[trux]

I'd tell that you were not nicely ventilated, but pretty much extremely hyperventilated. Hyperventilation (low CO2 content in lungs and blood) will cause vasoconstriction of carotids supplying the brain, and also increases binding of O2 to hemoglobin (it gets not only easier bind on it, but it is also harder to unload it where it is needed). Extreme hyperventilating leads to blackout or as in your case to LMC.