Cardiac Resynchronization Therapy Pacing Interruption: From Early Challenges to Cutting-Edge Solutions.

Background/purpose: In the current era of pacing, the loss of cardiac resynchronization therapy (CRT) pacing remains a significant challenge, especially in patients with heart failure (HF). Some manufacturers, such as Biotronik (Berlin, Germany), offer left ventricular (LV) sensing options to avoid pacing during vulnerable periods. However, even in the absence of LV sensing (LVs), CRT interruptions can still occur, though they often go unnoticed without this additional feature. When LVs is used, interruptions in biventricular pacing can sometimes lead even to device-induced ventricular tachycardia (VT).

Results: A careful review of all CRT pacing interruption episodes reveals the precise causes of these interruptions. Although interruptions may exist even in devices without LVs, grouping the causes allows for a clearer understanding of the phenomenon and its potential adverse effects. Furthermore, recent advancements in CRT algorithms could reduce these interruptions and improve device performance, ultimately leading to better clinical outcomes.

Conclusion: LVs plays a crucial role in identifying pacing interruptions, though it has its limitations. Even in the absence of LVs, interruptions may still occur, and minor algorithm adjustments can enhance the device's overall effectiveness and predictability. Careful analysis of each interruption episode provides valuable clinical insights that will help inform future management strategies aimed at achieving uninterrupted CRT pacing. Additionally, we are preparing two more studies to explore the clinical implications of CRT interruptions in HF management and propose new algorithms designed to minimize these interruptions.