A patient presents to the Emergency Department in Supraventricular Tachycardia (SVT). The patient is assessed with complaints of chest pain and a BP of 80/40. Synchronized cardioversion is ordered by the MD. What does the nurse do?

Choice A rationale Synchronized cardioversion requires the machine to sense the QRS complex specifically. If the discharge occurs during the P wave, it would not successfully terminate the tachyarrhythmia. The P wave represents atrial depolarization, but the goal is to safely reset the ventricular rhythm. Incorrectly timing the shock could lead to ineffective therapy or trigger more dangerous rhythms if the electrical discharge happens during the wrong phase of cardiac activity. Choice B rationale Defibrillation at 360 joules is an unsynchronized high energy shock used for pulseless rhythms like ventricular fibrillation or pulseless ventricular tachycardia. Using this for a patient with supraventricular tachycardia who still has a pulse and blood pressure, even if low, is inappropriate. An unsynchronized shock delivered during the vulnerable period of the T wave could actually induce ventricular fibrillation, worsening the patient's critical condition and leading to immediate cardiac arrest. Choice C rationale Defibrillation at 100 joules is also an unsynchronized delivery of electrical energy. While the energy level is lower than 360 joules, the lack of synchronization remains the primary safety concern. Patients in supraventricular tachycardia with signs of hemodynamic instability, such as a blood pressure of 80/40 and chest pain, require synchronized cardioversion to avoid the R on T phenomenon. Unsynchronized shocks are strictly reserved for patients who lack a discernible pulse or rhythm. Choice D rationale Selecting sync ensures the defibrillator delivers the electrical shock exactly on the R wave, which is the peak of ventricular depolarization. This timing avoids the vulnerable repolarization period of the T wave. For a patient with supraventricular tachycardia and hypotension, synchronization is vital to prevent inducing ventricular fibrillation. This precise timing allows the heart to depolarize simultaneously and provides the opportunity for the sinoatrial node to resume its role as the primary pacemaker.