1. Syncope Joseph P. Ornato, MD, FACP, FACC, FACEP
Professor & Chairman, Department of Emergency Medicine

2. 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
Brignole M, Alboni P, Benditt D, et al. Guidelines on management (diagnosis and treatment) of syncope—Update Europace. 2004;6:
Underlying mechanism is transient global cerebral hypoperfusion.
Brignole M, et al. Europace, 2004;6:

3. Classification of Transient Loss of Consciousness (TLOC)
Real or Apparent 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)
Without loss of consciousness, i.e., psychogenic “pseudo-syncope”
Brignole M, Alboni P, Benditt D, et al. Guidelines on management (diagnosis and treatment) of syncope—Update Europace. 2004;6:
Brignole M, et al. Europace, 2004;6:

4. Unexplained Causes = Approximately 1/3
Causes of true syncope
Orthostatic
Cardiac
Arrhythmia
Structural
Cardio-
Pulmonary 1
Vasovagal syndrome
Carotid sinus syndrome
• Situational
Cough
Post-
Micturition 2
Drug-induced
• Autonomic nervous system failure
Primary
Secondary 3
Bradyarrhythmia
Sinus node dysfunction
AV block
•Tachyarrhythmia VT
SVT
Long QT syndrome 4
Acute myocardial ischemia
Aortic stenosis
Hypertrophic cardiomyopathy
Pulmonary hypertension
Aortic dissection
Neurally-
Mediated
Unexplained Causes = Approximately 1/3
This slide provides a simple classification of the principal causes of syncope, listed from the most commonly observed (left) to the least common (right). This ranking may be helpful in thinking about the strategy for evaluating syncope in individual patients.
Within the boxes, the most common causes of syncope are indicated for each of the major diagnostic groups.
The terms ‘neurally-mediated syncope’, ‘neurally-mediated reflex syncope,’ and ‘neurocardiogenic syncope’ are generally used synonymously. For purposes of this presentation, ‘neurally-mediated syncope’ is used to define a broad category; ‘neurocardiogenic’ or ‘vasovagal syncope’ refer to a specific condition.
VVS—Vasovagal Syncope
CSS—Carotid Sinus Syndrome
ANS—Autonomic Nervous System
HCM—Hypertrophic Cardiomyopathy
DG Benditt, MD. University of Minnesota Cardiac Arrhythmia Center

5. Syncope mimics Acute intoxication (e.g., alcohol) Seizures
Sleep disorders
Somatization disorder (psychogenic pseudo-syncope)
Trauma/concussion
Hypoglycemia
Hyperventilation
Brignole M, Alboni P, Benditt D, et al. Guidelines on management (diagnosis and treatment) of syncope—Update Europace. 2004;6:
Brignole M, et al. Europace, 2004;6:

6. Impact of syncope
40% will experience syncope at least once in a lifetime1
1-6% of hospital admissions2
1% of emergency department visits per year3,4
10% of falls by elderly are due to syncope5
Major morbidity reported in 6%1 (fractures, motor vehicle crashes)
Minor injury in 29%1 (lacerations, bruises)
1Kenny RA, Kapoor WN. Epidemiology and social costs. In: Benditt D, Blanc J-J, et al. eds. The Evaluation and Treatment of Syncope. Elmsford, NY: Futura;2003:23-27.
2Kapoor W. Evaluation and outcome of patients with syncope. Medicine. 1990;69:
3Brignole M, Disertori M, Menozzi C, et al. Management of syncope referred urgently to general hospitals with and without syncope units. Europace. 2003;5:
4 Blanc J-J, L’ Her C, Touiza A, et al. Prospective evaluation and outcome of patients admitted for syncope over a 1 year period. Eur Heart J. 2002;23:
5Campbell A, Reinken J, Allan B, et al. Falls in old age: A study of frequency and related clinical factors. Age and Ageing. 1981;10:
1Kenny RA, Kapoor WN. In: Benditt D, et al. eds. The Evaluation and Treatment of Syncope. Futura;2003:23-27.
2Kapoor W. Medicine. 1990;69:
3Brignole M, et al. Europace. 2003;5:
4 Blanc J-J, et al. Eur Heart J. 2002;23:
5Campbell A, et al. Age and Ageing. 1981;10:

7. Impact of syncope: costs
Estimated hospital costs exceeded $10 billion1
Estimated physician office expenses exceeded $470 million2
Over $7 billion is spent annually in the US to treat falls in older adults4
1Kenny RA, Kapoor WN. Epidemiology and social costs. In: Benditt D, Blanc J-J, et al. eds. The Evaluation and Treatment of Syncope. Elmsford, NY: Futura;2003:23-27.
2 Solucient Outpatient View: OutPatientView v Solucient LLC, Evanston IL.
3Farwell D and Sulke N. How do we diagnose syncope? J Cardiovasc Electrophysiol. 2002;13(Supp):S9-S13.
4Olshansky B. Syncope: Overview and approach to management. In: Grubb B and Olshansky B. eds. Syncope: Mechanisms and Management. Armonk, NY:Futura;1998:15-71.
1Kenny RA, Kapoor WN. In: Benditt D, et al. eds. The Evaluation and Treatment of Syncope. Futura;2003:23-27.
2OutPatientView v Solucient LLC, Evanston IL.
3Farwell D, et al. J Cardiovasc Electrophysiol. 2002;13(Supp):S9-S13.
4Olshansky B. In: Grubb B and Olshansky B. eds. Syncope: Mechanisms and Management. Futura. 1998:15-71.

8. Impact of syncope: Quality of life
73%1
71%2
60%2
Percent of Patients
37%2
Syncope results in substantial cost to patients and to society. For example, syncope patients live with lifestyle altering restrictions that affect daily activities, mobility, and employment.
Linzer M, Pontinen M, Gold DT, et al. Impairment of physical and psychological function in recurrent syncope. J Clin Epidemiol. 1991;44:
Linzer M, Gold DT, Pontinen M, et al. Recurrent syncope as a chronic disease: Preliminary validation of a disease-specific measure of functional impairment. J Gen Int Med ;9:
Anxiety/ Depression
Alter Daily Activities
Restricted Driving
Change Employment
1Linzer M. J Clin Epidemiol. 1991;44:1037.
2Linzer M. J Gen Int Med. 1994;9:181.

9. Syncope mortality Low mortality vs. high mortality
Neurally-mediated syncope vs. syncope with a cardiac cause
Soteriades ES, Evans JC, Larson MG, et al. Incidence and prognosis of syncope. N Engl J Med. 2002;347(12): [Framingham Study Population]

10. Diagnostic objectives
Distinguish true syncope from syncope mimics
Determine presence of heart disease
Establish the cause of syncope with sufficient certainty to:
Assess prognosis confidently
Initiate effective preventive treatment

11. Diagnostic plan Initial Examination Monitoring Cardiac Imaging
Detailed patient history
Physical exam
ECG
Supine and upright blood pressure
Monitoring
Holter
Event
Insertable loop recorder (ILR)
Cardiac Imaging
Special Investigations
Head-up tilt test
Hemodynamics (cardiac cath)
Electrophysiology study
Brignole M, Alboni P, Benditt D, et al. Guidelines on management (diagnosis and treatment) of syncope—Update Europace. 2004;6:
Brignole M, et al. Europace, 2004;6:

12. Detailed patient history
Circumstances of recent event
Eyewitness account of event
Symptoms at onset of event
Sequelae
Medications
Circumstances of prior events
Concomitant disease, especially cardiac
Pertinent family history
Cardiac disease
Sudden death
Metabolic disorders
Past medical history
Neurological history
Syncope
The history must include detailed summary of events leading up to and following syncope events. Additionally, it is important to ascertain whether there is any evidence of underlying structural heart disease. The direction of subsequent evaluation differs in patients with and without heart disease.
Brignole M, Alboni P, Benditt D, et al. Guidelines on management (diagnosis and treatment) of syncope—Update Europace. 2004;6:
Raviele A, Alboni P, Sutton D, Kenny RA. Initial evaluation of the syncope patient. In: Benditt D, Blanc J-J, Brignole M, Sutton R, eds. The Evaluation and Treatment of Syncope. Elmsford, NY: Futura. 2003:38-45.
Brignole M, et al. Europace, 2004;6:

13. Initial 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, hypertrophic cardiomyopathy
Neurological exam
Carotid sinus massage
Perform under clinically appropriate conditions preferably during head-up tilt test
Monitor both ECG and BP
HCM—Hypertrophic Cardiomyopathy
Brignole M, Alboni P, Benditt D, et al. Guidelines on management (diagnosis and treatment) of syncope—Update Europace. 2004;6:
Brignole M, et al. Europace, 2004;6:

14. Specific conditions Neurally-mediated Cardiac arrhythmia
Vasovagal Syncope (VVS)
Carotid Sinus Syndrome (CSS)
Cardiac arrhythmia
Tachy-brady syndrome
Long QT syndrome
Torsade de pointes
Brugada syndrome
Drug-induced
Structural cardio-pulmonary disease
Orthostatic

15. Neurally-mediated reflex syncope
Vasovagal syncope (VVS)
Carotid sinus syndrome (CSS)
Situational syncope
Post-micturition
Cough
Swallow
Defecation
Blood drawing, etc.
The neurally-mediated reflex causes of syncope are a group of related conditions in terms of symptomatic hypotension being caused by a variable combination of bradycardia and vasodilatation.
Vasovagal syncope and carotid sinus syndrome are the most frequent conditions in this group. The others occur occasionally and are usually recognized only if a detailed medical history is obtained.
Brignole M, Alboni P, Benditt D, et al. Guidelines on management (diagnosis and treatment) of syncope—Update Europace. 2004;6:

16. Vasovagal syncope Most common form of syncope
8% to 37% (mean 18%) of syncope cases
Depends on population sampled
Young without structural heart disase, ↑ incidence
Older with structural heart disease, ↓ incidence
The incidence of vasovagal syncope is poorly known.
The published data that exists mostly dates from before the advent of tilt table testing.
Linzer surveyed the literature and found published prevalences varying from 8% to 37% (mean 18%) of cases of syncope.
Standards for diagnosis and reporting are still emerging.
Linzer MD, Yang EH, Estes M, et al. Diagnosing syncope. Part 1: Value of history, physical examination, and electrocardiography. Ann Intern Med. 1997;126(12):

17. Tilt table test
60° - 80°
Useful as diagnostic adjunct to confirm vasovagal syncope
Useful in teaching patients to recognize prodromal symptoms
The rationale for undertaking tilt table testing in patients suspected of having vasovagal (VVS) syncope is summarized here. The test may provide useful diagnostic information and also an opportunity for patients to become more familiar with the condition and its possible warning signs.
Brignole M, Alboni P, Benditt D, et al. Guidelines on management (diagnosis and treatment) of syncope—Update Europace. 2004;6:
Brignole M, et al. Europace. 2004;6:

18. 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
Orthostatic hypotension is an important cause of syncope. The medical history is usually sufficient to establish the diagnosis. However, defining the specific cause requires careful consideration of a number of important conditions.
The most important conditions predisposing to orthostatic syncope are listed here.
Brignole M, Alboni P, Benditt D, et al. Guidelines on management (diagnosis and treatment) of syncope—Update Europace. 2004;6:

19. Hypersensitive carotid sinus syndrome
Syncope clearly associated with carotid sinus stimulation is rare (≤1% of syncope)
CSS may be an important cause of unexplained syncope/falls in older individuals
Carotid sinus syndrome (CSS) is an important and often overlooked cause of syncope, and in addition is believed to be a frequent cause of unexplained falls in older individuals. The underlying cause of CSS is considered to be a hypersensitive carotid sinus. Carotid Sinus Hypersensitivity (CSH) is diagnosed by using Carotid Sinus Massage (CSM). The method of carotid sinus massage, and the findings diagnostic of CSS were presented on previous slides.
Kenny RA, Richardson D, Steen N, et al. Carotid sinus syndrome: A modifiable risk factor for nonaccidental falls in older adults (SAFE PACE). J Am Coll Cardiol. 2001;38:
Brignole M, Alboni P, Benditt D, et al. Guidelines on management (diagnosis and treatment) of syncope—Update Europace. 2004;6:
Sutton R. Carotid sinus syndrome: clinical presentation, epidemiology, and natural history. In: Neurally Mediated Syncope: Pathophysiology, Investigation and Treatment. Blanc JJ, Benditt D, Sutton R. eds. Armonk, NY: Futura;1996:138.
Kenny RA, et al. J Am Coll Cardiol. 2001;38:
Brignole M, et al. Europace. 2004;6:
Sutton R. In: Neurally Mediated Syncope: Pathophysiology, Investigation and Treatment. Blanc JJ, et al. eds. Armonk, NY: Futura;1996:138.

20. Carotid sinus massage (CSM)
Method1
Massage, 5-10 seconds
Don’t occlude
Supine and upright posture (on tilt table)
Outcome
3 second asystole and/or mmHg fall in systolic BP with reproduction of symptoms = Carotid Sinus Syndrome
Absolute contraindications2
Carotid bruit, known significant carotid arterial disease, previous CVA, MI last 3 months
Complications
Primarily neurological
Less than 0.2%3
Usually transient
Carotid sinus massage (CSM) is an often overlooked, yet highly cost effective test, especially in older syncope patients. CSM must be applied with care, and the method described here1 has proven both safe and effective.
Note that an abnormal response to CSM (i.e., Carotid Sinus Hypersensitivity, CSH) is not diagnostic of Carotid Sinus Syndrome (CSS). Reproduction of symptoms is a crucial diagnostic element. To achieve symptom reproduction, it may be useful to conduct CSM with the patient in the upright posture. If the latter is to be done, the patient should be safely secured to a tilt table in order to prevent injury from a fall.
1Kenny RA, O’Shea D, Parry SW. The Newcastle protocols for head-up tilt table testing in the diagnosis of vasovagal syncope, carotid sinus hypersensitivity, and related disorders. Heart. 2000;83:
2Linzer M, Yang EH, Estes M, et al. Diagnosing Syncope: Part 1: Value of history, physical examination, and electrocardiography. Ann Intern Med. 1997;126(12):
3Munro N, McIntosh S, Lawson J, et al. Incidence of complications after carotid sinus massage in older patients with syncope. J Am Geriatr Soc. 1994;42:
Brignole M, Alboni P, Benditt D, et al. Guidelines on management (diagnosis and treatment) of syncope—Update Europace. 2004;6:
1Kenny RA. Heart. 2000;83:564. 2Linzer M. Ann Intern Med. 1997;126:989.
3Munro N, et al. J Am Geriatr Soc. 1994;42:

21. Other diagnostic tests
Ambulatory ECG
Holter monitoring
Insertable loop recorder (ILR)
Tilt table test
Includes drug provocation (NTG, isoproterenol)
Cardiac catheterization
Electrophysiology study (EPS)
NTG = nitroglycerin
Brignole M, Alboni P, Benditt D, et al. Guidelines on management (diagnosis and treatment) of syncope—Update Europace. 2004;6:
Brignole M, et al. Europace, 2004;6:

22. Heart monitoring options
ILR
Event Recorders (non-lead and loop)
Holter Monitor
12-Lead
1 day
7-30 days
Up to 14 Months
10 Seconds
OPTION
TIME (Months) 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Brignole M, Alboni P, Benditt D, et al. Guidelines on management (diagnosis and treatment) of syncope—Update Europace. 2004;6:
Brignole M, et al. Europace, 2004;6:

23. Diagnostic yield of various tests
Initial Evaluation
Yield (%)
History, Physical Exam, ECG, Cardiac Massage
38-40
Other Tests/Procedures
Head-Up Tilt 27
External Cardiac Monitoring
5-13
Insertable Loop Recorder (ILR)
EP Study
<2-5
Exercise Test
0.5
EEG
1Alboni P, Brignole M, Menozzi C, et al. Diagnostic value of history in patients with syncope with or without heart disease. J Am Coll Cardiol. 2001;37:
2Kapoor W. Evaluation and outcome of patients with syncope. Medicine. 1990;69:
3Krahn AD, Klein GJ, Yee R, et al. for the Reveal Investigators. Use of an extended monitoring strategy in patients with problematic syncope. Circulation. 1999;99;
4Krahn AD, Klein GJ, Yee R, et al. Randomized Assessment of Syncope Trial. Conventional diagnostic testing versus a prolonged monitoring strategy. Circulation. 2001;104:46-51.
5Krahn AD, Klein GJ, Yee R, et al. The high cost of syncope: Cost implications of a new insertable loop recorder in the investigation of recurrent syncope. Am Heart J. 1999;137:
6Brignole M, Alboni P, Benditt D, et al. Guidelines on management (diagnosis and treatment) of syncope—Update Europace. 2004;6:

24. Neurological tests EEG Head CT
Neurological studies (Head CT and MRI, EEG) are rarely useful in the diagnostic evaluation for syncope. Imaging may be justified if there is concern that syncope may have resulted in a head injury. Otherwise, without apparent abnormal neurological signs, such testing should be relegated to low priority.
Brignole M, Alboni P, Benditt D, et al. Guidelines on management (diagnosis and treatment) of syncope—Update Europace. 2004;6:
Brignole M, et al. Europace. 2004;6:

25. Cardiac syncope
Includes cardiac arrhythmias and structural heart disease
Often life-threatening
Suspect if syncope exercise-induced
May be warning of critical CV disease
Tachy and brady arrhythmias
Myocardial ischemia, aortic stenosis, pulmonary hypertension, aortic dissection
Assess culprit arrhythmia or structural abnormality aggressively
Initiate treatment promptly
Syncope occurring as a result of cardiac arrhythmias or in association with underlying structural heart disease requires careful and aggressive evaluation. Whereas syncope in patients with normal hearts is often relatively benign, syncope in the presence of cardiac disease is often indicative of a potentially life-threatening problem.
Brignole M, Alboni P, Benditt D, et al. Guidelines on management (diagnosis and treatment) of syncope—Update Europace. 2004;6:

26. Syncope due to cardiac arrhythmias
Bradyarrhythmias
Sinus arrest, exit block
High grade or acute complete AV block
Can be accompanied by vasodilatation (VVS, CSS)
Tachyarrhythmias
Atrial fibrillation/flutter with rapid ventricular rate (eg, pre-excitation syndrome)
Paroxysmal SVT or VT
Torsade de pointes
Both excessively slow as well as excessively rapid heart rates may result in sufficient drop in systemic pressure to cause syncope. In the case of tachycardias, the syncope tends to occur at the onset of the episode, before vascular constriction has an opportunity to occur. Syncope may also occur at termination of tachyarrhythmias, if a prolonged pause occurs prior to resumption of a stable rhythm.
Brignole M, Alboni P, Benditt D, et al. Guidelines on management (diagnosis and treatment) of syncope—Update Europace. 2004;6:

27. Factors contributing to sudden death likelihood
Cardiovascular pathology
Coronary artery disease
Severe left ventricular dysfunction
Cardiomyopathy
Hypertrophic cardiomyopathy
Arrhythmogenic right ventricular cardiomyopathy
Congenital heart disease, especially coronary artery anomalies
Valvular heart disease
Cardiac pacemaker and conducting system disease
Hereditary channelopathies (Sudden Arrhythmic Death Syndrome (SADS))
Brugada syndrome
Early repolarization syndrome (ERS)
Long QT syndrome (LQTS)
Short QT syndrome (SQTS)
Catecholaminergic polymorphic ventricular tachycardia (CPVT)

28. Importance to emergency physicians
Often present as recurrent syncope or brief seizures in children or young adults before sudden death occurs
May have young relatives who have had sudden death
ECG findings are often diagnostic
Effective preventive treatment is available (ICD)
Astute emergency physician may be the ONLY healthcare provider who can make the diagnosis and prevent tragic loss of a young life

29. Brugada syndrome Male predominance Autosomal dominant Common in Asians
40-60% prevalence of life-threatening ventricular arrhythmias and SCD
Presents as syncope
Downsloping ST-segment elevation in ECG leads V1–3

30. Early repolarization syndrome (ERS)
Type I – 43% ↑ in SCD
Male predominance
1-2% of adults
Normalizes with exercise
Type II – no ↑ in SCD

31. Long Q-T syndrome Hereditary Acquired causes
Autosomal recessive (Jervell Lange-Nielsen syndrome) with hereditary nerve deafness
Autosomal dominant (Romano Ward syndrome w/out deafness)
Syncope, VF, SCD
𝑄𝑇𝑐𝑜𝑟𝑟𝑒𝑐𝑡𝑒𝑑= 𝑄𝑇𝑚𝑒𝑎𝑠𝑢𝑟𝑒𝑑 𝑅 𝑅𝑖𝑛𝑡𝑒𝑟𝑣𝑎𝑙
Bazett Formula
QTc = at HR= 60
Acquired causes
Hypocalcemia
Hypokalemia
Hypomagnesemia
Ischemia
Anorexia
CNS pathology
QT-prolonging drugs (

32. Short Q-T syndrome Hereditary Acquired causes Autosomal dominant
Atrial fibrillation
Syncope, VF, SCD
Early repolarization inferolateral leads in 65%
Acquired causes
Hypercalcemia
Hyperkalemia
Acidosis
Systemic inflammatory syndrome
Myocardial ischemia
Increased vagal tone

33. Exercise-related syncope
Anomalous L coronary artery off the pulmonary artery
Hypertrophic cardiomyopathy
Severe aortic stenosis
Catecholaminergic polymorphic ventricular tachycardia
Hereditary defect in myocardial calcium handling
Stress-related syncope, VF, SCD
ECG – unexplained sinus bradycardia at rest
50% carry a diagnosis of epilepsy before correct diagnosis established

34. Conclusion Syncope is a common symptom with many causes
Deserves thorough investigation and appropriate treatment
Clinical decision (observation) unit at VCU is an appropriate location to initiate the evaluation
Brignole M, Alboni P, Benditt D, et al. Guidelines on management (diagnosis and treatment) of syncope—Update Europace. 2004;6: