Synchronized Cardioversion Candidate Uncertainty
Immediate electrical cardioversion is recommended when tachycardia is causing serious signs and symptoms and is treated as a hemodynamically unstable tachyarrhythmia.[1] If synchronization cannot be performed promptly or synchronization delays occur and clinical condition is critical, unsynchronized (defibrillation) shocks should be used immediately.[2]
Hemodynamic Instability Versus Rhythm Uncertainty
Hemodynamically unstable tachycardia requires urgent restoration of sinus rhythm with cardioversion rather than additional time for detailed rhythm analysis.[1] Hemodynamic instability is supported by findings such as systolic blood pressure <80 mm Hg or altered mentation.[1]
Immediate Action When Synchronization Suitability Is Unclear
Sedation should be administered whenever feasible during preparation for cardioversion.[2] Continuous reassessment should occur after each cardioversion because resynchronization may be required after each shock.[2] If delays in synchronization occur and clinical condition is critical, the process should immediately transition to unsynchronized shocks.[2]
Shock Mode Selection Based on Rhythm Pattern
Synchronized cardioversion is used for narrow-complex tachycardia (100 J) and monomorphic VT (100 J).[2] Polymorphic VT requires an unsynchronized, high-energy shock (defibrillation).[2] Resynchronization is required after each synchronized cardioversion.[2]
Energy Preparation While Clarifying Rhythm
Oxygen saturation monitoring, suction availability, IV access, and intubation equipment should be available at the bedside during electrical cardioversion preparation.[2]
Targets of Immediate Therapy
The immediate goal is prompt termination of the unstable tachyarrhythmia and restoration of an organized rhythm.[1]
Common Pitfall: Deferring Shock Delivery for Synchronization
Synchronization should not delay shock delivery when clinical condition is critical.[2]