The implantable defibrillator (ICD) is one of the transformational technologies defining contemporary procedural cardiology. Advances in all aspects of device design have facilitated implantation and the detection, discrimination and correction of rhythms that otherwise can result in death.1 2 However, as with most advanced technologies, initial enthusiasm is tempered by experience, which in the case of ICDs has highlighted the leads as a major source of mischief.3 As emphasised in numerous articles, these highly engineered components, while generally withstanding the battering of the intravascular environment, can on occasion fail.4 Lead design has evolved, but failure with potential consequences of inappropriate shocks, the need for revision and possible death have softened the enthusiasm of referrers. The upside is that ICDs are extremely effective and provide almost complete protection against sudden cardiac death (SCD). The difficulties remain in balancing the benefits weighed in relation to the largely technical but very real potential risks of devices. Of course, the longer the device is in place, the greater both the potential benefit and the incremental risks,4 so in the younger patient the heavier the burden when deciding between options.

One disease that highlights the difficulty of these decisions is hypertrophic cardiomyopathy (HCM). This is by almost an order of magnitude more common than other diseases associated with SCD in the young and is likely to be seen in general cardiology practice. The literature …