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 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

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

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

❑ 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: 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 prior to LOC, carotid bruit ❑ 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

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 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.