The extravascular implantable cardioverter-defibrillator: technology, evidence, and clinical perspectives.

The extravascular implantable cardioverter-defibrillator (EV-ICD) offers a fully extravascular alternative to transvenous ICDs, combining substernal lead placement with defibrillation and limited pacing capabilities. Designed to mitigate intravascular complications while maintaining generator size and longevity comparable to conventional ICDs, the EV-ICD supports antitachycardia pacing, post-shock pacing, and temporary bradycardia management. Procedural experience demonstrates high implantation success, low rates of major complications, and effective arrhythmia termination. Early real-world data indicate that lead dislodgement, pneumothorax, and pocket infection are uncommon, and lead explantation is feasible when required. Antitachycardia pacing effectively terminates a substantial proportion of ventricular tachycardias, while inappropriate therapies have been reduced through optimized lead positioning and advanced detection algorithms. Patient selection should exclude, among others, those with permanent pacing needs, anatomical constraints, and prior radiotherapy or sternotomy. Future directions include optimization of lead design and exploration of alternative implantation sites, with ongoing evaluation of long-term device performance and safety. Current evidence supports the EV-ICD as a safe and effective option in selected patients, including younger populations or those with limited vascular access, although its definitive role in sudden cardiac death prevention requires further long-term study.