Europace Advance Access originally published online on March 11, 2009
Europace 2009 11(4):514-520; doi:10.1093/europace/eup051
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Non-invasive Electrophysiology and Risk Stratification
Complex T-wave morphology in body surface potential mapping in prediction of arrhythmic events in patients with acute myocardial infarction and cardiac dysfunction
1 Division of Cardiology, Helsinki University Hospital, PL 340, 00029 HUS Helsinki, Finland; 2 BioMag Laboratory, Helsinki University Hospital, Helsinki, Finland; 3 Department of Biomedical Engineering and Computational Science, Helsinki University of Technology, Espoo, Finland
Aims: Heterogeneous ventricular repolarization is associated with sudden cardiac death after myocardial infarction (MI). This prospective study investigated repolarization disparity with parameters based on T-wave morphology in body surface potential mapping (BSPM) in the assessment of arrhythmia risk in patients with a recent MI and cardiac dysfunction.
Methods and results: Patients (n = 158) had 120-lead BSPM and 12-lead electrocardiogram (ECG) registered soon after acute MI. Principal component analysis (PCA) of the T-wave and T-wave vector loop descriptors were applied to compute parameters describing T-wave morphology and its variation. The study endpoints were arrhythmic events and all-cause mortality. During a mean follow-up of 50 months, 30 patients (19%) died and 16 (10%) had an arrhythmic event. Most of the parameters differed significantly between patients with and without arrhythmic events. In univariate analysis, T-wave vector loop length (TLL) and PCA parameter PCA3 in BSPM and TLL in ECG were significant predictors of arrhythmic events. In multivariate analysis including several clinical variables, these parameters also showed an independent prediction, with parameters in BSPM performing somewhat better. None of the parameters predicted all-cause mortality.
Conclusion: Complex T-wave morphology in BSPM is a marker of arrhythmia propensity in patients with a recent MI and cardiac dysfunction.
Key Words: Heterogeneous repolarization, T-wave morphology, Body surface potential mapping, Ventricular arrhythmias, Myocardial infarction
* Corresponding author. Tel: +358 9 471 72442, Fax: +358 9 471 74574, Email: korhonen.petri{at}kolumbus.fi
Manuscript submitted 17 December 2008. Accepted after revision 3 February 2009.