This Part2-1 specifies requirements that are applicable to those active implantable medical devices intended to treat bradyarrhythmias. The tests that are specified in EN45502 are type tests, and are to be carried out on samples of a device to show compliance. This Part2-1 is also applicable to some non-implantable parts and accessories of the devices (see Note1). The characteristics of the implantable pulse generator or lead shall be determined by either the appropriate method detailed in this Part2-1 or by any other method demonstrated to have an accuracy equal to, or better than, the method specified. In the case of dispute, the method detailed in this Part2-1 shall apply. Any features of an active implantable medical device intended to treat tachyarrhythmias are covered by EN45502-2-2. NOTE1 The device that is commonly referred to as an active implantable medical device may 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. NOTE2 The terminology used in this European Standard is intended to be consistent with the terminology of Directive 90/385/EEC. NOTE3 In this European Standard, terms printed in small capital letters are used as defined in Clause3. 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.