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: Treat as according

Uncertain etiology

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

If arrhythmic cause identified: (EPS)

Risk stratification

Determine if there are any high risk criteria: ❑ Severe structural or CAD ❑ Clinical orECG features suggesting arrhythmic syncope: -syncope during exertion or supine -palpitations at the time of syncope -family history ofSCD -non-sustained VT -conduction abnormalities with QRS >120 ms -sinus bradycardia -pre-exited QRS complex -prolonged or short QR interval -brugada pattern -ARVC ❑ Important comorbidities: -Severe anemia -Electrolyte intolerance

❑ If yes: High risk

❑ If no: Low risk

Immediate in-hospital monitoring: In bed or telemetry

Low risk, recurrent syncopes: ❑ Cardiac or neurally mediated testst as appropriate: -Holter if >1 episode/week -ELR if interval between episodes <4 weeks Delayed treatment guided by ECK documentation

Low risk, single syncope

❑ If suspicion of structural heart disease: Echocardiography

Was it in high risk setting?

If yes: Treat as according

No structural heart disease

Yes

No: No further evaluation

Tilt testing

Treatment of Syncope

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.
• Perform tilt testing if psychiatric disease.
• Tilt testing may be considered for differentiating syncope with jerking movements from epilepsy.
• If syncope happened after standing up position, there should be documentation with active standing or tilt testing in order to diagnose OH.
• Perform CSM if patient >40 years with syncope of unknown aetiology after initial evaluation.
• If multiple unexplained falls; perform tilt testing.
• Consider ILR before embarking on cardiac pacing in patients with suspected or certain reflex syncope presenting with frequent or traumatic syncopal episodes.
• Evaluate neurologically if syncope is due to ANF, to evaluate underlying disease.

Don'ts

• Don't performCSM 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.
• Don't use tilt testing for assessment of treatment.
• Don't perform isoproterenol tilt testing in patients with ischaemic heart disease.
• Don't use ATP test as a diagnostic test to select patients for cardiac pacing, owing to lack of correlation with spontaneous syncope,.
• Don't perform EPS if there is already indication for ICD in patients with ischemic heart with suspected arrhythmic cause.
• Don't perform EPS in patients with normal ECK, no heart disease, and no palpitations.

References

Reflex and orthostatic intolerance

Cardiac

Unexplained and high risk SCD

Unpredictable or high- frequency

Preictable or low frequency

Cardiac arrythmias SCD

Structural (cardiac or pulmonary)

i.e. CAD, HOCM, ARV, channelopathies

Consider specific therapy or delayed treatment based by ECG documentation

Education, reassurance, avoidance of triggers

Specfic therapy of the culprit arrythmia

Treatment of underlying disease

Consider ICD therapy