Syncope

Joseph P. Ornato, MD, FACP, FACC, FACEP

Professor & Chairman, Department of Emergency Medicine

Syncope – A symptom, not a diagnosis

Self-limited loss of consciousness and postural tone

Relatively rapid onsetVariable warning symptomsSpontaneous, complete, and usually prompt

recovery without medical or surgical intervention

Underlying mechanism is transient global cerebral hypoperfusion.

Brignole M, et al. Europace, 2004;6:467-537.

Classification of Transient Loss of Consciousness (TLOC)

SyncopeNeurally-mediated reflex

syndromesOrthostatic hypotensionCardiac 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”

Real or Apparent TLOC

Brignole M, et al. Europace, 2004;6:467-537.

Causes of true syncope

OrthostaticCardiac

Arrhythmia

StructuralCardio-

Pulmonary

1• Vasovagal

syndrome• Carotid sinus

syndrome• Situational

CoughPost- Micturition

2• Drug-induced• Autonomic

nervous system failure

PrimarySecondary

3• Bradyarrhythmia

Sinus node dysfunction

AV block

•TachyarrhythmiaVTSVT

• Long QT syndrome

4 • Acute

myocardial ischemia

• Aortic stenosis• Hypertrophic

cardiomyopathy• Pulmonary

hypertension• Aortic dissection

Neurally-Mediated

Unexplained Causes = Approximately 1/3

Syncope mimics

Acute intoxication (e.g., alcohol)SeizuresSleep disordersSomatization disorder (psychogenic

pseudo-syncope)Trauma/concussionHypoglycemiaHyperventilation

Brignole M, et al. Europace, 2004;6:467-537.

Impact of syncope

1Kenny RA, Kapoor WN. In: Benditt D, et al. eds. The Evaluation and Treatment of Syncope. Futura;2003:23-27.2Kapoor W. Medicine. 1990;69:160-175.

3Brignole M, et al. Europace. 2003;5:293-298.4 Blanc J-J, et al. Eur Heart J. 2002;23:815-820.5Campbell A, et al. Age and Ageing. 1981;10:264-270.

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)

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. In: Benditt D, et al. eds. The Evaluation and Treatment of Syncope. Futura;2003:23-27.2OutPatientView v. 6.0. 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.

Impact of syncope: Quality of life

1Linzer M. J Clin Epidemiol. 1991;44:1037.2Linzer M. J Gen Int Med. 1994;9:181.

0

20

40

60

80

100

Anxiety/Depression

Alter DailyActivities

RestrictedDriving

ChangeEmployment

73%171%2

60%2

37%2

Per

cen

t o

f P

atie

nts

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):878-885. [Framingham Study Population]

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

Diagnostic plan

Initial ExaminationDetailed patient historyPhysical examECGSupine and upright

blood pressureMonitoring

HolterEventInsertable loop recorder (ILR)

Cardiac ImagingSpecial Investigations

Head-up tilt testHemodynamics (cardiac cath) Electrophysiology study Brignole M, et al. Europace, 2004;6:467-537.

Detailed patient history

Circumstances of recent eventEyewitness account of

eventSymptoms at onset of

eventSequelaeMedications

Circumstances of prior events

Brignole M, et al. Europace, 2004;6:467-537.

Concomitant disease, especially cardiac

Pertinent family historyCardiac diseaseSudden deathMetabolic disorders

Past medical historyNeurological historySyncope

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 BPBrignole M, et al. Europace, 2004;6:467-537.

Specific conditions

Neurally-mediatedVasovagal Syncope (VVS)

Carotid Sinus Syndrome (CSS)Cardiac arrhythmia

Tachy-brady syndrome

Long QT syndrome

Torsade de pointes

Brugada syndrome

Drug-inducedStructural cardio-pulmonary diseaseOrthostatic

Neurally-mediated reflex syncope

Vasovagal syncope (VVS)Carotid sinus syndrome (CSS)Situational syncope

Post-micturition

Cough

Swallow

Defecation

Blood drawing, etc.

Vasovagal syncope

Most common form of syncope8% to 37% (mean 18%) of syncope

casesDepends on population sampled

Young without structural heart disase, ↑ incidence

Older with structural heart disease, ↓ incidence

Tilt table test

Useful as diagnostic adjunct to confirm vasovagal syncope

Useful in teaching patients to recognize prodromal symptoms

Brignole M, et al. Europace. 2004;6:467-537.

60° - 80°

Orthostatic hypotension

EtiologyDrug-induced

(very common)DiureticsVasodilators

Primary autonomic failureMultiple system

atrophyParkinson’s

DiseasePostural

Orthostatic Tachycardia Syndrome (POTS)

Secondary autonomic failureDiabetes Alcohol Amyloid

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

Kenny RA, et al. J Am Coll Cardiol. 2001;38:1491-1496.Brignole M, et al. Europace. 2004;6:467-537.Sutton R. In: Neurally Mediated Syncope: Pathophysiology, Investigation and Treatment. Blanc JJ, et al. eds. Armonk, NY: Futura;1996:138.

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 50 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

1Kenny RA. Heart. 2000;83:564.2Linzer M. Ann Intern Med. 1997;126:989.3Munro N, et al. J Am Geriatr Soc. 1994;42:1248-1251.

Other diagnostic tests

Ambulatory ECGHolter monitoring

Insertable loop recorder (ILR)Tilt table test

Includes drug provocation (NTG, isoproterenol)

Cardiac catheterizationElectrophysiology study (EPS)

Brignole M, et al. Europace, 2004;6:467-537.

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)

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Brignole M, et al. Europace, 2004;6:467-537.

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) 43-883-5

EP Study <2-5

Exercise Test 0.5

EEG 0.3-0.5

Neurological tests

EEG

Head CT

Brignole M, et al. Europace. 2004;6:467-537.

Cardiac syncope

Includes cardiac arrhythmias and structural heart disease

Often life-threateningSuspect if syncope exercise-inducedMay 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 due to cardiac arrhythmias

BradyarrhythmiasSinus arrest, exit blockHigh grade or acute complete AV blockCan be accompanied by vasodilatation (VVS,

CSS)Tachyarrhythmias

Atrial fibrillation/flutter with rapid ventricular rate (eg, pre-excitation syndrome)

Paroxysmal SVT or VTTorsade de pointes

Factors contributing to sudden death likelihood

Cardiovascular pathologyCoronary artery disease Severe left ventricular dysfunction Cardiomyopathy

Hypertrophic cardiomyopathyArrhythmogenic right ventricular cardiomyopathy

Congenital heart disease, especially coronary artery anomaliesValvular heart diseaseCardiac pacemaker and conducting system disease Hereditary channelopathies (Sudden Arrhythmic Death Syndrome (SADS))Brugada syndromeEarly repolarization syndrome (ERS)Long QT syndrome (LQTS)Short QT syndrome (SQTS)Catecholaminergic polymorphic ventricular tachycardia (CPVT) 

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

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

Early repolarization syndrome (ERS)

Male predominance1-2% of adultsNormalizes with

exercise

Type I – 43% ↑ in SCD

Type II – no ↑ in SCD

Long Q-T syndrome

Bazett FormulaQTc = 0.35-0.44 at HR= 60

HereditaryAutosomal recessive (Jervell Lange-Nielsen syndrome) with hereditary nerve deafness

Autosomal dominant (Romano Ward syndrome w/out deafness)

Syncope, VF, SCDAcquired causes Hypocalcemia

Hypokalemia

Hypomagnesemia

Ischemia

Anorexia

CNS pathology

QT-prolonging drugs (www.azcert.org)

𝑄𝑇𝑐𝑜𝑟𝑟𝑒𝑐𝑡𝑒𝑑=𝑄𝑇𝑚𝑒𝑎𝑠𝑢𝑟𝑒𝑑  √𝑅𝑅𝑖𝑛𝑡𝑒𝑟𝑣𝑎𝑙

Short Q-T syndrome

HereditaryAutosomal dominantAtrial fibrillationSyncope, VF, SCDEarly repolarization inferolateral

leads in 65%

Acquired causesHypercalcemiaHyperkalemiaAcidosisSystemic inflammatory

syndromeMyocardial ischemiaIncreased vagal tone

Exercise-related syncope

Anomalous L coronary artery off the pulmonary artery

Hypertrophic cardiomyopathy Severe aortic stenosis Catecholaminergic polymorphic ventricular

tachycardiaHereditary 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

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