Wearable cardioverter defibrillator: Bridge or alternative to implantation?

Abstract

The implantable cardioverter-defibrillator (ICD) is effective to prevent sudden cardiac death (SCD) in selected patients with heart disease known to be at high risk for ventricular arrhythmia. Nevertheless, this invasive and definitive therapy is not indicated in patients with potentially transient or reversible causes of sudden death, or in patients with temporary contra-indication for ICD placement. The wearable cardioverter defibrillator (WCD) is increasingly used for SCD prevention both in patients awaiting ICD implantation or with an estimated high risk of ventricular arrhythmia though to be transient. We conducted a review of current clinical uses and benefits of the WCD, and described its technical aspects, limitations and perspectives.

Keywords: Primary prevention; Secondary prevention; Sudden cardiac death; Ventricular arrhythmias; Wearable cardioverter/defibrillator.

Figure 1

Wearable cardioverter defibrillator. The two defibrillator electrodes are worn on the back of the garment, when the four monitoring electrodes are placed on the elastic belt around the chest. Both systems are connected to the monitor unit.

Figure 2

Wearable cardioverter defibrillator worn by a patient under clothes; monitor unit is worn on waist belt or in a holster.

Figure 3

Four electrocardiographic electrodes position, and two left-right and front-back bipolar electrocardiographic vectors.

Figure 4

One defibrillator electrode with ten gel capsules inserted in, and one non-adhesive electrocardiogram electrode.

Figure 5

Ventricular tachycardia correctly diagnosed and treated by wearable cardioverter defibrillator. Red line corresponds to sound signal. A 150-J defibrillation shock, automatically delivered by the device, terminated the arrhythmia.