| Affiliation: | 1. Cardiology Department, Santa Maria University Hospital (CHULN), Lisbon Academic Medical Centre, Lisbon, Portugal;2. Research and Development Department, Biosense Webster, Johnson & Johnson, Yokneam, Israel;3. Biosense Webster, Johnson & Johnson, EMEA Clinical Development, Diegem, Belgium;4. Biosense Webster, Johnson & Johnson, Clinical Support, Porto Salvo, Portugal;5. Cardiology Department, Arrhythmia Unit, University Hospital Ramón y Cajal and CIBER-CV Madrid, Madrid, Spain;6. Department of Cardiology, Rennes University Hospital, Rennes, France;7. Cardiology Department, Santa Maria University Hospital (CHULN), Lisbon Academic Medical Centre, Lisbon, Portugal
Cardiac Rhythm Abnormalities Unit, Cardiovascular Centre of the University of Lisbon, Lisbon School of Medicine of the Universidade de Lisboa, Lisbon, Portugal |
| Abstract: | Introduction Scar-related ventricular tachycardia (VT) usually results from an underlying reentrant circuit facilitated by anatomical and functional barriers. The later are sensitive to the direction of ventricular activation wavefronts. We aim to evaluate the impact of different ventricular activation wavefronts on the functional electrophysiological properties of myocardial tissue. Methods Patients with ischemic heart disease referred for VT ablation underwent high-density mapping using Carto®3 (Biosense Webster). Maps were generated during sinus rhythm, right and left ventricular pacing, and analyzed using a new late potential map software, which allows to assess local conduction velocities and facilitates the delineation of intra-scar conduction corridors (ISCC); and for all stable VTs. Results In 16 patients, 31 high-resolution substrate maps from different ventricular activation wavefronts and 7 VT activation maps were obtained. Local abnormal ventricular activities (LAVAs) were found in VT isthmus, but also in noncritical areas. The VT isthmus was localized in areas of LAVAs overlapping surface between the different activation wavefronts. The deceleration zone location differed depending on activation wavefronts. Sixty-six percent of ISCCs were similarly identified in all activating wavefronts, but the one acting as VT isthmus was simultaneously identified in all activation wavefronts in all cases. Conclusion Functional based substrate mapping may improve the specificity to localize the most arrhythmogenic regions within the scar, making the use of different activation wavefronts unnecessary in most cases. |
