SVT Acute Management Algorithm¶

flowchart TD
    A[SVT Identified] --> B{Patient Stable?}

    B -->|Yes| C[Vagal Maneuvers]
    B -->|No - Hemodynamic Compromise| D[Synchronized Cardioversion<br/>0.5-1 J/kg]

    C --> E{Converted?}
    E -->|Yes| F[Monitor, ECG, Consider Echo]
    E -->|No| G[IV Access]

    G --> H[Adenosine 0.1 mg/kg IV push<br/>Max 6mg first dose]

    H --> I{Converted?}
    I -->|Yes| F
    I -->|No| J[Adenosine 0.2 mg/kg<br/>Max 12mg]

    J --> K{Converted?}
    K -->|Yes| F
    K -->|No| L{Is this WPW with<br/>wide complex?}

    L -->|Yes - Possible AF/Flutter| M[AVOID AV nodal blockers<br/>Consider Procainamide<br/>or Cardioversion]
    L -->|No - Narrow Complex| N[Consider:<br/>• IV Esmolol<br/>• IV Amiodarone<br/>• Cardioversion]

    D --> O{Converted?}
    O -->|Yes| F
    O -->|No| P[Increase to 2 J/kg<br/>Consider Amiodarone]

    F --> Q[Post-Conversion ECG]
    Q --> R{Delta Wave?}
    R -->|Yes| S[WPW - Cardiology Consult<br/>Prophylactic Therapy]
    R -->|No| T[Likely AVNRT<br/>Consider Prophylaxis if Recurrent]

    style D fill:#ff6b6b
    style M fill:#ff6b6b
    style S fill:#ffd93d

📋 Text Version (if diagram doesn't render)

**SVT Management Algorithm** 1. **SVT Identified** → Is patient stable? - **NO (Hemodynamic compromise)** → Synchronized Cardioversion 0.5-1 J/kg - If not converted → Increase to 2 J/kg, consider Amiodarone - **YES (Stable)** → Vagal Maneuvers 2. **Vagal Maneuvers** → Converted? - **YES** → Monitor, ECG, Consider Echo → Post-conversion ECG - **NO** → IV Access → Adenosine 0.1 mg/kg IV push (max 6mg) 3. **First Adenosine** → Converted? - **YES** → Post-conversion ECG - **NO** → Adenosine 0.2 mg/kg (max 12mg) 4. **Second Adenosine** → Converted? - **YES** → Post-conversion ECG - **NO** → Is this WPW with wide complex? - **YES (Possible AF/Flutter)** → AVOID AV nodal blockers, Consider Procainamide or Cardioversion - **NO (Narrow complex)** → Consider IV Esmolol, IV Amiodarone, or Cardioversion 5. **Post-Conversion ECG** → Delta wave present? - **YES** → WPW - Cardiology consult, Prophylactic therapy - **NO** → Likely AVNRT - Consider prophylaxis if recurrent

Key Points¶

Vagal Maneuvers¶

Infants: Ice to face (10-15 seconds)
Children: Valsalva, carotid massage, handstand

Adenosine Administration¶

Rapid IV push through large bore IV
Follow immediately with NS flush
Record rhythm strip during administration

Cardioversion Energies¶

First: 0.5-1 J/kg
Second: 2 J/kg
Maximum: 10 J/kg or adult dose

Medications to AVOID in WPW¶

Adenosine (can accelerate pathway)
Digoxin
Verapamil
Beta-blockers (relative caution)

Red Flags for WPW¶

Pre-excitation on baseline ECG
Wide complex tachycardia
Irregular wide complex (suggests AF with WPW)