Chapter 24 Cardiac Surgery

Chapter 24  Cardiac Surgery

MULTIPLE CHOICE

1. The internal mammary arteries are frequently used as grafts during coronary bypass surgery. Where are they located?

1. They diverge from the anterior interventricular branch of the right coronary artery.
2. They diverge from the subclavian arteries behind the sternum.
3. They diverge from the subclavian arteries anterior to the sternum.
4. They diverge from the innominate artery.

ANS: B
The right and left internal (thoracic) mammary arteries, used as grafts during coronary bypass surgery, branch off the subclavian arteries and course behind and parallel to the edges of the sternum.

REF: Page 1002

2. In the pulmonary circulatory system, blood is pumped from the right ventricle (RV) through the pulmonary valve into the main pulmonary artery (PA). The PA divides into the right and left pulmonary arteries, which further subdivide into the arterioles and capillaries of the lungs. Where does the blood from the lungs flow next?

1. Into the capillary beds
2. Into the alveoli
3. Through the pulmonary artery to the left atrium
4. Through the pulmonary veins to the left atrium

ANS: D
External respiration occurs in the capillary beds and the alveoli, where carbon dioxide is exchanged for oxygen. Freshly oxygenated blood from the lungs flows through the pulmonary veins into the left atrium.

REF: Page 1002

3. Identify the correct path of the cardiac conduction system.

1. From the area where the superior vena cava meets the right atrium to the

   atrioventricular junction close to the tricuspid valve to the right side of the interventricular system into a network of fibers by way of the right and left bundle branches

2. From the SA node to the AV node to the bundle of His to the Purkinje system
3. Both from the area where the superior vena cava meets the right atrium to the atrioventricular junction close to the tricuspid valve to the right side of the

   interventricular system into a network of fibers by way of the right and left bundle branches, and from the SA node to the AV node to the bundle of His to the

Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

Test Bank 24-2

Purkinje system
d. Neither from the area where the superior vena cava meets the right atrium to the

atrioventricular junction close to the tricuspid valve to the right side of the interventricular system into a network of fibers by way of the right and left bundle branches, and from the SA node to the AV node to the bundle of His to the Purkinje system

ANS: C
The conduction system process of excitation and contraction originates in the sinoatrial (SA) node, located in the area where the superior vena cava (SVC) meets the right atrium. The impulse spreads to the atria through intermodal pathways and travels to the AV junction (which contains the AV node) located medial to the entrance of the coronary sinus in the right atrium, close to the tricuspid valve. From the AV junction, the impulse spreads to the bundle of His, which extends down the right side of the interventricular septum. The bundle of His divides into the right and left bundle branches, which
terminate in a network of fibers called the Purkinje system. Purkinje fibers are spread throughout the inner surface of both ventricles and the papillary muscles, which when stimulated produce contraction of the heart muscle.

REF: Page 1006

4. The blood is oxygenated in the lungs and returns to the left atrium through the pulmonary veins. Where does the blood flow after leaving the left atrium?

1. Through the mitral valve into the left ventricle
2. Through the tricuspid valve into the left ventricle
3. Through the aortic valve into the left ventricle
4. Through the aorta into the systemic circulation

ANS: A
The blood is oxygenated in the lungs and returns to the left atrium through the pulmonary veins. From the left atrium, it flows through the mitral valve into the left ventricle, where it is ejected through the aortic valve into the aorta and the systemic circulation.

REF: Page 1004

5. During the preoperative nursing assessment for a patient scheduled for cardiac surgery, the perioperative nurse reviews the patient’s medication history with particular attention to medications that can affect the surgery or cause complications. Select the true statement about specific medications that can affect surgery or cause complications.

1. Aspirin may increase platelet levels.
2. Lipid-lowering drugs (statins) may affect coronary artery bypass patency.
3. Herbal products may promote the development of thromboemboli.
4. Angiotensin converting enzyme inhibitors (ACEIs) may cause malignant

   hypertension.

ANS: B

Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc.

Test Bank 24-3

Lipid-lowering drugs (statins) may affect postoperative coronary bypass graft patency; angiotensin converting enzyme inhibitors (ACEIs), used for patients with a history of MI or heart failure, may induce labile postoperative blood pressures. Patients taking herbal medicines may be at risk for increased bleeding, hypoglycemia, or other complications, depending on the specific side effects of some herbal drugs. In addition to risk factors and health status, the perioperative nurse reviews the patient’s medication history with particular attention to vasoactive drugs, anticoagulants, and other medications that can affect the surgery. Nurses should note that patients taking aspirin and other antiplatelet drugs may require intraoperative replacement of platelets.

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6. Select the noninvasive diagnostic test that illustrates heart wall motion and blood flow through the heart and quantifies cardiac function.

1. Radionuclide imaging
2. Cardiac catheterization
3. Echocardiography
4. Cardiac function studies

ANS: A
Radionuclide imaging is employed to illustrate wall motion and blood flow through the heart and to quantify cardiac function. These noninvasive techniques are generally well tolerated by patients, especially when patients may be too unstable to withstand a cardiac catheterization. These techniques may also be used as a complement to catheterization. Cardiac catheterization provides definitive information about the extent and location of ischemic heart disease and is an adjunct to echocardiography for diagnosing valvular heart disease.

REF: Page 1014