title: Body Surface Mapping of T-wave Alternans Depends on the Distribution of Myocardial Scarring.
abstract: T-Wave alternans (TWA) testing using 12-lead electrocardiogram/Frank leads is emerging as an important non-invasive biomarker to identify patients at high risk of Sudden Cardiac Death (SCD). Cardiac scarring is very common among cardiomyopathy patients; however, its influence on the body surface distribution of TWA has not yet been defined. Our objective was to perform a simulation study in order to determine whether cardiac scarring affects the distribution of TWA on thorax such that the standard leads fail to detect TWA in some of cardiomyopathy patients; thereby producing a false-negative test. Developing such a novel lead configuration could improve TWA quantification and potentially optimize electrocardiogram (ECG) lead configuration and risk stratification of SCD in cardiomyopathy patients. The simulation was performed in a 1500-node heart model using ECGSIM. TWA was mimicked by simulating action potential duration alternans in the ventricles. Cardiac scarring with different sizes were simulated by manipulating the apparent velocity, transmembrane potential and transition zone at varied locations along the left ventricular posterior wall. Our simulation study showed that the location of maximum TWA depends on the location and size of the myocardium scarring in patients with cardiomyopathy, which can give rise to false-negative TWA signal detection using standard clinical leads. The TWA amplitude generally increased with the increment of scar size (P<0.00001). We found one specific location (a non-standard lead) that consistently appeared as the top five maximum TWA leads and could be considered as an additional lead to improve the outcome of the TWA testing in cardiomyopathy patients.
authors.affiliation: Department of Biomedical Engineering, Rochester Institute of Technology, Rochester, NY, USA.
authors.forename: Amy
authors.initials: A
authors.lastname: Zeller
authors.affiliation: Department of Biomedical Engineering, Rochester Institute of Technology, Rochester, NY, USA.
authors.forename: Behnaz
authors.initials: B
authors.lastname: Ghoraani
keywords: Body surface mapping; ECGSIM; cardiomy-opathy; sudden cardiac death; t-wave alternans testing
references.citation: J Am Coll Cardiol. 2007 Jan 23;49(3):338-46
references.pmid: 17239715
references.citation: Heart. 2004 Feb;90(2):165-8
references.pmid: 14729788
references.citation: Heart Rhythm. 2009 Mar;6(3 Suppl):S36-44
references.pmid: 19168396
references.citation: Ann Noninvasive Electrocardiol. 2005 Jan;10(1):110-20
references.pmid: 15649246
references.citation: Circulation. 2006 Jun 27;113(25):2880-7
references.pmid: 16785339
references.citation: JAMA. 2013 Mar 6;309(9):896-908
references.pmid: 23462786
references.citation: Am Heart J. 1996 Sep;132(3):699-701
references.pmid: 8800049
references.citation: Circulation. 1999 Mar 16;99(10):1385-94
references.pmid: 10077525
references.citation: J Am Coll Cardiol. 2008 Nov 11;52(20):1607-15
references.pmid: 18992649
references.citation: Heart Rhythm. 2009 Aug;6(8):1211-9
references.pmid: 19632636
references.citation: Circulation. 2008 Nov 11;118(20):2022-8
references.pmid: 18955671
references.citation: J Cardiovasc Electrophysiol. 2002 May;13(5):502-12
references.pmid: 12030535
references.citation: Med Biol Eng Comput. 2009 Jan;47(1):11-20
references.pmid: 18766396
references.citation: Int J Cardiol. 2006 May 24;109(3):293-306
references.pmid: 16054250
references.citation: J Cardiovasc Electrophysiol. 2005 Jun;16(6):620-4
references.pmid: 15946361
references.citation: Circulation. 2011 Mar 15;123(10):1052-60
references.pmid: 21357826