Deck 15: Basic 12-Lead Ecg Interpretation

Question 1

Which of the following are indicators of myocardial injury?

A)ST segment depression and physiologic Q wave
B)ST segment depression and T wave inversion
C)ST segment elevation and T wave inversion
D)Wide QRS complex and absent P wave

Answer 1

ST segment elevation and T wave inversion

Question 2

Leads V3 and V4 view which coronary artery and branch?

A)Left coronary artery, left anterior descending branch
B)Left coronary artery, left circumflex branch
C)Left coronary artery, septal branch
D)Right coronary artery, marginal branch

Answer 2

Left coronary artery, left anterior descending branch

Question 3

What is the term for two or more leads that look at the same part of the heart or numerically consecutive chest leads?

A)Artifact continuing leads
B)Anatomically contiguous leads
C)Anatomical contraction leads
D)Automatic continuing leads

Answer 3

Anatomically contiguous leads

Question 4

What is the term for a normal Q wave that measures less than 0.04 second in duration and is less than one-third of the height of the R wave in a lead?

A)Premature Q wave
B)Physiologic Q wave
C)Pathologic Q wave
D)Positive Q wave

Question 5

Electrical axis deviation refers to the changes that occur on the 12-lead ECG as a result of the ________.

A)Patient's level of activity
B)Position of the heart within the chest
C)Patient's height and weight
D)Position of the ECG leads on the chest

Question 6

What is the term for a prolonged reduction or interruption of blood flow that causes the affected myocardial tissue to transition to a worse state?

A)Myocardial ischemia
B)Myocardial infarct
C)Myocardial injury
D)Myocardial interruption

Question 7

Which leads view the lateral wall of the left ventricle?

A)II, III, and aVF
B)V1 and V2
C)V3 and V4
D)I, aVL, V5, and V6

Question 8

A standard 12-lead ECG focuses directly on which portion of the heart?

A)Right ventricle
B)Right atrium
C)Left ventricle
D)Left atrium

Question 9

What does a pathologic Q wave indicate?

A)Tissue death
B)Tissue injury
C)Tissue ischemia
D)Tissue atrophy

Question 10

Leads II, III, and aVF view which coronary artery and which branch?

A)Right coronary artery, marginal branch
B)Left coronary artery, septal branch
C)Left coronary artery, left anterior descending branch
D)Left coronary artery, left circumflex branch

Question 11

Which leads view the septal wall?

A)II, III, and aVF
B)V1 and V2
C)V3 and V4
D)I, aVL, V5, and V6

Question 12

Which of the following are anatomically contiguous leads?

A)II, III, and aVF
B)I and aVF
C)V1, aVL, and aVF
D)I, II, and V3

Question 13

Which leads view the inferior wall of the left ventricle?

A)I, aVL, V5, and V6
B)V3 and V4
C)V1 and V2
D)II, III, and aVF

Question 14

Leads I, aVL, V5, and V6 view which coronary artery and branch?

A)Right coronary artery, marginal branch
B)Left coronary artery, septal branch
C)Left coronary artery, left anterior descending branch
D)Left coronary artery, left circumflex branch

Question 15

Which leads view the anterior wall of the left ventricle?

A)II, III, and aVF
B)V1 and V2
C)V3 and V4
D)I, aVL, V5, and V6

Question 16

Leads V1 and V2 view which coronary artery and branch?

A)Left coronary artery, left circumflex branch
B)Left coronary artery, left anterior descending branch
C)Right coronary artery, marginal branch
D)Left coronary artery, septal branch

Question 17

What is the term for a Q wave that is longer than 0.04 second in duration and is greater than or equal to one-third of the height of the R wave in a lead?

A)Premature Q wave
B)Physiologic Q wave
C)Pathologic Q wave
D)Positive Q wave

Question 18

Which of the following are indicators of myocardial ischemia?

A)Pathologic Q waves and ST segment elevation
B)ST segment depression and T wave inversion
C)Positively deflected T waves and physiologic Q waves
D)Wide QRS complex and absent P waves

Question 19

What is the term for a blockage of one or more of the coronary arteries, which then causes a lack of oxygen to the heart and death of the muscle tissue?

A)Myocardial injury
B)Myocardial ischemia
C)Myocardial infarction
D)Myocardial interruption

Question 20

What is the term for a reduction or interruption in blood flow and oxygen to the myocardium that occurs for a short period of time?

A)Myocardial ischemia
B)Myocardial infarct
C)Myocardial injury
D)Myocardial interruption

Question 21

What is the electrical axis of the patient's heart if lead I is predominantly negative and lead aVF is predominantly positive?

A)A normal axis (no deviation)
B)Right axis deviation
C)Left axis deviation
D)Extreme right axis deviation

Question 22

What does an ST elevation on a 12-lead ECG mean?

A)The heart tissue is healthy.
B)Minor ischemia is occurring.
C)The tissue is not dead yet, but immediate intervention is needed.
D)The heart tissue is already dead and cannot be revived.

Question 23

To indicate myocardial ischemia, two anatomically contiguous leads must show the ST segment to be ________.

A)Elevated by at least 1 mm
B)Elevated by at least 3 mm
C)Depressed by at least 1 mm
D)Depressed by at least 3 mm

Question 24

In left ventricular hypertrophy, how does the QRS complex appear?

A)Normal
B)Positively deflected
C)Negatively deflected
D)Taller and deeper than normal

Question 25

Which of the following can cause extreme right axis deviation?

A)Right ventricular hypertrophy
B)Pregnancy
C)Hyperkalemia
D)Obesity

Question 26

To determine the presence of left ventricular hypertrophy, which leads should you refer to?

A)V2, V3, V5, and V6
B)I, aVL, II, and III
C)V1, V2, V5, and V6
D)I, aVL, aVR, and V4

Question 27

When determining the electrical axis, which portion of the ECG tracing should you focus on?

A)PR interval
B)T wave
C)QRS complex
D)P wave

Question 28

You are analyzing a 12-lead ECG for the presence of left ventricular hypertrophy. After measuring carefully, you determine that the QS measurement is 12 mm and the R wave measurement is 20 mm. What does this patient have?

A)Minimal left ventricular hypertrophy
B)Advanced left ventricular hypertrophy
C)Both left and right ventricular hypertrophy
D)No clinical sign of hypertrophy

Question 29

If a patient has left ventricular hypertrophy, what type of axis deviation will be seen?

A)Left
B)Right
C)Extreme right
D)Normal

Question 30

When determining the presence of left ventricular hypertrophy, you measure to the tip of the deepest QS complex in V1 or V2 and to the tip of the tallest R wave in V5 or V6. For both of these measurements, where should you start the measurement?

A)Base of the P wave
B)Level of the ST segment
C)Base of the Q wave
D)Isoelectric line

Question 31

Ventricular hypertrophy occurs when the heart must exert more effort to maintain normal cardiac output. Why is this greater effort needed?

A)Smaller chamber capacity in the atria
B)Abnormal electrical conduction through the heart
C)Extensive use of blood thinners such as Coumadin
D)Increased peripheral vascular resistance

Question 32

Right axis deviation is considered normal in which group of patients?

A)Children and tall, thin adults
B)Pregnant women and patients with diabetes
C)Patients who are obese and patients who smoke
D)Men and women over the age of 40

Question 33

In left ventricular hypertrophy, more electricity flows through the heart. In practical terms, how will the QRS complexes appear?

A)Wider than normal and bizarre
B)Narrower than normal and bizarre
C)Taller and deeper than normal
D)Shorter and wider than normal

Question 34

Which of the following is not a possible cause of left axis deviation?

A)Left ventricular hypertrophy
B)Anterolateral wall MI
C)Pregnancy
D)Emphysema

Question 35

What is the term for an abnormal thickening of the ventricular wall due to chronic pressure overload that is often caused by hypertension?

A)Hyperpnea
B)Hypertension
C)Hyperkalemia
D)Hypertrophy

Question 36

What is the electrical axis of the patient's heart if leads I and aVF are both predominantly negative?

A)A normal axis (no deviation)
B)Right axis deviation
C)Left axis deviation
D)Extreme right axis deviation

Question 37

When totaled, how many millimeters are necessary in V1 or V2 from the isoelectric line to the tip of the deepest QS complex, plus the distance from the isoelectric line to the tip of the tallest R wave in V5 or V6, to suspect left ventricular hypertrophy?

A)20 mm
B)25 mm
C)30 mm
D)35 mm

Question 38

Which leads are used to determine the presence of axis deviation?

A)Leads II and aVR
B)Leads I and aVF
C)Leads I and aVR
D)Leads V1 and V2

Question 39

What is the electrical axis of the patient's heart if lead I is predominantly positive and lead aVF is predominantly negative?

A)A normal axis (no deviation)
B)Right axis deviation
C)Left axis deviation
D)Extreme right axis deviation

Question 40

What is the electrical axis of the patient's heart if leads I and aVF are both predominantly positive?

A)A normal axis (no deviation)
B)Right axis deviation
C)Left axis deviation
D)Extreme right axis deviation