For unstable tachyarrhythmia, which intervention is commonly performed?

• A. Adenosine administration
• B. Carotid sinus massage
• C. Watchful waiting
• D. Defibrillation

Answer: (D)

Unstable tachyarrhythmia means the heart is beating too fast and not pumping effectively, with the patient showing signs of poor perfusion. The quickest way to restore a safe rhythm and perfusion is an electric shock. Defibrillation delivers an unsynchronized shock that can stop the chaotic electrical activity of life-threatening rhythms like ventricular tachycardia or ventricular fibrillation, allowing the heart to reset to a normal rhythm. This immediate energy delivery is critical in an unstable scenario, where delays can be fatal. Adenosine is used for certain supraventricular tachycardias but won’t stabilize an unstable patient and can be harmful in this context. Carotid sinus massage is contraindicated in instability because it can worsen the situation. Watchful waiting offers no active treatment and isn’t appropriate when instability is present. If there is a pulse and the rhythm is shockable, a synchronized cardioversion is considered, but in the most urgent unstable cases, defibrillation is the common immediate intervention to save life.