What is the management of syncope in children?

Management of Syncope in Children

Initial Evaluation - Required for ALL Pediatric Syncope Patients

Every child presenting with syncope must receive a detailed medical history, physical examination, family history, and 12-lead ECG—this is the foundation of management and cannot be skipped. 1, 2

Critical History Elements to Obtain

• Circumstances of the event: Was the child upright, exercising, supine, or swimming when syncope occurred? 1
• Prodromal symptoms: Presence or absence of warning signs like dizziness, nausea, or visual changes 1
• Triggers: Emotional stress, loud noises, pain, prolonged standing, hot environments, or auditory stimuli 1, 3
• Associated symptoms: Palpitations within seconds of loss of consciousness, chest pain, or seizure-like movements 1, 4
• Family history: Sudden cardiac death in relatives under age 50, unexplained drowning, familial cardiomyopathy, or channelopathies 1, 3
• Past medical history: Known congenital heart disease, prior cardiac surgery, or diagnosed arrhythmias 1, 3

Physical Examination Focus

• Cardiac auscultation: Listen for murmurs suggesting hypertrophic cardiomyopathy, aortic stenosis, or other structural disease 1, 3
• Vital signs: Orthostatic blood pressure measurements, heart rate abnormalities 3, 5
• Signs of heart failure: Hepatomegaly, peripheral edema, jugular venous distension 3

Risk Stratification - Distinguishing Benign from Life-Threatening Causes

HIGH-RISK Features Requiring IMMEDIATE Cardiac Workup

If ANY of these features are present, proceed directly to comprehensive cardiac evaluation—do not assume vasovagal syncope: 1, 2, 3

• Exertional syncope (especially mid-exertion): Strongly associated with hypertrophic cardiomyopathy, LQTS, CPVT, or coronary anomalies 1, 3
• Absence of prodromal symptoms: Suggests arrhythmic cause rather than neurally mediated 1, 2
• Palpitations within seconds of loss of consciousness: Indicates primary arrhythmia 1, 2
• Syncope triggered by loud noise, fright, or extreme emotional stress: Classic for LQTS 1, 2
• Syncope while supine or during sleep: Cannot be vasovagal 1
• Family history of sudden cardiac death <30 years: Suggests inherited channelopathy or cardiomyopathy 1, 3
• Abnormal physical examination: Cardiac murmur, abnormal heart sounds 1, 2
• Abnormal ECG: Any conduction abnormality, prolonged QTc, Brugada pattern, pre-excitation, or ventricular hypertrophy 1

LOW-RISK Features Suggesting Vasovagal Syncope

Vasovagal syncope accounts for 75% of pediatric syncope and has these characteristic features: 1, 2

• Prolonged upright posture before event 1
• Clear prodromal symptoms (lightheadedness, nausea, diaphoresis, visual changes) 1
• Triggers: Pain, fear, hot crowded environments, dehydration 1
• Normal physical examination and ECG 1
• No family history of sudden cardiac death 1

Diagnostic Testing Algorithm

For LOW-RISK Patients (Suspected Vasovagal Syncope)

If history, physical examination, family history, and ECG are all normal and consistent with vasovagal syncope, no further testing is required—proceed directly to education and reassurance. 1, 2

• Tilt-table testing can be useful when the diagnosis remains unclear despite initial evaluation, but has variable sensitivity (20-90%) and should not be used for routine confirmation 1, 2

For HIGH-RISK Patients (Suspected Cardiac Syncope)

Noninvasive diagnostic testing MUST be performed when congenital heart disease, cardiomyopathy, or primary rhythm disorder is suspected: 1, 2

• Echocardiography: To evaluate for structural heart disease (hypertrophic cardiomyopathy, aortic stenosis, pulmonary hypertension, myocarditis) 1, 3
• Exercise stress testing: Essential for diagnosing channelopathies with adrenergically mediated arrhythmias (LQTS, CPVT) 1, 2
• Extended cardiac monitoring (Holter, event recorder, implantable loop recorder): When arrhythmia is suspected; diagnostic yield is 43% in pediatric syncope patients 1, 2
• Cardiac MRI: Consider for suspected cardiomyopathy or myocarditis 3

Treatment Approach

For Vasovagal Syncope (75% of Cases)

Education on symptom awareness of prodromes and reassurance are the cornerstone of treatment—this is a Class I recommendation and should be the first-line approach for all vasovagal syncope. 1, 2

Lifestyle Modifications (First-Line Treatment)

• Hydration: Aggressive fluid intake (at least 2 liters daily for adolescents) 1, 2, 6
• Dietary salt supplementation: Increase salt intake to expand intravascular volume 1, 2, 6
• Trigger avoidance: Prolonged standing, hot crowded environments, dehydration 1, 2
• Physical counterpressure maneuvers: Leg crossing, muscle tensing when prodrome occurs 1, 2
• Exercise program: Regular aerobic conditioning 6

Pharmacological Treatment (Second-Line)

For patients not responding to lifestyle measures, midodrine is reasonable as the preferred pharmacological agent. 1, 2

• Midodrine: Alpha-agonist that increases peripheral vascular resistance; shown to reduce recurrence in pediatric patients 1, 2
• Pseudoephedrine: Alternative alpha-agonist; reduced symptoms in 94% of children in one case series 1

For Cardiac Syncope (1.5-6% of Cases)

Interventions recommended for adults with similar cardiac conditions can be applied in children, including antiarrhythmic medications, implantable cardioverter-defibrillator, and surgical intervention. 1, 2

• Channelopathies (LQTS, CPVT, Brugada): Beta-blockers, ICD placement, lifestyle modifications specific to condition 1
• Structural heart disease: Surgical correction, medical management of heart failure, ICD as indicated 1
• Wolff-Parkinson-White syndrome: Catheter ablation 1

Special Pediatric Conditions

Breath-Holding Spells (Age 6 Months to 5 Years)

Reassurance is the primary treatment for breath-holding spells, with parental education on trigger avoidance—no further testing is indicated for classic presentations. 2, 7

• Cyanotic breath-holding spells: Expiratory cessation during crying leading to cyanosis and loss of consciousness 1, 7
• Pallid breath-holding spells: Early form of vasovagal syncope with vagally mediated cardiac inhibition; may have prolonged asystole 1, 7
• Management: Parental reassurance, avoidance of reinforcement of precipitating behavior, iron supplementation if anemic 1, 7

Critical Pitfalls to Avoid

• Never dismiss exertional syncope as benign vasovagal syncope: This has high specificity for life-threatening cardiac disease and requires full cardiac evaluation 1, 2, 3
• Do not confuse convulsive movements with epilepsy: Vasovagal syncope can cause brief seizure-like movements due to cerebral hypoxia; 64% of children with syncope and convulsions on tilt-table testing had cardiac asystole >3 seconds 1, 4
• Do not over-investigate typical vasovagal syncope: Once normal history, examination, family history, and ECG are documented, no further testing is needed 1, 2
• Do not use pacemakers for vasovagal syncope with asystole in children: Even with prolonged asystole, pacemakers should be avoided due to the transient and benign nature of the syndrome 1
• Do not assume normal echocardiography rules out all cardiac disease: Channelopathies have structurally normal hearts and require ECG and exercise testing for diagnosis 2, 3