Syncope

1. Syncope Ed Da Veiga, M.D. August 20, 2008

2. Learning Objectives Recognize the vast etiologies of syncope Understand the importance of uncovering underlying organic heart disease Learn diagnostic and management strategies for neurally mediated syncope

4. Case Presentation 38 year old male with hangover on flight for honeymoon to St. Lucia Stewardess asks for medical assistance as patient �felt funny� and then �passed out� What do you want to know?

5. Overview Syncope is a symptom, not a disease In all forms, consists of a sudden decrease or brief cessation of cerebral blood flow Accounts for 3.5% of ER visits and 1-6% of all hospital admissions per year

6. Definition Sudden and brief loss of consciousness associated with a loss of postural tone, from which recovery is spontaneous

7. Distinguishing Syncope Dizziness, presyncope, and vertigo No LOC or loss of postural tone �Drop attacks� Lead to falls without loss of consciousness Sometimes sign of vertebrobasilar TIA (15%) Features to distinguish syncope from seizure Prodromal/ Premonitory symptoms Precipitating event Events that follow it

8. Precipitants/Prodromal Symptoms LOC precipitated by pain, exercise, micturition, defecation, or stressful event usually syncope Sweating, nausea = syncope Aura = Seizure Disorientation/ LOC > 5 minutes usually seizure rather than syncope

10. Important information WITNESSES? Initial Assessment (especially HISTORY) will often lead to a clear diagnosis and help efficiently direct further workup and/ or treatment H and P leads to identification of cause in 45% of patients

11. Differential Diagnoses Neurally Mediated Syncope (24%) Vasovagal Situational Carotid Sinus Orthostatic Hypotension (10%) Psychiatric Disorders (2%) Neurologic Dz (10%) Cardiac Syncope Organic Heart Disease (4%) Arrhythmias (14%) UNKNOWN (34%) 50-66% may be neurally mediated based on tilt-table studies

13. Structural Heart Disease Presence of a structural heart disease (CAD, CHF, Valvular Heart Disease, CHD) is the most important risk factor for predicting the risk of death Have ? risk of death at one year Most arrhythmias are found in these patients

15. Risk Factors Predictors of arrhythmic syncope or cardiac death at one year CHF Ventricular tachyarrhythmias Abnormal ECG Age >45 years Presence of 2 or more of these is associated with >10% incidence of syncope or cardiac death

16. Cardiac Differential Cardiac Syncope: LOC often w/o prodrome Indicates Outflow Obstruction AS, HOCM, PAH, Pulmonic Stenosis, PE MI, USA, Coronary Artery Spasm, Aortic Dissection Arrhythmias Prolonged QT (either Congenital or Drug Induced) AV Block, Sinus Node Dysfunction Ventricular tachycardia Arrhythmogenic right ventricular dysplasia Supraventricular tachycardia (Wolff-Parkinson-White)

17. Neurally Mediated Syncope Most Common Causes Vasovagal, Situational, and Carotid Sinus Syncope Results from sudden reflex mediated hypotension/ and or bradycardia Triggered by various stretch/ mechanoreceptors (carotid sinus, bladder, esophagus, respiratory tract

19. Neurally Mediated Syncope Pathophysiology Peripheral Venous Pooling h causes sudden i in peripheral venous return Leads to cardiac �hypercontractile� state which activates stretch receptors Neural traffic h to brain mimics severe hypertension and provokes paradoxical bradycardia and i in PVR

20. TIMBER!!!

21. Orthostatic Hypotension Decline of >20mm Hg in SBP/ 10mm Hg in DBP from supine to standing Supine HTN common in these patients Elderly especially vulnerable ? Baroreceptor sensitivity, ? Cerebral Blood Flow, ? renal sodium wasting, ?thirst response with aging Peripheral sympathetic tone impairment Diabetic neuropathy, antihypertensive medication

22. Neurologic Causes Syncope rare manifestation of cerebrovascular disease Subclavian steal syndrome, Basilar Artery Migraine (syncope and HA) Vertebrobasilar insufficiency �Drop Attacks�

23. Diagnostic Evaluation H and P! � 45% of time can identify cause CBC, BMP ECG- Low yield but can be important clues to look for underlying heart disease CT Head, EEG: low yield Echocardiogram/ Stress Test: Helpful when presence of underlying cardiac disease cannot be determined clinically

24. History Time of day Activities preceding (recurrent/at rest, exercise associated, on standing) Prodromes, associated symptoms Duration of LOC Injuries Medications, ingestions Cardiac History

26. Family History Sudden unexplained death Deafness Arrhythmias Congenital heart disease Seizures Metabolic disorders Myocardial infarction at young age

27. Physical Exam Pulse, blood pressure � taken supine and standing after 3 minutes Murmurs, clicks of outflow tract obstruction Neurologic examination Carotid Massage (if no bruit)

28. Arrhythmia Testing Telemetry Holter: 12-24 hours symptoms w/ arrhythmia (5%) v. symptoms without arrhythmia (17%) External Loop Recorders : can wear for weeks to months Implantable Loop Recorders: Monitor for 12-18 months Provided diagnosis in 55% of pts with unexplained syncope compared to conventional methods EP Studies: Helpful with structural heart disease

29. Tilt Table Test Used to evaluate autonomic nervous system Evaluates predisposition to neurally mediated syncope Specificity of negative test 90%

30. Indications for Tilt Table Testing Unexplained recurrent syncope Single episode associated with injury or in settings that pose a high risk of injury If organic heart disease is present, than after cardiac causes have been excluded Evaluation of recurrent syncope in setting of autonomic failure Assessment of recurrent, unexplained falls

31. Indications for Hospital Admission History of CAD, CHF, Ventricular Arrhthmia Accompanying Chest Pain Abnormal ECG Moderate to severe orthostatic hypotension Age > 70 yrs Resulting Trauma

32. Management

33. Management of Neurally Mediated Syncope

34. Patient Instructions Preventing Syncope or Vasovagal Spells Avoid EtOH, lack of sleep, warm environment Maintain adequate hydration and food intake Avoid drugs that lead to hypotension Avoid activities that precipitate syncope Preventing LOC or Injury Assume supine position upon onset of prodrome Avoid driving or other activities that could lead to injury

35. Bibliography Kapoor, WN Syncope. NEJM 2000; 343: 1856-62 Freeman, R Neurogenic Orthostatic Hypotension NEJM 2008; 358: 615-624 Soteriades, et al. Incidence and Diagnosis of Syncope. NEJM 2002; 347:878-885 Grubb, B. Neurocardiogenic Syncope. NEJM 2005; 1004-1010

36. Thanks!