A nurse is caring for two patients: one with ventricular tachycardia (VT) who has a pulse but is hemodynamically unstable, and another in pulseless ventricular fibrillation (VF). Which statement best describes the nurse's appropriate interventions regarding cardioversion and defibrillation for these patients?

Management of life-threatening ventricular dysrhythmias depends on hemodynamic stability and presence of a pulse. Key principles include synchronized cardioversion, defibrillation, R-on-T avoidance, and organized versus disorganized ventricular activity, guiding timing and shock delivery mode selection. Rationale: A. Ventricular tachycardia with a pulse but hemodynamic instability requires synchronized cardioversion, which times the shock with the R wave to avoid inducing ventricular fibrillation. Pulseless ventricular fibrillation is a disorganized rhythm requiring immediate unsynchronized defibrillation to depolarize all myocardial cells simultaneously. B. Cardioversion is synchronized and cannot be used for pulseless rhythms like ventricular fibrillation. VF requires defibrillation because there is no organized QRS complex to synchronize with, making this statement physiologically incorrect. C. Both cardioversion and defibrillation are not interchangeable, and neither involves synchronized shocks for all rhythms. Using incorrect synchronization methods can worsen dysrhythmias, particularly in VF where immediate unsynchronized shock is required. D. Defibrillation is indicated only for pulseless, disorganized rhythms such as ventricular fibrillation or pulseless VT. Stable VT with a pulse requires synchronized cardioversion; applying defibrillation to all ventricular dysrhythmias ignores critical hemodynamic differences and increases risk of deterioration.