Catheter ablation lesion visualization with intracardiac strain imaging in canines and humans.

Catheter ablation is a common treatment for arrhythmia, but can fail if lesion lines are non-contiguous.Identification of gaps and non-transmural lesions can reduce the likelihood of treatment failure and recurrent arrhythmia.Intracardiac myocardial elastograph is a strain imaging technique that provides visualization of the lesion line. Lesion size estimation and gap resolution was evaluated in an open chest canine model (n=3), and clinical feasibility was investigated in patients undergoing ablation to treat typical cavotricuspid isthmus atrial flutter (n=5). A lesion line consisting of three lesions and two gaps was generated in each canine left ventricle via epicardial ablation. One lesion was generated in one canine right ventricle. Average lesion and gap areas were measured with high agreement (33 +/- 14 mm2 and 30 +/- 15 mm2, respectively) when compared against gross pathology (34 1 19 mm2 and 26 +/- 11 mm2, respectively). Gaps as small as 11 mm2 (3.6 mm on epicardial surface) were identifiable. Absolute error and relative error in estimated lesion area were 9.3 +/- 8.4 mm2 and 31 +/- 34 %; error in estimated gap area was 11 +/- 9.0 mm2 and 40 +/- 29 %. Flutter patients were imaged throughout the procedure. Strain was shown to be capable of differentiating between baseline and after ablation completion as confirmed by conduction block. In all patients, strain decreased in the cavotricuspid isthmus after ablation (mean paired difference of -17 1 11 %, p < 0.05). IME could potentially become a useful ablation monitoring tool in the clinic.