This document specifies requirements that are applicable to IMPLANTABLE CARDIOVERTER DEFIBRILLATORS AND CRT-DS and the functions of ACTIVE IMPLANTABLE MEDICAL DEVICES intended to treat tachyarrhythmia. The tests that are specified in ISO 14708 are type tests and are to be carried out on samples of a device to show compliance. This document was designed for tachyarrhythmia PULSE generators used with either endocardial or epicardial LEADs. At the time of this edition, the authors recognized the emergence of technologies that do not use ENDOCARDIAL or EPICARDIAL LEADS for which adaptations of this part will be required. Such adaptations are left to the discretion of MANUFACTURERS incorporating these technologies. This document is also applicable to some non-implantable parts and accessories of the devices (see Note 1). The characteristics of the IMPLANTABLE PULSE GENERATOR or LEAD shall be determined by either the appropriate method detailed in this document or by any other method demonstrated to have accuracy equal to, or better than, the method specified. In the case of dispute, the method detailed in this document shall apply. Any aspect of an ACTIVE IMPLANTABLE MEDICAL DEVICE intended to treat bradyarrhythmias or cardiac resynchronization is covered by ISO 14708-2. NOTE 1 The device that is commonly referred to as an ACTIVE IMPLANTABLE MEDICAL DEVICE might in fact be a single device, a combination of devices, or a combination of a device or devices and one or more accessories. Not all of these parts are required to be either partially or totally implantable, but there is a need to specify some requirements of non-implantable parts and accessories if they could affect the safety or performance of the implantable device. NOTE 2 The terminology used in this European Standard is intended to be consistent with the terminology of Directive 90/385/EEC. NOTE 3 In this document, terms printed in small capital letters are used as defined in Clause 3. Where a defined term is used as a qualifier in another term, it is not printed in small capital letters unless the concept thus qualified is also defined. NOTE 4 Particular requirements for congestive heart failure devices are under consideration. These types of devices are not covered by this document.