Three-dimensional electroanatomical voltage mapping and histologic evaluation of myocardial substrate in right ventricular outflow tract tachycardia.

Full Abstract

OBJECTIVES: We tested whether 3-dimensional electroanatomical voltage mapping (EVM) may help in the differential diagnosis between idiopathic right ventricular outflow tract (RVOT) tachycardia and arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D). BACKGROUND: Right ventricular EVM has been demonstrated to reliably identify low-voltage regions ("electroanatomical scar"), which in patients with ARVC/D correspond to areas of fibrofatty myocardial replacement. METHODS: The study population comprised 27 patients (15 men and 12 women, age 33.9 +/- 8 years) with RVOT tachycardia and no echocardiographic/angiographic evidence of right ventricular (RV) dilation/dysfunction, who underwent EVM and endomyocardial biopsy (EMB) for characterization of ventricular tachycardia (VT) substrate before catheter ablation. RESULTS: Electroanatomical voltage mapping was normal in 20 of 27 patients (74%, group A), with electrogram voltage >1.5 mV throughout the RV. The other 7 patients (26%, group B) showed >/=1 (1.4 +/- 07) RV electroanatomical scar area(s) (bipolar voltage <0.5 mV) that correlated with fibrofatty myocardial replacement at EMB (p < 0.001). Clinical predictors of RV scar were right precordial QRS prolongation (p < 0.001) and VT inducibility (p = 0.001). Catheter ablation successfully eliminated VT in 18 of 20 patients (90%). During a follow-up of 41 +/- 8 months, 3 of 7 patients (43%) from group B received an implantable defibrillator because of life-threatening ventricular arrhythmias, compared with no patients from group A (p = 0.016). CONCLUSIONS: An early/minor form of ARVC/D may mimic idiopathic RVOT tachycardia. Electroanatomical voltage mapping is able to identify RVOT tachycardia due to concealed ARVC/D by detecting RVOT electroanatomical scars that correlate with fibrofatty myocardial replacement at EMB and predispose to sudden arrhythmic death.

Author information

Author/s: Corrado, Domenico (D); Basso, Cristina (C); Leoni, Loira (L); Tokajuk, Barbara (B); Turrini, Pietro (P); Bauce, Barbara (B); Migliore, Federico (F); Pavei, Andrea (A); Tarantini, Giuseppe (G); Napodano, Massimo (M); Ramondo, Angelo (A); Buja, Gianfranco (G); Iliceto, Sabino (S); Thiene, Gaetano (G);

Affiliation: Department of Cardiac, Thoracic, and Vascular Sciences, University of Padua Medical School, Padua, Italy. domenico.corrado(-atsign-)unipd.it

Journal and publication information

Publication Type: Journal Article; Research Support, Non-U.S. Gov't

Journal: Journal of the American College of Cardiology (J Am Coll Cardiol), published in United States. (Language: eng)

Reference: 2008-Feb; vol 51 (issue 7) : pp 731-9

Dates: Created 2008/02/18; Completed 2008/03/12;

PMID: 18279737, status: MEDLINE (last retrieval date: 2/18/2009, IMS Date: )

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

Comments and Corrections

CommentIn: J Am Coll Cardiol. 2008 Feb 19;51(7):740-1. (PMID: 18279738)

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