A nurse is caring for a client with heart failure who is receiving continuous cardiac monitoring. The client suddenly develops ventricular tachycardia with a heart rate of 180 beats per minute. The client is conscious but reports chest pain and dizziness. What is the nurse's priority intervention?

Synchronized cardioversion is priority for conscious VT with hemodynamic compromise to immediately restore normal rhythm. Other interventions (medication, oxygen, ECG) are important but less urgent than rhythm conversion.

Understanding the Clinical Scenario
The client with heart failure is experiencing ventricular tachycardia (VT) at a rate of 180 bpm. The key assessment findings are that the client is conscious but symptomatic, reporting chest pain and dizziness. This presentation is critical because it distinguishes the client as having a pulse and being hemodynamically unstable, which directly dictates the treatment algorithm.

Prioritizing the Intervention
The priority intervention is to prepare for synchronized cardioversion. In the management of tachyarrhythmias, the decision tree splits based on the presence of a pulse and signs of hemodynamic instability. Chest pain and dizziness are classic indicators of instability because the extremely rapid ventricular rate compromises cardiac output, leading to myocardial ischemia and cerebral hypoperfusion. For unstable VT with a pulse, the standard of care is immediate synchronized cardioversion to rapidly terminate the arrhythmia and restore effective circulation.

Analysis of Incorrect Options
1. Administer amiodarone 150 mg IV push immediately: While amiodarone is a first-line antiarrhythmic for VT, it is the priority for a stable patient with a pulse. In an unstable patient, waiting for medication preparation, administration, and onset of action delays definitive electrical therapy and risks further deterioration to a pulseless state.
3. Increase oxygen flow rate to 6 L/min via nasal cannula: This is a supportive measure to address hypoxia and chest pain but does not treat the underlying cause of the instability—the arrhythmia itself. It is an important concurrent action but not the priority intervention.
4. Obtain a 12-lead ECG to confirm the rhythm: Delaying treatment to obtain a 12-lead ECG in an unstable patient is contraindicated. The monitor rhythm is sufficient to identify VT and the need for immediate cardioversion. A 12-lead ECG can be obtained after the patient is stabilized.

Pathophysiology and Rationale Connection
The client's heart failure history provides a substrate for arrhythmias. As noted in the reference material, patients with structural heart disease, such as heart failure, are at significant risk for ventricular arrhythmias, including sustained VT and electrical storm . The rapid rate of 180 bpm severely shortens diastolic filling time. This reduces stroke volume and coronary artery perfusion, which explains the client's chest pain (myocardial ischemia) and dizziness (cerebral hypoperfusion). Synchronized cardioversion delivers a timed electrical shock that depolarizes the myocardium simultaneously, allowing the sinoatrial node to resume its role as the primary pacemaker, thereby immediately improving hemodynamics. Delaying this intervention in an unstable patient can precipitate a transition to a pulseless rhythm or cardiac electrical storm, defined as three or more episodes of sustained VT or ventricular fibrillation within a 24-hour period .