📌 Transition to Adult Care – Key elements✔ Start planning by age 14-16 | ✔ Portable medical summary (diagnosis, surgeries, medications, allergies) | ✔ Identify adult congenital heart disease (ACHD) specialist | ✔ Discuss contraception, pregnancy risks, insurance, lifestyle | ✔ Screen for depression, anxiety, adherence | ✔ Use HEADSS assessment for adolescents.
📌 ACHD – High-risk conditions✔ Fontan circulation | ✔ Systemic right ventricle (TGA after atrial switch) | ✔ Pulmonary arterial hypertension (Eisenmenger) | ✔ Severe aortic stenosis/coarctation with aneurysm | ✔ Mechanical valve on anticoagulation | ✔ Cyanotic CHD with residual defects.
📌 Supraventricular Tachycardia (SVT) – Mechanisms✔ AVRT (accessory pathway – Wolff-Parkinson-White) – most common in infants | ✔ AVNRT (dual AV node physiology) – common in adolescents | ✔ Atrial flutter (intra-atrial reentry) – post-op CHD | ✔ Atrial ectopic tachycardia (automatic) – often incessant.
📌 SVT – ECG features✔ Narrow QRS (<0.09 sec) regular tachycardia | ✔ Rate: newborns >220 bpm, children >180 bpm | ✔ P waves: retrograde (inverted in II, III, aVF) or absent | ✔ Sudden onset/termination | ✔ WPW: delta wave, short PR in sinus rhythm.
📌 Acute SVT management – ABCDE✔ Vagal maneuvers (ice to face in infants, Valsalva in older) | ✔ Adenosine 0.1 mg/kg rapid IV push (max 6 mg) → repeat 0.2 mg/kg (max 12 mg) | ✔ Synchronized cardioversion if unstable (0.5-1 J/kg) | ✔ Esophageal overdrive pacing if available.
📌 Long-term SVT treatment✔ Beta-blockers (propranolol, nadolol) first-line | ✔ Digoxin (avoid in WPW) | ✔ Flecainide, propafenone, sotalol or amiodarone for refractory | ✔ Catheter ablation (curative) – especially AVRT, AVNRT, atrial flutter | ✔ Infant SVT often resolves by 12-18 months.
📌 WPW – risk stratification✔ Syncope + WPW = high risk | ✔ Intermittent preexcitation does not exclude risk | ✔ Invasive EP study for high-risk athletes/symptomatic | ✔ Ablation for high-risk accessory pathways (short refractory period).
📌 Transition: Transfer of Care Checklist✔ Transfer summary by age 18 | ✔ Adult provider introduction | ✔ Establish self-management skills (medication, appointments, insurance) | ✔ Discuss reproductive health (contraindicated pregnancy conditions: PAH, severe ventricular dysfunction, Fontan complications).
1️⃣ Immediate (unstable patient) ▪ Synchronized cardioversion: 0.5-1 J/kg, repeat 2 J/kg. ▪ If IV access: adenosine while preparing cardioversion. ▪ Prepare for intubation/resuscitation if deteriorated.
2️⃣ Stable patient – Vagal maneuvers ▪ Infant: ice bag to face (covering eyes and nose) for 15-30 sec. ▪ Child/adolescent: Valsalva (blow through syringe, strain), modified Valsalva (supine to leg raise), carotid massage (avoid in children). ▪ No ocular pressure.
3️⃣ Pharmacologic (stable) ▪ Adenosine: 0.1 mg/kg rapid IV push (max 6 mg) followed by saline flush; if no effect → 0.2 mg/kg (max 12 mg). ▪ Second-line: esmolol (IV), procainamide, amiodarone (only if refractory).
4️⃣ Post-conversion management ▪ ECG documentation, echocardiogram to exclude structural disease. ▪ Start oral propranolol (1-2 mg/kg/day) or nadolol. ▪ Avoid digoxin/verapamil if WPW (risk of VF). ▪ Refer to pediatric cardiology for long-term plan (ablation vs medication).
5️⃣ Long-term & Transition (CHD patients) ▪ For ACHD with residual arrhythmia: ablation, risk of recurrence. ▪ Transition planning: transfer of care summary, adult EP consult. ▪ Pregnancy counseling for women with SVT/WPW.
❓ Reflex prompt 1: A 2-week-old with heart rate 280 bpm, pale, poor feeding. What is your immediate action? ✅ Answer: Unstable → synchronized cardioversion 0.5-1 J/kg. If IV in place, adenosine first while preparing cardioverter.
❓ Reflex prompt 2: A 12-year-old with recurrent palpitations, ECG shows delta wave and short PR. Which medications are contraindicated? ✅ Answer: Digoxin and verapamil (calcium channel blockers) – can accelerate antegrade conduction over accessory pathway → VF risk. Use beta-blockers or refer for ablation.
❓ Reflex prompt 3: A 16-year-old with repaired tetralogy of Fallot presents with irregular tachycardia, ECG shows sawtooth flutter. Most likely arrhythmia? ✅ Answer: Atrial flutter (intra-atrial reentry). Common after atrial surgery. Needs anticoagulation before cardioversion (if >48hr) and may respond to class III agents or ablation.
❓ Reflex prompt 4: What are the essential components of a transition readiness plan for a 17-year-old with Fontan circulation? ✅ Answer: Portable medical summary, cardiac diagnosis & surgeries, list of medications, allergy, identify adult CHD specialist, discuss contraception (avoid OCPs), pregnancy risk (high risk), psychosocial assessment, insurance transfer, and self-management skills.
❓ Reflex prompt 5: Infant SVT: what is the success rate of adenosine? When would you use esophageal pacing? ✅ Answer: Adenosine success >90%. Esophageal pacing used when adenosine contraindicated (asthma, severe bronchospasm) or to differentiate from atrial flutter.
📌 Chapter 152 – Transitioning to Adult Care (Nelson 22e)
• Goal: Prepare youth with chronic conditions (CHD, cardiomyopathy) for adult healthcare. Start by age 14-16.
• Key elements: Portable medical summary (diagnosis, surgeries, medications, allergies, last echo), transition readiness assessment, transfer of care to ACHD specialist.
• High-risk conditions for pregnancy: Pulmonary hypertension, Fontan with complications, systemic RV dysfunction, severe aortic stenosis, Marfan with aorta >45mm. Contraindicated pregnancy.
• Psychosocial: Screen for depression, anxiety, adherence, substance use (HEADSS). Promote self-advocacy.
📌 Chapter 484.3 – Supraventricular Tachycardia (SVT)
• Mechanisms: AVRT (WPW – accessory pathway) most common in infants; AVNRT (dual AV node) adolescents; atrial flutter post-surgery CHD.
• Diagnosis: Narrow QRS tachycardia, rate >220 (infants) / >180 (children), sudden onset/offset. Differentiate from sinus tachycardia (gradual, variable).
• Acute treatment: Unstable → synchronized cardioversion (0.5-1 J/kg). Stable → vagal maneuvers (ice to face, Valsalva), adenosine 0.1-0.2 mg/kg IV push.
• Chronic management: Beta-blockers first-line (propranolol, nadolol). Avoid digoxin/verapamil in WPW. Catheter ablation curative (especially AVRT/AVNRT).
• WPW risk: Syncope, rapid conduction during atrial fibrillation, family history sudden death → EP study and ablation.
• Transition relevance: Patients with CHD and SVT need lifelong EP follow-up, pregnancy risk assessment, and planning for ablation in specialized ACHD centers.
💡 Clinical Pearl: In infants, SVT often presents with heart failure after 24h; suspect if unexplained poor feeding/irritability. Adenosine is safe and first-line in stable infants.