Leadless cardiac pacemaker implantation for bradyarrhythmias

Evidence-based recommendations on leadless cardiac pacemaker implantation for bradyarrhythmias in adults. This involves inserting a device into the heart that helps it beat at a normal rate.

# Recommendations
Evidence on the safety of leadless cardiac pacemaker implantation for bradyarrhythmias shows that there are serious but well-recognised complications. The evidence on efficacy is inadequate in quantity and quality:
For people who can have conventional cardiac pacemaker implantation, leadless pacemakers should only be used in the context of research. Find out what only in research means on the NICE interventional procedures guidance page.
For people in whom a conventional cardiac pacemaker implantation is contraindicated following a careful risk assessment by a multidisciplinary team, leadless cardiac pacemakers should only be used with special arrangements for clinical governance, consent and audit or research. Find out what special arrangements mean on the NICE interventional procedures guidance page.
Clinicians wishing to do leadless cardiac pacemaker implantation for bradyarrhythmias in people who cannot have conventional cardiac pacemaker implantation should:
Inform the clinical governance leads in their NHS trusts.
Ensure that patients and their carers understand the uncertainty about the procedure's safety and efficacy compared with conventional pacemaker implantation, and provide them with clear written information. In addition, the use of NICE's information for the public on leadless cardiac pacemaker implantation for bradyarrhythmias is recommended.
Further research in people who could have conventional cardiac pacemaker implantation should report the patient selection criteria and compare leadless pacemakers with conventional pacemakers. Followup should be for at least 5 years and outcomes should include adverse events, symptom relief, quality of life and device durability in the longterm.
Clinicians should enter details about all patients having leadless cardiac pacemaker implantation for bradyarrhythmias onto the National Institute for Cardiovascular Outcomes Research database and review local clinical outcomes.
The procedure should only be done in specialist centres by clinicians with specific training on, and supervised experience in, inserting the device. Centres where this procedure is done should have both cardiac and vascular surgical support for emergency treatment of complications.
NICE advises clinicians to follow the Medicines and Healthcare products Regulatory Agency's (MHRA) Expert Advisory Group recommendations on leadless cardiac pacemaker therapy.
NICE may review this procedure on publication of further evidence.# The condition, current treatments and procedure

# The condition
Bradyarrhythmias are abnormal heart rhythms that can result in a slow heart rate (bradycardia), usually defined as less than 60 beats per minute. There are a range of causes including diseases such as sick sinus syndrome or atrioventricular block. The most common causes are the natural ageing process, ischaemic heart disease, heart valve disorders and heart failure. If untreated, bradycardia may lead to fatigue, fainting, palpitations, dizziness, heart failure and an increased risk of death.

# Current treatments
Bradyarrhythmias are managed with pacemakers, as described in NICE technology appraisal guidance on dual-chamber pacemakers for symptomatic bradycardia due to sick sinus syndrome and/or atrioventricular block and dual-chamber pacemakers for symptomatic bradycardia due to sick sinus syndrome without atrioventricular block. Dual-chamber pacing is recommended for symptomatic bradycardia caused by sick sinus syndrome, atrioventricular block, or a combination of sick sinus syndrome and/or atrioventricular block, and also for sick sinus syndrome in people without atrioventricular block. Single-chamber ventricular pacemakers may be used for atrioventricular block alone or with sick sinus syndrome in people with continuous atrial fibrillation, or people who have specific factors such as frailty or comorbidities that influence the balance of risks and benefits in favour of single-chamber pacing.

# The procedure
The aim of implanting a leadless cardiac pacemaker is to detect cardiac bradyarrhythmias and deliver electric pulses to the heart to increase the heart rate. The leadless pacemaker has a builtin pulse generator, battery and electrodes. The procedure is done under local anaesthesia, with or without sedation, in a cardiac catheterisation laboratory. Under fluoroscopic guidance, the proximal end of the pacemaker is attached to a deflectable bespoke delivery catheter system and inserted percutaneously through the femoral vein using a dedicated introducer sheath. It is then advanced into the right atrium through the tricuspid valve, into the right ventricle and positioned near the apex or lower septum. Contrast may be injected into the right ventricle to visualise the desired location. Once positioned, the pacemaker is deployed and securely implanted into the endocardial wall using a fixation mechanism (a screwin helix or nitinol tines). An electrode at the distal end of the pacemaker delivers electrical impulses that pace the heart. Electrical measurements are taken and, if satisfactory, the pacemaker is released from the catheter and the catheter is removed. If the position is suboptimal, the pacemaker can be detached from the endocardium and repositioned prior to final release of the delivery catheter.
The pacemaker is programmed using an external programmer that transmits signals to it. The pacemaker can be retrieved using a catheter retrieval system, if device dislodgement is discovered at followup.
The device can only detect and pace the right ventricle (single chamber) in contrast to some conventional pacemakers that can provide dual-chamber (right atrium and right ventricle) detection and pacing. It is therefore suitable for people who only need single-chamber ventricular pacing.