Catheter tip force required for mechanical perforation of porcine cardiac chambers

Abstract

Aims Catheter manipulation during ablation procedures can produce injury and tamponade. We evaluated the mechanical forces required to perforate a porcine heart with an ablation catheter. Methods and results A 7 Fr, 3.5 mm irrigated radiofrequency (RF) ablation catheter with a force sensor (FS) within its tip was used to create right atrial (RA) free wall lesions in pigs. The intact heart was removed and the FS-equipped catheter was used to mechanically perforate (without RF delivery) the free walls of both atria and ventricles: directly and through an introducer sheath to prevent catheter shaft buckling. Perforation was also performed through epicardially visible RA lesions and adjacent unablated tissue. Twenty-four RA free wall lesions were created in four pigs. One hundred and forty-four mechanical perforations were performed: 44 RA, 30 left atrial (LA), 37 right ventricular (RV), and 33 left ventricular (LV). The RA and RV perforation force (PF) was lower than through the LA and LV (P < 0.0001). The LV perforation time was shorter when the catheter was gripped through an introducer sheath (0.8 ± 0.5 vs. 3.2 ± 3 s, P < 0.0001). Perforation force through transmural RA lesions was lower than through unablated RA tissue (172.4 ± 79.1 vs. 300.6 ± 116.8 g, P < 0.0002). Conclusion The force threshold for mechanical perforation in the porcine heart is lower for right-compared with left-sided chambers, and also lower through recently created RA RF lesions compared with unablated RA tissue. Left ventricular perforation is achieved more rapidly with the ablation catheter in a sheath despite the same PF because the sheath prevents catheter buckling. © 2010 The Author.