Conventional implantable defibrillators have a subcutaneous device and lead which is placed within the heart, through the venous system. Bardy GH et al has evaluated an entirely subcutaneous ICD and reported the preliminary results in NEJM. Initially they compared the thresholds for various configurations in 78 patients and later the best configuration in 49 patients to determine the defibrillation threshold with conventional ICD implants. Then they went on to a pilot study of long term use in 6 patients and finally a trial involving 55 patients. The best configuration was found to be one with a parasternal electrode and an ICD can location in the left lateral thoracic region. It was effective in terminating ventricular fibrillation with a higher energy requirement compared to transvenous lead systems (36.6±19.8 J vs. 11.1±8.5 J).Ventricular fibrillation was successfully detected in all the episodes induced. Two cases of pocket infection and four lead revisions were required in the trial. During the follow up period of 10 months, 12 episodes of spontaneous sustained ventricular tachyarrhythmias were detected and treated. Larger randomised studies of longer duration are needed to see if this entirely subcutaneous ICD will become a viable option for patients with life threatening arrhythmias. If it shown to be useful, it will avoid a lot of problems due to trans venous leads which could occur during the implantation as well as on long term follow up. Though transient back up pacing is available in an entirely subcutaneous system, long term antibradycardia pacing is not feasible in this system. Similarly anti-tachycardia pacing (for slower ventricular tachycardias) is also not available.