What is the appropriate treatment and management for syncope?

Syncope Treatment

Treatment of syncope must be directed at the underlying cause and mechanism, with the primary goals being prevention of recurrence, limitation of physical injuries, and in cardiac cases, reduction of mortality risk. 1

Initial Risk Stratification and Triage

The first critical step is determining whether the patient requires immediate hospitalization or can be managed as an outpatient:

• High-risk patients requiring immediate hospitalization include those with suspected or known significant heart disease, ECG abnormalities suggesting arrhythmic syncope, syncope during exercise, syncope causing severe injury, or family history of sudden death 2
• Low-risk patients with single episodes of vasovagal syncope and no cardiac disease can often be reassured and discharged without further investigation 1
• Intermediate-risk patients with recurrent syncope require systematic evaluation by syncope specialists 3

Treatment by Mechanism

Neurally-Mediated (Vasovagal) Syncope

Education and lifestyle modifications are the cornerstone of treatment, with physical counterpressure maneuvers as first-line therapy for patients with prodromal symptoms. 1

Lifestyle measures (Class I recommendation):

• Patient education and reassurance about the benign nature of the condition 1
• Trigger avoidance: hot crowded environments, volume depletion, prolonged standing, venipuncture when possible 1
• Recognition of prodromal symptoms (weakness, lightheadedness, visual changes) to allow early intervention 1
• Increased salt and fluid intake using sport drinks and salt tablets as volume expanders 1

Physical counterpressure maneuvers:

• Isometric leg crossing or hand grip with arm tensing induces significant blood pressure increases during impending syncope 1
• These maneuvers allow patients to avoid or delay loss of consciousness in most cases with recognizable prodromal symptoms 1
• Leg crossing and squatting are effective techniques 4

Pharmacological therapy (only when non-pharmacological methods fail):

• Beta-blockers are NOT recommended for vasovagal syncope, as five long-term controlled studies have failed to show efficacy 1
• Midodrine (alpha-agonist vasoconstrictor) showed benefit in short-term controlled studies in elderly patients with severe vasovagal hypotensive syncope (Class B evidence) 1, 4
• Fludrocortisone (salt-retaining steroid) is usually considered first for additional pharmacological benefit 4

Orthostatic Hypotension

Syncope due to orthostatic hypotension should be treated in all patients, with treatment often requiring only modification of drug treatment for concomitant conditions (Class I recommendation). 4

Non-pharmacological measures:

• Discontinue or adjust medications that lower blood pressure: diuretics, alpha-blockers, and vasodilators 1
• Avoid rapid changes from supine to standing position 5
• Increased intake of sodium and fluids 5
• Judicious exercise of leg and abdominal muscles, especially swimming 4
• Elastic garments to prevent gravitational pooling 6

Pharmacological therapy (when non-pharmacological methods unsuccessful):

• Fludrocortisone (salt-retaining steroid) is usually considered first 4, 6
• Midodrine appears to be of particular interest with rapidly expanding and generally positive experience (Class B evidence) 4, 6
• Desmopressin may be of value in patients with nocturnal polyuria 4
• Octreotide in those with post-prandial hypotension 4
• Erythropoietin in those with anemia 4

Cardiac Arrhythmias

In patients with cardiac syncope, treatment must address both the underlying structural disease and the arrhythmic mechanism to reduce mortality risk. 1

Sinus node dysfunction (including bradycardia/tachycardia syndrome):

• Cardiac pacemaker therapy is indicated (Class I, Level B) when bradyarrhythmia has been demonstrated to account for syncope 4
• Physiological pacing (atrial or dual-chamber) is superior to VVI pacing (Class I, Level A) and lowers the risk of developing atrial fibrillation 4
• VVI or VVIR pacing should be avoided in sick sinus syndrome 4
• Rate-adaptive pacing (especially atrial-based) may be warranted to minimize exertion-related symptoms 4

Ventricular arrhythmias:

• Implantable cardioverter-defibrillator (ICD) is indicated for ventricular tachycardia causing syncope, particularly in patients with structural heart disease or inherited cardiomyopathies 1
• ICD implantation for survivors of cardiac arrest due to ventricular fibrillation or tachycardia with LVEF ≤40% 2
• Beta-blockers as first-line therapy to suppress symptomatic ventricular extrasystoles and reduce arrhythmic risk 2
• Catheter ablation is strongly recommended (Class I) for ventricular extrasystoles triggering recurrent ventricular fibrillation with ICD discharges 2

Structural Heart Disease

Surgical intervention or device therapy is indicated based on the specific structural abnormality:

• Surgical intervention for severe aortic stenosis or atrial myxoma causing syncope 1
• Revascularization and/or pharmacological therapy for syncope associated with myocardial ischemia 1
• ICD implantation in hypertrophic cardiomyopathy with syncope to prevent sudden cardiac death 1
• Valve repair/replacement for valvular disease 2

Situational Syncope

Treatment focuses on identifying and managing the specific trigger:

• Identify and treat the underlying cause of cough (respiratory infections or asthma) 1
• Opioid-containing cough suppressants (dihydrocodeine or hydrocodone) for direct cough suppression 1

Critical Caveats and Pitfalls

• Even with effective cardiac treatment such as ICD, patients may remain at risk for syncope recurrence because only the sudden cardiac death risk is addressed, not necessarily the mechanism of syncope 1
• Cardiac pacing at relatively rapid rates for orthostatic hypotension has been reported but has not been subject to rigorous study and is not currently considered to be of treatment value 4
• In pediatric patients with cardioinhibitory syncope and exaggerated asystolic response, a pacemaker should be avoided whenever possible; effective management with pharmacological therapy without pacemaker implantation has been shown 4
• Drug therapy for orthostatic hypotension may aggravate supine hypertension 4
• Psychiatric assessment is recommended in patients with frequent recurrent syncope, multiple somatic complaints, and concerns for stress, anxiety, or psychiatric disorders 1
• Cardiac syncope carries a higher mortality risk compared to non-cardiac causes, with a 24% one-year mortality rate 2