Chapter 12 - Cardiovascular Toxicology Flashcards Preview

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Flashcards in Chapter 12 - Cardiovascular Toxicology Deck (53):
0

What is the resting potential of a cardiac myocyte relative to extracellular fluid?

A. -120 to -90 mV

B. -90 to -60 mV

C. -60 to -30 mV

D. -30 to -10 mV

B. -90 to -60 mV

1

All of the following positive ions are involved in the bioelectricity of the heart except...

A. Mg

B. Na

C. K

D. Ca

A. Mg

2

The phase of the action potential during which there is rapid inward movement of sodium ions is called phase...

A. 0

B. 1

C. 2

D. 3

A. 0

3

The sinus node pacemaker cells and Purkinje fibers in the ventricles are examples of cardiac cells that have the property of...

A. Dedifferentiation

B. phagocytosis

C. Automaticity

D. Six phases of the action potential

C. Automaticity

4

Excitation-contraction coupling requires all of the following except...

A. Entry of extracellular calcium into the cell

B. hydrolysis of ATP

C. A conformational change in the cardiac myocyte thin filament

D. Binding of calcium to acid phosphatase

D. Binding of calcium to acid phosphatase

5

Contraction and relaxation of individual cardiac myocytes in an organized manner to perform efficient pump function is achieved by...

A. Neurohormonal regulation

B. neurotransmitter release

C. Electronic cell-to-cell coupling

D. Local release of cytokines

C. Electronic cell-to-cell coupling

6

The QRS segment of the electrocardiograph represents...

A. Atrial depolarization

B. conduction time through the ventricles

C. Ventrical repolarization

D. B and C

B. conduction time through the ventricles

7

A normal ST segment is...

A. Biphasic

B. elevated 2-3 mm from baseline

C. Depressed 2-3 mm from baseline

D. None of the above

D. None of the above

8

Which of the following molecules is responsible for the largest energy stores in the heart?

A. ATP

B. Creatine

C. Phosphocreatine

D. ADP

C. Phosphocreatine

9

During toxicant-induced damage to cardiac mitochondria, there is an energy shift to reliance on...

A. Oxidation of free fatty acids

B. Deamination of amino acids

C. ATP produced in the liver

D. Anaerobic glucose metabolism

D. Anaerobic glucose metabolism

10

All of the following are cellular events causing cardiomyopathy from toxicant exposure except...

A. Myocardial cell death

B. Myocyte hyperplasia

C. Extracellular matrix remodeling

D. Apoptosis

B. Myocyte hyperplasia

11

Which of the following is asso w/ heart hypertrophy rather than heart failure after toxicant exposure?

A. Fetal gene expression

B. apoptosis

C. Dilation

D. All of the above

A. Fetal gene expression

12

Factors that can convert cardiac hypertrophy into cardiac failure include all of the following except...

A. ANP

B. ET-1

C. TNF

D. angiotensin II inhibitors

D. angiotensin II inhibitors

13

Lethal cardiac arrhythmia has been asso w/ ...

A. Maladaptive cardiac hypertrophy

B. QT prolongation

C. Myocardial infarction

D. All of the above

D. All of the above

14

A recent discovery that challenges the concept of the permanent loss of cardiac myocytes following cell death is the identification of...

A. Cardiac progenitor cells

B. Cytokines that inhibit apoptosis

C. Growth factors that stimulate hypertrophy

D. Cytokines that stimulate angiogenesis

A. Cardiac progenitor cells

15

A prolonged QTc interval in humans is considered greater than...

A. 400 ms

B. 420 ms

C. 460 ms

D. 500 ms

C. 460 ms

16

All of the following can prolong the QT interval except...

A. Genetic polymorphisms

B. Class III antiarrhythmics

C. Hyperkalemia

D. Exposure to particulate matter air polution

C. Hyperkalemia

17

A biomarker for inflammation that may predict future cardiac events in asymptomatic individuals is...

A. CK-MM

B. Myoglobin

C. BNP

D. C-reactive protein

D. C-reactive protein

18

One theory for arrhythmia secondary to cardiac hypertrophy is...

A. Unbalanced distribution of Purkinje fibers in the remodeling heart

B. Increase in intracellular Mg in hypertrophied cells

C. Increase in systolic blood pressure secondary to cardiac output

D. None of the above

A. Unbalanced distribution of Purkinje fibers in the remodeling heart

19

Besides alterations in potassium channels, long QT syndrome could result from dysfunctional...

A. Na channels

B. Cl channels

C. Glutamate channels

D. GABA channels

A. Na channels

20

At the cellular level, many toxicants cause cardiac toxicity by...

A. Increasing intracellular pH

B. Decreasing intracellular Ca

C. Stabilizing cardiac myocyte membranes

D. Increasing intracellular Ca

D. Increasing intracellular Ca

21

Hypertrophic growth of cardiac myocytes involves the activation of...

A. Calcineurin

B. Thromboxane

C. Retinoic acid receptor

D. All of the above

A. Calcineurin

22

One mechanism for anthracycline cardiac toxicity is...

A. Stimulation of salt and water retention

B. Inhibition of myocyte apoptosis

C. Stimulation of myocyte apoptosis

D. Inhibition of angiogenesis

C. Stimulation of myocyte apoptosis

23

All of the following are involved in cardiac toxic responses except...

A. BCRP

B. AMPK

C. MAPK

D. PKC

A. BCRP

24

An index that correlates with the severity of heart failure is...

A. C-reactive protein

B. urinary excretion of cyclic AMP

C. Myocardial phosphocreatine/ATP ratio

D. Total LDL

C. Myocardial phosphocreatine/ATP ratio

25

Myocardial degenerative responses to toxic insult include all of the following except...

A. Myocardial cell death

B. Fibrosis

C. Hyperplasia

D. Contractile dysfunction

C. Hyperplasia

26

In addition to toxic effects on cardiac myocytes, toxicants can cause cardiac toxicity by affecting ...

A. The AHR receptor

B. Angiogenesis

C. The corticosteroid receptor

D. All of the above

B. Angiogenesis

27

Which of the following is asso w/ pathological hypertrophy of the heart?

A. Hypertension

B. Exercise

C. Pregnancy

D. None of the above

A. Hypertension

28

Myocardial accumulation of collagen is not asso w/

A. Ischemic cardiomyopathy

B. Myocardial infarction

C. Pathological hypertrophy

D. Adaptive hypertrophy

D. Adaptive hypertrophy

29

At the molecular level,cardiac myocyte hypertrophy is asso w/

A. Inhibition of TNF

B. stimulation of p53

C. Reintroduction of the fetal gene program

D. Ligand binding to the androgen receptor

C. Reintroduction of the fetal gene program

30

Counterregulatory factors involved in the progression of heart hypertrophy to heart failure include all of the following except...

A. Oxytocin

B. BNP

C. ANP

D. TNF alpha

A. Oxytocin

31

Counterregulatory mechanisms in response to compensatory mechanisms to cardiac hypertrophy lead to...

A. Decreased heart size

B. Myocardial remodeling

C. Decreased cardiac fibrosis

D. Decrease in salt/water retention

B. Myocardial remodeling

32

Moxifloxacin is asso w/...

A. Acute congestive heart failure

B. prolonged QT interval

C. Coronary artery thrombotic events

D. Toxic cardiomyopathy

B. prolonged QT interval

33

COX-2 inhibitors presumably increase the risk for cardiovascular events by causing...

A. Heart block

B. systolic dysfunction heart failure

C. Toxic cardiomyopathy

D. Coronary artery thrombotic events

D. Coronary artery thrombotic events

34

Inflammatory lesions in the vasculature system are termed...

A. Vasculitis

B. Embolitis

C. Thrombitis

D. Angioinflammation

A. Vasculitis

35

The most prevalent vascular structural injury is...

A. Capillary hyperplasia

B. Varicose veins

C. Angioma

D. Atherosclerosis

D. Atherosclerosis

36

Elevation of serum ET-1 is a marker for...

A. Cardiac myxoma in humans

B. Heart failure in humans

C. QT interval shortening in humans

D. Fetal cardiac abnormalities during third trimester pregnancy

B. Heart failure in humans

37

Which of the following is false regarding the heart?

A. Cardiac hypertrophy during growth is a normal physiologic process

B. cardiac myocytes make up less than half of all the cells in the heart

C. Congestive heart failure is asso w/ an increase in the number of cardiac myocytes

D. Cardiac fibroblasts make up approx 90% of nonmyocyte cells

C. Congestive heart failure is asso w/ an increase in the number of cardiac myocytes

38

Which of the following is true regarding the heart?

A. Under normal conditions, glucose provides most of the energy demand

B. In CHF, there is a shift from glucose to fatty acid energy supply

C. Toxicants can impair oxidative phosphorylation and lead to anaerobic metabolism

D. Creatine is made in the heart

C. Toxicants can impair oxidative phosphorylation and lead to anaerobic metabolism

39

Which of the following is true regarding the heart in myocardial infarction?

A. Aspartate transaminase is the most sensitive marker of myocardial damage

B. apoptosis does not play a part

C. Myocytes undergo rapid cell division

D. None of the above

D. None of the above

40

A key event in initiation of apoptosis in the heart is the release of ...

A. Cytochrome c

B. sodium

C. Creatine

D. None of the above

A. Cytochrome c

41

Which of the following is true of mitochondrial DNA?

A. It is exposed to less oxidative damage than nuclear DNA

B. it is protected by histones

C. It has more efficient DNA repair mechanisms than nuclear DNA

D. Damage to it may be involved in the cardiac toxicity of doxirubicin

D. Damage to it may be involved in the cardiac toxicity of doxirubicin

42

A factor in whether a cell undergoes apoptosis or necrosis is...

A. ATP concentration

B. beta-2- microglobulin conc

C. Amyloid A conc

D. C-reactive protein conc

A. ATP concentration

43

All of the following are true of adaptive and maladaptive hypertrophy except...

A. Both are asso w/ cardiac myocyte hypertrophy

B. Both are asso w/ accumulation of collagen

C. Maladaptive hypertrophy increases the risk for serious arrhythmias

D. Adaptive hypertrophy occurs after exercise

B. Both are asso w/ accumulation of collagen

44

A risk factor for the development of tirsade de pointes is...

A. Hyperkalemia

B. hypernaturemia

C. Prolonged QT interval

D. All of the above

C. Prolonged QT interval

45

Which of the following toxicant-effect pairs is incorrect?

A. Carbon disulfide-atheogenic in lab animals

B. nicotine-Alzheimer's disease

C. Cadmium-hypertension

D. Tobacco smoke-endothelial injury

B. nicotine-Alzheimer's disease

46

All of the following are true of alcoholic cardiomyopathy except...

A. It is unrelated to the duration of alcohol exposure

B. Acetaldehyde may be involved in the genesis

C. Multiple factors such as malnutrition, beverage additives and cigarette smoking have been implicated

D. Alcohol has been implicated in causing up to 40% of nonischemic dilated cardiomyopathy

A. It is unrelated to the duration of alcohol exposure

47

Which of the following is true of class I antiarrythmic drugs?

A. They include lidocaine, quinidine and flecanide

B. They are sodium channel blockers

C. They have proarrythmic effects in patients with a past history of myocardial infarction

D. All of the above

D. All of the above

48

Sotalol is...

A. A beta-blocker and alpha-blocker

B. A beta-blocker and a class III antiarrhythmic

C. A class I and class III antiarrhythmic

D. A beta-blocker and a class IV antiarrhythmic

B. A beta-blocker and a class III antiarrhythmic

49

Class III antiarrhythmics are primarily...

A. Sodium channel blockers

B. potassium channel blockers

C. Chloride channel blockers

D. Beta-adrenergic blockers

B. potassium channel blockers

50

Cardiac glycosides like digoxin...

A. Increase the sensitivity of myocytes to Ca

B. Inhibit Na/K ATPase

C. Cause sinus tachycardia

D. Inhibit sympathetic outflow at high doses

B. Inhibit Na/K ATPase

51

Which of the following is the most sensitive clinical indicator of myocardial cell damage?

A. Urine CPK

B. serum troponin

C. Serum ALT

C. Serum creatine

B. serum troponin

52

Which of the following is an indicator of fluid overload in congestive heart failure?

A. Urine pH

B. serum CPK

C. BNP

D. First-degree AV block on ECG

C. BNP