Document Detail

Correlation between signal-averaged ECG and the histologic evaluation of the myocardial substrate in right ventricular outflow tract arrhythmias.
MedLine Citation:
PMID:  22423142     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: The differential diagnosis between idiopathic and cardiomyopathy-related right ventricular outflow tract (RVOT) ventricular arrhythmias (VAs) is crucial. Signal-averaged ECG (SAECG) abnormalities are frequent in cardiomyopathy-related RVOT-VAs, although their pathophysiologic basis and diagnostic value in this setting are undefined. We tested the association between SAECG and the myocardial substrate underlying RVOT-VAs.
METHODS AND RESULTS: Twenty-four consecutive patients (median age, 50 years [42-59]; 12 men) with RVOT-VAs (10 with frequent [>1000/24 hours] premature ventricular contractions, 14 with ventricular tachycardias) underwent SAECG with 40-Hz filtering and electroanatomic mapping (EAM) with EAM-guided biopsy for characterization of the RVOT-VAs substrate. A filtered averaged QRS (fQRS) was obtained and analyzed for fQRS duration, low amplitude signal duration<40 mV (LAS40), and root-mean-square voltage in the last 40 ms of the QRS (RMS40). Standard definition of EAM scar was used. EAM-guided biopsy diagnosed ARVC in 11 (46%), myocarditis in 8 (33%), and idiopathic RVOT-VAs in 5 (21%) patients. Patients with cardiomyopathy-related RVOT-VAs had ≥1 EAM scar (median, 2 [1-2]; all with RVOT scar). EAM of patients with idiopathic RVOT-VAs was normal. Patients with cardiomyopathy-related RVOT-VAs had significantly longer fQRS (106 ms [92-132] versus 83 ms [82-84], P=0.01) and LAS40 (39 ms [36-51] versus 19 ms [18-21], P=0.02), and lower RMS40 (18 µV [9-26] versus 33 µV [32-33], P=0.04). A significant linear correlation was found between the extension (cm2) of the RVOT scar and all 3 SAECG parameters (rs=0.76, P<0.001 for the fQRSd; rs=0.73, P<0.001 for the LAS40; and rs=-0.72, P<0.001 for the RMS40). Using the established 2 of 3 criteria (ie, late potentials), SAECG diagnosed cardiomyopathy-related RVOT-VAs with high positive (100%) but low negative (38%) predictive values and missed 7 of 9 (78%) patients with RVOT scar<8 cm2.
CONCLUSIONS: In patients with RVOT-VAs, abnormal SAECG parameters reflect the presence of extensive cardiomyopathic involvement of the RVOT. However, a negative SAECG does not reliably rule out cardiomyopathy-related RVOT-VAs in the presence of a small RVOT scar.
Pasquale Santangeli; Maurizio Pieroni; Antonio Dello Russo; Michela Casella; Gemma Pelargonio; Luigi Di Biase; Andrea Macchione; J David Burkhardt; Fulvio Bellocci; Pietro Santarelli; Claudio Tondo; Andrea Natale
Publication Detail:
Type:  Comparative Study; Evaluation Studies; Journal Article; Research Support, Non-U.S. Gov't     Date:  2012-03-15
Journal Detail:
Title:  Circulation. Arrhythmia and electrophysiology     Volume:  5     ISSN:  1941-3084     ISO Abbreviation:  Circ Arrhythm Electrophysiol     Publication Date:  2012 Jun 
Date Detail:
Created Date:  2012-06-20     Completed Date:  2012-09-04     Revised Date:  2014-03-19    
Medline Journal Info:
Nlm Unique ID:  101474365     Medline TA:  Circ Arrhythm Electrophysiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  475-83     Citation Subset:  IM    
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MeSH Terms
Arrhythmogenic Right Ventricular Dysplasia / diagnosis*,  physiopathology
Biopsy / methods
Diagnosis, Differential
Electrocardiography / methods*
Follow-Up Studies
Heart Conduction System / pathology,  physiopathology*
Imaging, Three-Dimensional
Magnetic Resonance Imaging, Cine / methods
Middle Aged
Myocardium / pathology*
Predictive Value of Tests
Grant Support
Comment In:
Circ Arrhythm Electrophysiol. 2012 Jun 1;5(3):453-5   [PMID:  22715235 ]
Erratum In:
Circ Arrhythm Electrophysiol. 2012 Oct;5(5):e102

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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