Cruz Aleixo Amanda Sarita, Alfonso Angélica, Oba Eunice, Ferreira de Souza Fabiana, Salgueiro Cruz Raíssa Karolliny, Fillippi Maurício Gianfrancesco, Chiacchio Simone Biagio, Tsunemi Miriam, Gomes Lourenço Maria Lucia
Department of Veterinary Clinics, School of Veterinary Medicine and Animal Science, UNESP, Botucatu, São Paulo, Brazil.
Department of Animal Reproduction and Veterinary Radiology, School of Veterinary Medicine and Animal Science, UNESP, Botucatu, São Paulo, Brazil.
Top Companion Anim Med. 2017 Jun;32(2):66-71. doi: 10.1053/j.tcam.2017.06.002. Epub 2017 Jun 27.
Although heart rate (HR) is one of the most important clinical parameters determined via physical examinations, little information is available on the normal HR in dogs, which may be related to the high variability of body weight (BW) in this species. HR is determined by the discharge rate of the sinus node, which is dependent on the autonomic nervous system and the release of catecholamines. The allometric relationship between BW and HR in different species has been described as inversely proportional; however, this relationship has been refuted. Certain authors have reported that the relationship between HR and BW in dogs is based on temperament as well as sympathetic autonomic stimulation of the sinus node in small breeds compared with large breeds. The aim of this study was to analyze the effects of weight, sex, age and temperament on the HR, heart rate variability and serum catecholamine (epinephrine and norepinephrine) levels in dogs. We evaluated 48 adult dogs of both sexes and various breeds and ages and divided the dogs into 5 BW groups: <5kg (n = 8), 5-10kg (n = 10), 10-25kg (n = 10), 25-45kg (n = 10), and >45kg (n = 10). The measured parameters were HR, breath rate (BR) and body temperature. We also performed an ambulatory electrocardiogram and electrocardiography (ECG) test for 24 hours (Holter monitor) and determined the serum levels of the catecholamines epinephrine and norepinephrine. We observed correlations between HR and sex; differences among the weight groups with respect to ECG variables and epinephrine levels; and differences among the temperament categories for certain clinical parameters, such as HR and BR. Age affected the R wave amplitude, and an allometric relationship was not observed between HR and BW in the dogs. Our results indicated that weight was associated with variations in the ECG variables; age and sex were associated with variations in HR; and temperament had a significant influence on the HR and BR of the dogs.
尽管心率（HR）是通过体格检查确定的最重要的临床参数之一，但关于犬正常心率的信息却很少，这可能与该物种体重（BW）的高度变异性有关。心率由窦房结的放电频率决定，而窦房结的放电频率取决于自主神经系统和儿茶酚胺的释放。不同物种中体重与心率之间的异速生长关系被描述为成反比；然而，这种关系已被反驳。某些作者报告称，与大型犬相比，小型犬的心率与体重之间的关系基于气质以及窦房结的交感自主神经刺激。本研究的目的是分析体重、性别、年龄和气质对犬心率、心率变异性和血清儿茶酚胺（肾上腺素和去甲肾上腺素）水平的影响。我们评估了48只不同性别、品种和年龄的成年犬，并将这些犬分为5个体重组：<5kg（n = 8）、5 - 10kg（n = 10）、10 - 25kg（n = 10）、25 - 45kg（n = 10）和>45kg（n = 10）。测量的参数为心率、呼吸频率（BR）和体温。我们还进行了24小时动态心电图和心电图（ECG）测试（动态心电图监测仪），并测定了血清中儿茶酚胺肾上腺素和去甲肾上腺素的水平。我们观察到心率与性别之间的相关性；体重组之间在心电图变量和肾上腺素水平方面的差异；以及某些临床参数（如心率和呼吸频率）在气质类别之间的差异。年龄影响R波振幅，并且在犬中未观察到心率与体重之间的异速生长关系。我们的结果表明，体重与心电图变量的变化有关；年龄和性别与心率的变化有关；气质对犬的心率和呼吸频率有显著影响。
