Assessment of NOGA catheter stability during the entire cardiac cycle by means of a special needle-tipped catheter.

The NOGA system maps regional myocardial function and delivers local catheter-based therapeutics, requiring stability and precise localization of the catheter tip throughout the cardiac cycle. A special catheter having a retractable needle at its tip was used to compare tip stability with and without needle insertion into the myocardium, assuming this prevents catheter slippage. For multiple sites in seven pig left ventricles, we recorded sets of three consecutive point locations: pre-, post-, and during needle insertion. In-point location stability (LocStab), defined as the mean displacement between catheter tip trajectories of two consecutive cardiac cycles at a specific point, did not differ among the three groups of points (mean, 1.33 +/- 0.61 mm; P = 0.37 by ANOVA), indicating that trajectories are equally stable and repeatable with or without needle insertion. Between-point LocStab(p1,p2), i.e., displacement between the trajectories of two different points (p1 and p2) at the same location, was not increased when p1 = a needle insertion point and p2 = a noninsertion point, compared to both p1,p2 = noninsertion points, suggesting that slippage of noninsertion points is negligible. In conclusion, catheter tip trajectories at any location are highly stable throughout the cardiac cycle.