Syncope: Tintinalli

Question 1

So what is syncope & most importantly: how do you pronounce it?

Answer 1

Syncope: symptom complex composed of brief loss of consciousness associated with inability to maintain postural tone that spontaneously & completely resolves without medical intervention. It is different from vertigo, seizures, coma, & altered consciousness.

It is pronounced “SIN-co-pee.” Do not say “sin-cope.” :)

Question 2

What causes syncope?

Answer 2

Regardless of mechanism, the final pathway is the same: a lack of blood flow or nutrient delivery to both cerebral cortices or the brainstem reticular activating system for 10-15 seconds will lead to loss of consciousness & postural tone.

If you don’t got blood in your brain, you’re gonna fall out.

Question 3

Why do people wake up when they fall out with syncope?

Answer 3

The reclined posture, the response of the autonomic centers, or a return to a perfusing cardiac rhythm reestablishes perfusion.

Question 4

What are some disorders that can lead to syncope?

Answer 4

#Vasovagal (reflex mediated): 21%
#Cardiac: 10%
#Orthostatic: 9%
#Medication related: 7%
#Seizure: 5%
#Neurologic: 4.1%
#Unknown: 37%

Question 5

Why is it important to make a diagnosis for the cause, if possible?

Answer 5

Each diagnostic classification carries prognostic risk. E.g., in the Framingham study, people with heart disease WITH syncope had twice the death rate of those with heart disease WITHOUT syncope.

Question 6

Which root cause of syncope is the most dangerous?

Answer 6

Cardiac. These are your sudden cardiac death folks.

Question 7

What’s the 6 month mortality rate for people with documented cardiac syncope?

Answer 7

> 10%

Dang.

Question 8

What are the 2 categories of cardiac related syncope?

Answer 8

#Structural cardiopulmonary lesions (outflow obstruction, PE, acute MI causing dyskinesia, etc)
#Dysrhythmias

Question 9

Syncope from dysrhythmia is usually gradual: true or false?

Answer 9

FALSE. It is sudden & has no prodromal symptoms.

They just fall over. thump

Question 10

What is vasovagal syncope?

Answer 10

Reflex-mediated. It’s associated with inappropriate vasodilation, bradycardia, or both as a result of inappropriate vagal or sympathetic tone.

Question 11

What are the characteristics of vasovagal syncope?

Answer 11

#Sensation of increased warmth
#Preceding lightheadedness
#Sweating & nausea
#Slow, progressive onset of syncope

Question 12

Carotid sinus hypersensitivity is what type of syncope? What group of patients should be evaluated for this?

Answer 12

It’s a subtype of vasovagal syncope. Should be considered in all older patients with recurrent syncope & negative cardiac evaluations

Question 13

What is orthostatic syncope? What causes it?

Answer 13

Upon standing, blood is shifted to the lower part of the body & cardiac output drops. Normally the body increases CO to compensate for this, but if autonomic response is not sufficient, decreased cerebral perfusion may occur.

Then they fall over. thump

Question 14

So if someone presents with orthostatic syncope, we should just tell them it’s benign & to dangle their legs, right?

Answer 14

Nope! Other life-threatening causes of syncope should be ruled out before it is considered benign orthostatic syncope.

Question 15

What psychiatric illnesses may cause syncope?

Answer 15

#Generalized anxiety disorder
#Major depressive disorder
#Psychiatric cause is A DIAGNOSIS OF EXCLUSION, assigned only after all organic causes are excluded

Question 16

Neurologic causes are rarely the cause of syncope: true or false?

Answer 16

True! To be true syncope, the symptom must be transient in nature with a return to baseline. Thus, PATIENTS WITH LOSS OF CONSCIOUSNESS WITH PERSISTENT DEFICITS are not true syncope!

Question 17

What neurologic issues can cause syncope?

Answer 17

#Brainstem ischemia
#Subclavian steal
#Vertebrobasiliar atherosclerotic disease
#Basilar artery migrains
#Subarachnoid hemorrhage (but really they're gonna have more than just syncope with this...)

Question 18

Medications contribute to syncope. What is the most common type of syncope caused by medications?

Answer 18

Orthostatic!

Question 19

What drugs are commonly implicated in syncope?

Answer 19

#Antihypertensives
#Beta-blockers
#Cardiac glycosides
#Diuretics
#Anti-dysrhythmics
#Anti-psychotics
#Anti-Parkinsonism drugs
#Anti-depressants
#Phenothiazines
#Nitrates
#Alcohol
#Cocaine

Question 20

What population is at increased risk for syncope? What type of syncope?

Answer 20

The elderly are at increased risk for ALL THE SYNCOPE!

Question 21

What’s the goal of syncope evaluation in the ED?

Answer 21

Identify those at increased risk for immediate decompensation & future risk of morbidity or sudden death.

Who is gonna fall out again right now? Who is gonna fall out & DIE in the future?

Question 22

What should we look for in a HISTORY for syncope?

Answer 22

#Patient account
#Witness accounts
#Emphasize events leading up to syncope: position, stimuli, activity, environment, premonitory symptoms
#Chest pain or palpitations
#Duration of loss of consciousness
#Symptoms upon regaining consciousness
#Prior history of syncopal event

Question 23

These symptoms should be very concerning when accompanying syncope:

Answer 23

#Chest pain (acute MI, aortic dissection, PE, aortic stenosis)
#Palpitations (rhythm disturbances)
#Shortness of breath (PE)
#Headache (subarachnoid hemorrhage)
#Abdominal or back pain (abdominal aortic aneurysm, ectopic pregnancy)

Question 24

Syncope with no warning or associated with exertion should make you think:

Answer 24

#Cardiac dysrhythmia
#Structural cardiopulmonary lesion

Question 25

What trauma event should prompt ED clinicians to evaluate for syncope?

Answer 25

Single-car MVA (frequently with history of driving off the road), particularly among the elderly.

Did they fall out, then crash?

Question 26

Most common event mistaken as syncope

Answer 26

Seizure

Question 27

What can be done to differentiate syncope from seizure?

Answer 27

History, history, history!

#Classic aura, post-ictal confusion, & muscle pain=seizure.
#Nausea & diaphoresis=vasovagal syncope.
#Witnesses: odd head posture or turning, prolonged post-ictal phase
#Transitory wide-anion gap follows generalized seizure but not syncope

Question 28

Why would blood pressure measurements be taken in both arms?

Answer 28

Subclavian steal syndrome or aortic dissection

Question 29

When evaluating orthostatic blood pressures, what change in BP is significant?

Answer 29

Decrease in systolic BP upon standing of > 20 is considered positive for orthostatic BP IF SYMPTOMATIC

Question 30

What should be ordered to evaluate syncope?

Answer 30

#ECG
#Labs: directed by the H&P (e.g. orthostatic symptoms with heme-positive blood gets a CBC)
#Carotid massage (positive if symptoms are reproduced with asystole for > 3 seconds or drop in systolic BP > 50). Should NOT be done if bruit present, known carotid stenosis, or history of v-fib or v-tach, or recent history of MI or CVA
#Hyperventilation: useful for diagnosing young patients with suspected psychogenic (anxiety) origin

Question 31

When the history does not suggest neurologic cause, is CT or MRI warranted?

Answer 31

No. Yield is very low for routine CT-scan, EEG, or lumbar puncture

Question 32

According to the San Francisco Syncope Rule, what are predictors of adverse events in patients with syncope?

Answer 32

1) History of CHF
2) Abnormal ECG
3) Hct < 30
4) Complaint of shortness of breath
5) Systolic BP < 90 in the ED

These 5 high-risk criteria had an 89% sensitivity & 52% specificity for death at 1 year.

Question 33

ALL patients admitted with syncope should have…

Answer 33

…continuous cardiac monitoring (telemetry).

Question 34

Inpatient evaluation of syncope is focused on…

Answer 34

…identification of underlying heart disease &/or dysrhythmia

Question 35

Tests helpful in diagnosing cardiac syncope:

Answer 35

#Cardiac rhythm monitoring
#Echocardiogram
#Stress testing
#Electrophysiology testing

Question 36

Tests helpful in diagnosing neurologic syncope:

Answer 36

#CT/MRI/carotid doppler (vascular abnormality or subclavian stenosis)
#EEG (documents underlying seizure disorder)

Question 37

Tests helpful in diagnosing reflex-mediated syncope:

Answer 37

tilt-table testing