stroke volume

  I had a cardiopulmonary exercise stress test and went back for the results, I had gotten info from you re the VO2max numbers so I could try to understand  what the doctor would tell me, instead   the doctor said  they measured the stroke volume and mine was "16"  which he thought was low,  what does this  16 mean, what would an average number   be for a 55 year old female?  thanks  Pat

[CCF Cardio MD - MTR]

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Dear Pat, thank you for your question.  The formula for stroke volume is cardiac output (in cc's/min) / heart rate (per min).  The normal range for stroke volume is 50-70 cc's and doesn't vary much with age.  Stroke volume refers to the amount of blood ejected from the heart with each heartbeat.  The only way to directly measure stroke volume is through a cardiac catheterization where the cardiac output can be directly measured with a catheter in the heart.  Sometimes, the stroke volume can be estimated with an echocardiogram (ultrasound of the heart), but those measurements are often inaccurate.  I'm not sure how they measured your stroke volume with a cardiopulmonary exercise test but I think there's some confusion here.  You would be deathly ill if your stroke volume were 16, so I think that value refers to your VO2 max instead.  I think you should check with your physician regarding this measurement.  I hope you find this information useful.  Information provided in the heart forum is for general purposes only.  Your physician can only provide specific diagnoses and therapies.