Hyperadrenergic Postural Tachycardia Syndrome in Mast Cell Activation Disorders

• Published in: Hypertension (Dallas, Tex. 1979) Vol. 45; no. 3; pp. 385 - 390
• Main Authors: Shibao, Cyndya, Arzubiaga, Carmen, Roberts, L Jackson, Raj, Satish, Black, Bonnie, Harris, Paul, Biaggioni, Italo
• Format: Journal Article
• Language: English
• Published: United States American Heart Association, Inc 01-03-2005
• Subjects: Adrenergic beta-Antagonists - adverse effects; Adrenergic beta-Antagonists - therapeutic use; Adult; Autonomic Nervous System - physiopathology; Case-Control Studies; Female; Histamine H1 Antagonists - therapeutic use; Histamine H2 Antagonists - therapeutic use; Humans; Hypotension, Orthostatic - drug therapy; Hypotension, Orthostatic - physiopathology; Mast Cells; Methyldopa - therapeutic use; Sympatholytics - therapeutic use; Syndrome; Tachycardia - drug therapy; Tachycardia - physiopathology
• ISSN: 0194-911X; 1524-4563; 1524-4563
• DOI: 10.1161/01.HYP.0000158259.68614.40

Postural tachycardia syndrome (POTS) is a disabling condition that commonly affects otherwise normal young females. Because these patients can present with a flushing disorder, we hypothesized that mast cell activation (MCA) can contribute to its pathogenesis. Here we describe POTS patients with MCA (MCA+POTS), diagnosed by episodes of flushing and abnormal increases in urine methylhistamine, and compared them to POTS patients with episodic flushing but normal urine methylhistamine and to normal healthy age-matched female controls. MCA+POTS patients were characterized by episodes of flushing, shortness of breath, headache, lightheadedness, excessive diuresis, and gastrointestinal symptoms such as diarrhea, nausea, and vomiting. Triggering events include long-term standing, exercise, premenstrual cycle, meals, and sexual intercourse. In addition, patients were disabled by orthostatic intolerance and a characteristic hyperadrenergic response to posture, with orthostatic tachycardia (from 79±4 to 114±6 bpm), increased systolic blood pressure on standing (from 117±5 to 126±7 mm Hg versus no change in POTS controls), increased systolic blood pressure at the end of phase II of the Valsalva maneuver (157±12 versus 117±9 in normal controls and 119±7 mm Hg in POTS; P=0.048), and an exaggerated phase IV blood pressure overshoot (50±10 versus 17±3 mm Hg in normal controls; P<0.05). In conclusion, MCA should be considered in patients with POTS presenting with flushing. These patients often present with a typical hyperadrenergic response, but β-blockers should be used with great caution, if at all, and treatment directed against mast cell mediators may be required.