Chapter 7

Question 1

Why is the heart considered to be two pumps functionally?

Answer 1

The right atrium and right ventricle serve functionally as one pump for ejecting blood to the lungs, and the left atrium and left ventricle pump blood to the systemic circulation.

Question 2

Cardiac cells are connected by intercalated disks and a fusion of cell membranes to form a ____

Answer 2

Syncytium (interconnected mass)

Question 3

Depolarization of cardiac cells is characterized by a rapid influx of ___ ions, a slower influx of ____ ions, and the outflow of ___ ions.

Answer 3

Sodium (Na+)
Calcium (Ca2+)
Potassium (K+)

Question 4

A relatively long ____ is important to cardiac cells to prevent a constant state of contraction from recycling impulses.

Answer 4

Refractory period

Question 5

Define chronotropic and inotropic effects in relation to the heart.

Answer 5

Chronotropic refers to the rate of contraction, whereas intotropic refers to the force or strength of contraction.

Question 6

Define preload and afterload in relation to the pumping mechanism of the heart.

Answer 6

Preload is the volume of blood in the ventricles at the end of diastole (the amount of blood that must be pumped out). Afterload is the resistance in the arteries that the ventricle must overcome to pump blood.

Question 7

List the 4 basic compensatory mechanisms of the cardiovascular system.

Answer 7

Increasing the heart rate, increasing the stroke volume, increasing the efficiency of the heart muscle, and heart enlargement

Question 8

List 5 objectives of treatment for heart failure

Answer 8

Control rhythm disturbances, maintain or increase cardiac output, relieve fluid accumulations, increase the oxygenation of blood, and provide oxygen/sedatives.

Question 9

List 4 beneficial effects and one potential toxic effect of the use of the cardiac glycosides.

Answer 9

Beneficial effects include improved cardiac contractility, decreased heart rate, antiarrhythmic effect, and decreased signs of dyspnea.

Toxic effect is vomiting

Question 10

Catecholamines such as epinephrine are used in veterinary cardiology primarily for…..

Answer 10

Stimulation of cardiac contraction in cardiac arrest

Question 11

List 5 factors that may predispose the heart to arrhythmias.

Answer 11

conditions that cause hypoxia;

electrolyte imbalances;

increased levels or sensitivity to catecholamines;

certain drugs such as digitalis, barbiturates, and others;

and cardiac trauma or disease

Question 12

List 6 categories of antiarrhythmic drugs and give an example of each

Answer 12

Class 1A: quinidine
Class 1B: lidocaine
Class 1C: flecainide
Class II : propranolol
Class III : bretylium
Class IV : diltiazem

Question 13

List 4 vasodilator drugs and classify each as arteriolar dilator, venodilator, or mixed.

Answer 13

• Hydralazine: arteriolar dilator
• Nitroglycerin: venodilator
• Prazosin: mixed
• Enalapril: mixed

Question 14

Why is lasix sometimes called loop diuretic?

Answer 14

Lasix is called a loop diuretic because it inhibits reabsorption of sodium in the loops of Henle.

Question 15

The use of many diuretics can lead to a dangerous loss of what electrolytes?

Answer 15

Potassium

Question 16

List 5 ancillary methods of treatment for cardiovascular disease.

Answer 16

Bronchodilation, oxygen therapy, sedation, aspiration, and centesis

Question 17

____ is characterized by the rapid influx of sodium ions into the cell through channels, the slower influx of calcium ions, and the outflow of potassium ions.

Answer 17

Depolarization

Question 18

The amount of blood that the heart is capable of pumping per minute is called ___

Answer 18

cardiac output

Question 19

_____ results when the pumping ability of the heart is impaired to the extent that sodium and water are retained in an effort to compensate for inadequate cardiac output.

Answer 19

Congestive heart failure

Question 20

ACE causes the conversion of ______ to _____

Answer 20

Angiotensin I to Angiotensin II

Question 21

Nitroglycerin is supplied as an ointment. List the precautions that should be taken when applying.

Answer 21

Wear gloves, rotate application sites, do not pet the animal at the application site, measure the dosage in inches, and contact the veterinarian is a rash appears at the application site.

Question 22

What diuretic is used most commonly in the treatment of heart failure?

Answer 22

Lasix

Question 23

What is hypokalemia?

Answer 23

An abnormally low potassium level in the blood

Question 24

What are the primary goals of the dietary management of heart disease?

Answer 24

The primary goals are

(1) sodium restriction

(2) maintenance of good body weight and
condition (reduction of obesity or cachexia). In
some instances, specific nutrient deficiencies,
concurrent disease, and/or electrolyte disorders
may need to be addressed.

Question 25

List 3 effects of administration of catecholamines:

Answer 25

1. Increased force of contracion
2. An increase in blood pressure
3. Elevated blood glucose levels

Question 26

The heart is a ___ -chambered pump that is responsible for moving blood through vascular system.

Answer 26

4

Question 27

__ is a faster than normal heart rate.

Answer 27

Tachycardia

Question 28

When situations cause spontaneous depolarization of cardiac muscle or abnormalities of the conduction system, _____ may occur.

Answer 28

arrhythmia

Question 29

Which of the following is not a way by which the cardiovascular system may increase its output during times of need, such as during athletic performance or to compensate for cardiac disease?

A. Decreasing heart rate to such an extent that the myocardium is protected from damage caused by the increased workload

B. Increasing the stroke volume

C. Increasing the efficiency of the heart muscle

D. Physiologic heart enlargement; the heart is composed of muscle that responds to work by increasing its size and becoming stronger

Answer 29

A. decreasing heart rate to such an extent that the myocardium is protected from damage caused by the increased workload

Question 30

Congestive heart failure (CHF) results when the pumping ability of the heart is impaired to the extent that Na and H2O are retained in an effort to compensate for inadequate cardiac output, It is associated with….

Answer 30

1. exercise intolerance
2. pulmonary edema
3. ascites

Question 31

Digitalis is a(an) ____. It is obtained from the dried leaves of the plant Digitalis purpurea.

Answer 31

Cardiac glycoside

Question 32

Quinidine is an alkaloid that is obtained from cinchona plants or is prepared from quinine. It is used to treat ventricular tachycardia, and atrial fibrillation. Quinidine doses must be ___ in patients who are being treated concurrently with digoxin.

Answer 32

decreased

Question 33

Gloves do not have to be worn when applying nitroglycerin. T/F

Answer 33

false

Question 34

Concurrent use of nonsteriodal antiinflammatory drugs may __ the effectiveness of captopril.

Answer 34

decrease

Question 35

Furosemide may cause ___ in patients

Answer 35

hypokalemia