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Syncope

Learning Objectives

Core Knowledge & Clinical Reasoning

  • [ ] Identify red flags requiring urgent cardiology evaluation (exertional syncope, family history SCD, abnormal ECG)
  • [ ] Differentiate vasovagal syncope from cardiac causes based on history and exam
  • [ ] Analyze when echocardiography is indicated vs NOT indicated (routine vasovagal does not require echo)
  • [ ] Evaluate ECG findings that suggest cardiac etiology (LQTS, WPW, HCM, Brugada)

Evidence-Based Management

  • [ ] Apply evidence that beta-blockers are NOT effective for vasovagal syncope (Class III: No Benefit)
  • [ ] Formulate conservative management plan (hydration, salt intake, physical counter-maneuvers)

Communication & Counseling

  • [ ] Reassure families when history is consistent with benign vasovagal syncope
  • [ ] Educate patients on prodrome recognition and physical counter-pressure maneuvers
  • [ ] Discuss driving restrictions for adolescents with recurrent syncope

Systems-Based Practice

  • [ ] Determine appropriate triage: primary care management vs cardiology referral
  • [ ] Avoid unnecessary testing for typical vasovagal presentations (cost-effective care)

Key Guidelines

2017 ACC/AHA/HRS Guideline for Evaluation and Management of Syncope Circulation. 2017;136:e60-e122 Includes pediatric-specific recommendations

Quick Reference: Syncope Evaluation Algorithm

Definition

Syncope: Transient loss of consciousness due to cerebral hypoperfusion - Rapid onset - Brief duration - Spontaneous complete recovery

Etiology in Children

Cause Prevalence Notes
Vasovagal (neurocardiogenic) ~75% MOST COMMON in children
Orthostatic 10-15% POTS, dehydration
Cardiac 2-5% Arrhythmia, structural
Other Variable Seizure, psychogenic, metabolic

Initial Evaluation (Class I)

All patients: 1. Detailed history of the event - Prodrome (nausea, warmth, vision changes) - Position (standing, sitting, supine) - Triggers (pain, emotion, heat, prolonged standing) - Activity (exertional vs non-exertional) - Post-event symptoms (confusion, injury) 2. Physical examination including orthostatic BP 3. Family history (SCD, arrhythmias, cardiomyopathy) 4. 12-lead ECG

RED FLAGS - Cardiology Referral

Finding Concern
Exertional syncope Cardiac cause (HCM, AAOCA, LQTS)
Post-exertional syncope More concerning than with exercise
No prodrome Arrhythmic cause
Syncope with chest pain/palpitations Arrhythmia
Syncope while supine Arrhythmia
Family history of SCD Channelopathy, cardiomyopathy
Family history of cardiomyopathy HCM, DCM
Abnormal ECG Structural or electrical disease
Known heart disease Increased risk
Significant injury from syncope Suggests no warning

When Echocardiography is NOT Indicated

Echo NOT indicated if ALL of the following: - Normal ECG - No family history of cardiomyopathy/SCD - Non-exertional syncope - No murmur concerning for structural disease - Clear vasovagal prodrome and trigger

Vasovagal Syncope

Characteristics

  • Clear prodrome (lightheadedness, warmth, nausea, pallor, diaphoresis)
  • Typical triggers (prolonged standing, pain, heat, emotion)
  • Brief LOC with rapid recovery
  • No post-ictal confusion

Management

  1. Education and reassurance (most important)
  2. Counter-pressure maneuvers (leg crossing, hand gripping)
  3. Hydration (increase fluid and salt intake)
  4. Avoid triggers (prolonged standing, heat)
  5. Tilt training (for recurrent cases)

What DOESN'T Work

Beta-blockers are NOT effective (Class III: No Benefit) Multiple studies show no benefit in pediatric vasovagal syncope

Pacemaker Consideration

  • Class IIb for severe pallid breath-holding spells (cardioinhibitory mechanism)
  • NOT routinely indicated for typical vasovagal syncope

POTS (Postural Orthostatic Tachycardia Syndrome)

Definition

  • HR increase ≥40 bpm (or ≥30 bpm in adults) within 10 minutes of standing
  • Without orthostatic hypotension
  • Symptoms of orthostatic intolerance

Management

  • Increased fluids (2-3 L/day)
  • Increased salt intake
  • Compression stockings
  • Exercise reconditioning
  • Consider fludrocortisone, midodrine, beta-blockers (if tachycardia symptomatic)

Board Pearls

Pearl: Vasovagal syncope is most common cause in children

~75% of pediatric syncope

Pearl: Beta-blockers are NOT effective for vasovagal syncope (Class III)

Despite common misconception, no benefit shown

Pearl: Echo NOT needed if: normal ECG + no family hx + no exertional symptoms + no concerning murmur

Avoid unnecessary testing

Self-Assessment

Q1: A 14-year-old girl faints while standing in line at an amusement park on a hot day. She felt nauseated and sweaty beforehand, was unconscious for 30 seconds, and recovered immediately. ECG is normal. Family history is negative. What is the most likely diagnosis and next step?

Answer **Answer**: Vasovagal syncope; reassurance and education **Rationale**: Classic prodrome (nausea, diaphoresis), trigger (prolonged standing, heat), brief LOC, rapid recovery. Normal ECG and negative family history. This is typical vasovagal syncope. Echo is NOT indicated. Management is education, hydration, avoiding triggers.

Q2: A 12-year-old collapses during a soccer game without warning. He regains consciousness after 1 minute but is confused. ECG shows borderline prolonged QTc. What is the most appropriate next step?

Answer **Answer**: Urgent cardiology referral and further evaluation for LQTS/structural disease **Rationale**: RED FLAGS present: exertional syncope, no prodrome, post-event confusion, abnormal ECG. This requires urgent cardiology evaluation including echo, extended ECG monitoring, exercise testing, and possibly genetic testing for channelopathy.

References

  • Shen WK, et al. Circulation. 2017;136:e60-e122