AICD

An Automatic Implantable Cardioverter Defibrillator (AICD), also called an implantable cardioverter defibrillator (ICD), is a small electronic device implanted under the skin to prevent sudden cardiac death from life-threatening ventricular arrhythmias. The device sits in a chest pocket and is connected to the heart by one or more leads. It continuously monitors the heart’s rhythm and can deliver therapies to restore normal rhythm when dangerous fast rhythms are detected.

AICDs can deliver anti-tachycardia pacing to interrupt certain rapid rhythms and, if needed, high-energy electric shocks to terminate ventricular tachycardia or ventricular fibrillation. Some systems provide bradycardia pacing or can be used with cardiac resynchronization therapy (CRT-D). Subcutaneous ICDs (S-ICDs) provide shocks without transvenous leads and typically do not offer pacing or ATP.

Indications include secondary prevention (survivors of cardiac arrest or sustained VT) and primary prevention in patients at high risk of VT/VF due to reduced left ventricular function or other cardiomyopathies. The decision to implant AICD is guided by current clinical guidelines and individualized risk assessment. Contraindications include limited life expectancy or other conditions that negate the benefit of implantation.

During implantation, the device is placed in a subcutaneous pocket with leads threaded through veins into the heart; testing ensures proper sensing and therapy delivery. Postoperative care involves regular follow-up and often remote monitoring. Battery life is typically several years, with generator replacement as the battery depletes. Potential risks include infection, lead malfunction, bleeding, and inappropriate shocks.