Introduction
Creating of sustainable ablation lesions is the key for successful
chronic pulmonary vein isolation using RF-Ablation. For this purpose,
different objective parameter like the impedance drop, reduction in
unipolar und bipolar voltage, the force time integral or the ablation
index (AI) were established 1,2. In this context, the
ablation index (AI, Biosense Webster Inc), combining RF power,
ablation-time, contact force, and catheter stability in a weighted,
non-linear formula, was well validated in the close protocol in a
prospective outcome trial 3,4. An ablation index
between 400 and 550 in dependence of the anatomical location has been
developed as standard of care, enabling reliable and reproducible
pulmonary vein isolation (PVI) as described by Taghji and Duytschaever
et al in the CLOSE protocol 4,5. However, there is an
ongoing discussion regarding the optimal RF power to achieve the
required AI in the most effective and safest way. While conventional PVI
is commonly performed using 20-30W on the thin posterior atrial wall in
proximity to the oesophagus to avoid thermal injury, 30-40W are used on
the thicker anterior wall and atrial roof. However, there is growing
evidence that high power short duration energy application (HPSD)
relying on the ablation index might be as efficient, safe, and durable,
whilst shortening procedure time 6,7.
Here, we thought to compare the standard energy delivery with an
ablation protocol of fixed high power 50W setting, both for
circumferential PVI as well as additional lesion sets, guided by AI and
the close-protocol to achieve durable PVI.