10/2/17

Objecves

• Define syncope • Discuss three common causes of syncope Syncope Review • Discuss an appropriate work up for syncope • Review “can’t miss” presentaons of syncope Nathaniel Shekem, PA-C • Discuss risk straficaon for explained and University of Iowa unexplained syncope Department of Emergency Medicine • Review treatments of syncope

Syncope…it’s probably Syncope nothing...but if you send your paent home they might die • Abrupt complete loss of consciousness and postural tone • Due to transient global cerebral hypoperfusion • Transient with short duraon and complete spontaneous recovery

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Epidemiology

• 1-3% of ER visits • 1-3% of hospital admissions • 3-37% lifeme prevalence • First peak 10-30 y/o • Second peak aer 65 y/o

Three Causes of Syncope Three Causes of Syncope

• Reflex mediated 20% Reflex Cardiac Orthostac • Cardiac 10% Mediated Hypotension • Orthostac 10% • Unknown 40%

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Paent arrives aer LOC…

• ALL paents get – Thorough history – Complete physical exam – EKG – +/- POC glucose

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Pathophysiology Reflex Mediated Syncope

Heart Rate • Triggered by inappropriate cardiovascular Cardiac Output reflexes that that produce hypotension and/or 10 seconds of complete bradycardia disrupon • Young, healthy person that becomes nauseous, sweaty, light-headed with tunnel vision and abdominal pain aer prolonged 35-50% reducon standing exposed to pain, fear, anxiety cerebral perusion

Blood pressure

Vasovagal Syncope Reflex Mediated Syncope

• Prolonged standing 37%, hot weather 42%, • Triggers lack of food 23%, fear/anxiety 21%, pain 14% – Vasovagal – Carod sinus syndrome/hypersensivity – Situaonal

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Reflex Mediated Syncope

• Diagnosis – Stop with typical history, benign exam, normal EKG, no heart disease or other red flags – Tilt table tesng (Sns 26-80%, Spc 90%) for vasovagal – Outpaent cardiac rhythm monitoring

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Reflex Mediated Syncope

• Treatment – Reassurance – Avoid triggers – Counterpressure maneuvers – Midodrine – Pacemaker • Severe recurrent cardioinhibitory reflex syncope

Cardiac Syncope Cardiac Syncope

• Structural cardiopulmonary disease • Most likely to causes syncope – Valvular, cardiomyopathy, congenital, pericardial, – Ventricular tachycardia MI/ischemia, pericardial, PE, pulm htn, dissecon – SVT with accessory pathway • Dysrhythmias – Sinus bradycardia (less than 35 BPM) – Tachyarrhythmia, bradyarrhythmia, AV – Sinus pauses (greater than 3 seconds) dysfuncon, channelopathies – Heart block (second or third degree) – Atrial fibrillaon with slow ventricular response

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Cardiac Syncope Cardiac Syncope

• 1 year mortality 18-33% • History • Mortality increases with severity of heart – CAD, HF, valvular disease, family history, disease exeronal syncope, supine/sing syncope, risk factors for cardiovascular disease – CHF 1-2, OR 7.7 – CP, SOB, palpitaons preceding syncope – CHF 3-4 13.5 • Exam • With dilated cardiomyopathy, 30% of subsequent SCD from presumed – HR, BP, palpitaons, S3 gallop, JVD/edema, crackles, murmur arrythmogenesis

EKG in syncope

• Yield is about 5%, but non-invasive, inexpensive and helps risk strafy • Without typical features of reflex or orthostac hypotension, an abnormal EKG increases the odds rao of cardiac arrhythmia OR 23.5

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Intraventricular Conducon Delay

• QRS duraon > 120 seconds – LBBB, RBBB, LAFB, LPFB – Le or right ventricular hypertrophy – Dilated cardiomyopathy – Hyperkalemia – Sodium-channel blocker toxicity – WPW – Brugada – ARVD

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Other Tesng for Cardiac Syncope Orthostac Hypotension

• Echocardiogram – LV funcon (EF), cardiac structure, valvular funcon • Exercise stress tesng with EKG – CP or SOB with syncope, exeronal syncope • Cardiac monitoring – Telemetry, Holter, ELR, ILR • Electrophysiological tests – Unexplained syncope with prior MI, structural heart disease, impaired LV funcon, SN/AV/bifasicular block – Elicit tachyarrhythmia and find accessory pathways

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Orthostac Hypotension Causes of Orthostac Hypotension

• 20% of paents over the age of 75 • Hypovolemia – 54—68% instuonalized vs 6% community – Dehydraon, blood loss dwelling • Autonomic insufficiency • Occurs in response to sudden postural change – Primary, secondary, prolonged immobilizaon – Prodromal symptoms similar to reflex mediated • Medicaons symptoms – BB/AB, CCB, ACE/ARB, diurecs, nitro/PDEI, psych • Oen exacerbated by prolonged standing, • Post-prandial exeron, warm temperatures and meals – Especially large carbohydrate meal and alcohol

Orthostac Vital Signs Autonomic Nervous System Tesng

• Greater than 20 mm Hg decrease in systolic or • Objecve evidence of autonomic failure and predisposion to neurally mediated syncope 10 mm Hg diastolic pressure within three • Parasympathec Nervous System minutes of standing – Heart rate variability with deep inspiraon and • Greater than 30 BPM increase in pulse within Valsalva 3 minutes of standing (Sns 97% and Spc 98% • Sympathec Cholinergic Funcon – Thermoregulatory sweat response, quantave for large volume loss) sudomotor axon reflex test • Neither BP or HR is sensive for moderate • Sympathec Adrenergic Funcon – Blood pressure response to Valsalva and lt table test volume loss with beat to beat blood pressure measurement

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Treatment for Orthostac Hypotension • NS bolus • Increase PO water and salt intake • Blood transfusion for acute blood loss • Disconnue offending medicaon • Stand up slowly, avoid large meals, avoid excessive heat, waist high support hose • Midodrine

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Other Syncope “Can’t Miss” Diagnoses

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Differenal Diagnosis

• Seizure • Neurologic • Hypoglycemia • Trauma • Intoxicaon • Cataplexy • Psychiatric

Syncope Versus Seizure

• Classic seizure – Aura, loss of postural tone, tonic-clonic acvity, inconnence, and prolonged post-ctal period • 90% of syncopal episodes are are associated with myoclonic jerks

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Differenal Diagnosis

• Seizure • Neurologic • Hypoglycemia • Trauma • Intoxicaon • Cataplexy • Psychiatric

Explain It To Your Paents Quesons?

Heart Rate Cardiac Output 10 seconds of complete disrupon

35-50% reducon cerebral perusion

Blood pressure

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