Volume: 56 Issue: 3
Year: 2025, Page: 436-443, Doi: https://doi.org/10.51966/jvas.2025.56.3.436-443
Received: Jan. 16, 2025 Accepted: Jan. 30, 2025 Published: Sept. 30, 2025
Holter monitoring has emerged as a reliable diagnostic tool in veterinary cardiology for identifying and analysing cardiac diseases associated with varying stages of abnormal electrophysiological activity. In conjunction with echocardiography, it is currently considered as the gold standard for diagnosing dilated cardiomyopathy (DCM) in dogs. This study aimed to evaluate heart rate, electrocardiographic pauses, heart rate variability and arrhythmias associated with overt phase of DCM in dogs. A total of eight dogs diagnosed with overt DCM underwent 24-hour Holter monitoring, following established protocols. The collected Holter data were analysed statistically, and ECG waveforms were manually reviewed to assess different arrhythmias. Ventricular premature complexes were the most common arrhythmia observed (87.50 per cent), followed by atrial fibrillation which may indicate advanced stages of cardiovascular compromise. Significantly elevated minimum and average heart rates, along with reduced electrocardiographic pause beats and pause times suggested cardiac compensation and sympathetic overstimulation. Among heart rate variability (HRV) parameters, time-domain measures such as SDNN, SDANN, and pNN50, indicative of sympathetic activity and compromised cardiovascular health were notably altered. Furthermore, frequency-domain HRV parameters, including VLF and LF, which reflect baroreceptor-mediated sympathetic stimulation, were significantly reduced in dogs with overt DCM. In conclusion, Holter monitoring serves as both a vital diagnostic tool for identifying predominant arrhythmias and assessing autonomic imbalances, and as a prognostic test to determine the severity and stage of overt DCM in dogs.
Keywords: Holter monitoring, cardiomyopathy, ventricular premature complex, heart rate variability
Alvarez, P. and Tang, W. W. 2017. Recent Advances in Understanding and Managing Cardiomyopathy. F1000Res. [online]. 6 (1659). Available: https://doi.org/ 10.12688/ f1000research.11669.1 [07 Sept. 2017].
[Anonymous]. 2021, May 6. How to fit a dog with a Holter monitor? Veterinary Teaching Hospital, College of Veterinary Medicine, Washington State University. Available: https://hospital.vetmed.wsu.edu/2021/05/06/ how-to-fit-a-dog-with-a-holter-monitor [6 May 2021].
Arcuri, G., Valente, C., Perini, C. and Guglielmini, C. 2024. Risk Factors for Atrial Fibrillation in the dog: A Systematic Review. Vet. Sci. [online]. 11(47). Available: https://doi.org/10.3390/ vetsci11010047 [21 Jan. 2024].
Billman, G. E. 2013. The effect of heart rate on the heart rate variability response to autonomic interventions. Front. Physiol.[online]. 4 (222). Available: 10.3389/fphys.2013.00222 [26 Aug. 2013].
Bogucki, S. and Noszczyk-Nowak, A. 2015. Short-term heart rate variability (HRV) in healthy dogs. Pol. J. Vet. Sci. 18:307-312.
Calvert, C. A. and Wall, M. 2001. Results of ambulatory electrocardiography in overtly healthy Doberman Pinschers with equivocal echocardiographic evidence of dilated cardiomyopathy. J. Am. Vet. Med. Assoc. 219:782–784.
Çolakoglu, E.C. and Sahal, M. 2015. Comparison of in-hospital and 24-Hour ambulatory electrocardiography in dogs with heart disease. Anim. Health Prod. Hyg. 4: 402–407.
Detweiler, D.K. 2010. The Dog Electrocardiogram: A Critical Review. In: Macfarlane, P.W., van Oosterom, A., Pahlm, O., Kligfield, P., Janse, M., Camm, J. (ed.). Comprehensive Electrocardiology. Springer, London, pp. 1861-1908.
Dukes-McEwan, J., Borgarelli, M., Tidholm, A., Vollmar, A. C. and Haggstrom, J. 2003. Proposed guidelines for the diagnosis of canine idiopathic dilated cardiomyopathy. J. Vet. Cardiol, 5: 7-19.
Estrada, A.H. and Maisenbacher III, H.W. 2014. Dilated Cardiomyopathy in Dogs. In: Bonagura, J.D. and Twedt, D.C. (ed.), Kirk’s Current Veterinary Therapy XV. Elsevier Saunders, St. Louis, Missouri, pp: 795-804.
Fernandes, L. G. and de Azevedo Cruz Seara, F. 2021. Heart rate variability for small animal veterinarians - A concise debate. Rev. Bras. Med. Vet.43:1-17.
Fye, W. B. 1994. A History of the Origin, Evolution, and Impact of Electrocardiography. Am. J. Cardiol. 73: 937-949.
García, C. A., Bardají, S., Pérez-Tirador, P. and Otero, A. 2024. RHRVEasy: Heart rate variability made easy. PloS one [online]. 19 (e0309055). Available: https://doi.org/10.1371/journal.pone.0309055. [27 Nov. 2014].
Goodwin, J. K. 1998. Holter monitoring and cardiac event recording. Vet. Clin. North Am. Small Anim. Pract. 28: 1391-1407.
Grutter, G., Giordano, U., Alfieri, S., Iodice, F., Drago, F., Rava, L. and Silvetti, M.S. 2012. Heart rate variability abnormalities in young patients with dilated cardiomyopathy. Pediatr. Cardiol.33:1171-1174.
Guglielmini, C., Valente, C., Romito, G., Mazzoldi, C., Baron Toaldo, M., Goncalves Sousa, M., Wolf, M., Beluque, T., Domenech, O., Patata, V., Porciello, F., Ferrari, P., Caivano, D., Contiero, B. and Poser, H. 2023. Risk factors for atrial fibrillation in dogs with dilated cardiomyopathy. Front. Vet. Sci. [online]. 10(1183689). Available: 10.3389/fvets.2023.1183689 [09 May 2023].
Harada, T., Abe, J., Shiotani, M., Hamada, Y. and Horii, I. 2005. Effect of Autonomic Nervous Function on QT Interval in Dogs. J. Toxicol. Sci. 30: 229-237.
Holter, N.J. 1961. New method for heart studies. Science. 134: 1214–1229.
Kazmi, S. Z. H., Zhang, H., Aziz, W., Monfredi, O., Abbas, S. A., Shah, S. A., Kazmi, S. S. H. and Butt, W. H. 2016. Inverse correlation between heart rate variability and heart rate demonstrated by linear and nonlinear analysis. PLoS ONE [online]. 11(e0157557). Available: 10.1371/journal. pone.0157557 [23 June 2016].
Kennedy, H. L. 2013. The evolution of ambulatory ECG monitoring. Prog. Cardiovasc. Dis. 56:127-132.
Kittleson, M.D. and Kienle, R.D. 2010. Small animal cardiovascular medicine. (2nd Ed.). Elsevier, Riverport Lane, St. Louis, Missouri, 663p.
Kleiger, R. E., Miller, J. P., Bigger, J. T. and Moss, A. J. 1987. Decreased heart rate variability and its association with increased mortality after acute myocardial infarction. Am. J. Cardiol. 59:256-262.
Kleiger, R. E., Stein, P. K. and Bigger, J. T. Jr. 2005. Heart rate variability: measurement and clinical utility. Ann. Noninvasive Electrocardiol. 10:88-101.
Kraus, M. S., Moïse, N. S., Rishniw, M., Dykes, N. and Erb, H. N. 2002. Morphology of ventricular arrhythmias in the boxer as measured by 12-lead electrocardiography with pace-mapping comparison. J. Vet. Intern. Med. 16:153-158.
Lee, P. T., Huang, M. H., Huang, T. C., Hsu, C. H., Lin, S. H. and Liu, P. Y. 2023. High Burden of Premature Ventricular Complex Increases the Risk of New-Onset Atrial Fibrillation. J. Am. Heart Assoc. [online]. 13(e027674). Available: 10.1161/JAHA.122.027674. [21 Feb. 2023].
Marek, M., Bigger, J. T., Camm, A.J., Kleiger, R. E., Malliani, A., Moss, A. J. and Schwartz, P.J. 1996. Heart rate variability: Standards of measurement, physiological interpretation, and clinical use, Euro. Heart J. 17: 354–381.
Meurs, K.M., Miller, M.W. and Wright, N. A. 2001. Clinical features of dilated cardiomyopathy in Great Danes and results of a pedigree analysis: 17 cases (1990-2000). J. Am. Vet. Med. Assoc. 218:729-732.
Oliveira, M. S., Muzzi, R. A. L., Araújo, R. B., Muzzi, L. A. L., Ferreira, D. F. and Silva, E. F. 2014. Heart rate variability and arrhythmias evaluated with Holter in dogs with degenerative mitral valve disease. Arq. Bras. Med. Vet. Zootec. 66:425-432.
Oyama, M.A. 2016. Canine Cardiomyopathy. In: Smith, Jr., F.W.K., Tilley, L. P., Oyama, M.A. and Sleeper, M.M. (ed.). Manual of canine and feline cardiology. (5th Ed.). Elsevier, 3251 Riverport Lane, St. Louis, Missouri, pp. 141-152.
Perez, J. M., Alessi, C. and Grzech-Wojciechowska, M. 2020. Diagnostic methods for the canine idiopathic dilated cardiomyopathy: A narrative evidence-based rapid review. Res. Vet. Sci. 128: 205-216.
Petrie, J. P. 2005. Practical application of holter monitoring in dogs and cats. Clin. Tech. Small Anim. Pract. 20:173–181.
Piccirillo, G., Ogawa, M., Song, J., Chong, V.J., Joung, B., Han, S., Magri, D., Chen, L.S., Lin, S.F. and Chen, P.S. 2009. Power spectral analysis of heart rate variability and autonomic nervous system activity measured directly in healthy dogs and dogs with tachycardia-induced heart failure. Heart Rhythm. 6: 546-552.
Schreiber, N., Willis, R., Glaus, T.and Baron Toaldo, M. 2023. Comparison of the diagnostic value of a small, single channel, electrocardiogram monitoring patch with a standard 3-lead Holter system over 24 h in dogs. J. Vet. Cardiol. 47:47-54.
Scollan, K.F. and Sisson, D. D. 2017. Pathophysiology of Heart Failure. In : Ettinger, S.J. and Feldman, E.C. (ed.), Textbook of Veterinary Internal Medicine: Diseases of dogs and cat. (8th Ed.) W. B. Saunders Co., Philadelphia, pp. 2853-2875.
Shaffer, F. and Ginsberg, J. P. 2017. An Overview of Heart Rate Variability Metrics and Norms. Front. Public Heal. 5:1-17.
Simpson, S., Kordtomeikel, K., Wong, S., Bennison, S., El-Gendy, S. A., Cobb, M. and Rutland, C. S. 2021. Diagnosis, Prognosis, Management, Treatment, Research and Advances in Canine Dilated Cardiomyopathy. In: Rutland, C. (ed.), Canine Genetics, Health and Medicine. [book on-line]. London: IntechOpen. Available: https://doi.org/10.5772/intechopen.97682 [05 May 2021].
Spier, A.W. and Meurs, K.M. 2004. Assessment of heart rate variability in Boxers with arrhythmogenic right ventricular cardiomyopathy. J. Am. Vet. Med. Assoc. 224: 534-537.
Stern, J. A. and Meurs, K.M. 2017. Myocardial Disease. In : Ettinger, S.J. and Feldman, E.C. (ed.), Textbook of Veterinary Internal Medicine: Diseases of dogs and cat. (8th Ed.) W. B. Saunders Co., Philadelphia, pp. 3071-3091.
Sztajzel, J. 2004. Heart rate variability: A noninvasive electrocardiographic method to measure the autonomic nervous system. Swiss Med. Wkly. 134:514-522.
Teslenko, A., Fries, R. C. and Selmic, L. E. 2021. Comparison of in-hospital continuous electrocardiography versus recordable Holter monitoring in dogs with ventricular arrhythmias. J. Vet. Emerg. Crit. Care. [online]. 31(6). Available: https://doi.org/10.1111/vec.13120 [04 Mar. 2020].
Uechi, M., Shimizu, A. and Mizuno, M. 2002. Heart rate modulation by sympathetic nerves in dogs with heart failure. J. Vet. Med. Sci. 64:1023-1029.
Valencia, J.F., Vallverdu, M., Rivero, I., Voss, A., de Luna, A.B., Porta, A. and Caminal, P. 2015. Symbolic dynamics to discriminate healthy and ischaemic dilated cardiomyopathy populations: an application to the variability of heart period and QT interval. Phil.Trans.R.Soc. [online]. A373 (20140092). Available: https://doi.org/10.1098/rsta.2014.0092 [13 Feb 2015].
Viljoen, C., Smith, R. and Chin, A. 2017. Reviewing the causes of electrocardiographic pauses. Cardiovasc. J. Afr. 28:257-260.
Wess, G. and Torti, M. 2018. Arrhythmias in Canine Cardiomyopathies and Valvular Heart Disease. In: Willis, R., Oliveira, P. and Mavropoulou, A. (ed.), Guide to Canine and Feline Electrocardiography, (1st Ed.) John Wiley & Sons Ltd, NJ, USA, pp. 285-300.
Wess G. 2022. Screening for dilated cardiomyopathy in dogs. J. Vet. Cardiol. 40: 51-68.
Wess, G., Domenech, O., Dukes-McEwan, J., Häggström, J. and Gordon, S. 2017. European Society of Veterinary Cardiology screening guidelines for dilated cardiomyopathy in Doberman Pinschers. J. Vet. Cardiol. 19:405–415.
© 2025 Umesh et al. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Umesh, C. G., Arun George, Madhavan Unny, N., Karthiayini, K., Shyma V. H. and Philip, L. M. 2024. Ambulatory electrocardiographic evaluation of overt cardiomyopathies in dogs.
J. Vet. Anim. Sci. 56 (3):436-443