What should be considered in history taking and physical examination in a patient with syncope?

Comprehensive Approach to History Taking and Physical Examination in Syncope

A detailed history and physical examination should be performed in all patients with syncope, as this approach alone can determine the cause in most cases, significantly reducing morbidity and mortality through proper diagnosis and management. 1

Key Elements of History Taking

Circumstances and Triggers

• Pre-syncope circumstances:
  • Position when syncope occurred (standing, sitting, supine)
  • Activity during episode (exertion, neck turning, micturition, defecation, coughing)
  • Environmental factors (warm crowded place, prolonged standing, after meals)
  • Potential triggers (fear, pain, emotional distress, medical instrumentation)

Prodromal Symptoms

• Cardiac causes: Brief prodrome or no prodrome, palpitations before loss of consciousness
• Neurally-mediated causes: Nausea, vomiting, feeling warm, sweating, visual blurring, abdominal discomfort
• Duration of prodrome: Longer prodrome (>5 seconds) suggests neurally-mediated syncope

Event Characteristics

• Eyewitness accounts: Essential for accurate diagnosis
• Duration of unconsciousness: Brief in vasovagal syncope, potentially longer in cardiac causes
• Presence of seizure-like activity: Can occur in both cardiac and neurological causes 1
• Color changes: Pallor is common in syncope; cyanosis suggests prolonged cardiac arrest
• Injury: Presence and severity of trauma
• Incontinence: May occur in both syncope and seizures

Post-event Symptoms

• Recovery pattern: Rapid in cardiac syncope, prolonged fatigue in neurally-mediated syncope
• Post-event confusion: Suggests seizure rather than syncope
• Chest pain, palpitations: Suggests cardiac cause

Past Medical History

• Cardiovascular disease: Ischemic heart disease, heart failure, valvular disease, arrhythmias
• Neurological disorders: Parkinson's disease, epilepsy, autonomic neuropathy
• Metabolic disorders: Diabetes (risk for autonomic dysfunction)
• Previous syncope episodes: Frequency, circumstances, similarity to current episode

Medication Review

• Antihypertensives: Risk of orthostatic hypotension
• Antiarrhythmics: Particularly Class IA and IC (risk of proarrhythmia)
• QT-prolonging medications: Risk of torsades de pointes
• Diuretics: Volume depletion and electrolyte disturbances
• Psychotropic medications: Phenothiazines and tricyclics (risk of orthostasis)
• Over-the-counter medications and supplements: Including ephedra-containing preparations 1

Family History

• Sudden cardiac death: Particularly in young relatives (<50 years)
• Inherited cardiac conditions: Long QT syndrome, Brugada syndrome, hypertrophic cardiomyopathy
• Family history of syncope: May suggest inherited conditions 1

Physical Examination Components

Vital Signs

• Orthostatic blood pressure measurements: Essential in all patients
  • Measure in lying position, then immediately upon standing, and after 3 minutes
  • Orthostatic hypotension: ≥20 mmHg drop in systolic BP or ≥10 mmHg drop in diastolic BP 1
• Heart rate: Bradycardia or tachycardia at rest

Cardiovascular Examination

• Heart rhythm: Irregularities suggesting arrhythmias
• Heart sounds: Murmurs (aortic stenosis, hypertrophic cardiomyopathy), gallops (heart failure), rubs
• Carotid bruits: Contraindication for carotid sinus massage
• Carotid sinus massage: Consider in patients >40 years with unexplained syncope (contraindicated with carotid bruits, recent stroke/TIA) 2

Neurological Examination

• Basic neurological assessment: Look for focal deficits
• Autonomic function: Signs of autonomic failure (e.g., parkinsonism)
• Gait and balance: Assessment for neurological disorders

Risk Stratification Based on History and Physical Findings

Features Suggesting Cardiac Causes (Higher Risk)

• Age >60 years
• Male sex
• Known cardiac disease (structural heart disease, arrhythmias)
• Brief or absent prodrome
• Syncope during exertion
• Syncope in supine position
• Low number of episodes (1-2)
• Abnormal cardiac examination
• Family history of sudden cardiac death 1

Features Suggesting Non-cardiac Causes (Lower Risk)

• Younger age
• No known cardiac disease
• Syncope only in standing position
• Clear positional trigger
• Typical prodrome present (nausea, warmth)
• Specific situational triggers (cough, micturition, defecation)
• Frequent recurrence with similar characteristics 1

Common Pitfalls to Avoid

1. Failing to obtain witness accounts: Eyewitness descriptions are crucial for accurate diagnosis
2. Incomplete medication review: Always check for medications that can cause syncope
3. Omitting orthostatic vital signs: Should be performed in all syncope patients
4. Neglecting age-specific considerations: Causes vary significantly by age group
5. Misinterpreting seizure-like activity: Can occur in cardiac syncope and does not necessarily indicate epilepsy
6. Overlooking subtle cardiac findings: Soft murmurs or irregular rhythms may be significant
7. Incomplete family history: Critical for identifying inherited cardiac conditions

Immediate Next Steps

• 12-lead ECG: Required for all patients with syncope (Class I recommendation) 1
• Risk stratification: Determine need for hospitalization vs. outpatient evaluation
• Targeted additional testing: Based on findings from history and physical examination

Following this systematic approach to history taking and physical examination will lead to a diagnosis in the majority of syncope cases, allowing for appropriate management and reduction in morbidity and mortality.