Diurnal Blood Pressure Variation in Progressive Autonomic Failure

Abstract

Abstract-To investigate the role of the autonomic nervous system (ANS) in the generation of the circadian blood pressure (BP) variation, the degree of impairment of the ANS was related to the results of ambulatory BP recordings in 212 patients with progressive autonomic failure due to familial amyloid polyneuropathy. On the basis of BP and/or heart rate (HR) responses to the Valsalva maneuver, 60°head-up tilting, deep-breathing tests, and plasma norepinephrine levels, 4 groups of patients were distinguished. In all patients and in 38 age-matched control subjects, ambulatory BP was monitored. Patients of group I (nϭ40, aged 32Ϯ3 y), with no evidence yet of impairment of their ANS, had circadian BP and HR variations indistinguishable from controls. Patients of group II (nϭ41, aged 34Ϯ5 y) had a variable degree of impairment of their parasympathetic ANS, but their sympathetic ANS was still intact. Twenty-four-hour HR was higher in these patients than in controls (88Ϯ11 versus 78Ϯ7 bpm, PϽ0.01). Their circadian HR variation was maintained, but their circadian BP variation was diminished (10Ϯ6/11Ϯ4 versus 17Ϯ6/16Ϯ4 mm Hg in controls, PϽ0.01) because of an attenuation of the nocturnal BP decline. Patients of group III (nϭ69, aged 36Ϯ6 y), with parasympathetic failure and intermediate sympathetic dysfunction, had a blunted diurnal BP variation, whereas patients of group IV (nϭ62, aged 38Ϯ6 y), with parasympathetic failure and severe sympathetic dysfunction, had an absent diurnal BP variation. In patients of groups III and IV, a decrease in daytime BP accounted for the blunted circadian BP variation. This extensive study in progressive autonomic failure confirms the important role of the ANS in the generation of circadian BP variation. For the maintenance of a normal circadian BP pattern, not only an intact sympathetic but also an intact afferent parasympathetic ANS is a prerequisite. (Hypertension. 2000;35:892-897.)

Ultradian but not Circadian Blood Pressure Rhythms Correlate with Renal Dysfunction in Children with Chronic Renal Failure

“…In addition, patients with secondary hypertension (2), autonomic failure (3), and chronic renal failure (CRF) (4) are particularly prone to loss of circadian BP rhythmicity, which also relates to their cardiovascular prognosis (5). In patients with CRF, derangements of diurnal BP rhythmicity have been associated with the degree of renal dysfunction (6), the rate of progression of renal failure (7), and with changes in the autonomic nervous system (5,8).…”

Blood pressure overshoot after tilt reversal in patients with familial amyloidotic polyneuropathy

“…Carvalho et al 23 reported that in contrast to various other autonomic disorders, severe autonomic failure in FAP is not associated with nocturnal hypertension. However, BP overshoot reaction was present in these patients.…”

“…8,22 Not only an intact sympathetic but also an intact (afferent) parasympathetic nervous system appears to be necessary for the generation of a normal circadian BP pattern. 23 On the other hand, vagal function is an important component of the efferent arm of the baroreflex that regulates BP by changing the HR. Delahaye et al 5 disclosed that cardiac autonomic denervation in FAP results in an upregulation of myocardial muscarinic receptors without any change in cardiac b-receptor responsiveness to catecholamine.…”

Severe orthostatic hypotension with diabetic autonomic neuropathy successfully treated with a β1-blocker: a case report

“…An increased night-time BP is an important component of autonomic failure. 12 In conclusion, a once-daily low dose of atenolol at bedtime improved supine hypertension and BP variability, and may be an optional method to treat severe orthostatic hypotension due to diabetic autonomic neuropathy.…”