Stopped Breathing After Fainting

I have been a blood donor for many years and only usually feel faint at the session. After my last session I passed out an hour later, long after leaving the session. I stopped breathing and had to be revived by my partner. My GP suspected vasovagal syncope and possibly mitral valve prolapse (which my younger sister has) and he detected a heart murmur. After having an echo' which was normal the cardiologist also diagnosed VVS but did not order any more tests or a holtor monitor. The only thing which showed up on the ECG was a non-specific T-wave abnormality, which I know usually means nothing, but I had this done after I saw him so he didn't discuss this with me.
I didn't bother telling him that I was still getting symptoms such as fluttering and palpitations and my BP is often low when I take it myself but is usually normal at the hospital or surgery because I'm anxious about being there. I am not an anxious person and often get these feelings even while meditating. I also often get chest pain, usually at night but sometimes during the day. I never usually go to the gp and tend to ignore things. I don't want to go back to my gp and waste his time and am not sure if I should just accept this diagnosis or go back to him.
I have lost a stone in weight since the episode 4 months ago. I often feel faint or dizzy but can usually prevent this with isometric exercises.
Any suggestions gratefully received. :)

[itdood]

So the part about you not breathing, was that all your partners observations?  Did your lips turn blue?  I'm just wondering if you were breathing still but your partner may have thought otherwise, incorrectly.  Respiratory arrest is usually preceded by cardiac arrest so unless your heart stopped for some time I have doubts that you went into respiratory arrest.  I can't think of anything that would cause respiratory arrest by itself, other than opiate overdose, drowning, head trauma.

Did you get enough sugar after your blood donation?  drink up the OJ...

EKGs are good starting point when assesing the heart, take the more benign findings with a grain of salt.  All too often I see heart disease NOT detected in an EKG and benign findings misinterpreted.  This is where having the echo was a good step.

I would want to know what the heart murmur was related to, did the doc ever tie this to something on the echo?

With your weight loss, are you eating the same you always have?  Have you been checked for diabetus?

[acoya]

Thanks for your comments but my partner does know what he is doing as he has been a qualified first aider for many years. My lips turned blue, under my eyes dark purple and I even had an out of body experience briefly. Dr thinks I may have slumped forward (was in a chair) and temporarily blocked my airway. Anyway these things do happen in ways other than those you named.

Yes I had plenty of water and sugar before and after the donation and have been donating for many years so always do the right things. The V V S hadn't been diagnosed before then so that was probably the cause.

The gp thought the murmur was due to MVP, which my sister has, but this didn't show up on the echo'. I still get flutterings and odd sensations but am just ignoring it, as I have always done. It's just sometimes nice to link up with others who have similar experiences, especially when you don't always get answers.

No I haven't changed my eating habits and am not diabetic. My father is so I often do an msu test.