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IT’S ENOUGH TO MAKE YOU FAINT POSTURAL ORTHOSTATIC TACHYCARDIA SYNDROME Evelyn Wiener, MD University of Pennsylvania 2

SH SEMESTER Fall 2008Freshman, completed four courses. Spring 2009Four courses. Completed none. Summer 2009Requested leave of absence. Fall 2009Requested return from leave. Fall 2010Requested return from leave, with accommodations. Spring 2011Three courses. Completed two. Fall 2011Four courses, completed all four. Spring 2012 Four courses, completed all four. 3

OBJECTIVES Explain physiologic response to changes in posture List proposed causes of postural orthostatic tachycardia syndrome (POTS) Describe clinical features of POTS Discuss management 4

WHY DON’T WE FALL OVER WHEN WE STAND UP?? 5

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Parasympathetic nervous system Sympathetic nervous system αβ Heart rate ↓↑ Contractility ↓↑ Arterial systemConstricts Venous systemConstrictsDilates 9

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BARORECEPTORS ARE THE KEY 11

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Lack of fuel – Decreased intravascular volume Mechanical failure – Decreased cardiac output Failure to respond appropriately – Neurogenic causes – Orthostatic failure/intolerance 13

NEUROGENIC SYNCOPE Inhibition of vascular sympathetic tone Neurogenic vasodepressor reactions – Vasodepressor (vasovagal) syncope – Neurocardiogenic syncope – Carotid sinus hypersensitivity – Severe pain 14

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NORMAL PHYSIOLOGY “VASOVAGAL” SYNCOPE POTS Venous return↓↓↓ Stroke volume↓↓↓ Pulse pressure↓↓↓ Sympathetic tone↑↑↑↑ Vagal tone↓↑ Heart rate ↑ (10 – 15 bpm) ↓ ↑↑↑ (>30 bpm) Systolic pressureStable↓↓↓ Diastolic pressure ↑ (~10 mm) ↓↓ 16

PATHOGENESIS ? 17

PROPOSED ETIOLOGIES Distal denervation Hypovolemia Changes in venous function Baroreflex abnormalities Increased sympathetic activity Genetic abnormalities Immune mediated 18

CLINICAL FEATURES CEREBRAL HYPOPERFUSION AUTONOMIC OVERACTIVITY DYSAUTONOMIA SUDOMOTOR SYMPTOMS GENERALIZED COMPLAINTS 19

Grading of Orthostatic Intolerance GRADE 0Normal orthostatic tolerance GRADE I Orthostatic symptoms infrequent or occur only under increased orthostatic stress Patient can stand > 15 minutes most occasions ADL typically unrestricted GRADE II Orthostatic symptoms frequent (weekly or more often) and commonly develop with orthostatic stress Patient can stand > 5 minutes on most occasions Typically some limitation in ADL GRADE III Orthostatic symptoms develop on most occasions and are regularly unmasked by orthostatic stresses Patient can stand > 1 minute on most occasions Patient is seriously incapacitated (bed- or wheelchair-bound) Syncope/presyncope common 20

Indications for head-up title-table testing 1. Unexplained recurrent syncope or single syncopal episode associated with injury (or significant risk of injury) in absence of organic heart disease 2. Unexplained recurrent syncopal episodes or single syncopal episode associated with injury (or significant risk of injury) in setting of organic heart disease after exclusion of potential cardiac cause of syncope 3. After identification of a cause of recurrent syncope in situations in which determination of an increased predisposition to neurocardiogenic syncope could alter treatment Conditions in which tilt-table testing may be useful 1. Differentiating conclusive syncope from epilepsy 2. Evaluation of recurrent near syncope or dizziness 3. Evaluation of syncope in autonomic failure syndromes 4. Exercise- or postexercise-induced syncope in absence of organic heart disease in whom exercise stress testing cannot reproduce an episode 5. Evaluation of recurrent unexplained falls Hurst's The Heart 21

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DIAGNOSTIC CRITERIA 1.Heart rate increase of > 30 beats/min within 10 minutes upright tilt or 2.Heart rate > 120 beats/min within 10 minutes upright tilt 3.Consistent symptoms of orthostatic intolerance 4.Absence of a known cause of autonomic neuropathy 5.Serum norepinephrine > 600 pg/mL (hyperadrenergic form) 23

DIFFERENTIAL DIAGNOSIS Conditions causing/exacerbating orthostatic intolerance Medications Autonomic orthostatic hypotension Inappropriate sinus tachycardia Chronic fatigue 24

NON-PHARMACOLOGIC MANAGEMENT Changing eating habits, diet Changing schedule Measures to lessen venous pooling Physical maneuvers, tilt training Avoid exacerbating activities/factors 25

PHARMACOLOGIC MANAGEMENT No medication currently approved by FDA: ALL MEDICATIONS ARE OFF-LABEL Increase intravascular volume Vasoconstrictors Block increased heart rate Treatment for autonomic disorder 26

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RESTRICTIONS? ACCOMMODATIONS? When/how to “protect” student at risk Living arrangements Snacks Excused absence Extra time Driving 28

ACKNOWLEDGEMENTS Dawn Marsh RN (Adrian College) Laura Champion, MD (Calvin College) Dina M. Oleksiak,MSN,CRNP (La Salle University) 29

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