Initial Evaluation and Management of Syncope
A comprehensive history of present illness (HPI) is the cornerstone of syncope evaluation, focusing on circumstances before, during, and after the event, as it can establish diagnosis in up to 50% of cases without additional testing. 1
Key Components of HPI for Syncope
Pre-Syncope Circumstances
- Position and activity: Document if patient was supine, sitting, or standing; at rest, changing posture, during/after exercise, during/after urination, defecation, cough, or swallowing 1
- Predisposing factors: Note presence of crowded/warm places, prolonged standing, post-prandial period 1
- Precipitating events: Document fear, intense pain, neck movements 1
Onset of Attack
- Prodromal symptoms: Record presence of:
During the Attack (from eyewitness)
- Manner of falling: Document if slumping or kneeling over
- Skin color: Note pallor, cyanosis, or flushing
- Duration of loss of consciousness: Brief episodes typically suggest reflex syncope
- Breathing pattern: Document presence of snoring
- Movements: Document tonic, clonic, tonic-clonic, minimal myoclonus, or automatisms (to distinguish from seizure) 1
Post-Syncope Phase
- Recovery symptoms: Document nausea, vomiting, sweating, cold sensation, confusion, muscle aches
- Injuries sustained: Document any trauma
- Post-event symptoms: Note chest pain, palpitations, urinary/fecal incontinence 1
Background Information
- Family history: Document sudden death, congenital arrhythmogenic heart disease, fainting
- Cardiac history: Document any previous cardiac disease
- Neurological history: Document Parkinsonism, epilepsy, narcolepsy
- Metabolic disorders: Document diabetes or other relevant conditions
- Medications: Document all medications, especially antihypertensives, antianginals, antidepressants, antiarrhythmics, diuretics, and QT-prolonging agents 1
- Recurrence pattern: Document time from first episode and frequency 1, 3
Physical Examination
- Vital signs: Include orthostatic blood pressure measurements
- Cardiovascular exam: Focus on murmurs, abnormal heart sounds
- Neurological exam: Perform if neurological cause suspected 1, 2
Initial Testing
- ECG: Required for all patients with syncope
- Additional tests based on initial findings:
- Carotid sinus massage in patients >40 years
- Echocardiogram if heart disease suspected
- ECG monitoring if arrhythmic syncope suspected
- Orthostatic challenge if related to standing position 1
Risk Stratification
High-risk features requiring urgent evaluation:
- Abnormal ECG
- History of cardiovascular disease
- Lack of prodrome
- Age >65 years
- Syncope during effort or while supine
- Palpitations before syncope 1, 3
Common Pitfalls to Avoid
Failure to distinguish syncope from other causes of loss of consciousness: Ensure all four key diagnostic questions are answered positively:
- Was loss of consciousness complete?
- Was it transient with rapid onset and short duration?
- Did patient recover spontaneously and completely?
- Did patient lose postural tone? 1
Overreliance on laboratory and imaging tests: These have low diagnostic yield unless specifically indicated by history and physical exam 2, 3
Missing cardiac syncope: This carries the highest mortality risk and requires prompt evaluation 2
Inadequate eyewitness accounts: Obtain detailed descriptions from witnesses whenever possible 1
The initial evaluation should conclusively answer whether the episode was truly syncope, determine its etiology when possible, and assess the risk of adverse cardiovascular outcomes or death 1.