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Is a blackout always from a drop in blood pressure?

7 day tracker showed heart rate often at 130, highest at 160 and lowest at 67. I didn't blackout that week but felt the racing heart and light headed at times. Am having a loop fitted and am referred to an autonomic unit "in case it's not heart related", does that mean I could blackout but not have a corresponding drop in heart rate? I was surprised when I felt lightheaded it didn't show as low HR on monitor.

2 Replies

Hiya! I have vasovagal syncope and i get symptoms when standing/sitting for periods of time and if i get up from sitting for ages.

With vasovagal syncope, your heart rate doesn’t decrease until your blood pressure has massively dropped (when your heart rate drops with the blood pressure, that is the syncopal period aka actually fainting). Before my diagnosis, a doctor took my heart rate and it was at 101, which he explained was too high and suggested I may have vasovagal syncope, which ended up being the final diagnosis.

Leading up to an episode, I feel my heart pumping, feel nauseous (like im going to vomit!), unsteady, warm around my eyes, tunnel vision then i lose consciousness and always feel like poo for hours after. Do you experience any of these symptoms aside a racing heart and lightheadedness?

It also sounds like it could be POTS (postural orthostatic tachycardia syndrome), a chronic illness where your heart rate increases way over 100 upon standing and doesnt always fall into low blood pressure.

There are also blackouts known as psychogenic blackouts, where there are no changes in heart rate/blood pressure at all and are usually hard to diagnose and due to stress. My mum had one when she was younger and was due to long term stress and she remembers laying on her back when it happened.

I hope you're okay! Let me know what the doctors said, but do visit theyve got lots of information there!


Thanks for replying, only just seen it! Yes I feel my heart getting faster and as if it's thudding loudly, I also hear my pulse in my right ear, I then start shaking, and get all hot and sweaty, sometimes my hearing and sight goes weird but that's not everytime, I get light headed then blackout. I come round really quick but am then ridiculously tired, just want to sleep, am still sweaty and shaking and I feel nauseous (but have never been sick). Takes me a day or two to feel "normal" again. I've found when I start to feel it coming on and go and sit or lie down to avoid it getting to blackout stage, drinking lots of water rapidly helps a quicker recovery though I'm still left feeling really tired.

Your mention of PoTS was the right one. Last week I was diagnosed with "tendency to PoTS" which apparently they use when you have lots if the symptoms but don't hit the criteria exactly, eg 28 instead of the 30 bpm. Now busy reading up on it more!


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