Lightheaded/Almost fainted at end of dive for 20 seconds - heart started pounding

[PVTAMPASCUBA]

Hi - first off I REALLY appreciate any assistance in this issue.

I've been diving for less than a year and have been anywhere from 30' - 100'. I'll typically dive Nitrox 32 percent

I was 25 minutes into my 2nd dive this past weekend at 45' with PLENTY of air left and wanted to ascend to move to a different spot.

I didn't make any sudden movements or look around quickly or anything, but roughly 5' into my ascent I started to get extremely lightheaded and was too the point where I thought I might faint. My heart started POUNDING. Maybe just nervousness. I didn't panic and never have panic attacks etc.. I'm 26, very healthy, run often, eat healthy, was hydrated, and don't have any ear issues that I'm aware of. My girlfriend is an audiologist and ruled out an ear infection. I coughed a couple times as I know this helps promote bloodflow and thankfully 20 seconds later the feeling went away. I have an Atomic Z2 reg so I know the equipment is good.

This is the 2nd time this has happened to me. It also happened to a friend of mine a couple months back but he was diving regular air.

It's extremely unnerving and holding me back from getting more into this sport I now love. Could I have been breathing TOO much air? (Adjust venturi valve next time?) I know you can get verigo from quickly looking up but I didn't do that.

Please help! Thank you greatly!

 

[fmerkel]

2 things come to mind, your blood pressure, and hyPERventilation.
If you have chronically low blood pressure the act of diving can redistribute blood to the core. Even though you are 'weightless' gravity is still in effect. A movement UP, could deprive your head of enough blood flow to cause the symptoms. The heart pounding is the autonomic system trying to catch up and rapidly get your pressure up and get blood to your brain. If you have [orthostatic hypotension] this is a higher probability of being an issue.

Hyperventilation will do much the same thing. New divers becoming anxious or excited about stuff may think they are starving for air when they are actually breathing TOO much. This becomes a vicious cycle. You can have many of the same symptoms. A combination of both would be unfortunately synergistic.

I would not call either of these things diagnostic so much as semi-educated speculation. A close and honest monitoring of your breathing rate and anxiety level while diving would be useful. There's a reason new divers go through air fast > over breathing (and excessive movement).

Since you are in FL I don't think cold water on the eardrum would be an issue.

 

[northernone]

Call DAN. They are very helpful.

 

[Beau640]

Were you lightheaded like when you stand up too quickly? Or were you dizzy like everything spinning around you?

 

[scubadada]

Call DAN. They are very helpful.

Call DAN to discuss. Could be many things, including an arrhythmia. Losing conscientiousness underwater could be disastrous.

 

[Altamira]

DAN might be helpful, but they are not going to be able to make a diagnosis. Make an appointment with a physician, preferably one that is familiar with diving, to get a physical and checkup.

 

[scubadada]

DAN might be helpful, but they are not going to be able to make a diagnosis. Make an appointment with a physician, preferably one that is familiar with diving, to get a physical and checkup.

Exactly what DAN will likely suggest

 

[fmerkel]

Call DAN to discuss. Could be many things, including an arrhythmia. Losing conscientiousness underwater could be disastrous.

Could be that also.
DAN could be a possible resource for referrals or maybe where to start but as Altamira indicates I doubt if they can do much more than that over the phone.

 

[BoltSnap]

What everybody said, call up DAN and make an appointment with a physician based on DAN's advice.

P.S. You can't adjust the venturi with Atomic regulators, it is done automatically and it will be at maximum when diving 60ft or deeper. You can only adjust the "cracking" pressure on the Atomic regulators (all models including the Z2).

 

[Jack Hammer]

Call DAN first.

A non medical potential issue could come from holding breath to control bouyancy or breathing too shallow. Also wont hurt to read up on shallow water blackout.

Oh, and call DAN first.