Question 3
(Multiple Choice)
A patient presents for her annual physical examination in seemingly good health.However,she is concerned about her heart because of family history,and you proceed to work up an examination of cardiovascular function.She has a blood pressure of 128/83 mm Hg,and echocardiography indicates that end-diastolic volume is 140 mL and end-systolic volume is 80 mL.A routine electrocardiogram (ECG)is obtained and is shown as follows: 
The ECG reveals the patient is in normal sinus rhythm with an R-R interval of 0.76 seconds.This corresponds to a heart rate of:
A)70 beats/minute
B)74 beats/minute
C)79 beats/minute
D)84 beats/minute
E)88 beats/minute
Answer
C