Synchronized cardioversion is simply a well-timed defibrillation. While it typically starts at lower doses, synchronization can occur at any energy level. When we hit “sync,” the monitor identifies the patient’s R waves. When we hit the shock button, we hold it and the monitor will deliver a shock on the next R wave (in contrast to a defib that full sends as soon as we hit the button). Why? In order to miss the relative refractory period: the second half of the T wave where stimulation can cause