Syncope, or fainting, is caused by insufficient blood flow to the brain. It is usually brief and self-limited. Evaluation of syncope involves obtaining a detailed history, physical exam, ECG, and testing based on risk factors. Causes are categorized as benign if due to things like vasovagal response, or dangerous if due to cardiac arrhythmias. High-risk patients warrant further cardiac workup and monitoring, while low-risk patients can often be evaluated as outpatients.

1. APPROACH TO SYNCOPE
SUPERVISOR :DR HO YI BIN
PRESENTER : ALI HUSAIN
FIRDAUS

2. SYNCOPE
 Motionless and limp and usually has cool extremities, a
weak pulse, and shallow breathing. Sometimes brief
involuntary muscle jerks occur, resembling a seizure.

3. NEAR SYNCOPE
 Near-syncope is light-headedness and a sense of an
impending faint without LOC. It is usually classified and
discussed with syncope because the causes are the same

4. PATOPHYSIOLOGY
 Insufficient cerebral blood flow. Some cases involve adequate flow but with insufficient
cerebral substrate (oxygen, glucose, or both).
 Most deficiencies in cerebral blood flow result from decreased cardiac output (CO).
Decreased CO can be caused by
1. Cardiac disorders that obstruct outflow
2. Cardiac disorders of systolic dysfunction
3. Cardiac disorders of diastolic dysfunction
4. Arrhythmias (too fast or too slow)
5. Conditions that decrease venous return

5. Insufficient cerebral substrate
 The CNS requires oxygen and glucose to function.
 Hypoglycemia is the primary cause because hypoxia
rarely develops in a manner causing abrupt LOC (other
than in flying or diving incidents). LOC due to
hypoglycemia is seldom as abrupt as in syncope or
seizures because warning symptoms occur

6. ETIOLOGY
 The most common causes are
Vasovagal (neurocardiogenic)
Idiopathic

8. EVALUATION
 History
 Physical examinations
 Interpretation of findings
 Testing

9. History of present illness
 Patient’s activity (eg, exercising, arguing, in a potentially
emotional situation), position (eg, lying or standing), and,
if standing, for how long.
 Sense of impending LOC, nausea, sweating, blurred or
tunnel vision, tingling of lips or fingertips, chest pain, or
palpitations.

10.  Length of time recovering should also be ascertained.
Witnesses, if any, should be sought and asked to describe
events, particularly the presence and duration of any
seizure activity.
 Asked about symptoms suggesting possible causes,
including bloody or tarry stools, heavy menses (anemia);
vomiting, diarrhea, or excess urination (dehydration or
electrolyte abnormalities)

11. Past medical history

 Ask about previous syncopal events, known
cardiovascular disease, and known seizure disorders.
 Drugs used should be identified (particularly
antihypertensives, diuretics, vasodilators, and
antiarrhythmics
 Family history

12. PHYSICAL EXAMINATIONS
 Vital signs are essential. Heart rate and BP are measured
with the patient supine and after 3min of standing. Pulse
is palpated for irregularity.
 General examination notes patient’s mental status,
including any confusion or hesitancy suggesting a
postictal state and any signs of injury (eg, bruising,
swelling, tenderness, tongue bite).

13.  The heart is auscultated for murmurs; if present, any
change in the murmur with a Valsalva maneuver,
standing, or squatting is noted.
 Abdomen is palpated for tenderness, and a rectal
examination is done to check for gross or occult blood.
 A full neurologic examination is done to identify any focal
abnormalities, which suggest a CNS cause (eg, seizure
disorder)

14. BENIGN CAUSES
 Syncope precipitated by unpleasant physical or emotional
stimuli (eg, pain, fright), usually occurring in the upright
position and often preceded by vagally mediated warning
symptoms (eg, nausea, weakness, yawning,
apprehension, blurred vision, diaphoresis), suggests
vasovagal syncope.

15.  Syncope that occurs most often when assuming an
upright position (particularly in elderly patients after
prolonged bed rest or in patients taking drugs in certain
classes) suggests orthostatic syncope.
 Syncope that occurs after standing for long periods
without moving is usually due to venous pooling.

16.  LOC that is abrupt in onset; is associated with muscular
jerking or convulsions that last more than a few seconds,
incontinence, drooling, or tongue biting; and is followed
by postictal confusion or somnolence suggests a seizure.

17. DANGEROUS CAUSES
 Syncope with exertion suggests cardiac outflow
obstruction or exercise-induced arrhythmia. Such patients
sometimes also have chest pain, palpitations, or both.
 Syncope that begins and ends suddenly and
spontaneously is typical of cardiac causes, most
commonly an arrhythmia.

18.  Syncope while lying down also suggests an arrhythmia
because vasovagal and orthostatic mechanisms do not
cause syncope in the recumbent position.
 Syncope accompanied by injury during the episode
increases the likelihood of a cardiac cause or seizure
somewhat, and therefore the event is of greater concern.

19. RED FLAGS
Certain findings suggest a more serious etiology:
 Syncope during exertion
 Multiple recurrences within a short time
 Heart murmur or other findings suggesting structural heart disease (eg, chest pain)
 Older age
 Significant injury during syncope
 Family history of sudden unexpected death, exertional syncope, or unexplained recurrent
syncope or seizures

20. TESTING
 ECG
 Pulse oximetry
 Sometimes echocardiography
 Sometimes tilt table testing
 Blood tests only if clinically indicated
 CNS imaging rarely indicated

21. CLASSIFICATION EXAMPLES SCENARIO
Cardiac Arrhythmia (e.g.,
bradyarrhythmias,
ventricular
tachyarrhythmias,
supraventricular
tachyarrhythmias, long
QT syndrome),
pacemaker dysfunction
Generally abrupt and
unprovoked, palpitations
may precede symptoms
Obstructive
cardiomyopathy
Hypertrophic
cardiomyopathy
Structural disease
(cardiac)
Aortic stenosis,
Pulmonary stenosis,
Acute myocardial
infarction/ischemia
Structural disease
(other)
Pulmonary embolus,
Acute aortic dissection,
Pulmonary hypertension

22. CLASSIFICATION EXAMPLES SCENARIO
Neurally mediated (reflex) Carotid sinus
syndrome/hypersensitivity
Head rotation or pressure on the
carotid sinus (e.g., shaving, tight
collar) can reproduce symptoms;
consider in patients with
unexplained falls
Situational Micturition, post-exercise,
postprandial, gastrointestinal
stimulation, cough, phobia of
needle or blood
Vasovagal Mediated by stress, fear, noxious
stimuli, heat exposure

23. CLASSIFICATION EXAMPLES SCENARIO
Neurologic/miscellaneou
s
Cerebrovascular Induced by a steal
syndrome
Neurogenic Preceding transient
ischemic
attack/cerebrovascular
injury symptoms; severe
basilar artery disease
Psychogenic Depression, anxiety,
panic disorder,
somatization disorders

24. CLASSIFICATION EXAMPLES SCENARIO
Orthostatic Drug-induced Alcohol, insulin or
antidiabetic agents,
antihypertensives,
antianginals,
antidepressants,
antiparkinsonian agents
Primary autonomic failure Parkinson
disease/parkinsonism,
multiple system atrophy
(i.e., Shy-Drager
syndrome), multiple
sclerosis, Wernicke
encephalopathy
Secondary autonomic
failure
Diabetes mellitus,
amyloidosis, uremia,
spinal cord injury, chronic
inflammatory
polyneuropathy,
connective tissue diseases
Volume depletion Vomiting, diarrhea, poor
intake, acute blood loss

25. Risk Stratification in Patients with Syncope
 High-risk (hospital admission recommended)
• Clinical history suggestive of arrhythmia syncope (e.g.,
syncope during exercise, palpitations at time of syncope)
• Comorbidities (e.g., severe anemia, electrolyte abnormalities)
• Electrocardiographic history suggestive of arrhythmia syncope
• Family history of sudden death
• Older age
• Severe structural heart or coronary artery disease

26.  Low-risk (outpatient evaluation recommended)
• Age younger than 50 years
• No history of cardiovascular disease
• Normal electrocardiographic findings
• Symptoms consistent with neurally mediated or
orthostatic syncoperdiographic findings
• Unremarkable cardiovascular examination

28. TEST INDICATION COMMENTS
Basic laboratory testing As clinically indicated,
including human
chorionic gonadotropin
in women of
childbearing age
Laboratory evaluation
rarely is helpful;
complete blood count for
anemia; brain natriuretic
peptide testing may be
beneficial for cardiac
etiology
Carotid sinus massage Syncope of unknown
etiology in patients older
than 40 years*
Diagnostic if ventricular
pause is more than
three seconds or if a
decrease in systolic
blood pressure > 50 mm
Hg, Contraindicated in
patients with bruits or a
history of transient
ischemic
attack/cerebrovascular
accident within the past
three months
Diagnostic Evaluation of Syncope

29. TEST INDICATION COMMENTS
ECG All patients with syncope Can aid in diagnosing
arrhythmia, ischemia,
pulmonary embolus
(increased pulmonary
pressures or right
ventricular
enlargement),
hypertrophic
cardiomyopathy,
Findings suggestive of
arrhythmia include
presence of bundle
branch block,
intraventricular
conduction delay, sinus
bradycardia (less than
50 beats per minute),
prolonged QT interval,
QRS preexcitation, Q
waves

30. TEST INDICATION COMMENTS
Recurrent syncope with
unremarkable initial
evaluation; clinical or
ECG features suggestive
of arrhythmic syncope;
patients with
unexplained falls*
Holter monitor for 24 to
48 hours, event
recorders for 30 to 60
days, implantable
recorders for up to 14
months,
Consider testing in
patients suspected of
having epilepsy not
responsive to therapy
Echocardiography When history,
examination, and ECG
do not provide a
diagnosis or if structural
cardiac disease is
suspected
Diagnostic in aortic
stenosis, pericardial
tamponade, obstructive
cardiac tumors or
thrombi, aortic
dissection, hypertrophic
cardiomyopathy,
congenital anomalies of
the coronary arteries

31. TEST INDICATION COMMENTS
Electrophysiology Patients with coronary
artery disease after
ischemic evaluation,
nonischemic dilated
cardiomyopathy, bundle
branch block,* syncope
preceded by
palpitations, Brugada
syndrome,
arrhythmogenic right
ventricular
dysplasia/cardiomyopath
y, or high-risk
occupations
Not recommended in
patients without
underlying heart disease
Consider in high-risk
patients with recurrent
unexplained syncope
Exercise testing Hemodynamic and ECG
abnormalities present
with syncope during
exercise, syncope
reproduced with
exercise, precipitate a
Mobitz type II second-
or third-degree block
Inadequate rise of blood
pressure in younger
patients is suggestive of
hypertrophic
cardiomyopathy or left
main disease; similar
findings in older persons
may suggest autonomic

32. TEST INDICATION COMMENTS
Neurologic testing Suspicious for seizures,
cerebrovascular event,
neurodegenerative
disorders, increased
intracranial pressure
Seizure can be
confirmed with
electroencephalography
Cranial imaging studies
as clinically indicated
Orthostatic blood
pressure
Evaluate neurally
mediated syncope from
orthostatic hypotension*
Diagnostic if decrease in
systolic blood pressure ≥
20 mm Hg; if systolic
blood pressure < 90 mm
Hg; or if decrease in
diastolic blood pressure
≥ 10 mm Hg with
symptoms
Consider diagnostic
even when patient is
asymptomatic

33. REFERENCE
1. Parry SW, Tan MP. An approach to the evaluation and
management of syncope in adults. BMJ. 2010;340:c880.
2. John Murtagh’s Patient Education, Fifth edition
3. Andrea D. Thompson
, MD, PhD, Department of Internal Medicine, Division of
Cardiovascular Medicine, University of Michigan;
4.Michael J. Shea , MD, Michigan Medicine at the University
of Michigan