Syncope Review Discuss an appropriate work up for syncope Review - - PDF document

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Syncope Review

Nathaniel Shekem, PA-C University of Iowa Department of Emergency Medicine

ObjecKves

• Define syncope
• Discuss three common causes of syncope
• Discuss an appropriate work up for syncope
• Review “can’t miss” presentaKons of syncope
• Discuss risk straKficaKon for explained and

unexplained syncope

• Review treatments of syncope

Syncope…it’s probably nothing...but if you send your paKent home they might die Syncope

• Abrupt complete loss of consciousness and

postural tone

• Due to transient global cerebral

hypoperfusion

• Transient with short duraKon and complete

spontaneous recovery

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Epidemiology

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

Three Causes of Syncope Cardiac

Reflex Mediated OrthostaKc Hypotension

Three Causes of Syncope

• Reflex mediated 20%
• Cardiac 10%
• OrthostaKc 10%
• Unknown 40%

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PaKent arrives aXer LOC…

• ALL paKents get

– Thorough history – Complete physical exam – EKG – +/- POC glucose

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Pathophysiology

Heart Rate Cardiac Output Blood pressure 10 seconds of complete disrupKon 35-50% reducKon cerebral perusion

Reflex Mediated Syncope

• Triggered by inappropriate cardiovascular

reflexes that that produce hypotension and/or bradycardia

• Young, healthy person that becomes

nauseous, sweaty, light-headed with tunnel vision and abdominal pain aXer prolonged standing exposed to pain, fear, anxiety

Vasovagal Syncope

• Prolonged standing 37%, hot weather 42%,

lack of food 23%, fear/anxiety 21%, pain 14%

Reflex Mediated Syncope

• Triggers

– Vasovagal – CaroKd sinus syndrome/hypersensiKvity – SituaKonal

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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 tesKng (Sns 26-80%, Spc 90%) for vasovagal – OutpaKent 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

• Structural cardiopulmonary disease

– Valvular, cardiomyopathy, congenital, pericardial, MI/ischemia, pericardial, PE, pulm htn, dissecKon

• Dysrhythmias

– Tachyarrhythmia, bradyarrhythmia, AV dysfuncKon, channelopathies

Cardiac Syncope

• Most likely to causes syncope

– Ventricular tachycardia – SVT with accessory pathway – Sinus bradycardia (less than 35 BPM) – Sinus pauses (greater than 3 seconds) – Heart block (second or third degree) – Atrial fibrillaKon with slow ventricular response

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Cardiac Syncope

• 1 year mortality 18-33%
• Mortality increases with severity of heart

disease

– CHF 1-2, OR 7.7 – CHF 3-4 13.5

• With dilated cardiomyopathy, 30% of

subsequent SCD from presumed arrythmogenesis

Cardiac Syncope

• History

– CAD, HF, valvular disease, family history, exerKonal syncope, supine/sikng syncope, risk factors for cardiovascular disease – CP, SOB, palpitaKons preceding syncope

• Exam

– HR, BP, palpitaKons, S3 gallop, JVD/edema, crackles, murmur

EKG in syncope

• Yield is about 5%, but non-invasive,

inexpensive and helps risk straKfy

• Without typical features of reflex or
• rthostaKc hypotension, an abnormal EKG

increases the odds raKo of cardiac arrhythmia OR 23.5

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Intraventricular ConducKon Delay

• QRS duraKon > 120 seconds

– LBBB, RBBB, LAFB, LPFB – LeX or right ventricular hypertrophy – Dilated cardiomyopathy – Hyperkalemia – Sodium-channel blocker toxicity – WPW – Brugada – ARVD

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Other TesKng for Cardiac Syncope

• Echocardiogram

– LV funcKon (EF), cardiac structure, valvular funcKon

• Exercise stress tesKng with EKG

– CP or SOB with syncope, exerKonal syncope

• Cardiac monitoring

– Telemetry, Holter, ELR, ILR

• Electrophysiological tests

– Unexplained syncope with prior MI, structural heart disease, impaired LV funcKon, SN/AV/bifasicular block – Elicit tachyarrhythmia and find accessory pathways

OrthostaKc Hypotension

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OrthostaKc Hypotension

• 20% of paKents over the age of 75

– 54—68% insKtuKonalized vs 6% community dwelling

• Occurs in response to sudden postural change

– Prodromal symptoms similar to reflex mediated symptoms

• OXen exacerbated by prolonged standing,

exerKon, warm temperatures and meals

Causes of OrthostaKc Hypotension

• Hypovolemia

– DehydraKon, blood loss

• Autonomic insufficiency

– Primary, secondary, prolonged immobilizaKon

• MedicaKons

– BB/AB, CCB, ACE/ARB, diureKcs, nitro/PDEI, psych

• Post-prandial

– Especially large carbohydrate meal and alcohol

OrthostaKc Vital Signs

• Greater than 20 mm Hg decrease in systolic or

10 mm Hg diastolic pressure within three minutes of standing

• Greater than 30 BPM increase in pulse within

3 minutes of standing (Sns 97% and Spc 98% for large volume loss)

• Neither BP or HR is sensiKve for moderate

volume loss

Autonomic Nervous System TesKng

• ObjecKve evidence of autonomic failure and

predisposiKon to neurally mediated syncope

• ParasympatheKc Nervous System

– Heart rate variability with deep inspiraKon and Valsalva

• SympatheKc Cholinergic FuncKon

– Thermoregulatory sweat response, quanKtaKve sudomotor axon reflex test

• SympatheKc Adrenergic FuncKon

– Blood pressure response to Valsalva and Klt table test with beat to beat blood pressure measurement

10/2/17 15 Treatment for OrthostaKc Hypotension

• NS bolus
• Increase PO water and salt intake
• Blood transfusion for acute blood loss
• DisconKnue offending medicaKon
• Stand up slowly, avoid large meals, avoid

excessive heat, waist high support hose

• Midodrine

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DifferenKal Diagnosis

• Seizure
• Neurologic
• Hypoglycemia
• Trauma
• IntoxicaKon
• Cataplexy
• Psychiatric

Syncope Versus Seizure

• Classic seizure

– Aura, loss of postural tone, tonic-clonic acKvity, inconKnence, and prolonged post-Kctal period

• 90% of syncopal episodes are are associated

with myoclonic jerks

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DifferenKal Diagnosis

• Seizure
• Neurologic
• Hypoglycemia
• Trauma
• IntoxicaKon
• Cataplexy
• Psychiatric

Explain It To Your PaKents

Heart Rate Cardiac Output Blood pressure 10 seconds of complete disrupKon 35-50% reducKon cerebral perusion

QuesKons?