Three-dimensional electroanatomic voltage mapping increases accuracy of diagnosing arrhythmogenic right ventricular cardiomyopathy/dysplasia.
BACKGROUND
Three-dimensional electroanatomic voltage mapping offers the potential to identify low-voltage areas that correspond to regions of right ventricular (RV) myocardial loss and fibrofatty replacement in patients with arrhythmogenic RV cardiomyopathy/dysplasia (ARVC/D).


RESULTS
Thirty-one consecutive patients (22 men and 9 women; mean age, 30.8+/-7 years) who fulfilled the criteria of the Task Force of the European Society of Cardiology and International Society and Federation of Cardiology (ESC/ISFC) for ARVC/D diagnosis after noninvasive clinical evaluation underwent further invasive study including RV electroanatomic voltage mapping and endomyocardial biopsy (EMB) to validate the diagnosis. Multiple RV endocardial, bipolar electrograms (175+/-23) were sampled during sinus rhythm. Twenty patients (group A; 65%) had an abnormal RV electroanatomic voltage mapping showing > or =1 area (mean 2.25+/-0.7) with low-voltage values (bipolar electrogram amplitude <0.5 mV), surrounded by a border zone (0.5 to 1.5 mV) that transitioned into normal myocardium (>1.5 mV). Low-voltage electrograms appeared fractionated with significantly prolonged duration and delayed activation. In 11 patients (group B; 35%), electroanatomic voltage mapping was normal, with preserved electrogram voltage (4.4+/-0.7 mV) and duration (37.2+/-0.9 ms) throughout the RV. Low-voltage areas in patients from group A corresponded to echocardiographic/angiographic RV wall motion abnormalities and were significantly associated with myocyte loss and fibrofatty replacement at EMB (P<0.0001) and familial ARVC/D (P<0.0001). Patients from group B had sporadic disease and histopathological evidence of inflammatory cardiomyopathy (P<0.0001). During the time interval from onset of symptoms to the invasive study, 11 patients (55%) with electroanatomic low-voltage regions received an implantable cardioverter/defibrillator because of life-threatening ventricular arrhythmias, whereas all but 1 patient with a normal voltage map remained stable on antiarrhythmic drug therapy (P=0.02).


CONCLUSIONS
Three-dimensional electroanatomic voltage mapping enhanced accuracy for diagnosing ARVC/D (1) by demonstrating low-voltage areas that were associated with fibrofatty myocardial replacement and (2) by identifying a subset of patients who fulfilled ESC/ISFC Task Force diagnostic criteria but showed a preserved electrogram voltage, an inflammatory cardiomyopathy mimicking ARVC/D, and a better arrhythmic outcome.
Corrado
Domenico
D
Division of Cardiology, University of Padua Medical School, Padua, Italy.
Basso
Cristina
C
Leoni
Loira
L
Tokajuk
Barbara
B
Bauce
Barbara
B
Frigo
Gianfranco
G
Tarantini
Giuseppe
G
Napodano
Massimo
M
Turrini
Pietro
P
Ramondo
Angelo
A
Daliento
Luciano
L
Nava
Andrea
A
Buja
Gianfranco
G
Iliceto
Sabino
S
Thiene
Gaetano
G
D000328:Adult; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D019571:Arrhythmogenic Right Ventricular Dysplasia / Q000175:diagnosis* / Q000628:therapy; D017147:Defibrillators, Implantable; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D009206:Myocardium / Q000473:pathology; D018497:Ventricular Dysfunction, Right / Q000503:physiopathology / Q000628:therapy
D000889:Anti-Arrhythmia Agents