Pulmonary vein isolation by high intensity focused ultrasound.

Pulmonary vein isolation (PVI) using radiofrequency current (RFC) ablation is a potentially curative treatment option for patients with atrial fibrillation (AF). The shortcomings of the RFC technology (technically challenging, long procedure times, complications) steadily kindle the interest in new energy sources and catheter designs. High intensity focused ultrasound (HIFU) has the ability to precisely focus ultrasound waves in a defined area with a high energy density. HIFU balloon catheters (BC) positioned at the PV ostia appear to be an ideal tool to transmit the ablation energy in a circumferential manner to the PV ostia and may therefore bear substantial advantage over conventional ablation catheters in PVI procedures. In clinical trials the HIFU BC has shown promising success rates similar to RFC catheter ablation for PVI in patients with AF. However, procedure times are still long and serious complications have been observed. Therefore, it may be a valuable alternative to the conventional techniques in selected patients but further clinical trials have to be initiated.