Diagnostic value of endomyocardial biopsy guided by electroanatomic voltage mapping in arrhythmogenic right ventricular cardiomyopathy/dysplasia.

UNLABELLED: Voltage Mapping-Guided Biopsy in ARVC/D.

INTRODUCTION: To improve the endomyocardial biopsy (EMB) diagnostic sensitivity for arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D), we hypothesized a biopsy sampling focused on selected right ventricle (RV) low-voltage areas identified by electroanatomic voltage mapping.

METHODS AND RESULTS: The study population (22 patients, 10 men; mean age 34 +/- 10 years) included 11 patients with overt ARVC/D (group A) and 11 patients with suspected ARVC/D (group B), according to both arrhythmic profile and standardized noninvasive diagnostic criteria. In all 22 patients, an RV bipolar voltage mapping was performed with CARTO system sampling multiple endocardial sites (262 +/- 61), during sinus rhythm, with a 0.5-1.5 mV color range setting of voltage display. All 11 (100%) group A patients and 8 of the 11 (73%) group B patients (P = nonsignificant [NS]) presented RV low-voltage areas (<0.5 mV). In 8 group A patients and in all 8 group B patients with a pathological RV voltage map, an EMB focused on the low-voltage areas was performed. In 6 (75%) group A patients and in 7 (87%) group B patients (P = NS), voltage mapping-guided EMB was diagnostic for ARVC/D. In the remaining 3 patients, only nonspecific histological findings were observed.

CONCLUSIONS: The results of our study (1) confirm the high diagnostic sensitivity of RV voltage mapping in patients with overt ARVC/D, (2) document a high prevalence of RV low-voltage areas even in patients with suspected ARVC/D, and (3) demonstrate that in patients with clinical evidence or suspicion for ARVC/D, presenting RV low-voltage areas, EMB guided by voltage mapping may provide ARVC/D diagnosis confirmation.