Emergency cardioversion and defibrillation are life-saving procedures that exert direct electric current to the heart through the chest wall in order to terminate lethal tachyarrhythmias. Early defibrillation is life-saving in the survival of adult patients who develop sudden cardiac arrest. In the defibrillation process, myocardial cells are depolarized, and VF is terminated by delivering a certain amount of direct current to the heart, passing through the chest wall. Proper timing and accurate performance of these procedures have a vital role in both survival and recovery postresuscitation neurological functions without sequelae. Return of spontaneous circulation (ROSC) rates in defibrillation performed without losing time (within 20-30 seconds) can be up to 100% following the occurrence of these lethal rhythms. While cardioversion is performed in pulsating contraction rhythms, defibrillation is an electrical stimulation procedure applied in rhythms that do not generate pulses. In the cardioversion, synchronous energy is exerted onto the QRS complex to convert the rhythm into a sinus rhythm.
When there are signs of instability in rhythms with a pulse, emergency cardioversion (ECV) can be preferred over all other treatments if it is known to have acute onset (less than 48 hours) in atrial rhythm disorders, Transcutaneous pacing (TCP) is a recommended practice for temporary stabilization and invasive techniques such as transvenous pacing (TVP) should be attempted for longer pacing requirements. This chapter gives a brief outline on the outstanding features of electrotherapies (i.e., ECV; defibrillation; TCP, TVP) both in case of life-threatening dysrhythmias and also in urgent non-lethal situations.