Abstract 16071: Electroanatomical Voltage and Morphology Characteristics in Post-infarction Patients Undergoing Ventricular Tachycardia Ablation
Introduction:We analyzed the endo-epicardial electroanatomical mapping (EAM) characteristics, their association with clinical data and their prognostic value in a large cohort of post-myocardial infarction (MI) patients.
Methods: We performed analysis of voltage (bipolar dense scar-DS and low voltage-LV areas, unipolar LV and penumbra areas) and morphology characteristics (presence of abnormal late-LPs and early potentials-EPs) in 100 post-MI patients undergoing EAM-based ventricular tachycardia (VT) ablation (26 endo-epicardial procedures). We defined as unipolar LV areas those with voltage <8 mV and unipolar penumbra area the unipolar LV area beyond the bipolar LV area. The ratio of bipolar DS to LV area reflected the fibrosis density within the infarct region.
Results: Mean endocardial surface area was 236.1 cm2. Of that, 10.2% was bipolar DS, 21.8% was bipolar LV and 46.7% was unipolar LV. Endocardial penumbra was present in all but one patients and mean area was 51.6 cm2 (24.9%). There was no endocardial bipolar DS in 18% of the patients. Endocardial bipolar DS area >22.5 cm2 (sensitivity 61.1% and specificity 87.5%) best predicted scar transmurality.
Endocardial LPs were recorded in 66% of the patients and epicardially in 17/26 (65.4%). Endocardial bipolar DS area >7 cm2 (sensitivity 88.2% and specificity 66.7%) and endocardial bipolar scar density >0.35 (sensitivity 52.9% and specificity 100%) predicted epicardial LPs. Abolition of endocardial LPs was achieved in 51/66 (77.3%) and of epicardial LPs in 10/17 (58.8%) patients.
As a primary strategy, LPs and VT-mapping ablation occurred in 48%, only VT-mapping ablation in 27%, only LPs ablation in 17% and EPs ablation (in the absence of LPs) in 6%. After a median follow-up time of 628 days, endocardial LP abolition was associated (HR 0.274, p=0.01) with reduced VT recurrence (32%). Endocardial LP presence (HR 0.177, p=0.041) acted as a prophylactic predictor while increased endocardial penumbra area (HR=1.028, p=0.044) as an adverse predictor of cardiac death (7%).
Conclusions: Endocardial scar extension and density predicted scar transmurality and endo-epicardial presence of LPs, although DS is not always identified in post-MI patients. LPs were abolished in 51% resulting in improved outcome.
Author Disclosures: D. Tsiachris: Consultant/Advisory Board; Significant; Proctor of Medtronic for cryoablation. Other; Modest; Travel expenses from Biosense, Boston and Medtronic. J. Silberbauer: None. T. Oloriz: None. H. Mizuno: None. F. Baratto: None. P. Della Bella: None. C. Stefanadis: None.
- © 2015 by American Heart Association, Inc.