Mini-Meds 2009 Syncope Christopher Hillis Class of 2009 Michael G. DeGroote School of Medicine

Disclosures I am not an MD (just yet) I was told you like jokes and cases, so watch out. Financial contributions have been received from Ontario Taxpayers… and I am very grateful. This powerpoint is not fancy. VOLUNTEERS NEEDED!

Syncope – A Symptom, Not a Diagnosis Self-limited loss of consciousness and postural tone Relatively rapid onset Variable warning symptoms Spontaneous, complete, and usually prompt recovery without medical or surgical intervention Underlying mechanism is transient global cerebral hypoperfusion. Brignole M, et al. Europace, 2004;6:

Classification of Transient Loss of Consciousness (TLOC) Syncope Neurally-mediated reflex syndromes Orthostatic hypotension Cardiac arrhythmias Structural cardiovascular disease Disorders Mimicking Syncope With loss of consciousness, i.e., seizure disorders, concussion, stroke Without loss of consciousness, i.e., psychogenic “pseudo-syncope”; Brignole M, et al. Europace, 2004;6:

Cases Syncope or not? Scary or not?

Guy walks into a bar…

Mechanisms of Syncope global cerebral hypoperfusion interruption of sympathetic outflow increased vagal tone other mechanisms -edema, cerebral autoregulation, central serotonin pathways

CO = SV X HR BP = CO X PVR

The Common Faint the nucleus tractus solitarius of the brainstem is activated directly or indirectly by the triggering stimulus, resulting in simultaneous enhancement of parasympathetic nervous system (vagal) tone and withdrawal of sympathetic nervous system tone.This results in a spectrum of hemodynamic responsesnucleus tractus solitariusbrainstem parasympathetic nervous systemvagalsympathetic nervous system REST & DIGEST beats up FIGHT or FLIGHT

Parasympathetic cardioinhibitory response: drop in heart rate drop in blood pressure that is significant enough to result in a loss of consciousness

Sympathetic vasodepressor response drop in blood pressure without much change in heart rate

A Diagnostic Puzzle History Syncope? Cardiac? Which pattern? Physical Diagnostic Tests Reassess Repeat

Pepsi Challenge - NEJM 1999 A 72-year-old man with recurrent dizziness, confusion, and syncope reported that cold, carbonated beverages caused him to feel strange, dizzy, and confused and might have triggered several episodes over a one-year study period. A carotid Doppler study, 24- hour Holter monitor, cranial MRI scan, CT scan, and echocardiogram were unremarkable. An EEG showed diffuse slowing. Phenytoin was given but provided no improvement. Another internist evaluated the patient's condition and ordered a ETT and another MRI scan, which were negative. A cardiologist was consulted, and the results of a tilt-table test and coronary angiography were normal. After this evaluation, the patient drank a carbonated beverage while driving and wrecked his car. The patient was referred to me for further evaluation, and he gave the same history. Because the episodes were initiated reproducibly with cold, carbonated beverages, a can of Pepsi was given to the patient to drink while he was being monitored with an electrocardiograph. Abrupt bradycardia and hypotension developed, along with the patient's usual symptoms. Carotid-sinus massage was negative.

History Circumstances of recent event Eyewitness account of event Symptoms at onset of event Sequelae - what happened after? Medications Circumstances of more remote events Concomitant disease, especially cardiac Pertinent family history Cardiac disease Sudden death Metabolic disorders Past medical history Neurological history Syncope

History Prodrome Associated symptoms Activity prior to event Position of patient Witnesses Duration; rate of recovery Trauma?

“He went right funny” 70% experience a prodrome Pallor, diaphoresis Nausea or vomiting Faintness, dizziness Blurring/dimming vision, constriction of visual fields, paralysis of voluntary lateral gaze, EOM fixed Yawning, ringing in ears Parasthesias

Red Flags Chest pain Dyspnea Back pain Palpitations Focal CNS deficits ‘worst headache ever’

Stable? Proceed with exam: Vital signs Heart rate Orthostatic blood pressure change Cardiovascular exam: Is heart disease present? ECG: Long QT, pre-excitation, conduction system disease Echo: LV function, valve status, HCM Neurological exam Carotid sinus massage Perform under clinically appropriate conditions preferably during head-up tilt test Monitor both ECG and BP

Orthostatic Vitals Recumbent for 5 minutes prior Stand at least 2 minutes Significant changes include Systolic ↓ 20 mm Hg Diastolic ↓ 10 mm Hg Heart rate ↑ 30 bpm High false positive rate in elderly (drop but asymptomatic)

Other Diagnostic Tests Blood Work Ambulatory ECG Holter monitoring Event recorder Intermittent vs. Loop Head-Up Tilt (HUT) Electrophysiology Study (EPS) Brignole M, et al. Europace, 2004;6:

Neurological Tests: Rarely Diagnostic for Syncope EEG, Head CT, Head MRI May help diagnose seizure Brignole M, et al. Europace. 2004;6:

Head-Up Tilt Test (HUT) Protocols vary Useful as diagnostic adjunct in atypical syncope cases Useful in teaching patients to recognize prodromal symptoms Not useful in assessing treatment Brignole M, et al. Europace. 2004;6: ° - 80°

Treatment Scary? REFER!! Urgently or emergently Educate to avoid triggers / postures Removing offending agent Treat cardiac arrhythmia / valve lesion

Cases! Syncope? Pattern: Reflex Orthostatic Cardiac (arrhythmia) Cardiac (structural)

Case 1* Case 1 (#22): A 23 yo man with GERD and “blacking out” while swallowing * From Garcia-Civera R. Syncope Cases. Blackwell Futura. Malden, MA

Cases! Syncope? Pattern: Reflex Orthostatic Cardiac (arrhythmia) Cardiac (structural)

Giada F, Raviele A. Swallow syncope associated with asystole. In: Syncope Cases. Garcia-Civera R, Baron- Esquivias G, Blanc JJ, Brignole M, et al. (eds), Blackwell Futura, Malden, MA. (2006) p. 62. Case 1

Case 2* Case 2 (#42): A 20 yo man with lightheadedness and LOC shortly (5-10 sec) after standing. *From Garcia-Civera R. Syncope Cases. Blackwell Futura. Malden, MA

Cases! Syncope? Pattern: Reflex Orthostatic Cardiac (arrhythmia) Cardiac (structural)

van Dijk N, Harms MPM, Wieling W. Initial orthostatic hypotension as a cause of syncope in an adolescent. In: Syncope Cases. Garcia-Civera R, Baron-Esquivias G, Blanc JJ, Brignole M, et al. (eds), Blackwell Futura, Malden, MA. (2006) p. 118 Case 4

Orthostatic Hypotension Etiology Drug-induced (very common) Diuretics Vasodilators Primary autonomic failure Multiple system atrophy Parkinson’s Disease Postural Orthostatic Tachycardia Syndrome (POTS) Secondary autonomic failure Diabetes Alcohol Amyloid Brignole M, et al. Europace, 2004;6:

Treatment Strategies for Orthostatic Intolerance Patient education, injury avoidance Hydration Fluids, salt, diet Minimize caffeine/alcohol Sleeping with head of bed elevated Tilt training, leg crossing, arm pull Support hose Drug therapies Fludrocortisone, midodrine, erythropoietin Tachy-Pacing (probably not useful) Brignole M, et al. Europace, 2004;6:

Case 3* Case 3 (#86): a 48 yo smoker with discomfort and dizziness while driving, and falls to ground after exiting the car (who then drove to the hospital). *From Garcia-Civera R. Syncope Cases. Blackwell Futura. Malden, MA

Cases! Syncope? Pattern: Reflex Orthostatic Cardiac (arrhythmia) Cardiac (structural)

Sanchez Gonzalez A, Fournier Andray JA, Ballesteros Pradas SM, Diaz de la Llera LS, Villa Gil-Ortega M. Syncope as an isolated manifestation of left main coronary artery occlusion. In: Syncope Cases. Garcia-Civera R, Baron-Esquivias G, Blanc JJ, Brignole M, et al. (eds), Blackwell Futura, Malden, MA. (2006) p Case 8

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