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 1 10/2/17 Epidemiology • 1-3% of ER visits • 1-3% of hospital admissions • 3-37% lifeKme 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% 2 10/2/17 Paent arrives aer LOC… • ALL paents get – Thorough history – Complete physical exam – EKG – +/- POC glucose 3 10/2/17 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 – CaroKd sinus syndrome/hypersensiKvity – Situaonal 4 10/2/17 5 10/2/17 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 – Outpaent cardiac rhythm monitoring 6 10/2/17 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 7 10/2/17 Cardiac Syncope Cardiac Syncope • 1 year mortality 18-33% • History • Mortality increases with severity of heart – CAD, HF, valvular disease, family history, disease exerKonal 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 8 10/2/17 Intraventricular ConducKon Delay • QRS duraon > 120 seconds – Lbbb, RBbb, LAFb, LPFb – LeX or right ventricular hypertrophy – Dilated cardiomyopathy – Hyperkalemia – Sodium-channel blocker toxicity – WPW – brugada – ARVD 9 10/2/17 10 10/2/17 11 10/2/17 12 10/2/17 Other TesKng for Cardiac Syncope Orthostac Hypotension • Echocardiogram – LV funcKon (EF), cardiac structure, valvular funcon • 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 13 10/2/17 Orthostac Hypotension Causes of Orthostac Hypotension • 20% of paents over the age of 75 • Hypovolemia – 54—68% insKtuKonalized 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, diureKcs, nitro/PDEI, psych • OXen exacerbated by prolonged standing, • Post-prandial exerKon, warm temperatures and meals – Especially large carbohydrate meal and alcohol Orthostac Vital Signs Autonomic Nervous System TesKng • Greater than 20 mm Hg decrease in systolic or • ObJecKve evidence of autonomic failure and predisposiKon to neurally mediated syncope 10 mm Hg diastolic pressure within three • ParasympatheKc 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% • SympatheKc Cholinergic FuncKon – Thermoregulatory sweat response, quanKtave for large volume loss) sudomotor axon reflex test • Neither bP or HR is sensiKve for moderate • SympatheKc Adrenergic FuncKon – blood pressure response to Valsalva and Klt table test volume loss with beat to beat blood pressure measurement 14 10/2/17 Treatment for Orthostac Hypotension • NS bolus • Increase PO water and salt intake • blood transfusion for acute blood loss • DisconKnue offending medicaon • Stand up slowly, avoid large meals, avoid excessive heat, waist high support hose • Midodrine 15 10/2/17 Other Syncope “Can’t Miss” Diagnoses 16 10/2/17 17 10/2/17 DifferenKal Diagnosis • Seizure • Neurologic • Hypoglycemia • Trauma • Intoxicaon • 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 18 10/2/17 DifferenKal 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 19 .