Blood Presure

[Mitchell]

Hope this doesn't sound stupid. Here it goes.

If all movement and temp are the same. Does your heart rate change when you are in the water?

 

[DocVikingo]

In short, "Yes." Heart rate drops.

More prolixly, even controlling for temperature the act of immersion itself results in the movement of blood from the limbs (especially the legs) to the thorax. This causes an increase in the volume of blood returning to the heart and in the volume pumped with each ventricular contraction. Since the heart endeavors to keep the total amount of blood pumped out per minute relatively constant, heart rate decreases to compensate for this increase in stroke volume.

Clear?

Best regards.

DocVikingo

 

[beche de mer]

Mitchell once bubbled...

If all movement and temp are the same. Does your heart rate change when you are in the water?

Immersion has the effect of reducing heart rate. This is known as the "mammalian diving reflex".

If my understanding is correct, it is mediated through 2 mechanisms:

1) Water on the face activates a "reflex arc", which stimulates the vagus nerve, reducing heart rate.

2) Compresion of the peripheries (i.e. limbs) forces the blood "centrally", i.e. back toward the heart. This increases the stroke volume and reduces the rate of the heart.

 

[beche de mer]

(Ooops. Beaten to it by DocVik.ut: )

 

[erubic]

Does that mean if someone has high or low blood pressure they shouldn't dive? What about other medical conditions like, heart trouble in general? Just curious, I never really visit the diving medicine forum.


Thanks
Eric

P.s If someone had a fast pulse( I'm sure there is a medical word for that - I don't know anything about health and medicine) does that mean scuba diving would be good for them?

 

[Rick Inman]

My blood pressure is a little high (but, according to my Doc, not too high to stop me from diving) at about 148. However, for the first 2-3 hrs after a dive, my blood pressure drops to less than 130. When I told my doc about this, he said, "Then I prescribe for you to dive as often as possible."
Yes, sir, Doc!!

 

[BigJetDriver]

Rick Inman once bubbled...
When I told my doc about this, he said, "Then I prescribe for you to dive as often as possible."
Yes, sir, Doc!!

Good Heavens, Rick! I need to meet your Doc. That way, when I want to get time off to go diving, I can just tell my company: "Hey! It's doctor's orders!"

What a deal! :rofL:

BJD