ST-Elevation Magnitude Correlates With Right Ventricular Outflow Tract Conduction Delay in Type I Brugada ECG
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
Background: The substrate location and underlying electrophysiological mechanisms that contribute to the characteristic ECG pattern of Brugada syndrome (BrS) are still debated. Using noninvasive electrocardiographical imaging, we studied whole heart conduction and repolarization patterns during ajmaline challenge in BrS individuals.
Methods and Results: A total of 13 participants (mean age, 44±12 years; 8 men), 11 concealed patients with type I BrS and 2 healthy controls, underwent an ajmaline infusion with electrocardiographical imaging and ECG recordings. Electrocardiographical imaging activation recovery intervals and activation timings across the right ventricle (RV) body, outflow tract (RVOT), and left ventricle were calculated and analyzed at baseline and when type I BrS pattern manifested after ajmaline infusion. Peak J-ST point elevation was calculated from the surface ECG and compared with the electrocardiographical imaging–derived parameters at the same time point. After ajmaline infusion, the RVOT had the greatest increase in conduction delay (5.4±2.8 versus 2.0±2.8 versus 1.1±1.6 ms; P=0.007) and activation recovery intervals prolongation (69±32 versus 39±29 versus 21±12 ms; P=0.0005) compared with RV or left ventricle. In controls, there was minimal change in J-ST point elevation, conduction delay, or activation recovery intervals at all sites with ajmaline. In patients with BrS, conduction delay in RVOT, but not RV or left ventricle, correlated to the degree of J-ST point elevation (Pearson R, 0.81; P<0.001). No correlation was found between J-ST point elevation and activation recovery intervals prolongation in the RVOT, RV, or left ventricle.
Conclusions: Magnitude of ST (J point) elevation in the type I BrS pattern is attributed to degree of conduction delay in the RVOT and not prolongation in repolarization time.
Methods and Results: A total of 13 participants (mean age, 44±12 years; 8 men), 11 concealed patients with type I BrS and 2 healthy controls, underwent an ajmaline infusion with electrocardiographical imaging and ECG recordings. Electrocardiographical imaging activation recovery intervals and activation timings across the right ventricle (RV) body, outflow tract (RVOT), and left ventricle were calculated and analyzed at baseline and when type I BrS pattern manifested after ajmaline infusion. Peak J-ST point elevation was calculated from the surface ECG and compared with the electrocardiographical imaging–derived parameters at the same time point. After ajmaline infusion, the RVOT had the greatest increase in conduction delay (5.4±2.8 versus 2.0±2.8 versus 1.1±1.6 ms; P=0.007) and activation recovery intervals prolongation (69±32 versus 39±29 versus 21±12 ms; P=0.0005) compared with RV or left ventricle. In controls, there was minimal change in J-ST point elevation, conduction delay, or activation recovery intervals at all sites with ajmaline. In patients with BrS, conduction delay in RVOT, but not RV or left ventricle, correlated to the degree of J-ST point elevation (Pearson R, 0.81; P<0.001). No correlation was found between J-ST point elevation and activation recovery intervals prolongation in the RVOT, RV, or left ventricle.
Conclusions: Magnitude of ST (J point) elevation in the type I BrS pattern is attributed to degree of conduction delay in the RVOT and not prolongation in repolarization time.
Date Issued
2017-10-16
Date Acceptance
2017-08-17
Citation
Circulation: Arrhythmia and Electrophysiology, 2017, 10 (10)
ISSN
1941-3084
Publisher
American Heart Association
Journal / Book Title
Circulation: Arrhythmia and Electrophysiology
Volume
10
Issue
10
Copyright Statement
© 2017 American Heart Association, Inc. This is a non-final version of an article published in final form in Circulation: Arrhythmia and Electrophysiology. 2017;10:e005107, https://dx.doi.org/10.1161/CIRCEP.117.005107
Sponsor
British Heart Foundation
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000413093000003&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
PG/15/20/31339
Subjects
Science & Technology
Life Sciences & Biomedicine
Cardiac & Cardiovascular Systems
Cardiovascular System & Cardiology
ajmaline
Brugada syndrome
electrocardiography
electrophysiologic techniques, cardiac
heart ventricles
sodium channels
LONG-QT SYNDROME
CATHETER ABLATION
T-WAVE
REPOLARIZATION
SUBSTRATE
EPICARDIUM
AJMALINE
ELECTROCARDIOGRAM
ABNORMALITIES
POTENTIALS
Action Potentials
Adult
Ajmaline
Anti-Arrhythmia Agents
Body Surface Potential Mapping
Brugada Syndrome
Case-Control Studies
Electrocardiography
Female
Heart Conduction System
Heart Rate
Humans
Male
Middle Aged
Predictive Value of Tests
Refractory Period, Electrophysiological
Signal Processing, Computer-Assisted
Time Factors
Cardiovascular System & Hematology
Publication Status
Published
Article Number
ARTN e005107
Date Publish Online
2017-10-16