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EM (Syncope)

Terms in this set (60)

What is a sudden loss of consciousness associated with an inability to maintain postural tone that spontaneously resolves without medical intervention
Syncope
This is a premonition of syncope without loss of consciousness
Presyncope
What are the things that are NOT syncope?
1) Vertigo

2) Seizure

3) Coma

4) Altered Mental Status
What is the most common cause of syncope?
An event drops cardiac output causing a dcrease in O2 and substrate to the brain
What is a less common cause of syncope?
Vasospasm or other alteration in blood flow limits cerebral perfusion
What is the common endpoint for syncope?
A lack of blood flow or vital nutrient delivery to both cerebral cortices or to the brainstem reticular activating system (RAS)
What are the common causes of syncope?
1) Vasovagal reflex mediated "Down slow, up fast"

2) Cardiac dysrhythmia "Down Fast, Up Fast" --> HCM

3) Orthostatic hypotension

4) Psychiatric

5) Neurovascular (Seizure) --> "Down Fast, Up Slow"

6) Medication "Down Slow, Up Slow"

7) Uknown
**What is the most dangerous cause of syncope?
Cardiac syncope because patients with documented cardiac syncope have a 6-month mortality rate that exceeds 10%
Cardiac syncope is when the heart is unable to provide adequate cardiac support. What are the two categories?
1) Structural cardiopulmonary lesions

2 Dysrhythmia (no absolute high or low HR to produce syncope)
T or F. Structural syncope usually occurs with physical exertion
True
What is an example of valvular disease that causes syncope?
Aortic Stenosis: The classic presentation is chest pain, dyspnea with exertion and syncope--> this must be ruled out in the elderly
What are other structural causes of cardiac syncope?
1) Hypertophic cardiomyopathy (HCM)

2) MI because myocardial dyskinesia results in reduced cardiac output

3) Pulmonary Embolism secondary to acute obstruction to blood flow by a large embolus
Makedly increased QRS voltage and ST-T abnormalities in a young person with syncope suggest the diagnosis of HCM
T or F. Bradydysrhythmia is more likely to be an incidental finding on ECG rather than the actual cause of syncope
True
What most likely causes syncope?
Most likely an underlying structural heart disease
- Congenital
- Acquired
What else could cause a dysrhythmia that would lead to syncope?
1) Hypomagnesemia (torsades de pointes)

2) Long QT syndrome
Describe the onset of syncope from a dysrhythmia
Sudden without prodromal symptoms
What are other names for Vasovagal syncope?
Reflex-mediated or Neurally mediated syncope
What is reflex mediated syncope associated with?
Inappropriate vasodilation, Bradycardia, or both as a result of inappropriate vagal or sympathetic tone
What are the types of reflex mediated syncope?
1) Vasovagal

2) Carotid sinus hypersensitivity

3) Situational syncope
What usually precedes a reflex mediated syncope?
A slow, progressive onset with associated prodrome (increased sensation of increased warmth and lightheadedness with sweating and nausea)
How does reflex mediated syncope differ from orthostatic syncope?
Orthostatic syncope should not have the sweating and nausea but will be a prodrome of lightheadedness
This is caused by insufficient autonomic compensatory mechanism to decreased cardiac output which leads to decreased cerebral perfusion
Orthostatic hypotension
What is the prodrome of orthostatic hypotension?
1) Dizziness

2) Tunnel vision

3) Blurred vision
What is a diagnosis of exclusion for syncope?
Psychiatric etiology

hyperventilation--> hypocarbia--> vasoconstriction
What is usually associated with a psychiatric etiology of syncope?
1) Usually young

2) Multiple episodes of syncope

3) Multiple prodromal symptoms

4) Positive ROS
What needs to be considered in all older patients with recurrent syncope and negative cardiac evaluations?
Carotid Sinus Syncope
T or F. Neurovascular causes of syncope are common
False
If a patient has a loss of consciousness with persistent neurologic deficits or altered mental status, is this syncope?
No
What is the most important of neurovascular possibilities of syncope?
Sub Arachnoid hemorrhage
What is a neurological syndrome that causes significant brainstem ischemia affecting the RAS
Brainstem ischemia
- diplopia
- vertigo
- nausea
What is a rare cause of brainstem ischemia?
Subclavian Steal- which is a narrowing of the subclavian artery proximal to the vertebral artery
**Medications may contribute t syncope by a variety of means, but what is the most common?
Orthostatic syncope
- Beta Blockers, CCBs--> Hypotension
- Diuretics -- > Volume depletion
Can medications lead to dysrhythmias that cause syncope?
Yes
Why do the elderly appear to have a grater risk of syncope?
1) Because they have a decreased atrial kick

2) Decreased
- Adrenergic receptor response
- Thirst sensation
- Incidence of vasovagal

3) Chronic hypertension = increased cerebral autoregulation

4) Increased atherosclerosis (Previous MI)

5) Polypharmacy
What are the physiologic changes in pregnancy that cause syncope?
1) Increases HR

2) Decreased peripheral vascular resistance

3) Increased stroke volume

3) The Uterus can compress the Inferior Vena Cava decreasing venous return

**There is not a positive correlation between presyncope and syncope in patients with cardiac dysrhythmia

** In pregnant women, vasovagal is a diagnosis of exclusion
What is the most common benign syncope in pediatrics?
Vasovagal
What is the most common cause of adolescent syncope without a known disease?
Hypertrophic Cardiomyopathy (HCM)

Exertion prior to syncope increases risk of a more serious etiology
*Other than ABCs and OMI, what is the only thing that Major Oliver wants on EVERY syncope patient?
STAT EKG
*What is the goal of the ED evaluation of a syncope patient?
Identify those at increased risk for both immediate decompensation and future risk of serious morbidity or sudden death
What does the evidence of trauma without defensive injuries suggest?
Dysrhythmia
In a syncope patient, why must I measure the BP in both arms?
1) Aortic dissection vs Subclavian Steal

2) Orthostatics
What is the most common event mistaken as syncope?
Seizure
**What are NOT reliable ways to differentiate seizure from syncope?
1) Extremity movement (because brief asynchronous movements may follow the loss of consciousness)

2) Urinary incontinence
**What ARE reliable ways to differentiate seizure from syncope?
1) A classic aura or postictal confusion and muscle pain indicate seizure

2) A prolonged postictal phase is more consistent with seizure

2) Prodromal symptoms of nausea and diaphoresis suggest reflex-mediated (vasovagal) syncope
Umm what random exam must I not forget when evaluating a seizure patient?
Rectal exam for GI Bleeding
What are the ways to diagnose syncope?
1) ECG (cardiopulmonary disease, acute ischemia, dsyrhythmia, hearrt block, and prolonged QT)

2) Laboratory Testing (orthostatic symptoms, heme positive stool, pregnancy test) ----> Remember electrolyte disturbances may be implicated as the cause of seizure but NOT syncope

3) Carotid Massage (to diagnose carotid sinus hypersensitivity)

4) Hyperventilation Maneuver (open mouthed, slow, deep breaths at a rate of 20-30 breaths per minute for 2-3 minutes) ---> Young patient with psychiatric illness

5) Neurologic Testing (But in an asymptomatic patient who has experienced an isolated, and those without head trauma from the event should NOT get a CT Scab or MRI
WPW EKG
Notice the delta waves
Brugadas EKG
Notice the ski slopes in V1, V2, V3 Leads

PRE-EXCITATORY
In syncope, when should I get a cardiac set?
If the patient has chest pain or dysrhythmia
In syncope, when should I get UHGC?
On all females of reproductive age
In syncope, when should I get CBC?
Heme positive stool (type and screen if gross blood)
In syncope, when should I get electrolytes (Potassium)?
Dehydration, weakness
In syncope, when should I get a head CT?
If I suspect SAH
- Hx of prodromal headache
- HTH especially if on an anticoagulant
- Hx of falling or trauma
- Focal deficit
In syncope, when should I get, when should I get a lumbar puncture?
If the CT came back normal and I still suspect SAH. I'm looking for xanthrochromia
In syncope, when should I do risk stratification for High vs. Non-High Risk for Sudden Cardia Death. Who is high risk?
1) History of arrhythmia

2) Abnormal ECG

3) Hx of CHF

4) > 45 years of age

These people need to be admitted!
Patient goes doen fast and gets up fast?
Cardiac
Patient goes down fast and gets up slow?
Seizure
Patient goes down slow and gets up slow?
Drugs
Patient goes down slow and gets up fast?
Reflex-Mediated Syncope
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