Question

A volunteer in a research study is found by Doppler echocardiography to have a cardiac output of 15 L/min during an exercise test. His heart rate is 150 beats per minute. Which of the following is the patient’s stroke volume?

A. 10 ml
B. 50 ml
C. 80 ml
D. 100 ml
E. 150 ml

Answer 1

To determine the patient’s stroke volume, we can use the formula:
Cardiac Output = Heart Rate x Stroke Volume
Given that the cardiac output is 15 L/min and the heart rate is 150 beats per minute, we can rearrange the formula to solve for stroke volume:
Stroke Volume = Cardiac Output / Heart Rate
Using the given values:
Stroke Volume = 15 L/min / 150 beats per minute
Stroke Volume = 0.1 L/beat
Since the options are given in milliliters, we can convert liters to milliliters by multiplying by 1000:
Stroke Volume = 0.1 L/beat * 1000 ml/L
Stroke Volume = 100 ml/beat
Therefore, the patient’s stroke volume is 100 ml. So the correct answer is option D) 100 ml.

I hope this helps.