title: Reversal of the relationship between heart rate and blood pressure in phaeochromocytoma: a non-invasive diagnostic approach?
abstract: A comparison was made between the relationship of heart rate and blood pressure over 24 hours in three patients with phaeochromocytoma and in 56 patients with untreated essential hypertension. All patients wore a non-invasive ambulatory monitor (Accutracker) for 24 hours. A diurnal rhythm of BP and pulse was seen in essential hypertension [daytime; BP 155 +/- 18/86 +/- 12 mmHg (mean +/- SD), pulse 79 +/- 13. Night-time; 142 +/- 21/73 +/- 14 mmHg, pulse 68 +/- 12, P less than 0.05] and a positive correlation was observed between BP and pulse (r = +0.53). Patients with phaeochromocytoma had no diurnal rhythm of BP and all three had a negative relationship between BP and pulse (r = -0.66, -0.51 and -0.79). This negative relationship was abolished by alpha blockade and became positive (+0.5 and +0.6) in two patients who were cured by surgery. The 'normalisation' of this relationship was associated with an increase in plasma volume of approximately 500 ml and probably reflects an intact baro-reflex system in phaeochromocytoma. The observation of a lack of diurnal rhythm together with a negative correlation between BP and pulse may be a clue to phaeochromocytoma in patients with raised blood pressure.
authors.affiliation: Department of Medicine, University of Edinburgh, Western General Hospital, Scotland, UK.
authors.forename: P L
authors.initials: PL
authors.lastname: Padfield
authors.forename: S G
authors.initials: SG
authors.lastname: Jyothinagaram
authors.forename: I M
authors.initials: IM
authors.lastname: McGinley
authors.forename: D M
authors.initials: DM
authors.lastname: Watson
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000175:diagnosis* / Q000503:physiopathology; D000328:Adult; D001794:Blood Pressure; D003937:Diagnosis, Differential; D005260:Female; D006339:Heart Rate; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000503:physiopathology; D008297:Male; D008991:Monitoring, Physiologic; D010673:Pheochromocytoma / Q000175:diagnosis* / Q000503:physiopathology