Evaluation and Management of Syncope

1
Evaluation and Management of Syncope
2
Syncope

• Definition
• Sudden transient loss of consciousness and
  postural tone with subsequent spontaneous
  recovery. ( Greek synkope, cessation, pause).
• Transient inadequate cerebral perfusion.

3
Syncope - Epidemiology

• 1 of hospital admissions
• 3 of ER visits
• 6 annual incidence in the elderly
• Upto 50 of young adults have history of isolated
  LOC
• Annual cost 2 B (2005)
• Clin
  Electrophysiol 221386,1999

Sun BC, Am J Cardiol 95668, 2005
4
Syncope - Prognosis

• Highest mortality in patients with cardiac cause
• Neurally mediated syncope/ medication induced
  syncope did not increase mortality
• Soteriades ES, et al N
  Eng J Med 347878, 2002

5
Causes of Syncope

• Vascular ( 58 62 ) Reflex mediated,
  orthostatic, anatomic
• Cardiac ( 10 23 ) Arrhythmias, anatomic
• Neurologic/cerebrovascular ( 0.5 5 )
• Metabolic/drugs ( 0 2 )
• Psychogenic ( 0.2 1.5 )
• Syncope of unknown origin ( 14 18 )

Sarasin FP, Am J Med 111 177, 2001 Alboni P,
JACC 37, 1921, 2001
6
Differential Diagnosis of Syncope
Obstruction to Flow Aortic Stenosis Hypertrophic Cardiomyopathy Atrial Myxoma Mitral Stenosis Pulmonic Stenosis Pulmonary Hypertension Pulmonary Embolism Cardiac Tamponade Aortic Dissection Bradyarrhythmias Sinus Node Dysfunction AV Block Pacemaker Malfunction Tachyarhythmias Ventricular Tachycardia Torsade de Pointes Supraventricular Tachycardia Other Causes of Syncope Vasovagal Syncope Carotid Sinus Hypersensitivity Drug-Induced Orthostatic Hypotension Cerbrovascular Disease Situational (e.g. cough/micturition syncope) Hypoglycemia Seizure Psychogenic
7
Syncope - Clinical Features Suggestive of
Specific Causes
Symptom or Finding Diagnostic Consideration
After sudden unexpected pain, unpleasant sight, sound or smell Vasovagal syncope
During/immediately after micturition, cough, swallow or defecation Situational syncope
On standing Orthostatic hypotension
Prolonged standing Vasovagal syncope
8
Syncope Clinical Features Suggestive of
Specific Causes (contd )
Symptom or Finding Diagnostic Consideration
Well-trained athlete after exertion Neurally mediated
Change in position ( from sitting to lying, bending, turning over in bed ) Atrial myxoma, thrombus
Syncope during exertion Aortic stenosis, pulmonary hypertension, pulmonary embolus, mitral stenosis, IHSS, CAD, neurally mediated syncope
9
Syncope Clinical Features Suggestive of
Specific Causes ( contd )
Symptom or Finding Diagnostic Consideration
With head rotation, pressure on cartoid sinus (as in tumors, shaving, tight collars) Cartoid sinus syncope
Associated with vertigo, dysarthria, diplopia, and other motor and sensory symptoms of brain stem ischemia Transient ischemic attack, subclavian steal, basilar artery migraine
With arm exercise Subclavian steal
Confusion after episode Seizure
10
Seizure vs Syncope

• Seizure
• Aura, frothing at the mouth
• Horizontal eye deviation, tongue biting
• Elevated BP, sinus tach
• Sustained tonic clonic movements,
  incontinence
• Disorientation, slow recovery

11
Syncope Diagnostic Tests

• History and physical examination cardiac
  disease, family h/o SCD, medications, witness
• Orthostatic BP check
• ECG Q waves, QTc, delta wave, epsilon wave
• Holter monitor V pause gt 3 sec while awake,
  Mobitz type 2 or CHB, VT.
• Arrhythmia event monitor
• Echocardiogram
• Tilt table test
• Electophysiologic testing

12
Diagnostic Tests for Syncope
Test Indication Disadvantage
Holter Monitor Frequent symptoms of palpitations or dizziness Low yield if symptoms are intermittent
Continuous-Loop Recorder Intermittent or very transient symptoms patient has little warning before symptoms occur Inconvenient to use for long periods of time
Implantable Loop Recorder Infrequent episodes of syncope diagnosis cannot be made noninvasively Requires invasive procedure
Signal-Averaged ECG Syncope and structural heart disease Low positive predictive value
13
Diagnostic Tests for Syncope (contd)
Test Indication Disadvantage
Upright Tilt Testing Suspected vasovagal syncope syncope without structural heart disease Inadequate reproducibility
Electrophysiologic Study Syncope when diagnosis cannot be made non-invasively syncope with structural heart disease Invasive low yield when no structural heart disease
14
Syncope Indications For Hospitalization

• Presence of heart disease, dyspnea, CHF, VT,
  acute coronary syndrome
• ECG suggestive of arrhythmic syncope in WPW,
  long QTc, Sick Sinus Syndrome, AV block, VT,
  Brugada syndrome, RV dysplasia
• Syncope with severe injury
• Syncope during exercise
• Family h/o sudden cardiac death

15
Sinus Arrest on Holter Monitor
ACCSAP 2005
16
Syncope Loop Event Recorder
ACCSAP 6, 2005
17
Implantable Loop Recorder
18
Implanted Loop Event Recorder
19
Head Up Tilt Table Testing
20
(No Transcript)
21
Tilt Table Testing When to do it?

• For diagnosis
• Suspected reflex, atypical presentation
• Unexplained syncope at the end of work-up,
  orthostatic trigger present
• Suspected delayed orthostatic hypotension

22
Neurally Mediated Syncope

• Also known as vasovagal syncope.
• Recurrent syncope in the absence of structural
  heart disease is most likely neurally mediated.
• Head-upright tilt test maximizes venous pooling,
  sympathetic activation and circulating
  catecholamines.
• Most vasovagal episodes involve both
  cardioinhibition (drop in heart rate) and
  vasodepressor response (drop in BP).

23
Case 1

• A 20 year old female presents with recurrent
  near syncope and syncope preceded by nausea,
  sweating and gradual tunnel visionusually after
  prolonged standing. The ECG and 2-D
  echocardiogram are normal. What would be the next
  step?
• Answer Tilt table test.
• Q What is the mechanism for the visual
  symptoms?
• Answer Collapse of peripheral vessels of the
  retina.

24
SyncopeThe Role of Electrophysiologic Testing

• Most important diagnostic tool is the history
• High risk historical elements
• Syncope resulting in injury
• Syncope resulting in motor vehicle accident
• Syncope in the setting of structural heart
  disease
• Syncope preceded by palpitations
• Syncope while supine
• Abnormal ECG
• Lack of low risk elements

25
Guidelines for EP Testing in Syncope

• Class I General agreement
• Patients with structural heart disease
  and unexplained syncope
• Class II Less certain, but accepted
• Patients with recurrent unexplained
  syncope without structural heart disease and a
  negative tilt test
• Class III Not indicated
• Patients with known cause of syncope
  in whom treatment will not be guided by EP testing

26
Electrophysiologic Testing in Syncope

• Sinus node function prolonged sinus node
  recovery time
• Abnormal AV conduction ?HV interval, infra His
  block
• Inducibility of sustained VT
• Inducibility of rapid SVT with symptoms,
  hypotension

27
Neurally Mediated Syncope

• Precipitating factors prolonged standing,
  dehydration, alcohol, diuretics, vasodilators.
• Sit/lie down at onset of symptoms, cross the legs
  and tense them together if sitting.
• Salt supplementation and fluids.
• Isometric arm, leg counterpressure.
• Moderate aerobic and isometric exercise.
• Tilt training.

28
Therapy of Neurocardiogenic Syncope
Treatment Mechanism
Volume expansion (increase salt and fluid intake, fludrocortisone) Maintain ventricular volume
Beta-Blockers Block response to adrenergic stimulation reduce ventricular contractility prevent activation of ventricular mechanoreceptors
Anticholinergic agents (scopolamine, disopyramide) Block vagal response reduce ventricular contractility (disopyramide)
Serotonin reuptake inhibitors Prevent vasodilation and bradycardia possibly by downregulation of response to serotonin
Methylxanthines Adenosine receptor antagonist Phophodiesterase and Ca transport inhibitor (maintain vascular tone)
Midodrine Adrenergic agonist
Cardiac pacing Maintain heart rate, AV synchrony
29
Pharmacologic Therapy of Neurally Mediated Syncope

• Despite the widespread use of drug therapy, none
  of these pharmacologic agents have been
  demonstrated to be effective in large prospective
  randomized clinical trials.
• A small study has reported the efficacy of
  midodrine.
• Metoprolol, propranolol and nadolol are no more
  effective than placebo.

30
Orthostatic Intolerance Syndrome
Delayed Orthostatic Intolerance
Vasovagal Syncope

Counterpressure Maneuvers
Elastic Stockings
JACC 2006 481652
JACC 2006 481425
31
Syncope - Prognosis

• Highest mortality in patients with cardiac cause
• Neurally mediated syncope/ medication induced
  syncope did not increase mortality
• Soteriades ES, et al N
  Eng J Med 347878, 2002

32
Suggested Strategies for Syncope Management
33
SyncopeMay be a harbinger of sudden cardiac
death

• Evaluation purpose is to determine if pt is at
  increased risk for death
• Identify pts with underlying heart disease
  (ischemic CM, non-ischemic CM, HCM), myocardial
  ischemia, WPW, genetic diseases (long-QT
  syndrome, Brugada Syndrome), catecholaminergic
  polymorphic VT

34
Case 2

• 65 year old male with h/o inferior wall
  myocardial infarction 1 year ago presents with
  rapid palpitation and syncope. An ECG shows SR
  and old inferior wall myocardial infarction. A 2D
  echo shows LVEF 40 with inferoapical
  dyskinesis. Coronary angiography reveals totally
  occluded right coronary artery with collaterals.
  What is the next step?
• Answer Electrophysiologic study (to look for
  inducible sustained VT)

35
Case 3

• 72 year old male with chronic atrial
  fibrillation of greater than 10 years duration
  is admitted following a syncopal episode. A 2D
  echo shows markedly dilated left atrium and LVEF
  60. Telemetry reveals atrial fibrillation with
  slow ventricular response and pauses of 5 to 7
  seconds associated with near syncope.
• How would you proceed?
• Answer Implant single chamber rate
  responsive pacemaker

36
Diagnostic Evaluation of Syncope
Syncope
Hx, physical exam, supine and upright BP, EKG
Unexplained syncope
Is there structural heart disease?
NO
YES
Electrophysiologic Study
Tilt table test