{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T01:52:08Z","timestamp":1791942728324,"version":"4.3.4"},"reference-count":47,"publisher":"American Veterinary Medical Association (AVMA)","issue":"5","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["ajvr"],"published-print":{"date-parts":[[2009,5]]},"abstract":"<jats:title>Abstract<\/jats:title>\n<jats:p><jats:bold>Objective<\/jats:bold>\u2014To investigate use of signal analysis of heart sounds and murmurs in assessing severity of mitral valve regurgitation (mitral regurgitation [MR]) in dogs with myxomatous mitral valve disease (MMVD).<\/jats:p>\n<jats:p><jats:bold>Animals<\/jats:bold>\u201477 client-owned dogs.<\/jats:p>\n<jats:p><jats:bold>Procedures<\/jats:bold>\u2014Cardiac sounds were recorded from dogs evaluated by use of auscultatory and echocardiographic classification systems. Signal analysis techniques were developed to extract 7 sound variables (first frequency peak, murmur energy ratio, murmur duration &gt; 200 Hz, sample entropy and first minimum of the auto mutual information function of the murmurs, and energy ratios of the first heart sound [S1] and second heart sound [S2]).<\/jats:p>\n<jats:p><jats:bold>Results<\/jats:bold>\u2014Significant associations were detected between severity of MR and all sound variables, except the energy ratio of S1. An increase in severity of MR resulted in greater contribution of higher frequencies, increased signal irregularity, and decreased energy ratio of S2. The optimal combination of variables for distinguishing dogs with high-intensity murmurs from other dogs was energy ratio of S2 and murmur duration &gt; 200 Hz (sensitivity, 79%; specificity, 71%) by use of the auscultatory classification. By use of the echocardiographic classification, corresponding variables were auto mutual information, first frequency peak, and energy ratio of S2 (sensitivity, 88%; specificity, 82%).<\/jats:p>\n<jats:p><jats:bold>Conclusions and Clinical Relevance<\/jats:bold>\u2014Most of the investigated sound variables were significantly associated with severity of MR, which indicated a powerful diagnostic potential for monitoring MMVD. Signal analysis techniques could be valuable for clinicians when performing risk assessment or determining whether special care and more extensive examinations are required.<\/jats:p>","DOI":"10.2460\/ajvr.70.5.604","type":"journal-article","created":{"date-parts":[[2009,5,1]],"date-time":"2009-05-01T07:05:47Z","timestamp":1241161547000},"page":"604-613","source":"Crossref","is-referenced-by-count":29,"title":["Use of signal analysis of heart sounds and murmurs to assess severity of mitral valve regurgitation attributable to myxomatous mitral valve disease in dogs"],"prefix":"10.2460","volume":"70","author":[{"given":"Ingrid","family":"Ljungvall","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christer","family":"Ahlstrom","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Katja","family":"H\u00f6glund","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Peter","family":"Hult","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Clarence","family":"Kvart","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michele","family":"Borgarelli","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Per","family":"Ask","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jens","family":"H\u00e4ggstr\u00f6m","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1272","reference":[{"key":"ref1","series-title":"Ann N Y Acad Sci","first-page":"481","article-title":"The prevalence and types of cardiovascular disease in dogs","volume":"127","author":"Detweiler","year":"1965"},{"key":"ref2","series-title":"Vet Med Small Anim Clin","first-page":"1209","article-title":"Chronic mitral valve disease in the dog","volume":"60","author":"Das","year":"1965"},{"key":"ref3","series-title":"J Small Anim Pract","doi-asserted-by":"publisher","first-page":"511","DOI":"10.1111\/j.1748-5827.1974.tb06529.x","article-title":"Observations on the effect of age on the severity of heart valve lesions in the dog","volume":"15","author":"Whitney","year":"1974"},{"key":"ref4","series-title":"Adv Vet Sci Comp Med","first-page":"75","article-title":"Chronic valvular disease (endocardiosis) in dogs","volume":"21","author":"Buchanan","year":"1977"},{"key":"ref5","series-title":"J Small Anim Pract","doi-asserted-by":"publisher","first-page":"709","DOI":"10.1111\/j.1748-5827.1985.tb02199.x","article-title":"Observations on breed and sex in relation to canine heart valve incompetence","volume":"26","author":"Thrusfield","year":"1985"},{"key":"ref6","series-title":"Vet Rec","doi-asserted-by":"publisher","first-page":"365","DOI":"10.1136\/vr.120.15.365","article-title":"Valvular incompetence in Cavalier King Charles spaniels","volume":"120","author":"Darke","year":"1987"},{"key":"ref7","series-title":"Vet Rec","first-page":"549","article-title":"Chronic valvular disease in the Cavalier King Charles spaniel in Sweden","volume":"131","author":"H\u00e4ggstr\u00f6m","year":"1992"},{"key":"ref8","series-title":"J Am Vet Med Assoc","first-page":"1023","article-title":"Chronic mitral valve disease in Cavalier King Charles Spaniels: 95 cases (1987\u20131991)","volume":"203","author":"Beardow","year":"1993"},{"key":"ref9","series-title":"Nippon Juigaku Zasshi","doi-asserted-by":"publisher","first-page":"323","DOI":"10.1292\/jvms1939.42.323","article-title":"Pathology of chronic mitral valvular disease in the dog","volume":"42","author":"Kogure","year":"1980"},{"key":"ref10","series-title":"J Vet Intern Med","doi-asserted-by":"publisher","first-page":"894","DOI":"10.1111\/j.1939-1676.2006.tb01803.x","article-title":"Heart disease as a cause of death in insured Swedish dogs younger than 10 years of age","volume":"20","author":"Egenvall","year":"2006"},{"key":"ref11","series-title":"J Vet Intern Med","doi-asserted-by":"publisher","first-page":"75","DOI":"10.1111\/j.1939-1676.1995.tb03276.x","article-title":"Heart sounds and murmurs: changes related to severity of chronic valvular disease in the Cavalier King Charles spaniel","volume":"9","author":"H\u00e4ggstr\u00f6m","year":"1995"},{"key":"ref12","series-title":"J Gen Intern Med","doi-asserted-by":"publisher","first-page":"429","DOI":"10.1007\/BF02595918","article-title":"Causes of false-negative auscultation of regurgitant lesions: a Doppler echocardiographic study of 294 patients","volume":"3","author":"Kinney","year":"1988"},{"key":"ref13","series-title":"J Vet Intern Med","doi-asserted-by":"publisher","first-page":"56","DOI":"10.1111\/j.1939-1676.1999.tb02166.x","article-title":"Auscultation in mild mitral regurgitation in dogs: observer variation, effects of physical maneuvers, and agreement with color Doppler echocardiography and phonocardiography","volume":"13","author":"Pedersen","year":"1999"},{"key":"ref14","series-title":"Clin Pediatr","doi-asserted-by":"publisher","first-page":"511","DOI":"10.1177\/000992289903800902","article-title":"Comparative study of clinical evaluation of heart murmurs by general pediatricians and pediatric cardiologists","volume":"38","author":"Rajakumar","year":"1999"},{"key":"ref15","series-title":"J Small Anim Pract","doi-asserted-by":"publisher","first-page":"178","DOI":"10.1111\/j.1748-5827.2004.tb00221.x","article-title":"Low intensity heart murmurs in Boxer dogs: inter-observer variation and effects of stress testing","volume":"45","author":"H\u00f6glund","year":"2004"},{"key":"ref16","series-title":"Am Heart J","doi-asserted-by":"publisher","first-page":"262","DOI":"10.1016\/S0002-8703(07)80050-0","article-title":"Stethoscopic and phonoaudio devices: historical and future perspectives","volume":"126","author":"Selig","year":"1993"},{"key":"ref17","series-title":"Crit Rev Biomed Eng","doi-asserted-by":"publisher","first-page":"163","DOI":"10.1615\/CritRevBiomedEng.v23.i3-4.10","article-title":"Digital signal processing of the phonocardiogram: review of the most recent advancements","volume":"23","author":"Durand","year":"1995"},{"key":"ref18","series-title":"Am J Cardiol","doi-asserted-by":"publisher","first-page":"625","DOI":"10.1016\/0002-9149(89)90491-8","article-title":"Continuous spectral analysis of heart murmurs for evaluating stenotic cardiac lesions","volume":"64","author":"Donnerstein","year":"1989"},{"key":"ref19","series-title":"J Heart Valve Dis","first-page":"454","article-title":"Assessing the severity of aortic valve stenosis by spectral analysis of cardiac murmurs (spectral vibrocardiography). Part I: technical aspects","volume":"2","author":"Nygaard","year":"1993"},{"key":"ref20","series-title":"Am J Cardiol","doi-asserted-by":"publisher","first-page":"902","DOI":"10.1016\/j.amjcard.2004.12.018","article-title":"Usefulness of a new sound spectral averaging technique to distinguish an innocent systolic murmur from that of aortic stenosis","volume":"95","author":"Tavel","year":"2005"},{"key":"ref21","series-title":"Ann Biomed Eng","doi-asserted-by":"publisher","first-page":"1666","DOI":"10.1007\/s10439-006-9187-4","article-title":"Feature extraction for systolic heart murmur classification","volume":"34","author":"Ahlstrom","year":"2006"},{"key":"ref22","series-title":"Canine and feline cardiology","first-page":"29","article-title":"The clinical approach to heart disease: history and physical examination","author":"Gompf","year":"1988"},{"key":"ref23","series-title":"J Vet Intern Med","doi-asserted-by":"publisher","first-page":"247","DOI":"10.1111\/j.1939-1676.1993.tb01015.x","article-title":"Recommendations for standards in transthoracic two-dimensional echocardiography in the dog and cat. Echocardiography Committee of the Specialty of Cardiology, American College of Veterinary Internal Medicine","volume":"7","author":"Thomas","year":"1993"},{"key":"ref24","series-title":"Vet Rec","doi-asserted-by":"publisher","first-page":"293","DOI":"10.1136\/vr.152.10.293","article-title":"Early echocardiographic predictors of myxomatous mitral valve disease in Dachshunds","volume":"152","author":"Olsen","year":"2003"},{"key":"ref25","series-title":"Vet Radiol Ultrasound","doi-asserted-by":"publisher","first-page":"568","DOI":"10.1111\/j.1740-8261.2002.tb01051.x","article-title":"Left atrial to aortic root indices using two-dimensional and M-mode echocardiography in Cavalier King Charles spaniels with and without left atrial enlargement","volume":"43","author":"Hansson","year":"2002"},{"key":"ref26","series-title":"Textbook of veterinary internal medicine, diseases of the dog and cat","first-page":"311","article-title":"Echocardiography","author":"B\u00e9langer","year":"2005"},{"key":"ref27","series-title":"J Vet Intern Med","doi-asserted-by":"publisher","first-page":"311","DOI":"10.1111\/j.1939-1676.2004.tb02551.x","article-title":"Allometric scaling of M-mode cardiac measurements in normal adult dogs","volume":"18","author":"Cornell","year":"2004"},{"key":"ref28","series-title":"System identification: theory for the user","first-page":"168","article-title":"Nonparametric time-and frequency-domain methods","author":"Ljung","year":"1999"},{"key":"ref29","series-title":"IEEE Trans Signal Process","doi-asserted-by":"publisher","first-page":"998","DOI":"10.1109\/78.492555","article-title":"Localization of the complex spectrum: the S transform","volume":"44","author":"Stockwell","year":"1996"},{"key":"ref30","series-title":"Am J Physiol Heart Circ Physiol","doi-asserted-by":"publisher","first-page":"H2039","DOI":"10.1152\/ajpheart.2000.278.6.H2039","article-title":"Physiological time-series analysis using approximate entropy and sample entropy","volume":"278","author":"Richman","year":"2000"},{"key":"ref31","series-title":"J Stat Phys","doi-asserted-by":"publisher","first-page":"587","DOI":"10.1007\/BF01054341","article-title":"Measuring statistical dependences in a time-series","volume":"73","author":"Pompe","year":"1993"},{"key":"ref32","series-title":"Med Biol Eng Comput","first-page":"269","article-title":"Spectral analysis and acoustic transmission of mitral and aortic valve closure sounds in dogs. Part 1: modelling the heart\/thorax acoustic system (Erratum published in Med Biol Eng Comput 1990;28:612)","volume":"28","author":"Durand","year":"1990"},{"key":"ref33","series-title":"Stat Med","doi-asserted-by":"publisher","first-page":"87","DOI":"10.1002\/sim.4780040112","article-title":"A Wilcoxon-type test for trend","volume":"4","author":"Cuzick","year":"1985"},{"key":"ref34","series-title":"J Acoust Soc Am","doi-asserted-by":"publisher","first-page":"82","DOI":"10.1121\/1.1915637","article-title":"Loudness, its definition, measurement and calculation","volume":"5","author":"Fletcher","year":"1933"},{"key":"ref35","series-title":"Physiol Meas","doi-asserted-by":"publisher","first-page":"1005","DOI":"10.1088\/0967-3334\/26\/6\/010","article-title":"Accessing heart dynamics to estimate durations of heart sounds","volume":"26","author":"Nigam","year":"2005"},{"key":"ref36","series-title":"Conf Proc IEEE Eng Med Biol Soc","first-page":"4502","article-title":"Nonlinear analysis of heart murmurs using wavelet-based higher-order spectral parameters","volume":"1","author":"Taplidou","year":"2006"},{"key":"ref37","series-title":"Am J Vet Res","doi-asserted-by":"publisher","first-page":"962","DOI":"10.2460\/ajvr.68.9.962","article-title":"Time-frequency and complexity analyses for differentiation of physiologic murmurs from heart murmurs caused by aortic stenosis in Boxers","volume":"68","author":"H\u00f6glund","year":"2007"},{"key":"ref38","series-title":"Nonlinear time series analysis","first-page":"75","article-title":"Self-similarity: dimensions","author":"Kantz","year":"2004"},{"key":"ref39","series-title":"Dis Chest","doi-asserted-by":"publisher","first-page":"545","DOI":"10.1378\/chest.53.5.545","article-title":"Intensity of the first heart sound and arterial pulse in mitral insufficiency","volume":"53","author":"Gould","year":"1968"},{"key":"ref40","series-title":"J Vet Intern Med","doi-asserted-by":"publisher","first-page":"61","DOI":"10.1111\/j.1939-1676.2007.tb02929.x","article-title":"Decreased systolic function and inadequate hypertrophy in large and small breed dogs with chronic mitral valve insufficiency","volume":"21","author":"Borgarelli","year":"2007"},{"key":"ref41","series-title":"Circ Res","doi-asserted-by":"publisher","first-page":"874","DOI":"10.1161\/01.RES.39.6.874","article-title":"Investigation of the theory and mechanism of the origin of the second heart sound","volume":"39","author":"Sabbah","year":"1976"},{"key":"ref42","series-title":"J Vet Intern Med","doi-asserted-by":"publisher","first-page":"84","DOI":"10.1111\/j.1939-1676.2003.tb01327.x","article-title":"Regurgitant fraction measured by using the proximal isovelocity surface area method in dogs with chronic myxomatous mitral valve disease","volume":"17","author":"Kittleson","year":"2003"},{"key":"ref43","series-title":"Angiology","doi-asserted-by":"publisher","first-page":"443","DOI":"10.1177\/000331977602700704","article-title":"A method for detecting and quantifying faint cardiovascular murmurs","volume":"27","author":"Tickner","year":"1976"},{"key":"ref44","series-title":"Cardiol Clin","doi-asserted-by":"publisher","first-page":"265","DOI":"10.1016\/S0733-8651(18)30367-9","article-title":"Doppler echocardiographic evaluation of mitral regurgitation","volume":"8","author":"Perry","year":"1990"},{"key":"ref45","series-title":"J Vet Med Sci","doi-asserted-by":"publisher","first-page":"973","DOI":"10.1292\/jvms.56.973","article-title":"Prevalence of valvular regurgitation in normal Beagle dogs detected by color Doppler echocardiography","volume":"56","author":"Nakayama","year":"1994"},{"key":"ref46","series-title":"Am J Vet Res","first-page":"698","article-title":"Plasma concentration of atrial natriuretic peptide in relation to severity of mitral regurgitation in Cavalier King Charles Spaniels","volume":"55","author":"H\u00e4ggstr\u00f6m","year":"1994"},{"key":"ref47","series-title":"J Vet Intern Med","doi-asserted-by":"publisher","first-page":"120","DOI":"10.1111\/j.1939-1676.2007.0008.x","article-title":"Survival characteristics and prognostic variables of dogs with mitral regurgitation attributable to myxomatous valve disease","volume":"22","author":"Borgarelli","year":"2008"}],"container-title":["American Journal of Veterinary Research"],"original-title":[],"link":[{"URL":"https:\/\/avmajournals.avma.org\/view\/journals\/ajvr\/70\/5\/ajvr.70.5.604.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/avmajournals.avma.org\/downloadpdf\/journals\/ajvr\/70\/5\/ajvr.70.5.604.xml","content-type":"text\/html","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/avmajournals.avma.org\/downloadpdf\/journals\/ajvr\/70\/5\/ajvr.70.5.604.xml","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,3,7]],"date-time":"2025-03-07T12:21:18Z","timestamp":1741350078000},"score":1,"resource":{"primary":{"URL":"https:\/\/avmajournals.avma.org\/view\/journals\/ajvr\/70\/5\/ajvr.70.5.604.xml"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2009,5]]},"references-count":47,"journal-issue":{"issue":"5"},"URL":"https:\/\/doi.org\/10.2460\/ajvr.70.5.604","relation":{},"ISSN":["0002-9645"],"issn-type":[{"value":"0002-9645","type":"print"}],"subject":[],"published":{"date-parts":[[2009,5]]}}}