In vivo preliminary test of a new biparietal bidirectional bipolar radiofrequency magnetic coupling system

Background To test in vivo a new design prototype for radio frequency (RF) ablation. Methods A prototype based on a concept of endo-epicardial biparietal bipolar RF ablation with the atrial tissue interposed and consisting of two specular endocardial-epicardial catheters was tested in four pigs (80 +/- 5 kg). The endocardial catheter was introduced into the left atrium through the left atrial appendage on the beating heart. The epicardial counterpart was placed manually on the atrial epicardial surface. The coupling of the two catheters was achieved using a neodymium magnet around the gold plate electrode, and RF was applied to the interposed tissue. The hearts were excised, and the lesions were examined using morphometric evaluation. Results The RF application resulted in transmural lesions in all of the four animals tested. In these animals the maximum endocardial width (W-endo) was 6.34 +/- 0.25, 6.54 +/- 0.33, 6.36 +/- 0.57, and 6.49 +/- 0.96 mm. The pericardial width (W-epi) was similar: 6.37 +/- 0.47, 6.58 +/- 0.32, 6.35 +/- 0.56 and 6.53 +/- 0.94 mm. The lesion area was 924.78, 949.25, 944.25, and 926.05 mm(2), and the lesion volume was 92.47, 94.92, 94.42, and 92.60 mm(3), respectively. Conclusions The idea of an endocardial-epicardial bidirectional biparietal bipolar radiofrequency tool such that the atrial tissue is fully interposed between the two RF poles might be promising for future clinical applications. Further research is warranted.