Walking Fails, Cycling Persists Delayed Upright Gait Dyscontrol, Recurrent Falls, and Suspected Cerebral Under- Perfusion in Multifactorial Secondary Autonomic Dysfunction
Abstract
Background: Delayed orthostatic intolerance may emerge only after sustained standing or walking and can be missed by brief office measurements. Delayed orthostatic hypotension (dOH) is a haemodynamic subtype in which a qualifying blood-pressure fall occurs beyond three minutes upright; delayed orthostatic intolerance is the broader symptom phenotype. In this paper, possible cerebral under-perfusion is inferred from systemic blood-pressure readings and contemporaneous head, visual, balance, and gait symptoms; cerebral blood flow was not measured [1-5].
Case: A 74-year-old man with a history of chikungunya infection presents with multifactorial secondary autonomic dysfunction. He has consulted with both cardiology and gastroenterology specialists. His medical history includes severe arrhythmia and an ablation procedure performed in 2021, which was complicated by cardiac tamponade, requiring emergency sternotomy and cardiopulmonary bypass. Following these events, he has experienced significant supine hypertension accompanied by major orthostatic falls. His reported usual pre-activity blood pressure was 165-195/85- 95 mmHg, with an immediate systolic reduction of approximately 30-50 mmHg on standing. In August 2026, sustained upright activity produced delayed head disequilibrium and unreliable step control while recumbent cycling remained substantially better tolerated. The pattern escalated to a fall after approximately 10 minutes of standing and walking on Pitt Street and four subsequent near-falls. On 19 August, BP/HR changed from 121/72 mmHg and 78 after three minutes standing without immediate symptoms to 107/53 and 85 after approximately 30 minutes of activity with head fog and reduced steadiness; standing pressure remained 103/56 after seated rest. On 23 August, BP/HR fell from 135/75 and 65 before a 50-minute brisk walk to a repeated standing value of 85/45 and 85 immediately afterwards, with head fog, impaired balance, and improvement during feet-elevated recumbent rest. On 24 August, symptoms began approximately 20 minutes into another 50-minute brisk walk. After returning home, BP/HR was 143/65 and 64 standing, 180/78 and 71 sitting, and 123/61 and 77 on re-standing—a 57/17 mmHg postural fall with only a 6-beat heart-rate increase.
Interpretation: The record suggests two orthostatic time scales: an immediate systolic fall from a markedly hypertensive starting range, followed by delayed head and gait symptoms as upright and exercise-related stresses accumulate. The 19 August series links delayed symptoms with a fall in systemic pressure; the 23 August event documents severe post-walk standing hypotension with recumbent recovery; and the 24 August event demonstrates marked post-exercise orthostatic susceptibility. Together, these observations support the descriptive formulation of delayed activity-provoked orthostatic intolerance with home-documented delayed symptomatic hypotension, compatible with dOH but not formally diagnostic of it. Preserved recumbent cycling supports a postural haemodynamic contribution but does not exclude arrhythmia, vestibular disease, or neurological and cerebrovascular causes [1-19]. Greater predictability of symptom onset may reflect improved warning or adaptation, but is not by itself evidence of recovered autonomic haemodynamic function.
Conclusion: A fall, four near-falls, and an apparent shortening of the upright threshold from approximately 20 minutes to approximately 10 minutes represent a clinically important escalation. Prompt fall-focused assessment and prolonged symptom-linked monitoring of beat-to-beat blood pressure, heart rate, and rhythm are warranted; cerebral-perfusion, neurological, or vestibular assessment should be added when clinically indicated.