Deck 20: Myocardial Ischemia and Infarction

Question 1

The _______ arteries deliver the needed blood supply to the myocardial cells.

A) cerebral
B) carotid
C) coronary
D) brachial

Answer 1

coronary

Question 2

To evaluate ST segment depression or elevation the ST segment is compared against the:

A) PR segment.
B) P wave.
C) QT interval.
D) QRS complex.

Answer 2

PR segment.

Question 3

The Q wave:

A) is the second part of the QRS complex.
B) is the first upward deflection from the baseline.
C) is always present.
D) has a duration of less than 0.04 seconds.

Answer 3

has a duration of less than 0.04 seconds.

Question 4

The ST segment:

A) begins where downward slope of the R wave extends below the baseline and ends at the point where the S wave deflects back up to the baseline.
B) is the flat line that follows the QRS complex and connects it to the T wave.
C) represents the entire ventricular repolarization.
D) appears as a curved, sloping line although it may vary by 1.5 to 2.0 mm in some precordial leads.

Question 5

To use the PR segment to evaluate the degree of displacement of the ST segment from the isoelectric line you measure at a point ____ seconds after the J point.

A) 0.02
B) 0.04
C) 0.08
D) 0.12

Question 6

The T wave:

A) is upright and equally round on the upslope and down slope and is oriented in the same direction as the preceding QRS complex.
B) is asymmetrical with a more abrupt upslope and is oriented in the same direction as the preceding P wave.
C) is slightly asymmetrical and oriented in the same direction as the preceding QRS complex.
D) is inverted and asymmetrical.

Question 7

Myocardial _______is a deprivation of oxygen and nutrients to the myocardium but no damage to the cells has occurred.

A) ischemia
B) injury
C) infarction
D) effusion

Question 8

Myocardial _______ is the death of myocardial cells.

A) ischemia
B) injury
C) infarction
D) effusion

Question 9

Inverted T waves and ST segment depression are considered two characteristic signs of myocardial:

A) inflammation.
B) injury.
C) effusion.
D) ischemia.

Question 10

Inverted T waves associated with myocardial ischemia indicate that ischemia is present through the ________ of the myocardium.

A) full thickness
B) outer wall
C) inner lining
D) middle layer

Question 11

A flat depression of the ST segment results from:

A) myocardial injury.
B) myocardial ischemia.
C) subendocardial infarction.
D) infarction involving the full thickness of the myocardium.

Question 12

ST segment elevation:

A) occurs with myocardial ischemia.
B) is the earliest reliable sign that myocardial infarction has occurred.
C) tells us the myocardial infarction is old.
D) usually returns to the baseline within a few minutes.

Question 13

ST segment is said to be significant when it is raised more than __ mm above the baseline at a point one small square to the right of the J point in the limb leads.

A) 1
B) 2
C) 4
D) 6

Question 14

Pathologic Q waves indicate the presence of:

A) myocardial ischemia.
B) subendocardial infarction.
C) myocardial injury.
D) irreversible myocardial damage or myocardial infarction.

Question 15

Leads _________provide the best view for identifying anterior myocardial infarction.

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

Question 16

Leads ______, while located more laterally, may also help identify anterior infarction.

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

Question 17

Lateral infarction is identified by ECG changes such as ST segment elevation; T wave inversion; and the development of significant Q waves in leads:

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

Question 18

Inferior infarction is determined by ECG changes such as ST segment elevation; T wave inversion; and the development of significant Q waves in leads:

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

Question 19

Posterior infarctions can be diagnosed by looking for reciprocal changes in leads:

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

Question 20

If ECG changes are seen in leads V1, V2, V3 and V4, we call it a/an _________ wall infarction.

A) inferior
B) lateral
C) anteroseptal
D) posterior

Question 21

Right ventricular infarction is determined by ECG changes such as ST segment elevation; T wave inversion; and the development of significant Q waves in leads:

A) V7, V8, and V9
B) V4R, V5R and V6R
C) I, aVL, V5, and V6.
D) II, III, and aVF.

Question 22

Inferior infarction is determined by ECG changes such as ST segment elevation; T wave inversion; and the development of significant Q waves in leads:

A) V4R, V5R and V6R
B) V5 and V6
C) I, aVL, V5, and V6
D) V7, V8, and V9

Question 23

The coronary arteries satisfy increased myocardial oxygen demands by increasing coronary blood flow primarily through vasodilation.

Question 24

The J point is the spot that marks the end of the QRS and the beginning of the ST segment.

Question 25

Often, characteristic ECG changes accompany MI.

Question 26

Myocardial ischemia, injury and infarction are reversible.

Question 27

The ECG can help identify the presence of ischemia, injury, and/or infarction of the heart muscle.

Question 28

T wave inversion seen with ischemia is both inverted and asymmetrical, meaning that the right and left sides are not the same.

Question 29

Myocardial infarction can occur without the development of Q waves.

Question 30

As a matter of practice, lead II of the ECG will provide enough information to detect myocardial injury and MI.