Syncope

Question 1

Cohort and population based studies suggest that around __% of the adult population has experienced a syncopal episode. Usually described as a “faint” or “blackout” or “Collapse”

Answer 1

40%

Question 2

What gender is more likely to report syncope

Answer 2

women

Question 3

Syncope incidence is higher with:

Answer 3

1. advancing age

2. prescription of vasoactive drugs and cardiac arrhythmias

Question 4

Describe the bimodal distribution of syncope based on age

Answer 4

1. in adolescents and young adults a reflex mechanism is the most common
2. above the age of 65 a cardiac cause or orthostatic hypotension should be suspected

Question 5

Syncope is a transient loss of consciousness (T-LOC) due to ___

Answer 5

transient global cerebral hypoperfusion

Question 6

Syncope is characterized by

Answer 6

1. rapid onset,
2. short duration, and
3. spontaneous complete recovery
4. episode typically lasts 20-30 seconds and almost invariable less than 5 min

Question 7

It is important to distinguish Syncope from other causes of T-LOC (Transient Loss of Consciousness). Some of these other causes are:

Answer 7

1. Pre-Syncope: lightheadedness without LOC
2. Drop Attack: loss of posture without LOC
3. Coma: LOC without spontaneous recovery
4. Seizure: Tonic-Clonic Movements that start WITH LOC (vs hypoxic myoclonus which can occur with syncope), post-ictal recovery period
5. Hypoglycemia
6. Hypoxia
7. TIA – NO LOC
8. Cardiac Arrest

Question 8

What is the most common type of syncope and the most dangerous type

Answer 8

Most common: reflex syncope (neurocardiogenic/vasovagal)

Most dangerous: cardiovascular

Question 9

What are different etiologies of syncope

Answer 9

1. Neurally-mediated (reflex syncope) (most common)
2. Cardiovascular (most dangerous)
3. orthostatic hypotension (D-A-A-D)

Question 10

Causes of Neurally-mediated (reflex syncope)

Answer 10

1. Pain/Noxious Stimuli
2. Situational (micturation, cough, defecation)
3. Carotid Sinus Hypersensitivity (CSH)
4. Fear
5. Prolonged standing / heat 5. exposure

Question 11

Causes of cardiovascular syncope

Answer 11

1. Arrhythmia – Tachy or Brady
2. Valve Stenosis (outflow obstruction)
3. HOCM (outflow obstruction)

Question 12

Causes of orthostatic hypotension syncope

Answer 12

D-A-A-D

1. Drugs (Vasodilator / volume Depletion): BP meds, Diuretics, TCAs
2. Autonomic Insufficiency (Parkinsons, Shy-Dragger, DM, Adrenal Insufficiency)
3. Alcohol
4. Dehydration

Question 13

‘Vasovagal’ syncope (VVS), also known as the ‘common faint’ is mediated by:

Answer 13

emotion or by orthostatic stress

e.g. fear, pain, blood phobia

Question 14

‘Vasovagal’ syncope (VVS) is usually preceded by:

Answer 14

prodromal sx of autonomic activation: sweating, pallor, nausea

Question 15

___ traditionally refers to reflex syncope associated with some specific circumstances.

Answer 15

Situational’ syncope

ex. cough, sneeze, GI Stimulation (swallow, defecation, visceral Pain), Urination, post-prandial, weightlifting, Laughter, brass instrument playing

Question 16

___ syncope can occur in young athletes as a form of reflex syncope as well as in middle-aged and elderly subjects as an early manifestation of ANF before they experience typical OH

Answer 16

Post-exercise

*type of situational syncope

Question 17

What is carotid sinus syncope

Answer 17

In its rare spontaneous form it is triggered by mechanical manipulation of the carotid sinuses. In the more common form no mechanical trigger is found and it is diagnosed by carotid sinus massage.

*type of reflex syncope

Question 18

Types of reflex syncope

Answer 18

1. Vasovagal syncope
2. situational syncope
3. carotid sinus syncope
4. “atypical” syncope

Question 19

The term ___ is used to describe those situations in which reflex syncope occurs with uncertain or even apparently absent triggers.

Answer 19

‘atypical form’

Question 20

how do you dx atypical syncope

Answer 20

rests less on history taking alone, and more on the exclusion of other causes of syncope (absence of structural heart disease) and on reproducing similar symptoms with tilt testing

Question 21

How does orthostatic hypotension syncope occur

Answer 21

• ANF sympathetic efferent activity is chronically impaired so that vasoconstriction is deficient.
• Upon standing, BP falls and syncope or pre-syncope occurs.

Question 22

What changes in BP need to occur for OH syncope

Answer 22

usually defined as a decrease in systolic BP >=20 mm Hg or a decrease of systolic BP to <90 mm Hg (associated with syncope or pre-syncope).

Question 23

____ refers to symptoms and signs in the upright position due to a circulatory abnormality.

Answer 23

Orthostatic intolerance’

Question 24

Symptoms of Orthostatic intolerance

Answer 24

1. syncope
2. dizziness/ LH, pre-syncope;
3. weakness, fatigue, lethargy;
4. palpitations, sweating;
5. visual disturbances (including blurring, enhanced brightness, tunnel vision);
6. hearing disturbances (including impaired hearing, crackles, and tinnitus)

Question 25

Clinical features that can suggest a reflex mediated syncope on initial evaluation

Answer 25

1. Absence of heart disease
2. long hx of recurrent syncope
3. after sudden unexpected unpleasant sight, sound, smell or pain
4. prolonged standing or crowded, hot places
5. N/V associated w. syncope
6. during meal or post-prandial
7. w/ head rotation or pressure on carotid sinus (as in shaving or tight collars)
8. after exertion

Question 26

Clinical features that can suggest a OH mediated syncope on initial evaluation

Answer 26

1. after standing up
2. temporal relationship w/ start or changes of dosages of vasodepressive drugs leading to hypotension
3. prolonged standing, esp. in crowded, hot places
4. presence of autonomic neuropathy or Parkinsonism
5. Standing after exertion

Question 27

___ are the most common cardiac causes of syncope. They induce hemodynamic impairment, which can cause a critical decrease in CO and cerebral blood flow.

Answer 27

Arrhythmias

Question 28

examples of arrhythmias that can cause syncope

Answer 28

1. Bradycardia
   - sinus node dysfunction
   - AV Conduction system disease – Heart block
   - Implanted device dysfunction
2. Tachycardia –
   - Supraventricular
   - Ventricular (idiopathic, secondary to structural heart disease or channelopathies)
3. Drug induced - antiarrhythmic drugs, QT prolonging drugs

Question 29

What structural cardiovascular diseases can cause syncope

Answer 29

1. valvular disease
2. AMI
3. HCM
4. Cardiac masses
5. pericardial disease/tamponade
6. prosthetic valve dysfunction
7. PE
8. aortic dissection
9. PHTN

Question 30

____ can cause syncope when circulatory demands outweigh the impaired ability of the heart to increase its output.

Answer 30

Structural cardiovascular diseases

Question 31

The syncope work-up should determine

Answer 31

who is at HIGH RISK for a dangerous short-term cardiac event

Question 32

The basic work up all syncope patients should get:

Answer 32

1. History/Physical including Orthostatics
2. Medication Review
3. ECG.
4. If age over 40, consider Carotid Sinus Massage to assess for Carotid Sinus Hypersensitivity
   **CONTRAINDICATED if carotid bruit present or recent TIA/Stroke
   + Test = bradycardia, hypotension, transient pause/asystole, or prodrome symptoms
5. All patients should then be Risk Stratified

Question 33

Who is at high risk for short term cardiac mortality and need appropriate cardiac work-up as an INPATIENT:

Answer 33

1. Evidence of significant heart disease (such as HF, low LV EF, structural abnormality, or previous MI)
2. Clinical (eg palpitations or syncope on exertion or supine)
3. family history of sudden cardiac death or non sustained VT
4. Hypotension (systolic less than 90 mmHg)
5. ECG features suggesting arrhythmia or otherwise abnormal
6. Comorbidities such as severe anemia or electrolyte disturbance

Question 34

What is the work up for syncope in high risk people

Answer 34

1. Echo,
2. Stress test, and/or
3. Ischemic Evaluation

**Carotid Ultrasound has POOR utility in the workup of Syncope and should not be ordered routinely.

Question 35

Identify patients at high risk for short term events, these patient’s should be

Answer 35

hospitalized and monitored on telemetry while you continue your cardiac workup

Question 36

Who are low risk patients w/ syncope

Answer 36

Patient’s with no High risk characteristics and/or with highly suspected Reflex or OH Etiology

*Single Episode: No further workup indicated

Question 37

Additional treatment may be necessary in low risk unpredictable and frequent syncope. In particular when:

Answer 37

1. Very frequent syncope alters quality of life
2. Recurrent syncope without, or with very short prodrome exposes patients to risk of trauma
3. Syncope occurs during high risk activity (e.g. driving, machine operation, flying, competitive athletics, etc.)

Question 38

How can syncope be evaluated as outpatient?

Answer 38

Multiple Episodes: Can workup as outpatient

1. Patient having FREQUENT Episodes: Holter Monitor or Event Monitor
2. Patient having INFREQUENT Episodes: Implantable Loop Recorder
3. +/- tilt table test— falling out of favor due to poor reproducibility and low sen/
4. EP Studies are also an option for rare or difficult to diagnose cardiac syndromes

Question 39

Neurological Causes of true Syncope

Answer 39

1. bilateral carotid or basilar artery disease
2. non-convulsive seizue

*Rare

Question 40

When is head CT indicated for syncope

Answer 40

ONLY if the patient has or experienced focal neurological deficits or they experienced head trauma from the event.

Question 41

Posterior Circulation evaluation with CTA/MRA or Ultrasound is useful only if ___ is suspected

Answer 41

Vertibro-basilar insufficiency

Question 42

how does Vertibro-basilar insufficiency typically present

Answer 42

1. dizziness
2. gait instability
3. blurry vision
4. nystagmus or
5. frank coma

Question 43

Treatment of reflex syncope and orthostatic intolerance

Answer 43

1. Education regarding awareness and possible avoidance of triggers (e.g. hot crowded environments, volume depletion)
2. Early recognition of prodromal symptoms (Tilt table testing can be employed to teach the patient to recognize early prodromal symptoms.)
3. Performing maneuvers to abort the episode [e.g. supine posture, physical counter pressure maneuvers )PCMs – e.g. leg crossing and squatting)
4. If possible, triggers should be addressed directly, such as cough suppression in cough syncope
5. Careful avoidance of agents that lower BP (including a-blockers, diuretics, and alcohol) is important

Question 44

The cornerstone of the non-pharmacological management of patients with reflex syncope is ___ and ___ regarding the benign nature of the condition

Answer 44

education and reassurance

Question 45

Treatment of OH

Answer 45

1. In the absence of HTN, take sufficient salt and water intake, targeting 2–3 L of fluids per day and 10 g of NaCl.
2. Rapid cool water ingestion is reported to be effective in combating orthostatic intolerance and post-prandial hypotension.
3. Sleeping with the head of the bed elevated (108) prevents nocturnal polyuria, maintains a more favorable distribution of body fluids, and ameliorates nocturnal HTN.
4. Gravitational venous pooling in older patients can be treated with abdominal binders or compression stockings.
5. Rx: Midodrine (5–20 mg, three times daily)–a-agonist

Question 46

Key DDX for syncope

Answer 46

1. Neurogenic / Reflex - most common
2. Cardiac – HIGH RISK PATIENTS, most dangerous
3. Orthostatic – “D A A D”
4. Other - Neurologic, Functional, Psych

Question 47

Key points of workup and risk stratification

Answer 47

1. H/P, Orthostatics, Meds, ECG, +/- Carotid Massage
2. Risk Stratify
   - High Risk - Admit w/ cardiac work-up
   - Low Risk - Outpatient workup based on frequency of episodes
3. Brain Imaging ONLY if focal Neuro Deficits or Head trauma

Question 48

What patients with syncope need to be referred to a specialist

Answer 48

Patients with suspected cardiac syncope or atypical neurally mediated syncope (particularly with injury or driving or occupational related implications)