title: Heart rate variability and non-linear dynamics in risk stratification.
abstract: The time-domain measures and power-spectral analysis of heart rate variability (HRV) are classic conventional methods to assess the complex regulatory system between autonomic nervous system and heart rate and are most widely used. There are abundant scientific data about the prognostic significance of the conventional measurements of HRV in patients with various conditions, particularly with myocardial infarction. Some studies have suggested that some newer measures describing non-linear dynamics of heart rate, such as fractal measures, may reveal prognostic information beyond that obtained by the conventional measures of HRV. An ideal risk indicator could specifically predict sudden arrhythmic death as the implantable cardioverter-defibrillator (ICD) therapy can prevent such events. There are numerically more sudden deaths among post-infarction patients with better preserved left ventricular function than in those with severe left ventricular dysfunction. Recent data support the concept that HRV measurements, when analyzed several weeks after acute myocardial infarction, predict life-threatening ventricular tachyarrhythmias in patients with moderately depressed left ventricular function. However, well-designed prospective randomized studies are needed to evaluate whether the ICD therapy based on the assessment of HRV alone or with other risk indicators improves the patients' prognosis. Several issues, such as the optimal target population, optimal timing of HRV measurements, optimal methods of HRV analysis, and optimal cutpoints for different HRV parameters, need clarification before the HRV analysis can be a widespread clinical tool in risk stratification.
authors.affiliation: Institute of Clinical Medicine, Division of Cardiology, Department of Internal Medicine, Centre of Excellence in Research, University of Oulu Oulu, Finland.
authors.forename: Juha S
authors.initials: JS
authors.lastname: Perkiömäki
references.citation: Am J Cardiol. 1997 Sep 15;80(6):779-83
references.pmid: 9315590
references.citation: Diabetes. 1982 Apr;31(4 Pt 1):339-45
references.pmid: 7152130
references.citation: Am J Cardiol. 1988 Jun 1;61(15):1292-9
references.pmid: 3376889
references.citation: Am J Cardiol. 2001 Oct 1;88(7):777-81
references.pmid: 11589848
references.citation: Circulation. 2000 Jan 4-11;101(1):47-53
references.pmid: 10618303
references.citation: Am Heart J. 2004 Feb;147(2):309-16
references.pmid: 14760330
references.citation: Circulation. 1993 Sep;88(3):927-34
references.pmid: 8353919
references.citation: Circulation. 1997 Aug 5;96(3):842-8
references.pmid: 9264491
references.citation: J Am Coll Cardiol. 2007 Dec 11;50(24):2275-84
references.pmid: 18068035
references.citation: Eur Heart J. 2009 Mar;30(6):689-98
references.pmid: 19155249
references.citation: Br Med J. 1973 Dec 8;4(5892):584-6
references.pmid: 4758519
references.citation: Am J Physiol. 1996 Oct;271(4 Pt 2):R1078-84
references.pmid: 8898003
references.citation: Am J Cardiol. 1999 Mar 15;83(6):880-4
references.pmid: 10190403
references.citation: Br Heart J. 1994 Jun;71(6):521-7
references.pmid: 8043330
references.citation: Ann Noninvasive Electrocardiol. 2008 Apr;13(2):120-9
references.pmid: 18426437
references.citation: Anesthesiology. 1993 Apr;78(4):683-92
references.pmid: 8466069
references.citation: Kidney Int Suppl. 1992 Jun;37:S14-8
references.pmid: 1630069
references.citation: Anesth Analg. 2006 Apr;102(4):1026-31
references.pmid: 16551892
references.citation: Ann Biomed Eng. 1990;18(2):195-8
references.pmid: 2350063
references.citation: Ann Noninvasive Electrocardiol. 2010 Jul;15(3):250-8
references.pmid: 20645968
references.citation: Circulation. 1996 Aug 1;94(3):432-6
references.pmid: 8759085
references.citation: Br Heart J. 1995 Feb;73(2):139-44
references.pmid: 7696023
references.citation: Am J Cardiol. 1992 Mar 15;69(8):761-7
references.pmid: 1546651
references.citation: Circulation. 1999 Nov 16;100(20):2079-84
references.pmid: 10562264
references.citation: Am J Cardiol. 1987 Feb 1;59(4):256-62
references.pmid: 3812275
references.citation: Circulation. 1996 Mar 1;93(5):1043-65
references.pmid: 8598068
references.citation: Philos Trans A Math Phys Eng Sci. 2009 Apr 13;367(1892):1223-38
references.pmid: 19324705
references.citation: Circulation. 1994 Jul;90(1):121-6
references.pmid: 8025987
references.citation: Am J Cardiol. 1994 Apr 1;73(9):653-7
references.pmid: 8166060
references.citation: Am Heart J. 1993 Mar;125(3):731-43
references.pmid: 7679868
references.citation: N Engl J Med. 2001 Nov 15;345(20):1473-82
references.pmid: 11794197
references.citation: Europace. 2006 Jun;8(6):398-402
references.pmid: 16687424
references.citation: Physiol Meas. 2007 Sep;28(9):1067-77
references.pmid: 17827654
references.citation: Circulation. 2005 Jul 19;112(3):314-9
references.pmid: 16009791
references.citation: Circulation. 1999 Sep 28;100(13):1416-22
references.pmid: 10500043
references.citation: Circulation. 1998 Oct 13;98(15):1510-6
references.pmid: 9769304
references.citation: Circulation. 1998 May 26;97(20):2031-6
references.pmid: 9610533
references.citation: Am J Physiol. 1990 Jun;258(6 Pt 2):H1722-6
references.pmid: 2360666
references.citation: Circulation. 1992 Jan;85(1):164-71
references.pmid: 1728446
references.citation: Am J Physiol. 1994 Apr;266(4 Pt 2):H1643-56
references.pmid: 8184944
references.citation: J Electrocardiol. 1994;27 Suppl:179-81
references.pmid: 7884357
references.citation: Am J Cardiol. 2003 Oct 15;92(8):907-12
references.pmid: 14556864
references.citation: Circulation. 1998 Aug 4;98(5):429-34
references.pmid: 9714093
references.citation: J Am Coll Cardiol. 1996 Nov 1;28(5):1183-9
references.pmid: 8890814
references.citation: Circulation. 1989 Jan;79(1):76-82
references.pmid: 2642758
references.citation: Circulation. 1996 Jun 15;93(12):2142-51
references.pmid: 8925583
references.citation: Nephron. 1987;45(3):202-6
references.pmid: 3574569
references.citation: Circulation. 1994 Aug;90(2):878-83
references.pmid: 8044959
references.citation: Lancet. 1999 Apr 24;353(9162):1390-6
references.pmid: 10227219
references.citation: Circulation. 1997 Mar 18;95(6):1449-54
references.pmid: 9118512
references.citation: Diabetes Res Clin Pract. 2002 Nov;58(2):131-8
references.pmid: 12213355
references.citation: Am J Cardiol. 2001 Jan 15;87(2):178-82
references.pmid: 11152835
references.citation: N Engl J Med. 2005 Jan 20;352(3):225-37
references.pmid: 15659722
references.citation: Shock. 2008 Jul;30(1):17-22
references.pmid: 18323736
references.citation: Am Heart J. 1990 Dec;120(6 Pt 1):1419-40
references.pmid: 2248188
references.citation: Pacing Clin Electrophysiol. 1998 Jan;21(1 Pt 2):186-92
references.pmid: 9474670
references.citation: Med J Aust. 1978 Jul 15;2(2):52-3
references.pmid: 713911
references.citation: N Engl J Med. 2002 Mar 21;346(12):877-83
references.pmid: 11907286
references.citation: Am J Hypertens. 1995 Dec;8(12 Pt 1):1206-13
references.pmid: 8998255
references.citation: Lancet. 1996 May 11;347(9011):1312-4
references.pmid: 8622511
references.citation: J Am Coll Cardiol. 1997 Nov 1;30(5):1331-8
references.pmid: 9350936
references.citation: Am J Cardiol. 1991 May 15;67(13):1154-8
references.pmid: 1809257
references.citation: Am J Cardiol. 1996 Apr 1;77(9):681-4
references.pmid: 8651116
references.citation: Br Med J (Clin Res Ed). 1982 Dec 4;285(6355):1599-601
references.pmid: 6814668
references.citation: J Hypertens. 1988 Sep;6(9):711-7
references.pmid: 3183374
references.citation: Am J Cardiol. 2001 Jul 1;88(1):17-22
references.pmid: 11423052
references.citation: J Am Coll Cardiol. 1991 Sep;18(3):687-97
references.pmid: 1822090
references.citation: J Neurol Neurosurg Psychiatry. 1978 May;41(5):417-9
references.pmid: 660203
references.citation: Circulation. 1999 Jul 27;100(4):393-9
references.pmid: 10421600
references.citation: Ann N Y Acad Sci. 1990;591:402-9
references.pmid: 2197932
references.citation: Am J Physiol Heart Circ Physiol. 2001 Mar;280(3):H1400-6
references.pmid: 11179090
references.citation: Chaos. 1995;5(1):82-7
references.pmid: 11538314
references.citation: Int J Cardiol. 1988 Jul;20(1):39-51
references.pmid: 3403082
references.citation: Am J Cardiol. 2001 Apr 1;87(7):905-8
references.pmid: 11274951
references.citation: Am J Cardiol. 1999 Mar 15;83(6):836-9
references.pmid: 10190395
references.citation: Am J Cardiol. 2002 Aug 15;90(4):347-52
references.pmid: 12161220
references.citation: Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 1994 Feb;49(2):1685-9
references.pmid: 9961383
references.citation: Eur Heart J. 2005 Apr;26(8):762-9
references.pmid: 15778204
references.citation: Hypertension. 1996 Jul;28(1):16-21
references.pmid: 8675257
references.citation: Br Heart J. 1987 Dec;58(6):592-7
references.pmid: 3426895
references.citation: Europace. 2011 Nov;13(11):1604-11
references.pmid: 21712280
references.citation: Am J Cardiol. 1989 Nov 15;64(18):1162-7
references.pmid: 2816768
references.citation: J Crit Care. 2008 Sep;23(3):399-405
references.pmid: 18725047
references.citation: Br Heart J. 1991 Jan;65(1):14-9
references.pmid: 1704246
references.citation: J Am Coll Cardiol. 1996 Aug;28(2):296-304
references.pmid: 8800101
references.citation: Neurology. 1983 Apr;33(4):463-7
references.pmid: 6682192
references.citation: Br Heart J. 1994 May;71(5):422-30
references.pmid: 8011405
references.citation: J Am Coll Cardiol. 1996 Feb;27(2):270-6
references.pmid: 8557893
references.citation: Am J Cardiol. 2003 Aug 1;92(3):247-51
references.pmid: 12888125
references.citation: J Am Coll Cardiol. 2001 Apr;37(5):1395-402
references.pmid: 11300452
references.citation: Br Heart J. 1992 Jun;67(6):482-5
references.pmid: 1622699
references.citation: Circulation. 1990 Apr;81(4):1217-24
references.pmid: 2317904
references.citation: Comput Cardiol. 1988;14:419-22
references.pmid: 11542156
references.citation: Arterioscler Thromb Vasc Biol. 1999 Aug;19(8):1979-85
references.pmid: 10446081