00:01
Ok, this question here says, what is the stroke volume of a woman with a heart rate of 66 beats per minute and a cardiac output of 4 .7 liters per minute? so remember that the formula for cardiac output is equal to stroke volume multiplied by the heart rate.
00:18
So in this case you have that the heart rate is 66 beats per minute and you have to multiply this by the stroke volume and this is equal to cardiac output that is 4 .7 liters per minute.
00:35
Ok, so if you solve for the stroke volume you have, well let's convert this 4 .7 liters to milliliters first, ok, so just in order to make it, to make the calculation easier.
00:50
So instead of 4 .7 you are going to have like this, 4 ,700 liters per minute, ok.
01:03
So you have now to solve for the stroke volume and you are going to get 4 ,700 divided by and this is going to be equal to approximately 7 .1 point, oh well, i'm sorry, 71 .2 liters and that's it, this is the stroke volume.
01:28
Ok, this is the, oh well, actually, ml's, ok, this is the stroke volume, ok, the stroke volume is going to be 71 .2 milliliters per beat, ok, per beat.
01:45
Now the next question says, ejection fraction is calculated as, you have ejection fraction is calculated as stroke volume, stroke volume divided by the end diastolic volume multiplied by 100.
02:06
So in this case, they are telling you that it is a patient with a stroke volume of 80 milliliters, so you have 80 here, you have the ejection fraction, 80 milliliters, and the end diastolic volume of 170, so you have to use, or to replace the values here, you are going to find the ejection fraction, so you have 80 divided by 170 and you are going to get here approximately 0 .47, 0 .47, 47 .1, ok.
02:41
Now you have to multiply this by 100 % and you are going to get that the ejection fraction is going to be approximately 47 .1%, this is the ejection fraction, ok.
02:52
The next question says, what is the length of the cardiac cycle if the heart rate is 70? so the cardiac cycle refers to the complete sequence of events that occur during one heartbeat, and it includes both the systolic phase and the diastolic phase also of the heart, ok...