Heart rate variability and arrhythmias evaluated with Holter in dogs with degenerative mitral valve disease

Abstract

Cardiac diseases promote alterations in the autonomic control of the heart, leading to an increase in heart rate and, as a result, a decrease in heart rate variability (HRV).The aim of this study was to evaluate if the development of heart failure secondary to degenerative mitral valve disease (DMVD) concurs with changes in autonomic modulation of heart rhythm which are assessed by long electrocardiography examination (Holter). Dogs were evaluated by clinical examination and echocardiography in order to be categorized into the following groups: Control (healthy; n=6), DMVD (disease without heart failure; n=8), and DMVD heart failure (disease with heart failure; n=13). Arrhythmias and frequency domain HRV were determined by Holter. Diseased animals, when compared to healthy, had significantly lower total power, which indicates overall HRV. DMVD heart failure dogs also showed other disturbances such as high incidence of supraventricular arrhythmias, high heart rate, little amount of pauses (2.0s long between consecutive heartbeats), longer time in tachycardia, shorter time in bradycardia, low high frequency (parasympathetic control), and high low frequency (sympathetic and parasympathetic control) when compared to control (p<0.05). In DMVD dogs, Holter-derived variables changed with the development of heart failure.Keywords: electrocardiography, heart failure, frequency-domain, cardiology RESUMO As cardiopatias cursam com alterações do controle autonômico do coração, resultando em taquicardia e consequente diminuição na variabilidade da frequência cardíaca (VFC). O objetivo deste estudo foi avaliar se o desenvolvimento de insuficiência cardíaca secundária à degeneração valvar mitral (DVM) leva a alterações no controle autonômico do coração, as quais podem ser determinadas pela eletrocardiografia contínua (Holter). Cães foram distribuídos em grupos experimentais após avaliação clínica e ecocardiográfica da seguinte maneira: controle (saudáveis; n=6), DVM sem insuficiência cardíaca (n=8) e DVM com insuficiência cardíaca (n=13). Arritmias e VFC foram determinadas pelo

Exercise training of dogs with myxomatous valve disease

“…The observation of the lower values of this variable in the CG compared to the TG, is opposed to findings by Oliveira et al (2014), which demonstrate that animals of more advanced endocardiosis stages present higher values of LF. However, smaller values of LF were obtained in patients with MVD canines in classes B1 and B2 treated with ACE inhibitor (Chompoosan et al, 2014), which can justify the finding in the CG, in which a few animals received this therapy.…”

“…It is believed that such differences relate to the more advanced stage of the MVD in dogs of CG (three dogs in stage C2), in agreement with the findings by Rasmussen et al (2012) and Oliveira et al (2014). According to these authors, the variables TP, VLF are smaller in stages C and D, while the variable LF/HF is greater, when compared to the stages A and B.…”

“…During the progression of the disease, the autonomic injury is observed through heart rate variability (HRV). Decrease of the parasympathetic tonus (PNS) and or increase of the sympathetic (SNS) is noted (Oliveira et al, 2012;Rasmussen et al, 2012;Oliveira et al, 2014).…”

Retrospective study of pre-anesthetic electrocardiogram examination of 700 dogs conducted at the Veterinary Hospital of UFMG (2013-2014)

“…The P wave disturbances could indicate right atrial enlargement, chronic pulmonary disease and atrial overload, generally associated with mitral valve disease which is the most common cardiopathy in elderly small dogs (Atkins et al 2009, Oliveira et al 2014. Olsen et al (1999) conducted a study with Dachshunds and also came to the conclusion that many ECG disturbances can be associated with mitral valve disease especially in older animals.…”

Trigeminismo supraventricular em um cão com doença mixomatosa da valva mitral

“…In studies evaluating cardiac arrhythmias in dogs with MMVD using conventional and Holter (24 hours) ECG, despite the higher incidence of arrhythmias of supraventricular origin, supraventricular trigeminy is not reported. One of the studies revealed that a significant percentage (69%) of dogs demonstrated isolated supraventricular premature complexes; however, the Holter monitoring did not indicate trigeminy (CROSARA et al, 2010;RASMUSSEN et al, 2012;OLIVEIRA et al, 2014). Some studies reported the occurrence of trigeminy; however, it was of ventricular origin (CROSARA et al, 2010).…”