syncope/arrhythmia Flashcards
Syncope is a transient loss — due to global — characterized by:
- – onset
- — duration (average— )
-Inability to maintain —
- — complete recovery
consiocunsess LOC
cerebral hypoperfuison
rapid
short
12 seconds
postural tone
spontaneous
syncope causes:
1-Reflex/Neurally mediated:
— /— e.g. — standing, sight of — , — stimuli
2-Orthostatic hypotension
—-induced (diuretic, anti-hypertensive), — depletion, — failure
3-Cardiac :
- —-
-Structural cardiovascular disease: — Stenosis, Hypertrophic Obstructive — etc
- — Heart Disease
vasovagal/situational
prolonged
sight of blood
noxious
drug
volume depletion
autonomic
arrhythmias
aortic stenosis
cardiomyopathy
ischeamic
1-why’s it important:
2- synscope mimics:
Important to note that not all LOC is syncope
Examples: Seizure, hypoglycaemia, intoxication
1- Prevalence of 42% and annual incidence of 6%, rising to 19.5% in over 80 age group 1,2
3-5% Emergency Dept visits
29% risk of physical injury, major trauma in 4.7%
18-33% mortality in cardiac causes, 0-12% for non-cardiac3
2.4 billion dollar annual cost4
- pathophysiology of syncope : cardiac output =
- pathophysiology of vasovagal syncope:
-How can we explain what causes someone to faint?
-Usually one of or combination of both:
Cardioinhibition: Increased activation of — nervous system -> —
Vasodepressor: Decreased activation of the — nervous system ->— and – in blood pressure
-End result is – reduction in cardiac output -> global cerebral —
Followed shortly by — recovery
CO = heart rate x stroke volume
parasympathetic
bradycardia
sympathetic
vasodilation
dro[
tempoary
hypo perfusion
spotnaous
- pathophysiology of orthostatic hypotension:
Orthostatic hypotension exacerbated by — e.g. - After —
-After – a meal – aka –
-After prolonged — aka –
-Can also be secondary to — or certain —
-pathophysiology of cardiac syncope: - —- cardiac output:
-Cardiac — / — heart disease
-Severe — NB! - Hypertrophic Obstructive —
Both can reduce—
venous pooling
expertise
eating
postprandial
bed rest
deconditioning
volume depletion or medication
low
cardiac arrhythmia
structural heart disease
aortic stenosis
cardiomyopathy
stroke volume
- symptoms of syncope:
1- —
LOC often preceded by nausea, light-headedness, palpitations
Look for — ! E.G. prolonged standing, unpleasant sight or smell
2- —
Change of position from – to — -> light-headedness and collapse
3- –
Sudden LOC often without prior – or rapid — - signs of syncope:
1- Orthostatic Hypotension
Lying and standing blood pressure: Drop of at least — mmHg systolic or — mmHg diastolic BP within – minutes of standing
2- Cardiogenic Syncope - – of the praecordium: displaced – beat, — and –
- — of the praecodium: —
3- cardiovascular exam critical :
heart—
parasternal —
— causes of syncope carry greatest risk of mortality e.g. —
4- neurological exam:
— abnormalities : weakness
Signs of — : – tremor, rigidity, bradykinesia
Peripheral neuropathy may suggest poor — control and possibility of – dysfunction
Vasovagal
triggers
Orthostatic Hypotension (OH)
sitting to standing
cardiac
prior warning or rapid palpitation
20
10
3
palpation
apex
heaves and thrills
auscultation
murmur
heart murmer
parasternal heave
cardiac
hypertrophic cardiomyopathy
focal
Parkinsonism
diabetic and autonomic
how each symptom/sign causes syncope:
SYMPTOMS :
1- When we stand: blood shifts from — to— extremities -> — the – and —
-Normal response: — in sympathetic tone and maintenance of blood pressure (increase in heart rate and systemic vascular resistance.
2- Syncope: Left ventricle hypercontracts, ventricular mechanoreceptors override baroreceptors -> feeds back to CNS via — -> inappropriate decrease in —and increase in —
-End result is —- and — -> —- in cerebral blood flow -> symptoms of light-headedness, clamminess, sweating, nausea -> —
3- cardiac symptoms: — likely in arrhythmia, particularly —
-Chest pain and shortness of breath on exertion
Concerning for ischaemia/valve disease/cardiomyopathy
-If above symptoms precede a syncope, think cardiac syncope and get an —!
SIGNS:
-Must check a – and — blood pressure in any patient with syncope with orthostatic features
-If significant drop + symptoms = OH
Exacerbated by — that lower BP by either — or —
Cardiovascular exam:
Heart murmur can be caused by — (see valvular disease content), hypertrophic obstructive — (see cardiomyopathy)
Both states can — cardiac output
thorax to lower
lower venous return and cardiac output
increase
vagus erve
sympathetic tone
parasympathetic tone
hypotension ad bradycardia
reduction
syncope
palpation
tachycardia
ecg
lying and standing
medication
vasodilation or volume depletion
aortic stenosis
cardiomyopathy
reduce
syncope is a — not — , spectrum of — to — and many varied causes
- differential diagnosis:
— is extremely important (may need collateral from a witness)
Ask how the patient felt prior to collapse
What were the circumstances – change in posture? Prolonged standing? Excessively warm weather/dehydration?
Absence of prior warning symptoms, especially occurring while seated/supine? Think cardiogenic
— often normal
symptom
diagnosis
bengin to life threatening
history
physical exam
1- normal cardiac rhythm:
-Normal sinus rhythm
- Originates in the — , spreads to the — and into the— via the — system
-ECG shows a regular —-complex rhythm with a rate of — bpm
-P-wave — every QRS complex
-PR interval remains — and lasts – ms
-Normal QRS complex duration —ms
2- arrhythmia:
-A group of conditions
-A problem with — and/or—
-Tachy – excessively — rate (—bpm)
Brady – excessively – rate (—bpm)
-Can be normal – with an irregular —
-Origin can be — or —
sinus node
AV node
ventricles
His-Purkinje
narrow
60-100
before
constant
120-200
<100
heart rate or rhythm
fast
>100
slow
<60
normal rate w irregular rhythm
ventricular or supraventiuclar
who gets arrhythmia/risk factors:
1- Cardiac:
— heart disease – Acute or chronic
— heart disease – valvular disease, cardiomyopathy etc
2-Systemic:
- —
- —
- — disturbance: Potassium, Magnesium, Calcium
3- Drugs
Proarrhythmic drugs, NB — prolongation
Even anti-arrhythmic drugs!
— recreational drugs
ischaemic
structural
hypoxia
acidosis
electrolyte
QT
stimulant
pathophysiology:
1- Bradyarrhythmia:
= Disease of the — system
–> Sinus node: Sinus — , – sinus syndrome
—> AV node: — , Types 1-3
2- Tachy-arrhythmia
- — outside of the normal conduction system responsible for generating and maintaining arrhythmia
Can be – or — in origin
electrical conduction
sinus pauses
sick
heart block
Ectopic foci
arterial or ventricular
symptoms and signs of arrhythmia:
1- symptoms:
Can be —
- —-
- — or –
- — of breath
- —
- —
2- signs:
-Irregular/fast –
- —
- —
- — : Lung crepitations, peripheral oedema, raised JVP etc.
asymptomatic
palpitation
syncope/presyncope
shortness
chest pain
fatigue
pulse
hypotension
hypoxia
heart failure
Explain how each symptom and sign is caused in arrhythmia:
1- symtpoms :
Often an — onset
Palpitations: sensation of abnormally fast heartbeat
Syncope: Heart rate becomes too slow or too fast to maintain appropriate cardiac output
Shortness of breath: Arrythmia can impair cardiac function and cause inefficient — of blood, which can lead to – into the – vasculature
Chest pain: Excessively fast heart rate can increase demand on myocardial — supply -> “demand —
2- signs:
Irregular pulse: Irregular conduction of – impulses through the – node to the — : — most commonly
Hypotension: Cardiac output strongly reduced in unstable tachy/brady-arrhythmias
Hypoxia/Heart Failure: More likely in patients with pre-existing heart disease/ history of heart failure – arrhythmia not well tolerated - fluid builds up in the lungs and in the venous system if severe enough to cause right-sided heart failure
abrupt
pumping
backflow
lung
oxygen
ichameia
arterial impulses
AV node
ventricles
artirl fibirllation
1- how to make a diagnosis:
- — most important first step
- Some arrhythmia paroxysmal and therefore not always present - need for more prolonged —
- Holter monitor: —
- Event monitor: —
-Implantable loop recorder: up to –
-New mobile app technology for self-monitoring
2- differential diagnosis:
Tachycardia
2 important questions
— or — ?
– complex or — complex
ECG
prolonged monitoring
24-72 hrs
7 days
3 years
regular or irregular
narrow or broad
arterial fibrillation:
= the most commonly encountered —
Atrial rate > — bpm
Ventricular rate generally — around 120-180bpm due to irregular – through the — node.
No — on ECG, may see — waves
Usually — QRS complex (– ms)
venaticular tachycardia:
= the most commonly encountered—
— HR
— complex reflects ventricular origin
Commonly seen in patients with — heart disease or— due to presence of —.
Needs emergency treatment
atrial tachyarrhythmia
350
slwoer
conduction
AV
p wave
fibrillatory wave
narrow
<120
ventricular tachyarrhythmia
rapid
broad
ischemic or cardiomyopathy
scar
check slide 48
diagnosis:
Usually a sign of severe – or — disease so further investigation required to determine underlying –
Bloods: — , —
Imaging: Echocardiography, Cardiac CT, Cardiac MRI
Invasive: Coronary angiogram, Electrophysiology study/ablation
key points:
Syncope is a common medical presentation
Can be benign - — , —
Can be sign of significant pathology – — causes
— often the most important diagnostic tool
— should focus on detection of cardiac pathology or orthostatic hypotension
Everyone gets an ECG
— is a broad term to describe many different abnormal heart rhythms
cardiac or systemic
electrolyte , troponin
vasovagal , orthostatic hypotension
cardiac causes
history
physical exam
arrhythmia
