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Autonomic Dysfunction Melloney Ferrar MSc, BSc, RGN Syncope and Cardiac Autonomic Nurse Specialist Sheffield Teaching HospitalsOr should I say……….. Orthostatic Intolerance SyndromesOrthostatic Intolerance Syndromes • Orthostatic/ Postural Hypotension • Reflex Syncope • Postural Tachycardia Syndrome • Inappropriate Sinus Tachycardia Definition: Orthostatic Hypotension • Orthostatic/postural hypotension • Excessive fall in BP occurring on postural change when orthostatic stress overwhelms autonomic defences • A decline of >20mmhg in systolic or >10mmHg in diastolic BP after 3 minutes standing • Compensatory heart rate increase • Initial orthostatic hypotension- a transient drop of systolic BP by 40mmHg /diastolic BP 20mmHg within 15 seconds of changing position from supine to upright Definition: Reflex Syncope • Other names – neurally mediated syncope/neurocardiogenic syncope • Types – vasovagal, situational syncope, carotid sinus syncope/hypersensitivity • Vasovagal - Body overreacts to certain triggers- eg venepuncture, extreme emotional stress, prolonged standing • Situational – cough, swallow, laugh • Carotid sinus- head turning, tight fitting collar, hypersensitive carotid baroreceptor reflexes • Nucleus tractus in the brainstem is activated by the trigger causing overstimulation of the parasympathetic nervous system and withdrawal of sympathetic nervous system • Cardio-inhibitor response- drop in HR, leading to decrease in BP (rare) • Vasodepressor response – drop in BP without much change in heart rate • Majority have a mixed response Definition: Postural Tachycardia Syndrome • Heart rate increases by 30 beats per minute or more, on standing, and is sustained, within 10 minutes in the absence of orthostatic hypotension • Symptom reproduction • Symptoms 3-6 months Definitions: Inappropriate Sinus Tachycardia • Sinus heart rate higher than 100bpm at rest, or a mean heart rate 90-95 bpm, associated with symptoms with no obvious cause Sheffield Syncope Service Reflex Syncope 31% Orthostatic Intolerance 31% Drug Induced OH 15 % Unknown 6% PoTS 5% Cardiac Syncope 4% Drugs/alcohol 3% NESD/functional 2% Cough syncope 1% Audio-vestibular 1% Sleep apnoea 1% The History • Ruling out /consideration of any other causes of symptoms of orthostatic intolerance • Ruling out cardiac /neurological cause of T-LoC The History • Syncope/presyncope/dizziness: • Consider medications e.g.Mirtazipine/Tamsulosin. • Adrenal insufficiency, • Parkinson’s/ MSA, • Diabetic neuropathy, • Vitamin B12 deficiency, • Anaemia, • Low BMI/eating disorders The History Increased heart rate on standing can be caused by many conditions and other causes always need to be excluded before a diagnosis is made. • Deconditioning • Adrenal insufficiency • Anaemia • Thyroid dysfunction • Medications eg Amytriptilline • Anxiety/ mental health issues • Low BMI/eating disorders Deconditioning • Inactivity and bed rest are unnatural states of the human body • Results in reduced functional capacity of multiple body systems • Causes numerous physiological adaptations in all organ systems often with negative consequences • Cardiovascular changes within 24 hrs of bed rest • Increase in heart rate • Decrease blood volume- 5% in 24 Hrs, 10% in 6 Days, • Decreased stroke volume, atrophy of myocardium, decreased max O2 consumption • Fluid shifts • Orthostatic hypotension • Increased risk of clot formation Symptoms • Transient Loss of Consciousness- T-LOC/presyncope • Prodrome- dizzy, lightheaded, sweaty, hot, visual/auditory disturbances, pale • Posture- prolonged standing/initial stand (prolonged sitting) • Provoking factors- pain/medical procedure/emotional stress • Length T-LoC short- seconds to minutes • Recovery – often left tried, drained afterwards • OH-chronic problem • Reflex syncope – episodic • NESD- frequent, prolonged episodes T-LOC with eye flickering, often occurs in all postures including lying Symptoms • Feeling faint/ dizziness/ light-headedness • Palpitations • Difficulty in breathing/ feeling out of breath • Chest discomfort • OH- dizzy/lightheaded/palpitations • PoTS / IST- lightheaded/palpitations/ SOB/chest pain + other signs of orthostatic stress Other Symptoms Autonomic dysfunction can cause problems with: • Sleep • Fatigue • Temperature regulation/sweating • Bowels • Bladder Associated conditions: • Joint hypermobility spectrum disorder/hEDS • Mast cell activation syndrome Tests Aim for objective evidence to support treatment and management • Tilt table test / active stand test • Holter monitoring • Echocardiogram • ECG • 24 hr blood pressure monitoring • Bloods tests – U&E, LFT, TFT, haematimics, vitamin D • Early morning cortisol • 24 hr urine tests Management • Fluids 2.5-3 litres clear fluid a day • Salt- at least a teaspoon a day • Aiming 6-10grams daily • Slow sodium tablets can be very corrosive to the gut always try dietary salt first • Test with 24 hr urine for urinary sodium (aim for >170mmol/L) Other Non Pharmalogical Treatments • Compression tights • Counter-maneouvres • Psychological support • Activity • Referral to other specialities Medications Postural tachycardia/symptomatic sinus tachycardia • Ivabradine – 2.5mg qds every 4 hrs • Propranolol 10-20mg tds Orthostatic hypotension • Fludrocortisone 50-200mcg od – regular U&E checks • Midodrine 2.5mg- 10mg every 3-4hrs x3-5 doses a day. Remember the timing is everything! Advise on preconception, pregnancy and breast feeding