How should syncope be evaluated and treated in an older adult patient?

Evaluation and Treatment of Syncope in Older Adults

In older adults with syncope, immediately perform a detailed history, physical examination with orthostatic vital signs, and 12-lead ECG to risk-stratify for cardiac causes, which carry 18-33% one-year mortality compared to 3-4% for non-cardiac syncope, then hospitalize high-risk patients while managing low-risk neurally-mediated or orthostatic syncope in the outpatient setting. 1

Initial Risk Stratification

The most critical first step is identifying high-risk features that predict cardiac syncope and increased mortality:

High-Risk Features Requiring Hospitalization 1

• Age >60 years (independent risk factor) 1
• Known structural heart disease including history of congestive heart failure, ventricular arrhythmias, coronary artery disease, or congenital heart disease 1
• Abnormal ECG findings: ischemia, arrhythmia, prolonged QT interval, bundle branch block, or bifascicular block 1
• Associated chest pain or symptoms of acute coronary syndrome 1
• Physical examination findings of significant heart failure or valvular disease 1
• Exertional syncope or syncope in supine position 1
• Brief or absent prodrome suggesting arrhythmic cause 1
• Family history of sudden cardiac death 1

Low-Risk Features Suggesting Outpatient Management 1

• Syncope only when standing with clear positional triggers 1
• Clear prodrome (nausea, warmth, diaphoresis) 1
• Specific situational triggers (pain, medical environment, dehydration) 1
• No known cardiac disease and normal ECG 1
• Recurrent episodes with similar characteristics 1

Mandatory Initial Evaluation for All Patients

History 1, 2

Focus on these specific elements:

• Position and activity at onset (standing, supine, exertional) 1, 2
• Prodromal symptoms (duration, quality—palpitations vs. nausea/warmth) 1, 2
• Eyewitness accounts of the event 1, 2
• Post-event symptoms and recovery time 1, 2
• Medication review (especially antihypertensives, diuretics, vasodilators) 1
• Relationship to meals and time of day 1

Physical Examination 1, 2

• Orthostatic vital signs: measure blood pressure and heart rate lying, sitting, and immediately upon standing 1, 2
  • Orthostatic hypotension defined as ≥20 mmHg drop in systolic BP or ≥20 bpm increase in heart rate within 3 minutes 1
• Cardiac examination for murmurs, gallops, signs of heart failure 1, 2
• Neurological examination for focal deficits, gait disturbance 1
• Carotid sinus massage in patients >40 years (after excluding carotid bruits) 1, 2

12-Lead ECG 1

Mandatory for all patients to identify:

• Conduction abnormalities (bradycardia, AV block, bundle branch block) 1
• Arrhythmias or ventricular ectopy 1
• Long QT syndrome or Brugada pattern 1
• Signs of ischemia or prior infarction 1
• Delta waves (Wolff-Parkinson-White syndrome) 1

Laboratory Testing 2

Only order if clinically indicated—not routine 2:

• Volume loss suspected (hematocrit, electrolytes) 2
• Metabolic cause suspected (glucose, renal function) 2

Common Causes in Older Adults

The three most common causes in older adults differ substantially from younger patients 1:

1. Orthostatic hypotension (20-30% of cases) 1

   • Prevalence ranges from 6% in community-dwelling elderly to 33% in hospitalized elderly 1
   • Causes: medications (most common), autonomic failure, diabetes, Parkinson's disease 1
   • Critical pitfall: Supine hypertension often coexists, complicating treatment 1

2. Carotid sinus hypersensitivity (up to 20% of cases) 1

   • Rare before age 40, increases with cardiovascular comorbidity 1
   • Cardioinhibitory type more clearly linked to syncope than vasodepressor type 1

3. Cardiac arrhythmias 1

   • Associated with 18-33% one-year mortality vs. 3-4% for non-cardiac causes 1
   • Independent predictor of mortality even after adjusting for comorbidities 1

Disposition Decisions

Admit to Hospital (Level B Recommendation) 1

Patients with ANY of the following:

• History of congestive heart failure or ventricular arrhythmias 1
• Chest pain or acute coronary syndrome symptoms 1
• Physical examination evidence of significant heart failure or valvular disease 1
• ECG findings of ischemia, arrhythmia, prolonged QT, or bundle branch block 1

Consider Admission (Level C Recommendation) 1

• Age >60 years 1
• History of coronary artery disease or congenital heart disease 1
• Family history of unexpected sudden death 1
• Exertional syncope in younger patients without obvious benign etiology 1

Safe for Outpatient Management 1, 2

Patients with:

• Isolated or rare episodes 1
• No structural heart disease 1
• Normal baseline ECG 1
• Clear neurally-mediated or orthostatic mechanism 2

Further Diagnostic Testing (When Initial Evaluation Non-Diagnostic)

For Suspected Cardiac Syncope 1, 2

• Echocardiography: if structural heart disease suspected or abnormal cardiac exam 1
• Exercise testing: especially if exertional syncope, to assess for ischemia, blood pressure response, and catecholaminergic VT 1
• Prolonged ECG monitoring: 1, 2
  • Holter monitor if daily symptoms 1
  • Event monitor if monthly symptoms 1
  • Implantable loop recorder for infrequent episodes with injury risk (52% vs. 20% diagnostic yield compared to conventional testing) 2
• Electrophysiologic studies: if high suspicion for arrhythmic cause 1

For Suspected Neurally-Mediated Syncope 2

• Tilt-table testing: first-line for younger patients (<40 years) with recurrent syncope 2
• Carotid sinus massage: first-line for older patients (>40 years) with recurrent syncope 2

Treatment Approaches

Orthostatic Hypotension 3, 4

Non-pharmacologic (first-line):

• Increase fluid intake (≥2 liters/day) and salt intake (6-10 g/day) 3
• Physical counter-pressure maneuvers (leg crossing, handgrip) 3
• Compression garments (at least thigh-high) 3
• Acute water ingestion (240-480 mL) for temporary relief, peak effect at 30 minutes 3
• Reduce or eliminate hypotensive medications and diuretics 3
• Sleep with head of bed elevated to minimize supine hypertension 4

Pharmacologic:

• Midodrine (alpha-agonist): dose-dependent improvement in standing BP 3, 4
  • Start 2.5 mg in renal impairment 4
  • Critical warning: Monitor for supine hypertension; avoid last dose within 3-4 hours of bedtime 4
  • Contraindicated in hypertension, heart failure, urinary retention 4
  • Use cautiously with cardiac glycosides (risk of bradycardia/AV block) 4
• Fludrocortisone: increases plasma volume 3
  • Use cautiously in diabetics (increases intraocular pressure risk) 4
• Droxidopa: for neurogenic orthostatic hypotension in Parkinson's, autonomic failure, multiple system atrophy 3

Vasovagal Syncope 2, 3

First-line (non-pharmacologic):

• Patient education: trigger avoidance, prodrome recognition, assume supine position when symptoms occur 2, 3
• Physical counter-pressure maneuvers: leg crossing with muscle tensing (39% reduction in recurrence when prodrome present) 2, 5
• Increased salt and fluid intake 2

Pharmacologic (for refractory cases):

• Midodrine: reasonable for recurrent episodes (Class IIa) 2
• Fludrocortisone: might be reasonable if inadequate response to salt/fluid (Class IIb) 2
• Beta-blockers: might be reasonable in patients ≥42 years (Class IIb) 2
• Dual-chamber pacing: only in highly selected patients ≥40 years with documented prolonged pauses (Class IIb) 2

Cardiac Syncope 5

Treatment must address the specific underlying cause:

• Arrhythmias: antiarrhythmic drugs, catheter ablation, pacemaker, or ICD as appropriate 5
• Structural disease: surgical or interventional correction when possible 5
• Ischemia: revascularization 1

Critical Pitfalls to Avoid

1. Do not assume benign vasovagal syncope without cardiac evaluation in patients >40 years or with cardiac risk factors 2
2. Do not rely on single negative Holter monitor to exclude arrhythmic causes if clinical suspicion remains high 2
3. Avoid routine neuroimaging and EEG unless head trauma or focal neurologic signs present 2, 6
4. Do not overlook medication review—polypharmacy is a leading cause in elderly 1
5. Monitor for supine hypertension when treating orthostatic hypotension with vasopressors 1, 4
6. Reappraise entire workup if syncope recurs despite presumed diagnosis and treatment 2, 3

When to Refer to Cardiology

Immediate referral indicated for: 2

• High-risk features (age >60, known heart disease, exertional syncope, abnormal ECG, family history of sudden death) 2
• Diagnostic uncertainty after initial evaluation 2
• Need for specialized testing (tilt-table, electrophysiology studies, implantable loop recorder) 2
• Prescription of cardiac medications (midodrine, fludrocortisone) requiring cardiovascular expertise 2
• Consideration of pacemaker or ICD implantation 2