Florida State Paramedic Practice Exam

Where does synchronized cardioversion typically occur on the QRS complex?

1. On the T wave

2. Between the R and S waves

3. On the R wave

4. At the P wave

The correct answer is: On the R wave

Synchronized cardioversion is a procedure used to restore a normal heart rhythm in patients experiencing certain types of tachycardia. During this procedure, the electrical shock is delivered in synchronization with the heart's electrical activity to minimize the risk of inducing ventricular fibrillation, which can occur if the shock is delivered during the T wave. The R wave is the most prominent part of the QRS complex and represents the depolarization of the ventricles. By timing the shock to be delivered on the R wave, the heart is less likely to be disrupted at a critical phase of the cardiac cycle. This synchronization helps ensure that the shock is effective in converting the abnormal rhythm back to a normal sinus rhythm without precipitating more severe arrhythmias. Understanding that the timing of the shock during cardioversion is crucial highlights the importance of recognizing when and how to deliver it, making it a vital aspect of emergency cardiac care.