Keywords
Atrial overload
Atrial vector
Electrocardiogram.
How to Cite
Abstract
Due to potential alterations in atrial depolarization vectors in canine heart disease, the atrial electrical axis (AEA) may appear altered in patients with atrial remodeling (AR). The aim of this study was to analyze the AEA and P-wave duration in the electrocardiogram of three groups of dogs: healthy patients, cardiac patients without left AR, and cardiac patients with left AR. Of the 56 evaluated dogs, nine were healthy, 27 were cardiac patients without left AR, and 20 were cardiac patients with left AR. The classification of myxomatous mitral valve disease includes stage A, comprising dogs at high risk of developing the condition; stage B, which includes asymptomatic dogs subdivided into B1, with mitral valve regurgitation not yet causing cardiac remodeling, and B2, with sufficient mitral valve regurgitation to cause cardiac remodeling, where treatment is indicated even in the absence of clinical signs; stage C, covering symptomatic dogs; and stage D, including dogs refractory to treatment. Therefore, 27 dogs were in stage B1, two in B2, 15 in C, and three in D. The P-wave duration in the remodeling group (53 milliseconds (ms)) was higher (p=0.0088) than in the group without left AR (46 ms). The P-wave duration in healthy dogs did not differ from that of dogs with and without remodeling. The AEA in healthy animals (43.65±19.79º) was lower (p=0.0015) than in the groups with and without left AR (69.58±18.00º and 63.40±15.89º). Animals without remodeling did not differ from those with remodeling, and despite the difference found in healthy animals, the values were within the normal range for the species, and no cardiac dogs exhibited a deviation of the AEA. Stage D dogs had longer P-wave durations than healthy and stage B1 dogs and did not differ from stage B2 and C groups (p=0.0269). Healthy dogs did not differ from stage B2, C, or D dogs in recording the AEA, only being lower than the B1 dogs (p=0.0120). The AEA and P wave duration are parameters that should not be used to define left AR in dogs with heart disease.
References
BrojbÇŽ, C. (2018). Determination of the mean electrical axis in dogs and cats (Mini-review). Bulletin UASVM Veterinary Medicine, 75(1), 137-138. doi: 10.15835/buasvmcn-vm:004717
Dillon, A. R., Dell'Italia, L. J., Tillson, M., Killingsworth, C., Denney, T., Hathcock, J., & Botzman, L. (2012). Left ventricular remodeling in preclinical experimental mitral regurgitation of dogs. Journal of Veterinary Cardiology, 14(1), 73-92. doi: 10.1016/j.jvc.2012.01.012
Hansson, K., Häggström, J., Kvart, C., & Lord, P. (2002). Left atrial to aortic root índices using two-dimensional and M-mode echocardiography in cavalier king charles spaniels with and without left atrial enlargement. Veterinary Radiology & Ultrasound, 46(6), 568-575. doi: 10.1111/j.1740-8261.2002.tb01051.x
Kuhn, L., & Rose, L. (2008). ECG interpretation part 1: understanding mean electrical axis. Journal of Emergency Nursing, 34(6), 530-534. doi: 10.1016/j.jen.2008.01.007
Keene, B. W., Atkins, C. E., Bonagura, J. D., Fox, P. R., Häggström, J., Fuentes, V. L., Oyama, M. A., Rush, J. E., Stepien, R., & Uechi, M. (2019). ACVIM consensus guidelines for the diagnosis and treatment of myxomatous mitral valve disease in dogs. Journal of Veterinary Internal Medicine, 33(3), 1127-1140. doi: 10.1111/jvim.15488
Madron, E. (2016). Normal echocardiographic values: TM, 2D and doppler spectral modes. In V. Chetboul, C. Bussadori, & E. Madron (Eds.), Clinical echocardiography of the dog and cat (Cap. 2, pp. 21-37). St. Louis, Missouri.
Na, Y., Lee, D., Yun, T., Koo, Y., Chae, Y., Kim, H., Yang, M. P., & Kang, B. T. (2021). Comparison of electrocardiographic parameters in dogs with different stages of myxomatous valve disease. Canadian Journal of Veterinary Research, 85(4), 261-270. PMID: 34602730; PMCID: PMC8451713.
Nattel, S., Burstein, B., & Dobrev, D. (2008). Atrial remodeling and atrial fibrillation: mechanisms and implications. Circulation: Arrhythmia and Electrophysiology, 1(1), 62-73. doi: 10.1161/CIRCEP.107.754564
Ogawa, M., Ogi, H., Miyakawa, H., Hsu, H. H., Miyagawa, Y., & Takemura, N. (2022). Evaluation of the association between electrocardiogram parameters and left cardiac remodeling in dogs with myxomatous mitral valve disease. Veterinary World, 15(8), 2072-2083. doi: 10.14202/vetworld.2022.2072-2083
Santilli, R., Moïse, N. S., Pariaut, T. R., & Perego, M. (2018a). Formation and interpretation of the electrocardiographic waves. In R. Santilli, N. S. Moïse, R. Pariaut, & M. Perego (Eds.), Electrocardiography of the dog and cat: diagnosis of arrhythmias (Cap. 3, pp. 52-89). Milano.
Santilli, R., Moïse, N. S., Pariaut, R., & Perego, M. (2018b). Principles of electrocardiography. In R. Santilli, N. S. Moïse, R. Pariaut, & M. Perego (Eds.), Electrocardiography of the dog and cat: diagnosis of arrhythmias (Cap. 2, pp. 37-51). Milano.
Soto-Bustos, A., Caro-Vandillo, A., Martínez-de-Merlo, E., & Alonso-Alegre, E. G. (2017). Diagnostic accuracy of electrocardiographic P wave related parameters in the assessment of left atrial size in dogs with degenerative mitral valve disease. The Journal of Veterinary Medical Science, 79(10), 1682-1689.doi: 10.1292/jvms.17-0049
Tilley, L. P., & Smith, F. W. K., Jr. (2001). Electrocardiography. In F. W. K. Smith, Jr., L. P. Tilley, M. A. Oyama, & M. M. Sleeper (Eds.), Manual of canine and feline cardiology (Cap. 3, pp. 49-76). St. Louis, Missouri.
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
Copyright (c) 2024 Raquel Merger Artuzo, Fernando Luis Cemenci Gnoatto, Melissa Rodrigues de Souza, Tatiana Champion