Syncope

syncope

dr. qais ajam

object of lecture

• understand consciousness.

• anatomy of nervous system.

• build concept map for syncope.

• differentiate between causes of syncope.

• way of dealing with syncopal case.

syncope- presyncope or faint:
• syncope: transient episodic loss of consciousness with loss of postural tone due to cerebral or brain stem hypo perfusion.
• pre syncope or faint ? it is lightheadedness or pre monitory symptoms before syncope (patient is
going to have syncope).





organization of
the nervous
system:



2 big initial divisions:
1. central nervous system
• the brain + the spinal cord
• the center of integration and
control

2. peripheral nervous system
• the nervous system outside of the
brain and spinal cord
• consists of:

• 31 spinal nerves
• carry info to and from
the spinal cord

• 12 cranial nerves
• carry info to and from
the brain.


autonomic nervous system

• can be divided into:
• sympathetic nervous system
• “fight or flight”

• parasympathetic nervous system
• “rest and digest”

these 2 systems are antagonistic. typically, we balance these 2 to keep ourselves in a state of dynamic balance. we’ll go further into the difference between these 2 later on !







definitions:
• consciousness? ability to maintain contact to the environment(time ,person, and place? how? continuous bilateral signals from mid pons to both thalami
and cerebral cortices(cortex) see figure of cns(n.s anatomy in simple way?

• dizziness ? nonspecific and wide term include pre -
syncope , vertigo , balance disturbance , epilepsy (you need good history to differentiate between them).

syncope and loc –pathophysiology-concept:
what are the elements of consciousness?

1-contents function of cortex lesion/disease - dementia
2-level (wakefulness and awareness?-function of reticular activating system (ras ) in mid pons to the cortex - lesion disturb consciousness ( syncope , confusion , delirium , and sever one is coma).

• factors we needs to maintain our consciousness?
blood (cardiac pump, volume, hb) , sugar , harmonic neural electrical signal
• can you mention some causes that lead to transient or episodic loc due affection of these factors ?

• if it is due to affection of cerebral perfusion cp -syncope
• if cp is reduced pre syncope symptom then syncope.

think like a doctor to help others



etiology:
syncope: transient episodic loss of consciousness with loss of postural tone usually due to global cerebral or brain stem hypo perfusion.

1-cardiovascualr disease .
• arrhythmias (techy or brady as in semester 2) .
• left ventricular dysfunction .
• aortic stenosis .
• obstructive cardiomyopathy.

2-neuro-cardiogenic causes(abnormal autonomic reflex)
• vasovagal syncope (simple faint) =8-41% of cases.
• situational syncope ( cough or micturition syncope)
• carotid sinus syncope.

3-orhostatic hypotension.=bp droping on standing from sitting or flat position
• hypovolemia (loss of fluid or blood) .

differential diagnosis = syncope like
hypoglycemia , seizure , loss of balance ,
anemia (after exertion).

clinical types and scenarios of presentations? how we can solve the problem and reach diagnosis-group discussion.
history(pt. or witness) : listen and ask about
premonitory s. and triggers ,unconscious period and
recovery period these will give you hint about diagnosis.
ask about recurrence? previous health ? diet? drugs? any ,fluid loss (diarrhea) or blood loss(bleeding)?
menstruation? stress related? family history -e ct

examination check the patient for relevant signs.

investigate to confirm or rule out a cause
treatment.

clinical types of syncope:
case1 : a 32 years old iraqi man with recurrent attacks of loc with full recovery, not related to position it is brief for less than one minute.

is it syncope? type ? cause? discussion -

*is it preceded by feeling of palpitation as pt. describes (pt.: yes)
* any involuntary movement during falling (pt.: no).
*you had any history of blood loss or fluid loss(pt. no),
*any drug intake or
*missing meals(pt: no)

initial diagnosis?
cardiac syncope
neural mediated –vasovagal or hypotension syncope
psychogenic s.
neurological disease or seizure
it is? cardiac ? then you should think about probable cardiac
cause (see etiology of cardiac syncope)

• so you need subsequent qs to ask again to rule out or
confirm certain causes, this is the aim of module( think
about causes of arrhythmia)
ex1: if there is history of fluid loss , anorexia , thyroid problem the
cause will be electrolyte disturbance most likely hypokalemia causing arrhythmia ? stress related syncope (panic)?missing meals in hypoglycemia ? all negatives.

ex2: or history of deafness/ family history of arrhythmias or sudden death( patient answer : yes yes ?
make diagnosis at this stage????
a: congenital prolonged qt syndrome ?
then think about causes of prolonged qt syndrome?
questions you should ask? same as above additional information
• acquired causes as certain drugs(antipsychotic ,anti-diabetes drugs)
,or electrolytes disturbance(magnesium and k+) low k+ as in
thyroid problem , diarrhea ,and anorexia
• inherited as in our cause ? ask history of deafness/ family history of arrhythmias or sudden death( patient : yes ,yes)

how you investigate this case
***to confirm the main problem 1st ?
ex: cardiac syncope ?
a/ ecg , ambulatory ecg to confirm arrhythmia
***then search the cause or rule out some(see etiology)
a/ ecg to see features of prolonged qt interval &
echocardiogram to exclude structural heart lesions in

ex.2.
(prolonged qt syndrome) and serum k+ level in ex.1(case of fluid loss)
in certain cases you should perform blood sugar to rule out
hypoglycemia ?? hb , blood picture to rule out anemia and
eeg to rule out seizure. next slides.
confirmatory test in congenital prolonged qt syndrome?
genetic test –autosomal or recessive inheritance(semester 2) .

neuro-cardiac syncope-vasovagal:
• case 2 : a 20 years old medical student in his 2nd year class while he standing in the clinical session
watching his 1st anatomy lab. , felt down on the ground suddenly ?
• good questions you should ask? same in c. syncope.
• you have to ask about premonitory symptom and
triggers, blackout period , and recovery.
• additional information were asking about out any h/o blood loss* ,drug intake* or missing meals* ,any
involuntary movement* and family history*? (group
discussion)
• a/ he was in standing for long time* , emotional
factors (emotionless standing) ,then he developed
nausea , pallor and sweating then fell down with slow
recovery ,his pulse was slow in black out period .
• questions ? no blood or fluid loss , no drug intake

(mechanism of vvs)
• mechanism of vasovagal s. ? decrease venous return to the heart(prolonged standing) -sympathetic
stimulation as compensatory mechanism –abnormal
contraction of under filled v. lead to tachycardia then,
there is stimulation of cardiac mechanoreceptor lead to
stimulation of parasympathetic mediated via vagus
nerve result in hypotension (vasodepressor response)
and bradycardia (cardiac inhibitory response) making
diagnosis of vvs.(in physiology)



vasovagal syncope =vvs
• seen in all age , commonest type of s. .
• triggers: prolonged standing specially emotionless state , pain , sight of blood ,medical instrumentations and excess of heat exposure.
• position standing .
• premonitory s. –sweating ,pallor , dizziness , blurred
vision , tachycardia (sympathetic stim. 1st ).
• unconscious period : brief loc with droping of bp ,
bradycardia (parasympathetic effect).
• recovery rapid when assuming horizontal position with headache.
• investigations? head tilt test provocative test for
vasovagal response pt connected to ecg and bp tool the head of table elevated 60-70 degree for 45 min.
• htt indicated also in border line case of orthostatic

dd –syncope like important
• anemia loss of conscious seen in exertion ,see pallor
in examination and hb is low in blood test.
• hypoglycemia : missing meal , poor diet intake , over
dose of insulin in dm patient , slowly evolving (pallor,
sweating , tachycardia for longer period than that in
vvs. blood sugar is low , response to sweets or hypertonic fluid infusion.
• is it syncope? a/ we call it blackout(wide term) not
syncope?
• seizure ? abnormal excessive hyper neuronal discharge

case 3
• a 34 years old man presented to emergency with
recurrent loss of consciousness at his work and
brought by his friend to hospital who mentioned that
all of sudden, he collapsed on the ground with spasm
all over and abnormal movement sound and tongue
bite the symptoms subsided within 2-3 minutes and
his cons recovered after 60 minutes he was oriented
but with severe headache and minimal deficit on right
side.
• questions you ask as before? blood loss ,drug intake,
missing meal, stress related -all negative
• is it syncope ? what is most likely diagnosis?
• diagnosis ? which one is true?
1-eeg, ct or/ and mri
2-ecg , blood sugar , blood film
other types of syncope
• situational(cough , micturition s.)
• carotid sinus syncope
• orthostatic hypotension.=sudden droping of bp on
standing from static posture.
(cause many like drug ,fluid or blood loss ,varicose
vein(polling of blood in legs up on standing) and
autonomic dysfunction as in dm)
• neurological diseases like tia =transient
ischemic attack or stroke.