TY - JOUR
T1 - Ischemic ventricular tachycardia from below the posteromedial papillary muscle, a particular entity
T2 - Substrate characterization and challenges for catheter ablation
AU - Enriquez, Andres
AU - Briceno, David
AU - Tapias, Carlos
AU - Shirai, Yasuhiro
AU - Muser, Daniele
AU - Liang, Jackson
AU - Hayashi, Tatsuya
AU - Santangeli, Pasquale
AU - Frankel, David S.
AU - Supple, Gregory E.
AU - Schaller, Robert D.
AU - Arkles, Jeffrey
AU - Rodriguez, Diego
AU - Callans, David J.
AU - Marchlinski, Francis E.
AU - Saenz, Luis
AU - Garcia, Fermin C.
N1 - Publisher Copyright:
© 2019 Heart Rhythm Society
PY - 2019/8
Y1 - 2019/8
N2 - Background: In patients with ischemic ventricular tachycardia (VT), substrate may be “protected” by the posteromedial papillary muscle (PMPM), explaining failure of endocardial-only ablation. Objective: We sought to characterize the arrhythmogenic substrate and ablation approach in patients with ischemic VT mapped to the inferior left ventricle in which endocardial ablation failed because of inaccessible substrate underlying the PMPM. Methods: We included 10 patients with recurrent ischemic VT, evidence of inferior scar, and failed endocardial ablation. In all patients, epicardial mapping was performed via a percutaneous (n = 9) or surgical (n = 1) approach, and VT elimination was achieved by ablation opposite to the PMPM. Clinical characteristics, electrocardiographic characteristics, and procedural data were analyzed. Results: In all patients, intracardiac echocardiography showed hyperechoic scar below the PMPM, and 5 exhibited a pattern characterized by subendocardial basal scar that became intramural and epicardial at distal segments. In 4 patients, VT remained inducible despite endocardial scar isolation, manifested by the absence of electrograms, dissociated potentials, and/or exit block. Eleven inducible VTs were mapped to the epicardium underlying the PMPM: 8 had a right bundle branch block configuration with variable transition, while 3 exhibited left bundle branch block with negative concordance. An inferior QS pattern was present in 10 of 11 VTs. Noninducibility was achieved in 8 patients, and 7 patients remained arrhythmia-free after a mean follow-up of 27 ± 23 months. Conclusion: In patients with inferior ischemic scar, VT may arise from the area underneath the PMPM, limiting endocardial ablation. Intracardiac echocardiography accurately defines the substrate distribution, and an epicardial approach may eliminate VT. A pattern of “basal-endocardial/apical-epicardial” ischemic involvement is described.
AB - Background: In patients with ischemic ventricular tachycardia (VT), substrate may be “protected” by the posteromedial papillary muscle (PMPM), explaining failure of endocardial-only ablation. Objective: We sought to characterize the arrhythmogenic substrate and ablation approach in patients with ischemic VT mapped to the inferior left ventricle in which endocardial ablation failed because of inaccessible substrate underlying the PMPM. Methods: We included 10 patients with recurrent ischemic VT, evidence of inferior scar, and failed endocardial ablation. In all patients, epicardial mapping was performed via a percutaneous (n = 9) or surgical (n = 1) approach, and VT elimination was achieved by ablation opposite to the PMPM. Clinical characteristics, electrocardiographic characteristics, and procedural data were analyzed. Results: In all patients, intracardiac echocardiography showed hyperechoic scar below the PMPM, and 5 exhibited a pattern characterized by subendocardial basal scar that became intramural and epicardial at distal segments. In 4 patients, VT remained inducible despite endocardial scar isolation, manifested by the absence of electrograms, dissociated potentials, and/or exit block. Eleven inducible VTs were mapped to the epicardium underlying the PMPM: 8 had a right bundle branch block configuration with variable transition, while 3 exhibited left bundle branch block with negative concordance. An inferior QS pattern was present in 10 of 11 VTs. Noninducibility was achieved in 8 patients, and 7 patients remained arrhythmia-free after a mean follow-up of 27 ± 23 months. Conclusion: In patients with inferior ischemic scar, VT may arise from the area underneath the PMPM, limiting endocardial ablation. Intracardiac echocardiography accurately defines the substrate distribution, and an epicardial approach may eliminate VT. A pattern of “basal-endocardial/apical-epicardial” ischemic involvement is described.
KW - Catheter ablation
KW - Ischemic cardiomyopathy
KW - Papillary muscle
KW - Substrate
KW - Ventricular tachycardia
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U2 - 10.1016/j.hrthm.2019.02.016
DO - 10.1016/j.hrthm.2019.02.016
M3 - Article
C2 - 31085181
AN - SCOPUS:85068976708
SN - 1547-5271
VL - 16
SP - 1174
EP - 1181
JO - Heart Rhythm
JF - Heart Rhythm
IS - 8
ER -