A.  The patient passed out because of a decrease in his

a. diastolic blood pressure.

b. cardiac output.

c. epinephrine levels.

d. heart rate.

B. The formula for cardiac output is

a. heart rate × systolic blood pressure.

b. systolic blood pressure/diastolic blood pressure.

c. stroke volume × heart rate.

d. heart rate × respiratory rate.

C. The normal PR interval is __________ seconds.

a. 0.06 to 0.10

b. 0.10 to 0.20

c. 0.12 to 0.20

d. 0.20 to 0.24

D.  PR intervals of less than 0.12 seconds in duration indica a(n)

a. intermittent blocking of the impulse as it passes through the AV node.

b. delay in conduction of the impulse between the SA node and the

ventricles.

c. increased rate of impulse discharge from the SA node.

d. pacemaker site, either in or close to the AV junction.