PRACTICE QUESTIONS

1. In which of the following arrhythmias will the ECG characteristically show the same number of P waves and QRS complexes?

a. Complete (third-degree) AV block

b. First-degree AV block

c.

d. Atrial flutter

e. All the above

2. The time required for the conduction of the cardiac action potential through the AV node would be approximately equal to the:

a. RR interval

b. PR interval

c. ST interval

d. PP interval

e. QT interval

3. The T wave in a normal ECG is:

a. Always negative,

b. Always positive if the R wave is positive.

c. Also known as the “pacemaker potential.”

d. Caused by the delay between atrial and ventricular depolarization.

e. Caused by ventricular repolarization.

4. The ECG in Figure 20-13, A, indicates:

a. Sinus arrhythmia

b. Right ventricular hypertrophy

c. ST segment elevation

d. Premature ventricular contraction

e. Atrial fibrillation

5. The ECG in Figure 20-13, B, indicates

a. Second-degree AV block

b. Third-degree AV block

c. Sinus bradycardia

d. Ventricular tachycardia

e. ST segment elevation