**1. Introduction**

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58 Cardiac Defibrillation

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A *guideline* is a statement by which to determine a course of action. A guideline aims to streamline particular processes according to a set routine or sound practice. By definition, following a guideline is never mandatory. Guidelines are not binding and are not enforced [5]. In effect guidelines are derived from 3 sources of data: 1. randomized clinical trials; 2. observational data from cohorts of high-risk patients with less common diseases; and 3. ex‐ pert opinion on potential benefit for clinical condition or specific circumstances in which da‐ ta are limited or uncertain. For all 3 categories of clinical guidance, there are limitations in available data that reinforce the importance of physician judgment in decision making, based on circumstances of individual cases or subgroups of patients [6]. Understanding the value and limitations of current information is important not only for the clinical electro‐ physiologist, but also for general cardiologists and primary care physicians because of their roles in referring appropriate patients for consideration of implantable cardioverter- defib‐ rillator therapy and for the clinical management of patients at risk of sudden cardiac death. While the high stakes and unpredictable nature of sudden cardiac death justifiably provoke fear and uncertainty, emotional factors should not outweigh scientific evidence. In this con‐ text the obligation to adhere to guidelines could, in effects, to have paradoxically dulled our discriminatory senses as clinicians [7].

© 2013 Giaccardi et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2013 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
