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]; Alejandro Lemor, M.D. [3]

Overview

Syncope is the transient loss of consciousness(LOC) due to cerebral hypoperfusion and it is characterized by a rapid onset, a short duration and a spontaneous complete recovery.

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 is LOC

Yes

No

Characterize the syncope: ❑ Rapid onset, AND ❑ Short duration, AND ❑ Spontaneous complete recovery

Consider alternative diagnoses: ❑ Cataplexy ❑ Drop attacks ❑ Functional /psychogenic pseudosyncope ❑ TIA

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

Yes: ❑ Transient LOC

Non traumatic

Traumatic

Syncope

Seizure

Psychogenic

Diagnostic and Treatment Flowchart in Patients with Suspected Syncope

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

Characterize symptoms ❑ Loss of consciousness (LOC) ❑ Rapid onset ❑ Short duration ❑ Spontaneous complete recovery ❑ Prodrome (diaphoresis, nausea, blurry vision) ❑ Chest pain ❑ Palpitations ❑ Bowel or bladder incontinence ❑ Activity prior to LOC (driving, machine operation, flying, competitive athletics) ❑ Position prior to LOC ❑ Supine ❑ Sitting ❑ Standing Inquire about medications intake: ❑ Nitrate ❑ Diuretics ❑ Antiarrhythmic ❑ Alpha blocker ❑ Beta blocker ❑ ACE inhibitors or ARB ❑ Hydralazine ❑ Ethanol ❑ Benzodiazepines ❑Antipsychotics ❑ Tricyclic antidepressants ❑ Barbiturates Inquire about the past medical history: ❑ Previously healthy ❑ Previous syncope episodes ❑ Cardiovascular disease (arrhythmia, valvular disease, heart failure) ❑ Neurological diseases ❑ Recent trauma

Identify possible triggers: ❑ Emotional stress ❑ Change in position ❑ Fatigue ❑ Exertion ❑ Warm weather ❑ Prolonged standing ❑ Cough ❑ Micturition ❑ Defecation ❑ Swallowing ❑ Head motion ❑ Arm motion ❑ Shaving Trauma

Rule out other possible diagnoses: With loss of consciousness: ❑ 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 Without loss of consciousness: ❑ Cataplexy ❑ Drop attacks ❑ Functional /psychogenic pseudosyncope ❑ TIA

❑ Examine the patient ❑ Order EKG

Findings: ❑ Heart rate: tachycardia, normal or bradycardia ❑ Absence of heart disease ❑ History of recurrent syncope ❑ After unpleasant sight or smell ❑ Associated to nausea ❑ Head rotation or pressure to carotid sinsus ❑ Neurological system: look for focal findings

Findings: ❑ Blood pressure: ❑ Measure in both arms, while standing and supine ❑ Fall in systolic BP ≥ 20 mmHg and/or in diastolic BP of at least≥ 10 mmHg between the supine and sitting BP reading ❑ Heart rate: tachycardia ❑ Cardiac evaluation: palpitations ❑ After standing up or prolonged standing ❑ Start of new vasodepresive drug ❑ Presence of autonomic neuropathy

Findings: ❑ Heart rate: tachycardia, normal or bradycardia ❑ Cardiac evaluation: palpitations, carotid bruits ❑ Presence of structural hearth disease ❑ During exertion ❑ Abnormal EKG findings: ❑ Bifascicular block, Wide QRS(≥ 0.12 s) ❑ Mobitz I second degree AV block ❑ Non-sustained VT , Early repolarization ❑ Pre-excited QRS complexes ❑ Long or short QT intervals ❑ Q waves (myocardial infarction)

Reflex

Orthostatic hypotension

Cardiovascular

Treatment ❑ Explain diagnosis, provide reassurance ❑ Explain risk of recurrence and avoidance of triggers ❑ Isometric PCM in patients with prodrome

Treatment ❑ Adequate hydration and salt intake ❑ Midodrine or fludrocortisone as adjunctive therapy if needed

Treatment (depends on the cause of the arrhythmia): ❑ Cardiac pacing: for sinus node disease, Mobitz II AV block, BBB with positive EPS ❑ Catheter ablation: for SVT and VT in absence of structural hearth disease ❑ Antiarrhythmic drug therapy: for AF, failed catheter ablation ❑ Implantable cardioverter defibrillator: VT with heart disease, EPS induced VT in patients with previous MI, VT and inherited cardiomyopathy

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 perform carotid sinus massage (CSM) 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.