Deck 7: Critical Thinking

Question 1

In the setting of myocardial infarction, a new onset of BBB carries an increased mortality rate.

Answer 1

True

Question 2

BBB increases the width of the QRS complex.

Answer 2

True

Question 3

Two conditions must exist to suspect BBB. First, the QRS complex must have an abnormal duration (120 ms or more in width), and second:

A) a slurred upstroke of the QRS complex must exist.
B) the QRS complex must arise as the result of supraventricular activity.
C) an RSR' complex must be seen in leads V₁-V₆.
D) a QS pattern must be seen in leads I, II, and III.

Answer 3

the QRS complex must arise as the result of supraventricular activity.

Question 4

ECG signs of pericarditis include all of the following EXCEPT:

A) PR segment depression.
B) notching of the J-point.
C) R-wave amplitude in V₅ that is greater than or equal to 35 mV.
D) ST-segment elevation that is not strictly grouped into anatomically contiguous leads.

Question 5

Which of the following statements is TRUE regarding ventricular hypertrophy?

A) Hypertrophy increases the duration of the QRS complex.
B) Leads I, aVL, V₅, and V₆ are the best leads to use when looking for ECG evidence of hypertrophy.
C) ECG evidence of right ventricular hypertrophy is usually more readily evident than LVH.
D) Hypertrophy increases the QRS amplitude.

Question 6

Benign early repolarization (BER):

A) is associated with a significant incidence of cardiogenic shock.
B) produces ST-segment elevation and tall T waves resembling those seen in the hyperacute phase of myocardial infarction.
C) most often occurs in elderly males.
D) should be suspected if the J-point is more than 25% of the height of the T-wave apex.

Question 7

A complete BBB is characterized by a:

A) QRS measuring 100 to 120 ms.
B) QRS measuring more than 120 ms.
C) PR interval measuring more than 200 ms.
D) QT interval measuring less than 440 ms.

Question 8

Patients experiencing ____________ infarctions are most likely to develop BBB.

A) inferior and lateral
B) anterior and posterior
C) septal and anteroseptal
D) inferior and septal

Question 9

Which lead is probably the best to use when differentiating between right and left BBB?

A) aVR
B) V₁
C) V₄
D) II

Question 10

Whenever the two criteria for BBB have been met, and lead V₁ displays an RSR' pattern, you should suspect a:

A) left BBB.
B) right BBB.

Question 11

A QRS measuring 100 to 120 ms in adults is called a(n) _________________ right or left BBB.

Question 12

List five conditions that can mimic myocardial infarction by producing ST-segment elevation.

Question 13

Briefly describe how to determine the presence of LVH using the 12-lead ECG.

Question 14

List the ECG criteria for bundle branch recognition.

Question 15

What is meant by the phrase terminal force of the QRS complex?