# Miguel is a 25-year-old jogger with a target heart rate of 125 bpm. His resting pulse is 70 bpm. His blood volume is approximately 6.8 litres. At rest, his cardiac output is 6.3 litres/minute and his EDV is 150 ml. What is his stroke volume at rest?

Apr 7, 2017

0.09 ("Liters")/("beat")" at rest"

#### Explanation:

The equation that is going to be helpful for us is the following:

$\textcolor{w h i t e}{a a a a a a a a a a a a a a a} \textcolor{b l u e}{C O = H R \cdot S V}$

Where:

$\text{CO=cardiac output: volume of blood the hearts pumps out}$
$\textcolor{w h i t e}{a a a a a a} \text{every minute (mL/min)}$

$\text{HR=heart rate:the number of beats per minute (beats/min)}$

$\text{SV= stroke volume:volume of blood pumped out by the}$
$\textcolor{w h i t e}{a a a a a a} \text{heart in 1 beat (Liters/beat)}$

$- - - - - - - - - - - - - - - - - - - - -$

Isolate the unknown, plug in and solve.

Given

"CO" = 6.3 "Liters"/("min")color(white)(---)"HR" = 70 "beats"/("min")

• $\textcolor{b l u e}{C O = H R \cdot S V}$
$\textcolor{w h i t e}{- -}$
• $\frac{C O}{H R} = S V$
$\textcolor{w h i t e}{- -}$
• $\left(6.3 \text{Liters"/cancel(min))/(70 "beats"/cancelmin) = "SV" = 0.09 ("Liters")/("beat}\right)$

$\textcolor{\mathmr{and} a n \ge}{\text{Answer": "SV"= 0.09 ("Liters")/("beat")" at rest}}$