I know our condition can cause bradycardia (slow heartrate) as well as Tachycardia (fast heartrate). What that rate is, is dependant on our (malfunctioning) autonomic nervous system remember, so it may be temporarily maladjusted. Various other things can affect it including the level of our exhaustion. Staying alert in conversation, as with any intense brainwork, uses a lot of energy.
I’m going to ask what position you were sat in, in relation to your visitors ? I always find it exhausting when I have a group of visitors, particularly more so if I have to move my head or neck a lot, or if I have been sat with my head mainly to one side. I always make a point of sitting at the head of the table, so that I can chat with my head more or less straight forwards, believe me, this lessens the hassle afterwards.
My heartrate drops to low 60’s when I’m very tired, like my body is preparing to sleep and it’s very important that we listen to it. I know you say you can’t nap but I think your body is telling you to get your head and neck comfy and put your feet up, leave the clearing up until tomorrow! It’s all about supply and demand – you’re not currently in a position to supply so, you’ve no option but to limit the demand (or pay the consequences!).
Head & Neck Injury (June 2002); Mild Concussion; Post Concussion Syndrome; Postural Orthostatic Tachycardia Syndrome (POTS); Peripheral Vestibular Dysfunction; Mild Radiculopathy & Small Fibre Neuropathy (right leg & foot resp.); Partially Empty Sella (Oct 2002) Fully Blown Empty Sella (Oct 2004); Whiplash Associated Disorder (WAD); Cerebellar Ectopia (Chiari 0); Cranio-cervical Instability (CCI) with Posterior Gliding (PG) & Cranial Settling (CS); Brain Compression; Retroflexed Odontoid; Stretched/Elongated Brainstem; Vitamin D deficiency; Ehlers Danlos (EDS) type 111; and now Osteoarthritis!