Leadless cardiac pacemaker implantation for bradyarrhythmias

The aim of implanting a leadless cardiac pacemaker is to detect cardiac bradyarrhythmias and deliver electric pulses to help regulate the heartbeat. Most leadless cardiac pacemakers deliver single-chamber right ventricular pacing (with or without atrial sensing), but dual-chamber systems that deliver atrial or atrioventricular pacing using 2 devices are also available.Right atrial leadless cardiac pacemakers are a recent advancement and are suitable for people needing right atrial pacing only.

The procedure is usually done under local anaesthesia in a cardiac catheterisation laboratory. Fluoroscopic guidance is needed, and intracardiac echocardiography or contrast may be needed to guide implantation in the desired location in the heart chamber (right ventricle or atrium). For right ventricular leadless cardiac pacemakers, the proximal end of the leadless cardiac pacemaker is attached to a deflectable delivery catheter system. It is usually inserted percutaneously through the femoral vein or a vein in the neck (jugular access) using an introducer sheath. It is then moved into the right atrium, through the tricuspid valve into the right ventricle, and positioned near the apex or lower septum. An atrial device does not cross the tricuspid valve into the right ventricle. Once in place, the leadless cardiac pacemaker is securely implanted into the endocardial wall using a fixation mechanism. Electrical measurements are taken and, if satisfactory, the leadless cardiac pacemaker is released from the catheter and the catheter is removed. If the position is suboptimal, the leadless cardiac pacemaker can be detached from the endocardium and repositioned before the catheter is released.

The cardiac pacemaker delivers electrical impulses that pace the heart through an electrode at the distal end of the device. It is adjusted using an external programming system. A catheter retrieval system is used for removal and replacement of the leadless cardiac pacemaker when needed.

A dual-chamber leadless cardiac pacemaker system consists of 2 devices implanted percutaneously, either in a single procedure or over multiple procedures, into the target chambers: one in the right atrium and another in the right ventricle.

Several different devices are available for leadless cardiac pacemaker implantation for bradyarrhythmias.