## Clinical Diagnosis **Key Point:** This patient has ventricular tachycardia (VT) with hemodynamic instability (syncope, hypotension, elevated JVP). The ECG findings of AV dissociation and fusion beats are pathognomonic for VT. ## Immediate Management Algorithm ```mermaid flowchart TD A[Wide-complex tachycardia]:::outcome --> B{Hemodynamically stable?}:::decision B -->|No - Hypotensive/syncope| C[Synchronized DC cardioversion]:::action B -->|Yes - Stable| D[Antiarrhythmic drugs]:::action C --> E[100 J initial dose]:::action E --> F[Repeat if needed]:::action D --> G[Amiodarone or Procainamide]:::action ``` ## Why Synchronized DC Cardioversion? **High-Yield:** In **hemodynamically unstable VT** (BP <90 mmHg, syncope, pulmonary edema, altered mental status), synchronized DC cardioversion is the definitive first-line treatment regardless of drug options. **Clinical Pearl:** AV dissociation and fusion beats are diagnostic of VT and confirm the need for immediate electrical therapy in this unstable patient. ## Dosing & Sequence | Finding | Implication | |---------|-------------| | Syncope + hypotension | Hemodynamic instability present | | AV dissociation + fusion beats | Confirms VT diagnosis | | EF 35% | Reduced ejection fraction (contraindication for verapamil) | **Warning:** Verapamil is contraindicated in VT and in patients with reduced ejection fraction—it can cause cardiovascular collapse. Antiarrhythmic drugs (amiodarone, procainamide) are second-line, used only after cardioversion or in stable VT. ## Rationale for Other Options - **Amiodarone:** Appropriate for hemodynamically stable VT or as post-cardioversion therapy, not for unstable VT requiring immediate electrical intervention. - **Verapamil:** Absolutely contraindicated in VT (can degenerate to VF) and in reduced EF. - **Procainamide:** Slower onset than cardioversion; reserved for stable VT. [cite:Harrison 21e Ch 226]
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