Cardioversion and Defibrillation

👍🏻 Support us: Mastercard: 5106 2110 8086 3207 (ARMEN ASTVATSATRYAN) A transthoracic direct-current (DC) shock of sufficient magnitude depolarizes the entire myocardium, rendering the entire heart momentarily refractory to repeat depolarization. Thereafter, the most rapid intrinsic pacemaker, usually the sinoatrial node, reassumes control of heart rhythm. Thus, DC cardioversion-defibrillation very effectively terminates tachyarrhythmias that result from reentry. However, it is less effective for terminating tachyarrhythmias that result from automaticity because the return rhythm is likely to be the automatic tachyarrhythmia. For tachyarrhythmias other than ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT), the DC shock must be synchronized to the QRS complex (called DC cardioversion) because a shock that falls during the vulnerable period (near the peak of the T wave) can induce VF. In VF, synchronization of a shock to the QRS complex is neither necessary nor possible. A DC shock applied without synchronization to a QRS complex is DC defibrillation. Video is on YouTube - https://youtu.be/a6u4PgYq3P4