This document defines and describes various types of syncope (transient loss of consciousness) including their causes and treatments. It discusses neurocardiogenic syncope (vasovagal and vasodepressor) which are common faints triggered by situations that cause reduced cerebral blood flow. It also covers postural (orthostatic) hypotension and disorders like hypertrophic cardiomyopathy that can cause cardiac syncope, a more serious condition. Tilt table testing is used to diagnose neurocardiogenic syncope. Management depends on the underlying cause but aims to prevent injury and address premonitory symptoms.

2. SYNCOPE
 It is defined as transient loss of
consciousness due to reduced
cerebral blood flow.
 It is associated with postural
collapse and spontaneous recovery.
 It may occur suddenly, without
warning or may be preceded by
symptoms of faintness

3. SYNCOPE
 It may be benign when it occurs as a result
of normal cardiovascular reflexes effects
on heart rate and vascular tone.
 It may be serious, when due to a life-
threatening arrhythmia.
 Syncope may be single event or recurrent.
 Recurrent, unexplained syncope,
particularly in an individual with structural
heart disease, is associated with a high
risk of death ( 40% mortality within 2 years
)

4. PRESYNCOPE
 It is impending loss of consciousness.
 It is preceded by symptoms of faintness,
includes, lightheadedness, “dizziness”
without true vertigo, a feeling of warmth,
nausea, diaphoresis and visual blurring
occasionally proceeding to blindness.
 Presyncopal symptoms vary in duration
and may increase in severity until loss of
consciousness occurs or may resolve
prior to loss of consciousness of the
cerebral ischemia is corrected.

5. CAUSES OF SYNCOPE
 Disorders of vascular tone or blood volume
-Vaso-vagal (vasodepressor, neurocardiogenic)
-Situational
Micturation
Cough
Defecation
Swallow
-Carotid sinus hypersensitivity

6.  Postural ( Orthostatic ) hypotention
– Drug induced esp. anti-HTN and vasodialtors
– Peripheral neuropathy (DM, Alcohol, nutritio)
– Idiopathic postural hypotension
– Multisystem atrophies
– Physical deconditioning
– Sympathectomy
– Acute dysautonomia ( GBS variant )
– Decreased blood volume ( Adrenal def., Acute
blood loss etc. )
 Glossopharyngeal neuralgia

7. CARDIOGENIC SYNCOPE
 DYSRHTHYMIAS
Tachyarrhythmias
-VT
-VF
-SVT
Bradyarrythmias
-Sinus-node disease
-2nd or 3rd degree block
-pacemaker malfunction
-Drug induced or prolonged-QT Syndrome

8.  ORGANIC HEART DISEASE
– Aortic Stenosis
– Hypertrophic Cardiomyopathy
– Myocardial infarction
– Coronary spasm
– Cardiac Tamponade
– Aortic dissection
– Cardiac myxoma

9.  Cerebrovascular disease
– Vertebrobasilar insufficiency
– Basilar artery Migraine

10.  CARDIOPULMONARY PROBLEMS
– Pulmonary embolism
– Pulmonary hypertension

11.  Other disorders
 A. Metabolic
– Hypoxia
– Anemia
– Hyperventilation causing reduction of
CO2
– Hypoglycemia

12.  Seizures
 Psychogenic
– Anxiety attacks
– Hysterical fainting.

13. NEUROCARDIOGENIC
SYNCOPE
(Vasovagal and vasodepressor)
– VASOVAGAL SYNCOPE
It is associated with both sympathetic
withdrawl (vasodilatation) and
increased parasympathetic activity
(bradycardia)
– VASODEPRESSOR
It is associated with sympathetic
withdrawl.

14. Neurocardiogenic syncope
 These forms of syncope are the “common
faints”.
 Experienced by normal persons
 These accounts for approx. half of all
episodes of syncope.
 These are frequently recurrent
 Commonly precipitated by a hot or
crowded environment, alcohol, extreme
fatigue, severe pain, hunger and emotional
and stressful situation.

15. Neurocardiogenic syncope
 The depth and duration of
unconsciousness vary.
 The patients lies motionless, with muscle
relaxed, but a few clonic jerks of the limbs
and face may occur.
 Sphincter control is usually maintained.
 The pulse may be feeble or absent, BP low
and breathing may be almost
imperceptible.
 The duration rarely longer than a few
minutes.

16. Neurocardiogenic syncope
 Once the patient is placed in a
horizontal position, the pulse
improves, colour begins to return to
the face, breathing becomes quicker
and deeper and consciousness is
restored.
 Although commonly benign, It can be
associated with prolonged asystole
and hypotension, resulting injury.

18. UPRIGHT TILT TABLE
TESTING
 It is indicated for recurrent syncope,
a single syncopal episode that
caused injury or event in a high risk
setting ( pilot, commercial heavy
vehicle driver etc )
 In susceptible patients, upright tilt at
an angle between 60 and 80 degree
for 30 to 60 min induces a vasovagal
episode.

19. Tilt Table Testing

20. Tilt Table Testing

22. Treatment
 At first sign of symptoms, patients
should make every effort to avoid
injury.
 Patients who have lost
consciousness should be placed in a
position that maximize cerebral blood
flow, offers protection from trauma
and secures airway.

23. Treatment
 Patients should avoid situations or stimuli
that have caused them to lose
consciousness to assume a recumbent
position when premonitory symptoms
occur.
 Drug therapy
– Beta antagonist
– SSRI
– Bupriopion
– Disopyramide

24. POSTURAL (ORTHOSTATIC)
HYPOTENTION
 This occurs in patients who have a
chronic defect in or variable
instability of vasomotor reflexes.
 Systemic arterial BP falls on
assumption of upright posture due to
loss of vasoconstriction reflexes in
resistance and capacitance vessels
of the lower extremities.

25. POSTURAL (ORTHOSTATIC)
HYPOTENTION
 Orthostatic Hypotension may be the
cause of syncope in up to 30% of the
elderly; polypharmacy with
antihypertensive or antidepressant
drugs is often a contributor in these
patients
 Postural syncope may occur in
otherwise normal persons with
defective postural reflexes.

26. POSTURAL (ORTHOSTATIC)
HYPOTENTION
 Orthostatic changes marked by a
decrease in systolic BP by 20 mm
Hg, a decrease in diastolic BP by 10
mm Hg, or an increase in heart rate
by 20 beats per minute (bpm) with
positional changes or systolic BP
less than 90 mm Hg with the
presence of symptoms may indicate
postural hypotension.

27. CAROTID SINUS
HYPERSENSTIVITY
 It is precipitated by pressure on the
carotid sinus barorecepters.
 This typically occurs in the setting of
shaving a tight collar or turning the
head to one side.

28. SITUATIONAL SYNCOPE
It is caused at least in part by abnormal
autonomic control and may involve
cadioinhibitory response, a vasodepressor
response or both.
GLOSSOPHARYNGEAL
NEURALGIA
It is preceded by pain in oropharynx,
tonsillar fossa, or tongue.
Loss of consciousness is usually
associated with asystole rather than
vasodialtaion.

29. CARDIOVASCULAR
DISORDERS
 Cardiac syncope, in contrast to vasovagal
syncope, can be a harbinger of serious
disease.
 Arrhythmias are the most common cardiac
cause of syncope, accounting for up to
14% of all cases of cardiogenic syncope.
 These includes brady-arryhthmias from
sinus-node dysfunction, atrio-ventricular
disturbances.
 Ventricular tachyarrythymias may be due
to structural heart disease (in 85 to 90 % of
cases), the long-QT syndrome, or the
Barguada syndrome.

30. Hypertrophic cardiomyopathy
 It is an atuosomal dominant disorder,
characterized by idiopathic
hypertrophy of the left (and
sometimes right) ventricle, heart
failure due to diastolic dysfunction,
ischemia even the absence of CAD,
and arrhythmias.
 Its prevalence is estimated at 0.2 %.
 There are several variants.

33. Hypertrophic cardiomyopathy.
 The clinical manifestations of the disease
are dyspnea, angina, and a continuum
encompassing lightheadedness,
presyncope, ssyncope and sudden death.
The incidence of sudden death is 1 %.
 Symptoms often occur during physical
exertion.
 Hypertrophic cardiomyopathy is the most
common disease found in cases of
sudden death in young athletes.

35. Hypertrophic cardiomyopathy.
 Sudden death generally results from
VT or VF.
 The gold standard for the diagnosis
is echocardiography.
 MRI may help in apical HCM

36. Hypertrophic cardiomyopathy.
 Management includes
– Avoid strenuous exertion
– Control of symptoms by Beta blockers
or Disopyramide
– Endocarditis prophylaxis for HOCM
– Prevent sudden death by implantable
cardioverter –defibrillator
– Screening of first degree relatives.

37. HCM
 Normal heart  Abnormal heart