Syncope resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Karol Gema Hernandez, M.D. [2]

Definition

Syncope is defined as a transient LOC, characterized by rapid onset, short duration and spontaneous complete recovery due to cerebral hypoperfusion.

Causes

Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

• Hemorrhage
• Hypotension
• Hypoxia
• Ruptured abdominal aortic aneurysm
• Ventricular arrhythmia

Common Causes

• Arrhythmia
• Medication
• Orthostatic hypotension
• Vagal stimulation
• Vertebrobasilar insufficiency

Management

Syncope in the Context of Transient LOC

Determine if there was LOC

If yes: ❑ Rapid onset? ❑ Short duration? ❑ Spontaneous complete recovery?

If no: ❑ Cataplexy ❑ Drop attacks ❑ Falls ❑ Functional /psychogenic pseudosyncope ♦ Psychiatric evaluation ❑ TIA of carotid origin

If no to ≥1; exclude the following before proceeding with syncope evaluation: ❑ Coma ❑ Aborted SCD ❑ Epilepsy -Perform neurological evaluation -Perform tilt testing, preferably with concurrent EEG and video monitoring if doubt of mimicking epilepsy ❑ Metabolic disorders: ♦ Hypoglycemia ♦ Hypoxia ♦ Hyperventilation with hypocapnia ❑ Intoxication ❑ Vertebrobasilar TIA

If yes: ❑ Transient LOC

Non traumatic

Traumatic

Suspect: ❑ Syncope ❑ Seizure ❑ Psychogenic

Diagnostic Flowchart in Patients with Suspected Syncope

❑ Initial Assessment:

❑ Clinical history ❑ Physical examination (including supine and standing BP measurement after 3 minutes if OH is suspected) ❑ EKG

Syncope

T-LOC non syncopal

Certain diagnosis

Uncertain etiology

❑ Confirm with specific test: - EEG - US of neck arteries - Brain CT - Brain MRI OR ❑ Consult with specialist

Risk stratification

Treatment

High risk: ❑ Early Evaluation and treatment

Low risk, recurrent syncopes: ❑ Cardiac or neurally mediated tests as appropriate OR ❑ Delayed treatment guided by EKG documentation

Low risk, single or rare syncope: ❑ No further evaluation

Specific etiology diagnostic evaluation

Algorithms based in 2009 ESC Guidelines for the Diagnosis and Management of Syncope.

Do's

• Tilt testing is indicated when it is of clinical value to demonstrate susceptibility to reflex syncope to the patient.
• Tilt testing should be considered to discriminate between reflex and OH syncope.
• Tilt testing may be considered for differentiating syncope with jerking movements from epilepsy.

Don'ts

• CSM should be avoided in patients with previous TIA or stroke within the past 3 months and in patients with carotid sinus bruits (except if carotid sinus Doppler studies excluded significant stenosis.
• Tilt testing is not recommended for assessment of treatment.
• Isoproterenol tilt testing is contraindicaated in patients with ischaemic heart disease.
• Owing to lack of correlation with spontaneous syncope, ATP test cannot be used as a diagnostic test to select patients for cardiac pacing.