Dr Graham Exelby December 2025 By late 2025 a clearer picture is emerging.  A simple change in diagnostic technique—standing (or active-stand) echocardiography instead of passive tilt-table testing—has revealed a pattern that appears in the majority of patients with postural tachycardia syndrome (POTS): a pronounced drop in stroke volume and cardiac filling on assuming upright posture, despite a structurally normal heart. This has been variously labelled “preload dependence,”

Dr Graham Exelby December 2025 “Long COVID is much more than a classic ‘post-viral syndrome” It is a condition in which the acute-phase inflammatory program never fully switches off  — and remains easily re-triggered months or years after the initial infection. Figure 1: Simplified Immune Pathways The Two Phases of COVID Never Separate For millions worldwide (conservatively 1–3% of those infected), SARS-CoV-2 leaves behind: persistent spike protein and/or viral RNA in subsets

Dr Graham Exelby December 2025- in peer review Preview: This diagram shows the root network of all chronic immunometabolic diseases: hypoxia HIF-1α → HIF-2α reprogramming ROS / RAGE / NF-κB activation STAT3–CCL2 macrophage/microglial loops NLRP3 inflammasome pericyte dropout BBB leak mast-cell activation mitochondrial failure / PDH shutdown glycolytic trap autonomic failure central sensitisation This is the “motherboard,” where from this “motherboard,” you can derive variants

Dr Graham Exelby, Ms Michelle Hill

Author: Dr Graham Exelby, revised by Dr Valerio Vittone (PhD)

Dr Graham Exelby October 2025 Abstract Background: Postural Orthostatic Tachycardia Syndrome (POTS) is a multisystem disorder of orthostatic intolerance characterised by excessive heart-rate increments (≥ 30 bpm in adults) upon standing, accompanied by fatigue, cognitive dysfunction, and visceral dysregulation. (Vernino et al., 2021) Emerging haemodynamic and metabolic evidence reframes POTS not as primary autonomic denervation but as a syndrome of dynamic preload failure —a

Author: Dr Graham Exelby October 2025. A Reanalysis of: Exelby,G & Vittone,V.  DNA Mutations in POTS and Long COVID. 2023 (redacted), with translational assistance from Dr Valerio Vittone. Abstract Background: Dysautonomia, Postural Orthostatic Tachycardia Syndrome (POTS), ME/CFS, Long COVID, vaccine injury, and malignancy have traditionally been considered distinct conditions. However, accumulating evidence suggests they share molecular drivers. Methods:   We conducted SNP-

Christoper Thomas, Graham Exelby November 2025 A preview Abstract Background: Orthostatic intolerance in Postural Orthostatic Tachycardia Syndrome (POTS) and Long COVID has been framed primarily as an autonomic disorder, despite weak correlations between symptoms, heart rate, and autonomic testing.(Zhang, Zhou & Yu. Zhong Nan Da Xue Xue Bao Yi Xue Ban.2009)    Tilt-table testing does not assess venous return, ventricular filling, or thoracic inlet dynamics. We investigated w

Simplified from “Gastroparesis in POTS and Long COVID: A Unified Hydraulic–Neuroimmune Model” by Dr Graham Exelby November 2025 Abstract Gastroparesis—delayed gastric emptying in the absence of obstruction—is common among patients with Postural Orthostatic Tachycardia Syndrome (POTS) and Long COVID. Mounting evidence shows it to be a systemic, potentially reversible disorder driven by impaired venous return, lymphatic congestion, and neuro-immune-metabolic imbalance. In uprig

Dr Graham Exelby November 2025 Abstract Gastroparesis—delayed gastric emptying without mechanical obstruction—is increasingly observed in Postural Orthostatic Tachycardia Syndrome (POTS) and Long COVID, yet its mechanisms remain fragmented across vascular, metabolic, and neurogenic domains. We propose a unified hydraulic–neuroimmune model  integrating preload failure, lymphatic obstruction, microvascular hypoxia, and persistent viral neuroinflammation. Orthostatic preload fai

A Patient Guide to Understanding Mechanisms and Management Condensed and adapted from “ Reframing Postural Orthostatic Tachycardia Syndrome (POTS)-  as a Disorder of Preload Failure: Integrating Neurovascular and Immune Pathways ” by Dr Graham Exelby October 2025 What POTS Is and Why It Matters Postural Orthostatic Tachycardia Syndrome (POTS) is a condition of orthostatic intolerance—the body struggles to maintain blood flow to the brain when upright. Heart rate rises excessi

A Clinician Guide to Understanding Mechanisms and Management Condensed and adapted from “ Reframing Postural Orthostatic Tachycardia Syndrome (POTS)-  as a Disorder of Preload Failure: Integrating Neurovascular and Immune Pathways ” by Dr Graham Exelby November 2025 Abstract Postural Orthostatic Tachycardia Syndrome (POTS) is a disorder of orthostatic intolerance marked by excessive heart-rate increase upon standing, fatigue, cognitive fog, and visceral dysregulation. Emergin

Integrating Immune–Metabolic and Neurovascular Mechanisms in Long COVID and POTS: A Synthesis of Emerging Evidence and Clinical Observations. Dr Graham Exelby November 2025, with translational directions from Dr Valerio Vittone. Preface / Source Note This paper synthesises findings from a wide body of peer-reviewed research, including recent work in Nature , Science , PNAS , JCI , Frontiers , and related journals. It integrates published evidence on hypoxia signalling, STAT3

Dr Graham Exelby, September 2025 Extracted from “EBV Reactivation in Long COVID: A Mechanistic Synthesis,” September 2025...

Dr Graham Exelby October 2025. Simplified and condensed from: “Genomic Redundancy as a Driver of Chronicity in POTS and Long COVID” Introduction Conditions like Postural Orthostatic Tachycardia Syndrome (POTS), Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), and Long COVID affect many people with symptoms such as dizziness, fatigue, brain fog, palpitations, and post-exertional malaise (PEM, where even mild activity leads to a crash in energy). These conditions ca

Dr Graham Exelby September 2025. This is a personal opinion and may differ from that of your medical advisers. Introduction Many centres...

Authors: Dr Graham Exelby, Ms Michelle Hille, certified Vodder Therapist.  September 2025 Executive Summary Sensitization explains why...

Simplified Overview condensed from Exelby & Hill, 2025,  “ Upright Head Pressure in Long COVID- from Acute Neurovascular Injury to...

Dr Graham Exelby, September 2025 A simplified an condensed version of “ Malignancy in the Post-COVID Terrain: A Systems Biology...

Dr Graham Exelby September 2025 Background : I have been involved in a long term longitudinal study of this problem, initially comparing...