Rahul Samanta1, Saurabh Kumar1, William Chik1, Pierre Qian1, Michael A Barry1, Sara Al Raisi1, Abhishek Bhaskaran1, Melad Farraha1, Fazlur Nadri1, Eddy Kizana1, Aravinda Thiagalingam1, Pramesh Kovoor1, Jim Pouliopoulos2. 1. From the Department of Cardiology, Westmead Hospital, New South Wales, Australia (R.S., S.K., W.C., P.Q., M.A.B., S.A.R., A.B., F.N., E.K., A.T., P.K., J.P.); and Sydney Medical School, University of Sydney, Australia (R.S., W.C., S.A.R., A.B., M.F., E.K., A.T., P.K., J.P.). 2. From the Department of Cardiology, Westmead Hospital, New South Wales, Australia (R.S., S.K., W.C., P.Q., M.A.B., S.A.R., A.B., F.N., E.K., A.T., P.K., J.P.); and Sydney Medical School, University of Sydney, Australia (R.S., W.C., S.A.R., A.B., M.F., E.K., A.T., P.K., J.P.). jim.pouliopoulos@sydney.edu.au.
Abstract
BACKGROUND: Recent studies have demonstrated that intramyocardial adipose tissue (IMAT) may contribute to ventricular electrophysiological remodeling in patients with chronic myocardial infarction. Using an ovine model of myocardial infarction, we aimed to determine the influence of IMAT on scar tissue identification during endocardial contact mapping and optimal voltage-based mapping criteria for defining IMAT dense regions. METHOD AND RESULTS: In 7 sheep, left ventricular endocardial and transmural mapping was performed 84 weeks (15-111 weeks) post-myocardial infarction. Spearman rank correlation coefficient was used to assess the relationship between endocardial contact electrogram amplitude and histological composition of myocardium. Receiver operator characteristic curves were used to derive optimal electrogram thresholds for IMAT delineation during endocardial mapping and to describe the use of endocardial mapping for delineation of IMAT dense regions within scar. Endocardial electrogram amplitude correlated significantly with IMAT (unipolar r=-0.48±0.12, P<0.001; bipolar r=-0.45±0.22, P=0.04) but not collagen (unipolar r=-0.36±0.24, P=0.13; bipolar r=-0.43±0.31, P=0.16). IMAT dense regions of myocardium reliably identified using endocardial mapping with thresholds of <3.7 and <0.6 mV, respectively, for unipolar, bipolar, and combined modalities (single modality area under the curve=0.80, P<0.001; combined modality area under the curve=0.84, P<0.001). Unipolar mapping using optimal thresholding remained significantly reliable (area under the curve=0.76, P<0.001) during mapping of IMAT, confined to putative scar border zones (bipolar amplitude, 0.5-1.5 mV). CONCLUSIONS: These novel findings enhance our understanding of the confounding influence of IMAT on endocardial scar mapping. Combined bipolar and unipolar voltage mapping using optimal thresholds may be useful for delineating IMAT dense regions of myocardium, in postinfarct cardiomyopathy.
BACKGROUND: Recent studies have demonstrated that intramyocardial adipose tissue (IMAT) may contribute to ventricular electrophysiological remodeling in patients with chronic myocardial infarction. Using an ovine model of myocardial infarction, we aimed to determine the influence of IMAT on scar tissue identification during endocardial contact mapping and optimal voltage-based mapping criteria for defining IMAT dense regions. METHOD AND RESULTS: In 7 sheep, left ventricular endocardial and transmural mapping was performed 84 weeks (15-111 weeks) post-myocardial infarction. Spearman rank correlation coefficient was used to assess the relationship between endocardial contact electrogram amplitude and histological composition of myocardium. Receiver operator characteristic curves were used to derive optimal electrogram thresholds for IMAT delineation during endocardial mapping and to describe the use of endocardial mapping for delineation of IMAT dense regions within scar. Endocardial electrogram amplitude correlated significantly with IMAT (unipolar r=-0.48±0.12, P<0.001; bipolar r=-0.45±0.22, P=0.04) but not collagen (unipolar r=-0.36±0.24, P=0.13; bipolar r=-0.43±0.31, P=0.16). IMAT dense regions of myocardium reliably identified using endocardial mapping with thresholds of <3.7 and <0.6 mV, respectively, for unipolar, bipolar, and combined modalities (single modality area under the curve=0.80, P<0.001; combined modality area under the curve=0.84, P<0.001). Unipolar mapping using optimal thresholding remained significantly reliable (area under the curve=0.76, P<0.001) during mapping of IMAT, confined to putative scar border zones (bipolar amplitude, 0.5-1.5 mV). CONCLUSIONS: These novel findings enhance our understanding of the confounding influence of IMAT on endocardial scar mapping. Combined bipolar and unipolar voltage mapping using optimal thresholds may be useful for delineating IMAT dense regions of myocardium, in postinfarct cardiomyopathy.
Authors: C Pandozi; Marco Valerio Mariani; C Chimenti; V Maestrini; D Filomena; M Magnocavallo; M Straito; A Piro; M Russo; M Galeazzi; S Ficili; F Colivicchi; P Severino; M Mancone; F Fedele; C Lavalle Journal: J Interv Card Electrophysiol Date: 2022-01-24 Impact factor: 1.900
Authors: María Elena Soto; Israel Pérez-Torres; María Esther Rubio-Ruiz; Linaloe Manzano-Pech; Verónica Guarner-Lans Journal: Cells Date: 2022-03-18 Impact factor: 6.600