What are the recommendations for pacing pause settings in dual-chamber pacemakers (DCPs) to prevent disruptions in cardiac rhythm?

From the Guidelines

Long pauses more than 4 ms are not indicated for dual-chamber pacemakers, and instead, programming longer AV delays, such as 220-250 ms, is recommended to minimize right ventricular pacing. This approach is supported by the HRS/ACCF expert consensus statement on pacemaker device and mode selection 1, which highlights the importance of minimizing right ventricular pacing to prevent disruptions in cardiac rhythm. The statement suggests that high proportions of right ventricular pacing, particularly in patients with left ventricular systolic dysfunction, can lead to detrimental effects, including an increased risk of heart failure or atrial fibrillation.

Key considerations for pacing pause settings in dual-chamber pacemakers include:

• Programming longer AV delays to minimize right ventricular pacing
• Using algorithms that reduce the cumulative percentage of ventricular pacing
• Avoiding unnecessary right ventricular pacing by turning off rate response or rate-responsive AV delay in certain patients
• Individualizing programming based on the patient's underlying cardiac condition, intrinsic conduction, and specific arrhythmia history

According to the HRS/ACCF expert consensus statement 1, minimizing right ventricular pacing can be achieved effectively by programming longer AV delays or implanting pacemakers with specific algorithms for minimizing ventricular pacing. These algorithms have been shown to substantially reduce the percentage of ventricular pacing and lower the burden of atrial fibrillation. Regular follow-up evaluations are essential to adjust pacing settings as the patient's cardiac status changes.

From the Research

Pacing Pause Settings in Dual-Chamber Pacemakers

• The optimal pacing pause settings in dual-chamber pacemakers (DCPs) are crucial to prevent disruptions in cardiac rhythm.
• A long pause of more than 4 milliseconds is not specifically indicated for DCPs, as the optimal atrioventricular (AV) delay is typically between 100-200 ms 2.
• Studies have shown that dual-chamber pacing with a short AV delay does not improve hemodynamic and clinical status or ejection fraction in patients with chronic congestive heart failure 2.
• However, dual-chamber pacing is preferred over single-chamber pacing in patients with atrioventricular block, as it maintains AV synchrony and reduces the risk of pacemaker syndrome, atrial fibrillation, and stroke 3, 4.
• Recent advancements in leadless pacemaker technology have enabled dual-chamber pacing without transvenous leads, offering a breakthrough alternative for patients at high risk of infection or with limited vascular access 5.

Recommendations for Pacing Pause Settings

• The optimal AV delay for dual-chamber pacing is typically between 100-200 ms, with no specific recommendation for a pause of more than 4 milliseconds.
• Dual-chamber pacing is recommended over single-chamber pacing in patients with atrioventricular block, as it provides better AV synchrony and reduces the risk of complications.
• The choice of pacing mode and settings should be individualized based on the patient's underlying cardiac condition and clinical needs.

Clinical Implications

• Dual-chamber pacing with optimal AV delay settings can improve cardiac function and reduce the risk of complications in patients with atrioventricular block.
• The use of leadless pacemaker technology may revolutionize future cardiac rhythm management, including defibrillation and resynchronization therapies.
• Further studies are needed to determine the optimal pacing pause settings and to evaluate the long-term clinical outcomes of dual-chamber pacing in different patient populations 6, 4.