Defibrillation and cardioversion

Abstract

Going back to the ‘archaic past and to obsolete ancestors’ [1] provides insight not only where we came from but where we might be heading. Indeed history matters in medicine as it does in everyday life. It is now 40 years since the introduction of DC defibrillation and cardioversion [2,3]. Like the proverbial pebble cast in the water, the ripple effects of these technologies extend beyond the horizon of early prediction. Among the more important consequences were: stimulating the development of coronary care units, facilitating the emergence of coronary bypass and other heart operations, focusing attention on the still formidable out-of-hospital problem of sudden cardiac death, advancing the field of clinical electrophysiology and contributing to implantable devices to protect against death from malignant arrhythmias. Most important are the countless lives saved with this straightforward medical advance. From time immemorial, drugs, potions and herbs were the mainstay in treating arrhythmias of the heart. This therapeutic approach presented formidable limitations. In the individual patient the effective dose of the drug was unknown. A tedious biological titration was required to avoid serious or even life threatening toxic reactions. When the arrhythmia was ventricular tachycardia, the route for administering drugs was necessarily intravenous, thereby maximizing the likelihood of adverse reactions. When drugs were given orally, the required incremental dosing consumed hours and at times days. Even with the most scrupulous monitoring, toxic reactions were nearly unavoidable. Looking back it is remarkable how the clinical topography has changed since the introduction of DC defibrillation and cardioversion. One example may be illustrative. Levine, during 33 years of clinical practice, observed only 137 episodes in 107 cases of paroxysmal ventricular tachycardia [4]. This represents approximately three patients annually; it may be far less, since all wide complex tachycardias were designated as ventricular. In contrast during …