Donders Institute for Brain, Cognition and Behaviour
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Thesis defense Joep Lagro (Donders Series 122)

September 11, 2013

Promotor: Prof. dr. M. Olde Rikert, copromotor: Dr. J. Claassen

Cardiovascular and cerebrovascular physiological measurements in clinical practice and prognostics in geriatric patients

Orthostatic hypotension, post prandial hypotension and carotid sinus hypersensitivity are hypotensive syndromes with high prevalence in the elderly. The exact pathophysiology of these hypotensive syndromes and their impact on mortality is not clear. We found no clustering of these three syndromes in geriatric patients visiting a falls-syncope outpatient clinic suggesting different underlying pathophysiological mechanisms for the different hypotensive syndromes. Also there was no difference in autonomic function indices in geriatric patients with and without these hypotensive syndromes which argues against autonomic dysfunction as a dominant factor in the pathophysiology of these hypotensive syndromes.

Post prandial hypotension and carotid sinus hypersensitivity did not predict mortality. Orthostatic hypotension, determined between 1 and 3 minutes after standing, did predict mortality but this relationship was no longer significant after adjusting for baseline characteristics. However, orthostatic hypotension with a severe diastolic blood pressure decrease of 20 mmHg or more remained a powerful independent predictor of mortality. We also looked at the influence on mortality of the initial blood pressure drop and recovery in the first minute directly after standing. Neither the absolute nor the relative initial blood pressure drop after standing predicted mortality. However, systolic blood pressure recovery of less than 80% from baseline after 60 seconds was a powerful independent predictor of mortality.

Alzheimer’s dementia is a frequent occurring progressive neurodegenerative disorder which might affect cardiovascular and cerebrovascular regulation capacity. We therefore studied the baroreflex, dynamic cerebral autoregulation and brain tissue oxygenation in Alzheimer dementia patients. We found that the baroreflex is reduced in Alzheimer dementia, but dynamic cerebral autoregulation is preserved in Alzheimer dementia patients. However, the brain tissue oxygenation in Alzheimer dementia patients is different from healthy age and sex matched controls.