodilator that work through cGMP pathway.

A

nitric oxide (produced by endothelial cells)

273
Q

Nitric oxide is produced within endothelial cells from what amino acid?

A

L-arginine

274
Q

List 4 agents that stimulate endothelial cell nitric oxide production.

A

acetylcholine
bradykinin
vasoactive intestinal peptide
substance P

275
Q

Bradykinin is a (vasodilator/vasoconstritor) and is formed by the action of ________ enzyme.

A

vasodilator, kallikrein

276
Q

Vasopressin is released from where?

A

Posterior pituitary

277
Q

In the resting state, myocardial oxygen extraction is ___.

A

70-75%

278
Q

What is the most important influence on coronary blood flow?

A

Myocardial oxygen consumption

279
Q

Cerebral blood flow (increases or decreases) in response to decreased PaCO2

A

Decreases

280
Q

CSF is made where?

A

choroid plexus

281
Q

Organs of splanchnic region receive ____ % of resting CO and contain more than ____ % of circulating blood volume.

A

25%, 20%

282
Q

Maximal activation of the sympathetic vasoconstrictor nerves can produce an ___% reduction in flow to the splanchnic region and also cause a large shift of blood from the splanchnic organs to central venous pool.

A

80%

283
Q

What are the ECG features of VT

A

wide QRS complex tachycardia with AV dissociation, fusion beats, and capture beats

284
Q

What are 3 arrhythmogenic mechanisms?

A

Enhanced automaticity
Triggered activity
Reentry

285
Q

What is a fusion beat?

A

result from summation of a ventricular impulse and a simultaneous supraventricular impulse resulting in a QRS complex of intermediate morphology and preceded by a p wave (unless concurrent a fib)

286
Q

What is a capture beat?

A

supraventricular impulse conducting through the normal conduction pathways to the ventricle during an episode of VT or AIVR

287
Q

What is the infectious agent causing Chagas disease?

A

Trypanosoma cruzi

288
Q

What is the max cumulative dose of doxorubicin?

A

250 mg/m2

289
Q

What is systemic inflammatory response after bypass?

A

nonseptic inflammation, consumptive coagulopathy, increased vascular permeability

290
Q

What is milrinone?

A

PDE3 inhibitor, potent inotrope

291
Q

What is an unexpected electrolyte abnormality after CPB?

A

hypokalemia (high K cardioplegia solutions used during bypass)

292
Q

What predisposes to digoxin toxicity?

A

renal dysfunction, hypokalemia, hypomagnesemia, advanced age, chronic lung disease, hypothyroidism,

293
Q

What is the MOA of digoxin?

A

Positive inotrope: Inhibits Na-K-ATPase which causes increase in cytosolic sodium, the increased sodium is pumped out in exchange for calcium, raising the concentration of available calcium to mediate contractility.

Reduces SNS activity, RAAS, and vagomimetic to decrease HR and slow conduction thru AV node and atrial conduction, slows refractory periods

294
Q

How is digoxin excreted?

A

renal, so if patient acutely develops toxic signs on a stable dose, check kidney function

295
Q

What is digoxin half life in dogs? cat?

A

23-29 h dogs, 63-81 h cats

296
Q

Uses for digoxin?

A

ventricular rate control and SVTs (a fib, paroxysmal atrial tachycardia, atrial flutter)

systolic dysfunction in CHF (DCM and LV volume overload)

297
Q

How do you do therapeutic drug monitoring of dig?

A

5-7 d after starting, 6-8 h after dose, over 2.5 ng/ml is toxic

298
Q

Side effects of digoxin

A

prolonged PR interval (don’t treat), ventricular arrhythmia (stop drug), anorexia, nausea, vomiting, diarrhea, bradycardia

299
Q

How do you treat digoxin overdose?

A

lidocaine if ventricular arrhythmia, activated charcoal, digoxin-specific antibodies (Digibind)

300
Q

List the Vaughn Williams Classification.

A

Class 1: sodium channel blockers
a - procainamide, quinidine
b - lidocaine, mexiletine
c - flecainide, propafenone
Class 2: beta blockers (atenolol, propanolol)
Class 3: potassium channel blockers (sotalol, amiodarone)
Class 4: calcium channel blockers

301
Q

What is the MOA of class 1 antiarrhythmics?

A

Inhibit fast sodium channel and decrease slope of phase 0

302
Q

MOA class 1a

A

powerful, fast sodium channel blockade, moderate blockade of the rapid component of the delayed rectifier potassium current (Ik) causing action potential prolongation

Ik blockade proarrhythmic; depression of conduction velocity predisposes to reentrant phenomenon

303
Q

Procainamide MOA

A

class 1a - blocks fast Na and Ik, depresses conduction velocity, prolongs ERP in atrial/ventricular/accessory/retrograde fast AV

hypotension if give too fast

304
Q

Agents that prolong ______ are given first for acute atrial tachyarrythmias, b/c procainamide can enhance _______, thus worsening the ________.

A

AV nodal conduction, AV nodal conduction, ventricular response rate

305
Q

Procainamide side effects.

A

hypotension if bolused, anorexia, nausea, vomiting, SLE, rash, fever, arthralgia, myalgia, agranulocytosis

306
Q

Lidocaine MOA

A

inhibits fast sodium channels

307
Q

Lidocaine’s ability to block I^Na enhanced by…

A

acidosis, hyperkalemia, and partially depolarized cells

308
Q

What can predispose a patient to lidocaine toxicity?

A

heart failure, hypotension, severe hepatic disease

hepatic clearance of lidocaine determines serum concentration

309
Q

Side effects of lidocaine.

A

nausea, vomiting, lethargy, tremors, seizures

310
Q

Tocainide side effects (class 1b)

A

NOT used b/c renal failure and corneal dystrophy common

311
Q

Beta blocker MOA

A

inhibits If and inward calcium current, ICa-L, indirectly by decreasing tissue cAMP levels

312
Q

Beta blockers contraindicated in….

A

sinus node dysfunction, AV node conduction disturaces, pulmonary dz, CHF

313
Q

Difference in metabolism of atenolol vs. metoprolol?

A

atenolol eliminated in kidney, metoprolol undergoes hepatic metabolism and elimination

314
Q

Class 3 MOA

A

block rapid repolarizing Ik, resulting in prolongation of action potential duration and ERP

315
Q

Proarrhythmic effects of class 3 agents increased with concurrent…

A

hypokalemia, bradycardia, intact female, increasing age, and macrolide antibiotics

316
Q

Which drug is least proarrhythmic in class 3?

A

Amiodarone b/c blocks both rapid and slow Ik

317
Q

Sotalol MOA

A

nonselective beta blockade and rapid Ik blockade

318
Q

How is sotalol excreted?

A

kidneys

319
Q

Adverse effects of amiodarone?

A

vomiting, anorexia, hepatopathy, thrombocytopenia

320
Q

Non-dihydropyridine (diltiazem, verapamil) CCB MOA

A

slow AV nodal conduction and prolong ERP

321
Q

JAVMA, 2011, Murmurs in healthy Whippets. Findings:

A

41% healthy dogs had murmurs, PMI most commonly at level of aortic valve (50%); Dogs with murmur at aortic valve had * higher aortic and pulmonic blood flow velocity and CO, compared to dogs w/o murmur; no assc’n w/ sex, pedigree, training

322
Q

Where are innocent murmurs usually?

A

aortic or pulmonic valve

323
Q

DOSE trial findings, NEJM, 2011. Diuretic Optimization Strategies Evaluation trial

A

CRI not better than bolus, high dose greater relief of dyspnea and greater net fluid loss with slightly more transient worsening of renal fxn, no diff in LOH

324
Q

Instances where PCWP is:

  1. Artificially > LVEDP
  2. Artificially < LVEDP
A
  1. mitral stenosis, PEEP, atrial myxoma

2. noncompliant LV, LVEDP >25 mm HG, aortic insufficiency

325
Q

SVR equation

A

((MAP-CVP)/CO) x 80

326
Q

Pulmonary vascular resistance formula

A

((mean PAP - PCWP) / CO) x 80

327
Q

Causes or pulmonary hypertension

A
  1. increased pulmonary blood flow (shunt)
  2. increased pulmonary resistance (hypoxia, increased CO2, acidosis, lung dz, embolism)
  3. increased back pressure (mitral stenosis/regurg, left sided heart failure)
328
Q

Definition/equation for:

  1. Frequency
  2. Wavelength
  3. Speed of sound
  4. Hertz
A
  1. Frequency = # cycles/s
  2. WL = distance traveled by sound per cycle
  3. Speed of sound = frequency x wavelength
  4. Hertz = frequency of 1 cycle/s
329
Q
  1. Resolution of ultrasound image related to what physics property?
  2. Depth of penetration of ultrasound related to what image property?
A
  1. Frequency (high freq = high resolution)

2. Frequency (low freq = deeper penetration)

330
Q

PROTECT study (Pimo in preclinical DCM Dobes), JVIM, 2012.

A

Pimo amazing - CHF occcured day 718 with pimo vs. 441 w/o pimo. MST with pimo 623d vs. 466 d without pimo

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