Rikke Buhl – University of Copenhagen

Rikke Buhl

Professor, PhD, DVM

rib@sund.ku.dk

Research Profile:

Equine cardiology has been my main research area since graduation from Vet school in 1999. In 2004, I defended my PhD thesis within cardiology with focus on “Equine Athlete’s Heart”. I have continued the research within this area first as assistant professor and later as associate professor within Large Animal Internal Medicine. Lately I have been appointed as professor within equine cardiology.

My research area was for the first years concentrated within the area of “Athlete’s Heart”. I was the first to describe the development of heart size and prevalence of valvular regurgitation in trotters as a result of long standing physical exercise. The main results of these studies are that training induces significant cardiac hypertrophy with large individual variation among horses. Also a dramatic increase in the prevalence of valvular regurgitation was observed, and for some horses this lead to reduced racing performance. Also, the research has shown that heart size are positive correlated with racing performance of the horse. As one of the few researchers in the world I have focused on the development of exercise-induced cardiac arrhythmias in trotters and riding horses and the research has shown that equine athletes develops arrhythmias in accordance with human athletes. Although the above described response to exercise is considered generally to be a beneficial and physiological adaptation to increased demands, human studies have shown that exercise-induced cardiac hypertrophy can become dangerous with increasing risk of the athlete collapsing or even dying during exercise. There is a high attention on these tragically events among intensively trained athletes. Whether these events are caused by repolarisation defects in the heart in horses is unknown. In addition racehorses are in risk of develop atrial fibrillation which is also seen in humans. At the moment four PhD projects are working on the above described topics. For all projects, the synergy between equine and human research is strong and visible and we hope our research will gain new insight into diseases that are of importance for both horse and man.

Clinical examination is fundamental for most research projects I have been involved with. And I strongly believe that improving this area is essential for all clinical research. Sophisticated diagnostic methods such as cardiac ultrasound, ECG measurements and exercise testing of horses where cardiac function is examined during physical exercise where telemetric ECG and stress echocardiography are an integrated part of diagnosis of performance related diseases is used routinely used during my clinical work both for teaching and research purposes.

Publications:

2016

Flethøj M, Schwarzwald CC, Haugaard MM, Carstensen H, Kanters JK, Olsen LH, Buhl R. Left ventricular function after prolonged exercise in equine endurance athletes: Does cardiac fatigue exist in horses? In press J Vet Intern Med 2016

Pedersen PJ, Karlsson M, Flethøj M, Trachsel DS, Kanters JK, Klaerke DA, Buhl R. Differences in the electrocardiographic QT interval of various breeds of athletic horses during rest and exercise. In press J Vet Cardiol 2016

Skarsfeldt MA, Carstensen H, Skibsbye L, Tang C, Buhl R, Bentzen BH, Jespersen T. Pharmacological inhibition of IK1 by PA-6 in isolated rat hearts affects ventricular repolarization and refractoriness. Physiol Rep 2016;4: e12734, doi 10.14814/phy2.12734

Flethøj M, Kanters JK, Haugaard MM, Pedersen PJ, Carstensen H, Balling JD, Olsen LH, Buhl R. Changes in heart rate, arrhythmia frequency, and circulating cardiac markers during recovery after long-distance endurance riding. JAVMA 2016;248:1034-1042

2015

Pedersen PJ, Thomsen KB, Olander E, Hauser F, Tejada MA, Poulsen PL, Grubb S, Buhl R, Calloe K and Klaerke DA. Molecular cloning and functional expression of the equine K+ channel KV11.1 (ether à go-go-related/KCNH2 gene) and the regulatory subunit KCNE2 from equine myocardium. PlosOne 2015 DOI: 10.1371/journal.pone.0138320

Haugaard, MM, Hesselkilde, EZ, Pehrson, S, Carstensen H, Flethøj M, Præstegaard KF, Sørensen US, Diness JG, Grunnet M, Buhl R and Jespersen T. Pharmacological inhibition of small-conductance calcium-activated potassium (SK) channels reveals atrial antiarrhythmic potential in horses. Heart Rhythm 2015;12:825-835

Haugaard MM, Pehrson S, Carstensen H, Flethøj M, Hesselkilde EZ, Præstegaard K, Diness JG, Grunnet M, Jespersen T, Buhl R (2014): Antiarrhythmic and Electrophysiological Effects of Flecainide on Acutely Induced Atrial Fibrillation in Healthy Horses. JVIM 2015;29:339-347

Laursen SH, van Galen G, Wolf-Jäckel GA and Buhl R. Acquired pulmonic stenosis due to a compressing intrathoracic abscess in a Thoroughbred yearling. Accepted for publication Journal of Equine veterinary science

2014

Pedersen PJ, Moeller SB, Kanters JK, Buhl R, Klaerke DA (2014): Diurnal variation of QT interval in Warmblood horses. Journal of Veterinary Cardiology 16:265-276.

Buhl R. (2014): Diagnosis and significance of Cardiac Murmurs. In Current Therapy of Equine Medicine, 7th ed. Ed: Robinson E and Sprayberry K. Saunders, p. 510-515.

Hesselkilde EZ, Almind EA, Petersen J, Flethøj M, Præstegaard K, Buhl R (2014): Cardiac arrhythmias and electrolyte disturbances in colic horses in comparison to healthy controls. Acta Vet Scandinavia;2014:56:58.
 
Reef VB, Bonagura J, Buhl R, McGurrin MKJ, Schwarzwald CC, van Loon G, Young LE (2014): Recommendations for management of equine athletes with cardiovascular abnormalities. J Vet Intern Med;28:749-761.

Madsen MF, Kanters JK, Buhl R. Heart rate recovery time in exercise testing of endurance horses, ICEEP (International Conference on Equine Exercise Physiology), Chester, UK, 2014.

Buhl R, Kanters JK, Olsen LH, Madsen MF. Cardiac beat-to-beat variation and arrhythmias in endurance horses, ACVIM Forum (American College of Veterinary Internal Medicine), Nashville, TN, USA, 2014.

Pedersen PJ, Flak JB, Buhl R, Klaerke DA. Cloning of equine KCNH2 and KCNQ1 as the basis for diagnosing long QT syndrome in horses, Biophysical Journal, Volume 106, Issue 2, Supplement 1, 28 January 2014, Pages 552a

Hesselkilde EZ, Haugaard MM, Skibsbye L, Buhl R, Jespersen T. In Vitro Characterization of the equine cardiac ion channels, ECAS 2014.

Carstensen H, Skarsfeldt M, Diness J, Buhl R, Jespersen T. Pharmacological inhibition of IK1 in the rat heart. Equine Cardiac Arrhythmia Society 2014.

2013

Pedersen PJ, Kanters JK, Buhl R, Klaerke DA. (2013): Electrocardiographic QT interval in the horse. Journal of Veterinary Cardiology, 15-23-31.

Buhl R, Andersen LOF, Karlshøj M, Kanters JK. (2013): Evaluation of clinical and electrocardiographic changes during euthanasia of horses, Veterinary Journal 196;483-491.

Buhl R, Petersen EE, Lindholm M, Bak LR, Nostell K. (2013): Cardiac arrhythmias in Standardbreds during and after racing - possible association between heart size, valvular regurgitations and arrhythmias. Journal of Equine Veterinary Science 33;590-596.

Kristensen L, Buhl R, Nostell K, Bak L, Petersen EE, Petersen M, Jacobsen S. (2014): Acute exercise does not induce an acute phase response in Standardbred trotters. Canadian Journal of Veterinary Research 78:97-102

Buhl R. (2013) Exercise induced changes in the equine athlete’s heart – does the clinician need to bother? American College of Veterinary Internal Medicine, Seattle, USA, June 2013, pp 766-768.

Pedersen PJ, Moeller SB, Klaerke DA, Kanters JK, Buhl R. Sources and magnitude of variation of QT interval measurements in Warmblood horses, DACRA summer meeting, 2013 (abstract).

2012

Buhl R, Ersbøll AK. (2012): Echocardiographic evaluation of changes in left ventricular size and valvular regurgitation associated with physical training during and after maturity in Standardbred trotters. J Am Vet Med Assoc 240:205-212

Pedersen PJ, Kanters JK, Buhl R, Klaerke DA. Electrocardiographic QT interval in the horse, BEVA 2012.

2011

Olsen E, Kronborg C, Buhl R, Andersen P H. (2011): How to Obtain Indirect Blood Pressure in the Standing Horse, ACVIM congress, USA

Buhl R. (2011): Cardiac response to exercise. Invited speaker for World Equine Veterinary Association congress, India

Buhl R. (2011): Clinical examination of the cardiovascular system. Invited speaker for World Equine Veterinary Association congress, India

Buhl R. (2011): The most common cardiac arrhythmia and murmurs. Invited speaker for World Equine Veterinary Association congress, India

Buhl R. (2011): Clinical cases - what is your decision? Invited speaker for World Equine Veterinary Association congress, India

Pedersen P, Kanters J, Klaerke DA, Buhl R. (2011): Building a platform for diagnosing long QT syndrome in the horse. Fundamental and clinical pharmacology, Volume: 25, Issue: 6, pp III-III

Buhl R. (2011): Heart murmurs. Clinical Veterinary Advisor, The Horse, Ed: Wilson DA, Elsevier Saunders, pp. 242-244

Buhl R. (2011): Endocarditis. Clinical Veterinary Advisor, The Horse, Ed: Wilson DA, Elsevier Saunders, pp. 162-164

Buhl R. (2011): Aortic/pulmonary regurgitation. Clinical Veterinary Advisor, The Horse, Ed: Wilson DA, Elsevier Saunders, pp. 35-37

Buhl R. (2011): Mitral/tricuspid regurgitation. Clinical Veterinary Advisor, The Horse, Ed: Wilson DA, Elsevier Saunders, pp. 362-364

2010

Buhl R. (2010): Valvular regurgitation in the horse: The importance of an exercise ECG. Guest Editorial, Veterinary Journal. 183;117-118

Buhl R, Meldgaard C, Barbesgaard L. (2010): Cardiac arrhythmias in clinically healthy show jumping horses. Equine Vet J. Suppl. 42:196-201

Barbesgaard L, Buhl R, Meldgaard C. (2010): Prevalence of exercise-associated arrhythmias in normal performing dressage horses. Equine Vet J. Suppl. 42:202-207

Buhl R, Meldgaard C, Barbesgaard L. (2010): Cardiac arrhythmias in clinically normal show jumping horses during rest, show jumping and recovery. ICEEP congress, South Africa

Barbesgaard L, Buhl R, Meldgaard C. (2010): Prevalence of exercise-associated arrhythmias in normal performing dressage horses. ICEEP congress, South Africa

2009

Brøndum E, Hasenkam JM, Secher NH, Bertelsen M, Grøndal C, Petersen K, Buhl R, Aalkjær C, Baandrup U, Nygaard H, Smerup M, Stegman F, Sloth E, Østergaard KH, Nissen P, Runge M, Pitsillides K, Wang T. (2009): Jugular venous pooling during lowering of the head affects blood pressure of the anesthetised giraffe. Am J Physiol Regul Integr Comp Physiol, 297;1058-1065

Brøndum ET, Wang T, Hasenkam M, Secher NH, Nygaard H, Kastberg K, Buhl R, Aalkjær C. (2009): Regulation of blood pressure during head movement in the anesthetized giraffe. J Physiol Sciences, vol 59, suppl 1, p. 99-99

2008

Lindholm M, Petersen EE, Johanson LB, Schuback-Nostell K, Buhl R. (2008): Prevalence of arrhythmias during and immediately after racing in Standardbred trotters: Is there an association between arrhythmias and valvular regurgitation or myocardial hypertrophy? BEVA congress, UK

Nørgaard LM, Johnsen EB, Restrepo J, Buhl R. (2008): Evaluation of RR-intervals from equine ECG recordings during submaximal and maximal exercise intensity: Is there a standard criterion for arrhythmia assessment? BEVA congress, UK

Petersen E E, Petersen M L, Johansson LB, Schuback-Nostell K, Buhl R. (2008): Prevalence of arrhythmias during and immediately after racing in Standardbred trotters – Is there an association between arrhythmias and myocardial hypertrophy? BEVA congress, UK

Buhl R. (2008): A Review of structural features of the equine athelete’s heart: Is a large heart an advantage for racing success? AAEP congress, USA

Wang T, Brøndum ET, Hasenkam M, Secher NH, Betelsen M, Grøndal C, Petersen KK, Buhl R, Aalkjær C, Baandrup U, Nygaard H, Smerup M, Sloth E, Nissen P, Runge, M. (2008): Blood flows and pressures when the giraffe lowers its head. Annual meeting of the Soc. of Exp. Biology, France

Buhl R, Ersbøll, AK. (2008): The effects of training on echocardiographic measurement. In Current Therapy of Equine Medicine, 8th ed. Ed: Robinson E. Saunders pp. 198-204

2007

Buhl R, Ersbøll AK, Larsen NH, Eriksen L, Koch J. (2007): The effects of detomidine, romifidine or acepromazine on echocardiographic measurements and cardiac function in normal horses. Veterinary Anaesthesia and Analgesia

Buhl R, Larsen NH, Eriksen L, Ersbøll AK, Koch J. (2007): Sedative effects of detomidine, romifidine or acepromazine upon echocardiographic measurements and cardiac function in normal horses. Veterinary Anaesthesia and Analgesia 34:1-8

Aalbæk B, Østergaard S, Buhl R, Jensen HE, Christensen H, Bisgaard M. (2007): Actinobacillus equili subspecies euuli associated with equine valvular endocarditis. APMIS, 115:1437-1442

Brøndum ET, Wang T, Hasenkam M, Nygaard H, Secher NH, Petersen KK, Buhl R, Aalkjær C. (2007): Regulation of blood pressure during head movement in the anaesthetized giraffe. Fed Amer Soc Exp Biol Journal. 21;A1400

2006

Buhl R, Ersbøll AK. (2006): The effect of heart rate on valvular regurgitation in Standardbred trotters. Equine Vet. J Suppl. 36:178-182

Buhl R, Ersbøll AK. (2006): The effect of heart rate on valvular regurgitation in Standardbred trotters. ICEEP, France

Buhl R, Ersbøll AK. (2006): Cardiac development in Standardbred trotters – The athletes’ heart. BEVA congress, UK

2005

Buhl R, Ersbøll AK, Eriksen L, Koch J. (2005): Changes over time in echocardiographic measurements in young Standardbred racehorses undergoing training and racing and association with racing performance. J Am Vet Med Assoc;226:1881-1887

Buhl R, Ersbøll AK, Eriksen L, Koch J. (2005): Color Doppler evaluation of valvular regurgitation in young Standardbred trotters – development and influence on racing performance. J Am Vet Assoc. 227:1630-1635

Buhl R, Ersbøll AK, Eriksen L, Koch J. (2005): Use of color Doppler echocardiography to assess the development of valvular regurgitation in Standardbred trotters. J Am Vet Med Assoc.

2004

Buhl R, Koch J, Agerholm J, Maddox-Hüttel P, Eriksen L. (2004): Complete Situs Inversus in a two-year-old Standardbred trotter. Veterinary Record;154:600-602

Buhl R, Kjær-Ersbøll A, Eriksen L, Koch J. (2004): Sources and magnitude of variation of echocardiographic measurements in normal Standardbred horses. Veterinary Radiology and Ultrasound;45:1-8

Buhl R. (2004): Prevalence and development of valvular regurgitation in young Standardbred trotters. The Abildgaard Symposia, The Royal Veterinary and Agricultural University, Copenhagen

Buhl, R. (2004): Ph.D Thesis: Cardiac development assessed by echocardiography in young Standardbred trotters

2003

Buhl R, Kjær-Ersbøll A, Eriksen L. (2003): Low intensity race training does not influence on left ventricular dimensions. J Equine Vet Sci;24:295-300

Buhl R. (2003): Cardiac development in young Standardbred trotters. The Abildgaard Symposia, The Royal Veterinary and Agricultural University, Copenhagen