Syncope Flashcards
what is syncope
Transient loss of postural tone and consciousness caused by a period of inadequate cerebral perfusion. Episodes rarely last > 1 minute. Full recovery to baseline mental status without resuscitation, no postictal state.
Syncope ddx is very broad, but ___ and ___ causes are generally at the forefront
Cardiac
Neurologic
Cardiopulmonary ddx of snyncope
- Valvular Disease
- Arrhythmias - VT, VF, Torsades, Afib/flutter
- Brugada Syndrome
- 2nd / 3rd AV Heart Block
- WPW
- Aortic Dissection
- Heart Failure
- HCOM
- Pulmonary Embolism
- Myocardial Infarction
- Pacemaker dysfunction
- Carotid Sinus hypersensitivity
neurologic ddx for syncope
- Vasovagal (coughing, seeing blood, fear, defecation, valsalva)
- Subarachnoid Hemorrhage
- Stroke / TIA
- Seizure
- Narcolepsy
other ddx for syncope
- Anxiety
- Volume depletion (Vomiting, dehydration, sweating)
- Hemorrhage (GI bleed, ectopic pregnancy, abdominal trauma)
4 conditions/hx that are more likely syncope
- Reflex Syncope (Vasovagal - vasodilation / bradycardia)
- Orthostatic Syncope (Severe orthostatic hypotension) 5-24%
- Cardiac Arrhythmias
- Structural cardiopulmonary disease
6 conditions/hx that are not likely syncope
- Vertigo
- Seizure
- Narcolepsy (Loss of Consciousness) vs. Cataplexy (Loss of muscle tone)
- Traumatic Brain Injury (Concussion / Brain Bleeds)
- Intoxication
- Metabolic abnormalities - Hypoglycemia
syncope hx of Number, frequency, duration
- Multiple events with new onset - consider AV block
- Multiple events over many years - may be susceptible to vasovagal syncope
- Multiple episodes daily lasting multiple minutes - psychogenic possibility
Onset Activity of syncope
Extended prodrome - ?
No prodrome - ?
vasovagal
more concerning for cardiac
syncope hx of position?
- Supine - more significant for cardiac etiology
- Change in position - Orthostatic Hypotension (Can be multiple minutes after change)
- Upright - Reflex Syncope (Vasodilation +/- bradycardia)
what is reflex syncope?
Immediately after exercise, defecation or urination, coughing, swallowing, post-prandial, warm and crowded place, prolonged standing, fear, sight of blood, stress, abrupt neck movements.
preceding sx of syncope hx
Prodrome
- Lightheadedness
- Warmth or cold
- Sweating
- Palpitations
- Nausea - abdominal discomfort
- Blurred vision (blindness possible)
- Diminished hearing or tinnitus
- Pallor reported by observers
post event of syncope hx
- Continued nausea, pallor, diaphoresis often associated with Reflex Syncope
- True syncope is usually 1-2 minutes at most as the supine position restores cerebral perfusion
- Extended syncope - think seizure vs. psychogenic
Associated Signs and Symptoms of syncope hx
- Syncope in the presence of new/severe HA - rule out subarachnoid
- Chest pain or shortness of breath - Rule out PE, MI, HF
- Fever - Do sepsis workup if indicated. Consider COVID-19 infection (Some pts this is the only symptom)
Pre-existing Medical Conditions for syncope hx
- CAD, valvular disease, cardiomyopathy, congenital heart disease, previous cardiac surgery all at high risk for arrhythmias
- DM - risk for Orthostatic Hypotension d/t autonomic neuropathy and hypoglycemia
- Previous psych or drug use hx
- Seizure, stroke hx
what rhythm can cause pts to pass out?
torsades (QT prolongation)
common drugs that can cause QT prolongation
- Diuretics, Beta or Alpha Blockers, CCB (Non-DHP)
- MANY psych and neuro drugs, antiemetics, antiarrhythmics, antifungals, some antibiotics
what measurement of QTx is when concern for torsades
> 500
QTc >440 in Men
QTc> 460 in Women
Concerning hx factors for Cardiac etiology for syncope
- Absence of Prodrome
- Event during exertion or supine
- Associated with Chest Pain
- Family hx of sudden death
- Known structural heart disease
- Abnormal rhythm hx
General PE for syncope
- ABC’s with every ER patient
- Do they appear awake and alert at the time of examination
- Vital Signs
- O2 saturation, HR, BP, Temperature
— BP very low (Sepsis, Cardiac issue, Overdose, Late HF)
— BP very high (Stroke, HF, Anxiety)
Syncope - components of complete CARDIAC physical exam
- Murmurs
- Aortic Stenosis, Mitral regurgitation, Tricuspid Stenosis - Irregular or Bradycardic Rhythms
- Atrial Fibrillation, Significant PVCs
- Heart Blocks (Especially 3rd Degree)
- Symptomatic Bradycardia - Signs and Symptoms of Heart Failure
- Bilateral lower extremity swelling
- Increased JVD
- S3 / S4
syncope - components of complete neuro exam
- Mental Status
- Cranial Nerves
- Motor Strength
- Sensation
- Gait
- Reflexes
- Finger to Nose, Heel to Shin, Romberg, Pronator Drift
- Irregular exam would be cause for CT of brain
syncope - Evaluate for Head and Neck Trauma if appropriate:
- CT scan Canadian CT Rules and NEXUS Criteria if head or neck hit during fall
- Skin Turgor / Oral Mucosa / Volume Status
- Abdominal
- AAA - Pulsatile Mass
- Rectal exam for GI Bleed (FOBT only for non visible blood samples) - Any other exam that the history deems relevant
required w/u for syncope
EKG
Cardiac Monitor throughout stay
everything else - consider based on hx, age, RFs
2 tools to determine syncope disposition
- Canadian Syncope Risk Score shows better sensitivity
- San Francisco Syncope Rule - you will see both utilized
Do NOT use Canadian Syncope Calculator if…
- LOC >5 min
- Change in mental status
- Obvious witnessed seizure
- Major trauma / head trauma causing LOC
- Intoxication - ETOH or drugs
- Language barrier
San Francisco Syncope rules
CHESS
- CHF hx
- Hct < 30%
- ECG or cardiac monitoring abnml
- SOB hx
- SBP < 90 at triage
All reflex syncopes refer to ____ and/or ____ causing systemic hypotension and cerebral underperfusion.
vasodilation
bradycardia
Most common cause of syncope in patients of all ages
Vasovagal Syncope
- 60% of pts with a heart condition and syncope will be diagnosed with vasovagal syncope
- Prodrome usually present - pale, N, feeling warm, cold sweats, blurred vision
presentation of Vasovagal Syncope
- Prodrome usually present
- Classic - donating or seeing blood, emotionally upset
- After vigorous exercise - athletes (Not during exertional exercise)
- Typically occurs in the sitting or standing position
- Post episode fatigue possible (Not so with cardiac induced syncope)
PE of vasovagal syncope
No neurologic deficits
No cardiac abnormalities
w/u for vasovagal syncope
- EKG - usually normal or non-specific
- Strong History - Episode + Previous Medical History
- Other investigations as indicated from history
disposition of vasovagal syncope
If convinced vasovagal, patient is evaluated with a risk evaluation device.
Low-moderate risk - DC home with appropriate follow-up with primary care.
High risk - admitted
Failure of sympathetic efferent vasoconstrictor traffic (and hypotension) occurs episodically and typically in response to a trigger (emotional stress, painful or noxious stimuli, etc). During reflex syncope, concomitant with withdrawal of sympathetic efferent activity, parasympathetic (vagal) activity increases, slowing the heart
Reflex Syncope
Change in position causes BP to drop d/t gravity. Homeostasis interrupted as Sympathetic efferent activity is chronically impaired, and upon standing, blood pressure always falls. There is often a reflexive tachycardic response.
which type of syncope
Orthostatic Syncope
definition of orthostatic HoTN
↓ 20 mm/Hg systolic or 10 mm/Hg diastolic and often HR ↑ 20 BPM
Remember, HR normally decreases with reflex syncope.
causes of orthostatic hypotension
Neurodegenerative disorders (Baroreceptor dysfunction, Parkinson Disease, Dementia with Lewy Body) Neuropathies (Baroreflex dysfunction can be caused by peripheral neuropathies), Autoimmune disorders, Volume depletion, Medications
how to dx orthostatic hypotension
- After a careful hx - Supine and standing BP and pulse will be obtained.
- Pt should rest x 5 min before first reading.
- BP retaken after pt is standing x 2 min
- Some geriatric providers prefer an immediate BP - risk of falls. - Supine, seated, standing with identical diagnostic criteria
orthostatic hypotension - Besides the neurologic component, as we age the arterial walls lose elasticity and may become ____; therefore, a ____ response to vasodilation may cause a low BP for a brief time after position change.
calcified
sluggish
A reflex syncope (drop in HR) d/t turning of head, tight collar, shaving
Carotid Sinus Syncope
Carotid Sinus Syncope is MC seen in who
- older individuals (predominantly males) who have atherosclerotic vascular disease.
- Other: abnormalities of structure of neck (eg, prior neck surgery and/or irradiation) or tumors in the region of the carotid sinuses.
dx CSH
Per History and Carotid Massage
tx and disposition for CSH
- ED Tx: None
- Disposition: F/U w/ PCP.
- if problematic - consider pacer or Midodrine, a vasoconstrictive drug
CSH is positive if there is a decrease SBP of ? mmHg OR if pt becomes ____
- > 50 mmHg
- symptomatic
aortic stenosis can be seen in older and younger pts due to?
- Usually older pts due to calcification of the aortic valve
- Younger pts if congenital
presentation of aortic stenosis
- Chest pain, Syncope, Dyspnea (Due to HF)
- Progression of symptoms per above
- Survival 2-3 years from symptom onset
how to dx aortic stenosis
- Systolic Murmur (Aortic Post) radiating to the carotids
- Narrowed Pulse Pressure
- Echo - often will need admission for this test
ED care for aortic stenosis (avoid what?)
- Avoid negative inotropes - BB, CCB (DHP or Non DHP?)
- Avoid dropping preload for chest pain - Nitroglycerin
disposition of aortic stenosis
- Likely admit to floor with cardiology consult
- Indications for Aortic Valve Replacement
- Severe AS in symptomatic pt
- Severe AS undergoing CABG, aortic, or valve surgery
- Severe AS with LV dysfunction, EF < 50%
what is Subclavian Steal Syndrome?
- Stenosis (It will not be 100%) of the subclavian artery, proximal to origin of vertebral vessel = decreased perfusion pressure to the distal subclavian artery, leading to retrograde flow in the ipsilateral vertebral artery with exercise of the ipsilateral arm.
- TLDR: arm steals blood flow from the vertebrobasilar system = neurologic and UE sx due to arterial insufficiency.
presentation of subclavian steal syndrome
- UE - Pain, fatigue, coolness, paresthesia, numbness
- Blockage of the efferent flow of blood into the arm - neuro - Fatigue, Syncope, Vertigo
- Loss of blood from posterior circulation of brain falling into R extremity - SBP reduced compared to contralateral arm
- Bruit may be heard in supraclavicular area
dx subclavian steal syndrome
- arterial US or CTA w/ contrast
- If admitted - MRA (angiography)
tx and disposition subclavian steal syndrome
- Statins for generalized atherosclerosis
- Antiplatelet / Anticoagulant therapy
- Smoking Cessation
- BP Management
Disposition: Admit w/ consult to Vascular Surgery all sx pts; DC w/ quick vascular surgery outpatient if incidental finding
what is Basilar Artery Insufficiency
Basilar artery carries blood to brainstem (core functions including HR, BP, and rsp), cerebellum (balance and coordination), and occipital lobes of the brain (vision)
Basilar artery insufficiency is caused by?
blockage - dissection, lesion, subclavian steal - form of ischemic stroke/TIA
presenation of basilar artery insufficiency
Change of head position may cause sx. Syncope if contralateral side stenotic
- Nausea / Vomiting
- Weakness
- Numbness
- Dysphagia
- Dysarthria
- Syncope
- Vision Changes
how to dx basilar artery insufficiency
- Glucose Check
- CT Brain Without, CTA Head & Neck With IV Contrast
- Full neuro exam
- HINTS Exam - Distinguishes between central causes of vertigo from peripheral - use if vertigo lasts hours to days
tx and disposition for basilar artery insufficiency
- Treatment
- Per recommendations of Neurology or vascular surgery
- Possible endarterectomy, cholesterol management, Antiplatelets, Smoking cessation - Disposition - All will be admitted
what antiarrhythmics can cause prolonged QT?
- Class I Na Blockers: Quinidine, procainamide, disopyramide
- Class III K Blockers: amiodarone, sotalol, dofetilidev, ibutilide, dronedarone
what abx can cause prolonged QT
- FQ
- Macrolides
- trimethoprim
- pentamidine
- -azole antifungals
what antipsychotics can cause prolonged QT
- haloperidol
- droperidol
- thioridazine
- pimozide
what antiemetics can cause prolonged QT
- ondansetron
- granisetron
- metoclopramide
