Chapter 17

Question 1

Stroke Volume (SV)

Answer 1

amount of blood ejected with each contraction of the ventricle (SV = EDV -ESV)

Question 2

End Diastolic Volume (EDV)

Answer 2

volume of blood in the ventricle prior to ejection

Question 3

End Systolic Volume (ESV)

Answer 3

amount of blood that remains in the ventricle after ejection

Question 4

Ejection Fraction

Answer 4

= SV/EDV

normal is 60% to 80%

Question 5

EKG Waveforms

Answer 5

• P wave corresponds to atrial depolarization
• QRS complex represents ventricular depolarization
• T wave reflects ventricular repolarization
• U wave when slow heart rate and low potassium (called hypokalemia)

Question 6

Cardiac Output

Answer 6

stroke volume x heart rate

Question 7

Electrocaridiography

Answer 7

• provides graphic illustration of the electrical currents generated by cardiac cells
• uses electrodes
• 12 lead ECGs
• holter monitors
• Exercise/ stress test

Question 8

!2 lead ECGs

Answer 8

• standard bipolar limb leads I, II, III
• Unipolar augmented leads aVR, aVL, aVF
• Unipolar chest leads V 1-6

Question 9

Holter Monitors

Answer 9

electrodes on chest and monitors

Question 10

Exercise/stress test

Answer 10

stress heart by increasing heart rate and myocardial load

Question 11

MUGA scan

Answer 11

gives information regarding movement of heart and ejection fraction

Question 12

Magnetic Resonance Imaging (MRI) and Computed Tomography (CT scan)

Answer 12

• useful for imaging cardiac structures
• MRI may identify myocardial thickening, pericardial sac disease, valvular structures, congenital malformations
• MRI with contrast media identifies acute and chronic myocardial infarcts
• MRI and CT identify coronary plaque burden

Question 13

Echochardiography

Answer 13

• uses reflected sound waves (ultrasound) to provide an image of cardiac structure and motion within the chest
• useful in diagnosis of heart enlargement valvular disorders, collections of fluid in the pericardial space, cardiac tumors, and abnormalities in left ventricular motion
• provides estimations of ejection fraction an assessments of ventricular systolic and diastolic function

Question 14

Nuclear Cardiography

Answer 14

• radioactive substances injected into the bloodstream are used to trace the patterns of blood flow in the heart
• assesses the adequacy of blood flow to cardiac tissues (cold spots: inadequate perfusion)
• Positron Emission Tomography (PET): evaluate cardiac perfusion and metabolism

Question 15

Cardiac Catheterization/coronary angiography

Answer 15

• catheter passed from the femoral or brachial artery into the aorta to the heart: assesses L side of the heart
• Catheter passed from the femoral vein to the inferior vena cava to the heart: assesses R side of the heart
• used to directly measure pressures within cardiac chambers; visualize chamber size, shape, and movement; sample for blood oxygen content in various heart regions; measure CO and ejection fraction; and visualize and manage coronary artery obstructions
• can be used in conjunction with thrombolytic drugs, laser therapy, stents, and coronary balloon angioplasty