title: Abnormal repolarization in the acute myocardial infarction patients: a frequency-based characterization.
abstract: Despite ST elevation having poor sensitivity for acute myocardial infarction (AMI), it remains the main electrocardiographic (ECG) repolarization index for AMI diagnosis. Aim of the present study was to propose a new f99 index, defined as the frequency at which the repolarization normalized cumulative energy reaches 99%, for ECG AMI discrimination from health with good sensitivity and good specificity. Evaluation of such f99 index was performed on 12-standard-lead (I, II, III, aV1, aVr, aVf, V1 to V6) ECG recordings of 47 healthy controls and 108 acute myocardial infarction (AMI) patients. Repolarization dispersion caused f99 distributions to be significantly lead dependent. In most leads (leads I, II, aVl, aVr, V2-V6), f99 median value was lower in the healthy controls (10-17 Hz) than in the AMI patients (12-38 Hz) indicating higher frequency components (i.e. a more fragmented repolarization) in the latter population. AMI patients from healthy controls discrimination by f99, evaluated in terms of sensitivity (Se) and specificity (Sp), was also lead dependent. Single-lead analysis indicated leads I (Se=80%, Sp=77%) and aVl (Se=84%, Sp=74%) as optimal. Instead, lead-system analysis, performed to overcome dispersion issues, provided the best results when averaging over the 6 precordial leads (Se= 81% and Sp=74%). In conclusion, our new f99 index appears as a promising tool for non-invasively and reliably discriminate AMI patients from healthy subjects.
authors.affiliation: Department of Information Engineering, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Corrado
authors.initials: C
authors.lastname: Giuliani
authors.affiliation: Department of Information Engineering, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Agostinelli
authors.affiliation: Department of Information Engineering, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Sandro
authors.initials: S
authors.lastname: Fioretti
authors.affiliation: Department of Information Engineering, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Francesco D
authors.initials: FD
authors.lastname: Nardo
authors.affiliation: Department of Information Engineering, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Laura B
authors.initials: LB
authors.lastname: Burattini
keywords: Digital electrocardiography; ECG repolarization index; T-wave frequency content.; myocardial infarction; repolarization variability
references.citation: Eur Heart J. 2000 Feb;21(4):275-83
references.pmid: 10653675
references.citation: Med Eng Phys. 2012 Apr;34(3):305-12
references.pmid: 21835679
references.citation: Heart Rhythm. 2009 Dec;6(12):1765-71
references.pmid: 19959127
references.citation: Open Biomed Eng J. 2010;4:217-22
references.pmid: 21625645
references.citation: Circulation. 2013 Jan 29;127(4):e362-425
references.pmid: 23247304
references.citation: J Electrocardiol. 2011 Jul-Aug;44(4):453-9
references.pmid: 21704222
references.citation: Europace. 2007 Sep;9 Suppl 4:iv4-15
references.pmid: 17766323
references.citation: Am J Physiol Heart Circ Physiol. 2007 Oct;293(4):H2024-38
references.pmid: 17586620
references.citation: Am J Emerg Med. 2002 Nov;20(7):609-12
references.pmid: 12442239
references.citation: Am J Cardiol. 1988 Jan 1;61(1):83-7
references.pmid: 3337022
references.citation: J Electrocardiol. 2003;36 Suppl:115-20
references.pmid: 14716611
references.citation: J Electrocardiol. 1999;32 Suppl:166-72
references.pmid: 10688321
references.citation: J Am Coll Cardiol. 2006 May 2;47(9):1828-34
references.pmid: 16682308
references.citation: Ann Noninvasive Electrocardiol. 2012 Apr;17(2):130-40
references.pmid: 22537331
references.citation: J Electrocardiol. 1998;30 Suppl:137-44
references.pmid: 9535491
references.citation: Pacing Clin Electrophysiol. 1999 Nov;22(11):1581-92
references.pmid: 10598960
references.citation: N Engl J Med. 2008 May 8;358(19):2016-23
references.pmid: 18463377
references.citation: J Cardiovasc Electrophysiol. 2012 Aug;23(8):846-52
references.pmid: 22509793
references.citation: J Electrocardiol. 2004;37 Suppl:25-33
references.pmid: 15534789
references.citation: Ann Emerg Med. 1994 Jan;23(1):17-24
references.pmid: 8273952
references.citation: J Electrocardiol. 2012 May-Jun;45(3):252-9
references.pmid: 22240011
references.citation: Acad Emerg Med. 2006 Apr;13(4):406-12
references.pmid: 16531592
references.citation: Circulation. 2012 May 29;125(21):2572-7
references.pmid: 22576982
references.citation: Circulation. 2000 Sep 12;102(11):1252-7
references.pmid: 10982539
references.citation: Heart Rhythm. 2006 Dec;3(12):1460-6
references.pmid: 17161789
references.citation: Epidemiology. 2011 Sep;22(5):660-70
references.pmid: 21709561
references.citation: Circulation. 2012 Jan 3;125(1):188-97
references.pmid: 22215894