Importance of maintained atrio-ventricular synchrony in patients with pacemakers

Area of Science:

• Cardiology
• Biomedical Engineering

Background:

• Atrial contraction significantly impacts cardiac function, particularly in patients with pacemakers.
• The comparison between dual-chamber pacemakers (maintaining AV synchrony) and rate-responsive ventricular pacemakers is crucial for understanding optimal pacing strategies.

Purpose of the Study:

• To review the haemodynamic, clinical, and prognostic advantages of AV synchrony in dual-chamber pacemakers compared to rate-responsive ventricular pacemakers.
• To assess the impact of AV synchrony on cardiac performance during rest and exercise, and in daily activities.

Main Methods:

• Review of existing literature on dual-chamber and rate-responsive ventricular pacemakers.
• Analysis of haemodynamic, clinical, and prognostic data related to AV synchrony and pacing modes.

Main Results:

• Optimal AV delay in dual-chamber pacing enhances cardiac performance at rest.
• During exercise, heart rate increase is a more significant factor than AV synchrony for cardiac performance and capacity.
• Patients with pacemakers maintaining AV synchrony show reduced morbidity and mortality compared to those with ventricular pacing alone.

Conclusions:

• While dual-chamber pacemakers with AV synchrony may offer prognostic benefits, their advantages during daily activities require further investigation.
• Pacemaker complications are comparable between single and dual-chamber devices, with distinct issues like pacemaker syndrome and atrial sensing problems.
• Dual-chamber pacemakers present challenges including higher costs and intensive follow-up requirements.