Wearable Cardioverter Defibrillators

The use of implantable cardioverter defibrillators (ICD) has favorably impacted the prevention and treatment of sudden cardiac death (SCD) associated with ventricular arrhythmias. However, there are situations where an ICD cannot be immediately implanted, even though the patient is at high risk for SCD. The wearable cardioverter defibrillator (WCD) is a unique technology that can bridge this gap for patients. The WCD has been demonstrated to terminate ventricular tachycardia/fibrillation if worn and used correctly. With proper training, it is relatively easy to put on, maintain, and use. Most patients are compliant and are able to consistently wear the device. The WCD negates the infection risk or procedural complications associated with insertion and possible extraction of leads, as with an ICD. In terms of primary prevention of ventricular tachycardia/fibrillation in patients with a left ventricular ejection fraction ≤35%, prospective, randomized studies evaluating the survival of patients utilizing the WCD will need to be performed before evidenced-based criteria for its use can be established. On the basis of current data, WCD use for those awaiting heart transplant, for those with ICD indications status post-ICD explant, and for high-risk SCD patients with possible reversible cardiomyopathy appears to be a reasonable approach on the basis of current data.