Heart rate variability parameters of myxomatous mitral valve disease in dogs with and without heart failure obtained using 24‐hour Holter electrocardiography

Abstract

Time-domain heart rate variability (HRV) parameters and the correlation between echocardiography and Holter examinations in dogs with myxomatous mitral valve disease (MMVD) were determined. Holter examination was also performed at different time frames: an entire 24-hour period, a four-hour period during sleep, and a four-hour period while awake. Ten healthy (control group) and 28 MMVD dogs, 15 with and 13 without heart failure, were evaluated. The SDANN (sd of the mean normal RR intervals for all five-minute segments during 24-hour Holter) and pNN(50) (percentage of differences between adjacent normal RR intervals that are >50 ms computed over 24-hour Holter) variables were significantly lower in the dogs with MMVD heart failure. The differences in HRV between the groups were only detected during the 24-hour evaluation period (P<0.05). There were high correlations (canonical analysis) between Holter and echocardiography examinations when considering pNN(50), SDANN, and LA/AO (left atrial to aortic root ratio) (r=0.92; P<0.05), indicating that both are important in evaluating MMVD dogs. SDANN and pNN(50) are measures of parasympathetic control of the heart, and thus, it is possible to infer that the MMVD dogs exhibit parasympathetic withdrawal during the development of heart failure.

Vasovagal tonus index in dog with myxomatous mitral valve disease

“…Therefore, the lower the VVTI becomes, the more suggestive that an asymptomatic MMVD patient may evolve into CHF. This finding is extremely valuable for clinical decision making, and is in accordance with previously reported data that suggests parasympathetic withdrawal in CHF syndrome (Eckberg et al 1971, Oliveira et al 2012. Left atrial enlargement is associated with the progression of MMVD, and the degree of dilation is recognized as a prognostic surrogate (Borgarelli et al 2008, Reynolds et al 2012.…”

“…Conventional HRV measures have been studied in people with heart disease, and were found to be an excellent predictor of adverse outcome (Saul et al 1988, Nolan et al 1998, Lahiri et al 2008. Time-domain heart rate variability parameters have also shown to have prognostic potential for determining the severity of MMVD in dogs (Rasmussen et al 2012, Oliveira et al 2012). These measures, however, usually hold the disadvantage of requiring a 24 hour Holter monitoring.…”

Short-term heart rate variability (HRV) in healthy dogs

“…Although we did not find significant correlations between the HRV parameters and body weight, it should be remembered that our study included solely dogs <20 kg. The spectrum of breeds qualified for our study and/or the predefined 20-kg body weight limit were associated with the fact that dogs with such characteristics most often present with MVD, the most common cause for canine heart failure (Oliveira et al 2012, Rasmussen et al 2012. We observed an age-related increase in SDNN and SDANN and a decrease in HF.…”

“…Furthermore, it proved to be a useful marker of early subclinical autonomic dysfunction associated with diabetic neuropathy (Chessa et al 2002, Turker et al 2013. HRV obtained during 24-hour Holter electrocardiography was also examined in dogs, both in a clinical and experimental setting and in patients with mitral valve endocardiosis, tachycardiomyopathy and diabetes (Piccirillo et al 2009, Oliveira et al 2012, Pirintr et al 2012, Rasmussen et al 2012, Chompoosan et al 2014. Rasmussen et al (2012) found an increase in the heart rate/min (HR) and mean HR in Cavalier King Charles Spaniels with advanced chronic mitral valve disease and a decrease in most of the measured HRV parameters (total power -TP, ultra low frequency-ULF, very low frequency -VLF, % of successive NN-intervals that differ more than 50 ms -pNN50 and the square root of the mean squared differences of successive NN-intervals -RMSSD) compared to healthy dogs and those with minimal mitral regurgitation.…”

Exercise training of dogs with myxomatous valve disease

“…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).…”