Syncope UCI Internal Medicine Core Curriculum - Mini Lecture Monica Sapo, PGY2 April 2017

Learning Objectives Definition of Syncope Basic Etiologies of Syncope Initial Evaluation Risk Stratification: High vs Low Risk Work-up & Additional Studies

What is Syncope? Abrupt, transient, complete loss of consciousness, associated with inability to maintain postural tone, caused by brief period of global cerebral hypoperfusion which is by definition spontaneously self-limited. There should not be clinical features of other non- syncopal causes of loss of consciousness

Non-syncopal Causes of Transient-LOC Seizures disorders Traumatic brain injury (i.e. concussion) Intoxications Metabolic disturbances (i.e. hypoglycemia) Conversion disorders (i.e. psychogenic, pseudosyncope) Key factor here is the underlying mechanism of syncope is presumed to be cerebral hypoperfusion, whereas nonsyncope conditions are attributed to different mechanisms.

Basic Etiologies of Syncope MOST DANGEROUS Neurally-Mediated (Vasovagal Reflex) Situational (micturition, defecation, cough) Prolonged standing Crowded, hot places During meal or post-prandial Pain/Noxious stimuli Fear Carotid Sinus Hypersensitivity Orthostatic Hypotension Dehydration Volume depletion/Blood loss Autonomic insufficiency Shy-Drager, Parkinsons, DM, adrenal insufficency Medication-induced Drug/Alcohol-induced Cardiovascular Structural HOCM Prolapsing atrial myxoma Severe aortic stenosis Arrhythmias VT or SVT, NSVT + short or long QT interval Bradycardias/Block/Pauses Bifasicular block Pacemaker/ICD malfunction Pulmonary HTN Pulmonary Embolus Acute aortic dissection Divided into 3 etiologies Neurally mediated (i.e. vasovagal) which is most common Orthostatic hypotension Cardiovascular, either arrhythmic or structural which is most dangerous MOST COMMON

Initial Evaluation Purpose: To determine who is at HIGH RISK for a dangerous short-term cardiac event. Initial Evaluation: Detailed History & Physical Examination Orthostatic Vitals 12-Lead ECG *Routine laboratory testing is not indicated

Features More Often Associated with Cardiac Causes of Syncope: HIGH RISK • Older age (>60 y) • Male sex • Presence of known ischemic heart disease, structural heart disease, previous arrhythmias, or reduced ventricular function • Brief prodrome, such as palpitations, or sudden loss of consciousness without prodrome • Syncope during exertion • Syncope in the supine position • Low number of syncope episodes (1 or 2) • Abnormal cardiac examination • Family history of inheritable conditions or premature sudden cardiac death (<50 y of age) • Presence of known congenital heart disease Table above mostly to be used as reference. Most importantly, high risk patients are those with hx of heart disease, abnormal exam or ECG, syncope with exertion or in supine position

High Risk Work-up & Additional Studies High risk patients are at high risk for for short term cardiac mortality and need appropriate cardiac work-up as an INPATIENT Transthoracic echocardiography (TTE) if structural heart disease is suspected Exercise stress testing in selected patients who experience syncope or presyncope during exertion EP study in selected patients with syncope suspected of arrhythmic etiology Head CT and/or Carotid US are not recommended in the absence of focal neurologic findings

Features More Often Associated with Noncardiac Causes of Syncope: LOW RISK • Younger age • No known cardiac disease • Syncope only in the standing position • Positional change from supine or sitting to standing • Presence of prodrome: nausea, vomiting, feeling warmth • Presence of specific triggers: dehydration, pain, distressful stimulus, medical environment • Situational triggers: cough, laugh, micturition, defecation, deglutition • Frequent recurrence and prolonged history of syncope with similar characteristics Features that are associated with orthostasis or vasovagal syncope: prodromal symptoms, situational triggers, prior diagnosis, etc.

Low Risk Work-Up Low risk patients are those that have no high risk characteristics or present with features highly suspicious of vasovagal or orthostatic etiology Typically do no require hospitalization No further work-up indicated (i.e. do not require imaging or ACS rule out) Tilt-table testing can be used if the diagnosis is unclear after initial evaluation for suspected vasovagal syncope, delayed orthostatic hypotension, or to distinguish convulsive syncope from epilepsy Vasovasal Syncope: Key point Reassurance and patient education on the diagnosis and prognosis Orthostatic Hypotension: Key point Fluid resuscitation, IV or PO, If necessary, medication adjustment, Consider referral for autonomic evaluation if known or suspected neurodegenerative disease

Case #1 71y/o M presents after he passed out while walking up the stairs. He felt slightly lightheaded just prior to the event. Wife saw him fall but was able to quickly arouse him. He had no incontinence or tongue biting. Similar event occurred 2 weeks prior while he was doing yard-work for which he did not seek medical care. He has a long history of DM, and hypertension for which he takes Glipizide, Amlodipine, Lisinopril, and HCTZ. He does not drink. Vitals, orthostatics, and blood sugar are unremarkable. ECG shows left axis deviation and LVH. Exam shows 1+ bilateral edema and 4/6 ejection murmur radiating to the carotids. What do we do next?

Case #1 Is this patient high or low risk? HIGH RISK given recurrent episodes of syncope and exam suspicious for aortic stenosis. What are the next steps in work-up? Inpatient cardiac monitoring Echocardiogram

Case #2 35 year old healthy male presents with an episode of syncope while standing. He did not experience any prodrome symptoms. This has never happened before. He has no medical history and uses no medications, drugs, or EtoH. Physical exam and ECG are normal. No orthostasis. Carotid massage is negative. Routine labs are unremarkable. What do we do next?

Case #2 Is this patient high or low risk? LOW RISK given age, syncope while standing, no heart disease and no other concerning features What are the next steps in work-up? No further work-up indicated

Case #3 28 year old male presents with an episode of syncope while working out at the gym. He did not experience any prodrome symptoms. This has never happened before. He has no medical history and uses no medications, drugs, or EtoH. Patient has 3/6 systolic murmur on exam was louder with Valsalva maneuver. ECG are normal. No orthostasis. Routine labs are unremarkable. What do we do next?

Case #3 Is this patient high or low risk? HIGH RISK given abnormal cardiac exam suspicious for hypertrophic cardiomyopathy and syncope during exertion What are the next steps in work-up? Inpatient cardiac monitoring Echocardiogram to evaluate for HOCM

Key Points Syncope is a transient and self-limited loss of consciousness due to global cerebral hypoperfusion Basic Etiologies include: Vasovagal / Neurally Mediated - MOST COMMON Orthostatic Hypotension Cardiovascular - MOST DANGEROUS Initial Evaluation: H&P/Orthostatics/ECG  followed by risk stratification High Risk: Admit for further cardiac work-up Low Risk: Outpatient management

References Shen WK, Sheldon RS, Benditt DG, et al. 2017 ACC/AHA/HRS Guideline for the Evaluation and Management of Patients With Syncope: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines, and the Heart Rhythm Society. J Am Coll Cardiol 2017;Mar 9:[Epub ahead of print]. Uptodate: Syncope in adults: Clinical manifestations and diagnostic evaluation