Electroanatomical mapping variables in endomyocardial biopsy guided by electroanatomic mapping: electrophysiological predictors of histological diagnosis in patients with myocarditis and inflammator
R L Roberta Lo Nano, F B Federico Ballacci, A C Antonio Crocamo, M F N Maria Francesca Notarangelo, V C Veronica Carmina, L S Ludovico Sicignano, L G Laura Gerardino, E V Elena Verrecchia, M D B Marco Giuseppe Del Buono, G B Gianluigi Bencardino, G P Gemma Pelargonio, F B Francesco Burzotta, M I Massimo Imazio, G N Giampaolo Niccoli, M L N Maria Lucia NarducciAbstract
Background
Endomyocardial biopsy (EMB) is an invasive procedure initially developed to monitor heart transplant rejection (1). Over time, its role has expanded to include the diagnosis of various cardiac disorders, such as cardiomyopathies, myocarditis (2), drug-related cardiotoxicity, amyloidosis, and other infiltrative diseases. The integration of three-dimensional electroanatomic mapping (3D-EAM) (3) with EMB and subsequent histological analysis has significantly enhanced the diagnostic accuracy of this procedure.
Purpose
This study aims to evaluate predictors of histopathological diagnoses guided by ventricular endocardial 3D-EAM, with the goal of improving the diagnostic accuracy of EMB.
Methods
In this multicenter retrospective study, we analyzed data from 54 patients who underwent EMB guided by 3D-EAM targeting the right ventricle (RV) and/or left ventricle (LV), based on clinical and radiological suspicions of myocarditis, inflammatory cardiomyopathy, and arrhythmogenic dysplasia. Ventricular voltage substrate mapping was performed, with 13 patients utilizing the Ensite Navx system and 41 the CARTO system. The bioptome was connected to the mapping system to direct EMB towards targeted electroanatomic scar regions. Biopsy samples (3-6 per patient) were collected: 24 from the LV, 28 from the RV, and 2 from biventricular regions, guided by 3D-EAM. In cases without identifiable scar areas, conventional EMB was performed directed at the right interventricular septum.
Results
In cases where EMB yielded positive results for inflammatory cardiomyopathy, myocarditis, or arrhythmogenic right ventricular dysplasia, unipolar and bipolar potentials, as well as conduction velocity, were statistically significantly lower than those observed in healthy control EMB samples. Univariate logistic regression analysis identified the presence of an electroanatomical scar at the right interventricular septum as a significant predictor of a positive histopathological diagnosis for cardiomyopathy (p<0.05). Furthermore, the impedance of the biopsied tissue demonstrated an area under the curve of 0.87, effectively differentiating pathological tissue from healthy tissue.
Conclusions
Alongside the presence of low unipolar and bipolar voltage and slow conduction zones, electroanatomical mapping variables, such as tissue impedance during 3D-EAM, may serve as critical components in guiding EMB, thereby enhancing diagnostic accuracy and informing treatment strategies for various types of cardiomyopathies.