Syncope

1. Syncope Abdul Gofir Blok 18

2. Syncope (Greek – to interrupt) • Syncope is the sudden transient loss of consciousness and postural tone with spontaneous recovery. • Loss of consciousness occurs within 10 seconds of hypoperfusion of the reticular activating system in the mid brain.

3. Establishing Diagnosis of Syncope Presyncope & syncope: similar etiologies & workup Syncope: sudden transient loss of consciousness with loss of postural tone and spontaneous recovery Mechanism: transient hypoperfusion of brainstem or both cerebral hemispheres Differential diagnosis: coma narcolepsy seizure

4. Syncope: scope of the problem • Common • 3% Emergency Department visits • 1-6% hospital admissions • Costly • Multiple diagnostic tests often performed • Average charge for each diagnostic test ranges from $284 to $4678 Linzer, Ann Intern Med, 1997

5. Diagnostic Challenges • History often unclear • Prognosis varies widely • Common etiologies are benign • Potentially high mortality • Need to identify high-risk patient early • Many available tests • 40% of patients may elude diagnosis

6. Syncope: management questions Diagnostic challenges • What is the best diagnostic test? • How and when to rule out arrhythmia? • How to diagnose neurocardiogenic syncope? • How to decrease the # “idiopathic”? Management dilemmas • When to admit? • How are the elderly different? • When to resume driving?

7. Case Presentation • 50 yo healthy woman, standing at church • Becomes weak, lightheaded, & nauseated • Collapses, awakens after 1 minute • Feels well in ED - “I want to go home” • Normal exam, EKG, labs, CXR • Diagnosis? • Plan - Admit? Further testing? Glassman, Arch Intern Med, 1997

8. Etiology of Syncope Idiopathic 34% Neurally-mediated Vasovagal 18% Other (situational, carotid sinus) 6% Cardiac Arrhythmia 14% Mechanical 4% Neurologic 10% Orthostatic 8% Medications 3% Psychiatric 2% Linzer, Ann Intern Med, 1997

9. The Key to Diagnostic Evaluation • History and Exam establish diagnosis in 45% • History: setting, symptoms, medical hx, meds • Exam: HR, BP, cardiovascular, neurologic • EKG adds 5% diagnostic yield • Cheap, non-invasive, readily available • Can indicate important cardiac disease • Prior MI, ventricular hypertrophy, long QT • Bradycardia, conduction block • Abnormalities guide further testing

10. Diagnostic Algorithm Syncope Idiopathic Noncardiac Cardiac Neurocardiogenic Orthostatic Neurologic Psychiatric Arrhythmia Mechanical

11. Cardiac syncope: inadequate cardiac output, arrhythmia Cardiac enzymes - onlyif history or EKG suggestive of MI • 1-10% MI’s present with syncope • EKG up to 100% sensitive for MI Echo-rule out structural heart disease • before stress test if obstruction suspected • yield: 5-10% Exercise stress test - exertional syncope • identifies exertional arrhythmia • yield: low (1%) Georgeson, J Gen Intern Med, 1992 Linzer, Ann Intern Med, 1997

12. Arrhythmia evaluation - telemetry • Indication: suspected arrhythmia • palpitations, no prodrome • Idiopathic syncope or underlying heart disease • Routine telemetry low yield • 2240 non-ICU telemetry patients • 10% syncope/dizzy all syncope ICU transfer-arrhythmia 0.8% 0.4% Telemetry “Helpful” 12.6% 16% Mortality 0.9% 0 Linzer, Ann Intern Med, 1997 Estrada, Am J Cardiol, 1995 Glassman, Arch Intern Med, 1997. Estrada, Am J Cardiol, 1995

13. Arrhythmia evaluation: 24 hr ambulatory (Holter) monitoring 2612 syncope/dizzy patients • Symptomatic arrhythmia = positive result • Diagnostic arrhythmia in 4% • Symptoms without arrhythmia • Arrhythmia ruled out in 15% Bottom line • Benefit: monitors during usual activity • Limitation: brief duration limits yield unless daily symptoms Linzer, Ann Intern Med, 1997

14. Arrhythmia evaluation: improving the yield • Loop recorder • Indication: recurrent syncope with normal heart • frequent syncope -> continuous loop recorder (weeks) • infrequent syncope -> implantable loop recorder (years) • Electrophysiologic study • Indication: syncope with organic heart disease • Signal average EKG • Detectslate potential in QRS - substrate for VT/VF • indication: normal heart, idiopathic syncope? Linzer, Ann Intern Med, 1997 Zimetbaum , Ann Intern Med, 1999

15. Reflexive Vasodepressor Micturition Orthostatic intolerance Neurocardiogenic Syncope Vasovagal Carotid sinus syncope Neurally - mediated Cardioneurogenic

16. Neurocardiogenic SyncopeClinical Presentation May be predominantly • Cardioinhibitory • (bradycardia) • Vasodepressor • (hypotension) or • Both Trigger Syncope

17. Neurocardiogenic Syncope: Pathophysiology

18. Diagnosing neurocardiogenic syncope by history and exam • Precipitant • Vasovagal: pain, emotion, standing • Situational: vagal stimulus • Autonomic symptoms • Rapid recovery of mental status • Bradycardia, pallor may persist • Carotid sinus massage • >3 sec asystole or hypotension=hypersensitivity

19. Neurocardiogenic syncope: treatment Indicated for frequent syncope • Lifestyle modification • Add salt, avoid triggers • Handgrip, tense arms and legs • Medications • B blocker, SSRI, midodrine, fludrocortisone • Repeat tilt test on therapy? • Pacemaker

20. Is Laughter Really the Best Medicine? • “A 63-year-old man was referred with a 20-year history of syncope preceded by intense laughter. We were able to diagnose a gelastic syncope (from the Greek ‘gelos’, laughter). Laughter-related syncope may be induced by the Valsalva manoeuvre. • We advised him not to laugh so hard in the future, and when we saw him again, he had been able to follow this advice, and had suffered no further syncope.” Braga. Lancet 2005

21. Tilt table testing • Goal: provoke neurocardiogenic syncope • Indication: recurrent unexplained syncope without cardiac disease • Protocol: passive tilt 45-60 min • positive response reproduces symptom 60-80˚

22. Tilt table testing: why the controversy? • Accuracy difficult to define • Gold standard? • Protocol? • Reproducibility 71-87% • Positive tilt test with idiopathic syncope: • 49% with passive tilt • 66% with tilt plus isoproterenol • Tradeoff: decreased specificity Kapoor, Am J Med, 1994

23. Randomized double-blind trial DDD pacer vs. sensing-only pacer Vasovagal syncope: pacemakers ineffective % p = NS Connolly, JAMA 2003

24. “Idiopathic” syncope: improving diagnostic yield • Up to 40% patients • Prognosis good • Potential morbidity, lifestyle implications • Consider: Diagnosis Testing Neurocardiogenic Tilt table Anxiety/depression Psychiatric evaluation Arrhythmia EPS, implanted event monitor • Empiric pacemaker?

25. Prognosis:Framingham 25 year follow up *p<0.01 NEJM 2002;347:878

26. Prognosis: ED risk stratification • ED predictors of arrhythmia or mortality • Abnormal EKG • Prior VT/VF • History of CHF • Age > 45 Martin, Ann Emerg Med, 1997

27. Prediction rule to identify patients at risk of bad outcomes (need admit) over 30 days Death, MI, arrhythmia, PE, stroke, transfusion Syncope or related event requiring procedure, ED visit or admit First assess the patient for cause of syncope If cause unknown, apply the rule 98% sensitive 56% specific Quinn, Ann Emerg Med, 2006 Prognosis: Guideline for admission - the San Francisco Syncope Rule

28. CHF - history of Hematocrit <30% ECG abnormal Shortness of breath Systolic blood pressure <90 mm Hg at triage Quinn, Ann Emerg Med, 2006 Prognosis: Guideline for admission - the San Francisco Syncope Rule

29. Definitely admit HPI: chest pain PMH: CAD, CHF, ventricular arrhythmia Exam: CHF, valve dz, focal neurologic deficit EKG: ischemia/MI, arrhythmia, bundle branch block Often admit HPI: age >70, exertional syncope, frequent syncope Exam: tachycardia, orthostatic hypotension, injury Cardiac dz suspected Linzer, Ann Intern Med, 1997 ACP Guidelines for Hospital Admission

30. Guidelines for Hospital Admission:implications for practice • Myth: Every syncope patient should be admitted • Recommendation: Establish clear goals for admission, usually diagnostic • Myth: Every syncope patient requires “rule out MI” • Recommendation: Admission not necessary with careful history ruling out symptoms of ischemia and normal EKG • Myth: Telemetry improves outcomes • Recommendation: One-year mortality rarely affected by 24 hours of monitoring

31. Syncope in the elderly:the geriatric challenge • History often obscure • Syncope vs. dizziness vs. fall? • Often multifactorial - elderly at high risk for • Situational syncope • Polypharmacy, adverse drug events • Cardiac, neurovascular disease • Decreased physiologic reserve • Atypical presentation of disease • Abnormalities do not prove causation

32. Recommendations for Driving: following the law • Laws vary by state - available from DMV • California law requires reporting of any loss of consciousness • County health officer receives report • DMV determines fitness to drive • Physician can provide influential prognostic information to DMV • Physicians’ recommendations variable • Awareness of law often poor

33. American Heart Association Guidelines for Driving • VT/VF (treated with medical or ICD therapy) • Risk greatest 1st 6 mo, up to 10% at 1 year • Resume driving: 6 months arrhythmia free • Bradycardia with syncope • Resume driving: 1 week after pacemaker • Neurocardiogenic syncope -> risk stratify • Mild: presyncope, clear warning & precipitant • Resume driving: immediately • Severe: syncope, no warning or precipitant, frequent • Resume driving: after therapy, waiting period (duration?)

34. Thank for attention Reference from Lecture Karen E. Hauer, MD University of California, San Francisco