Synchronized cardioversion is the recommended treatment for patients who have a symptomatic, unstable reentry SVT or V-tach with pulses. Synchronized cardioversion is also routinely used to treat unstable atrial flutter and unstable atrial fibrillation. Synchronized cardioversion is used to treat arrhythmias where there is a QRS complex present, allowing the device to synchronize the shock. This avoids delivering a shock during the heart's vulnerable period (T wave), which could induce ventricular fibrillation. Synchronized cardioversion is used for unstable tachyarrhythmias, such as atrial fibrillation or ventricular tachycardia with a pulse. The energy level of the shock is determined based on the specific rhythm being treated. Synchronized cardioversion is used to restore normal heart rhythm in specific arrhythmias such as atrial fibrillation, ventricular tachycardia with a pulse, and atrial flutter. It delivers a controlled electric shock to the heart that is synchronized to the R-wave of the QRS complex. Synchronized cardioversion is used to treat other arrhythmias, including atrial fibrillation (AF), atrial flutter, and stable ventricular tachycardia when medications have failed to convert the rhythm, or when the patient is becoming unstable and the rhythm must be immediately terminated. The most common indications for synchronized cardioversion are unstable atrial fibrillation, atrial flutter, atrial tachycardia, and supraventricular tachycardias. Cardioversion also treats other kinds of abnormal heartbeats, including atrial flutter, atrial tachycardia and ventricular tachycardia. Cardioversion or defibrillation is also used in emergency situations for people who suffer sudden life-threatening arrhythmias. We use synchronized cardioversion for hemodynamically unstable tachycardias with a pulse still present. Common indications include unstable Atrial Fibrillation (AF), Atrial Flutter, Supraventricular Tachycardia (SVT), and Ventricular Tachycardia (VT) with a pulse. At present, two types of defibrillators are in use for external cardioversion and defibrillation: a monophasic sinusoidal waveform (positive sine wave) and a biphasic truncated waveform. Synchronized cardioversion is utilized on hemodynamically unstable patients with a pulse. Hemodynamic instability may be demonstrated through signs and symptoms, such as an altered mental status, hypotension, chest pain, dyspnea, diaphoresis, acute congestive heart failure, or myocardial ischemia.