Exercise training of dogs with myxomatous valve disease

ABSTRACT The present study has the objective of evaluating the effects of exercise training, using moderate intensity walking (60 to 80% of maximum heart rate), from 30 to 50 minutes, three times a week, in alternate days, during eight weeks, on heart rate variability in dogs with myxomatous valve disease (MVD). For that, 20 dogs in stages B1 (1), B2 (14) and C2 (5) of MVD (ACVIM classification) were divided into untrained control group (CG, n=9) and training group (TG, n=11), and assessed at baseline (T0), after four (T1) and eight weeks (T2). Only one B1 and five B2 dogs completed the training program. In the time domain, the rMSSD was greater in TG in T1 (155,5+42,07) and T2 (199,8+83,54) than CG (T1:91,17+35,79 and T2:88,17+57,51). In the frequency domain, the variable High Frequency (HF) increased in TG in T1 (30950+25810) and T2 (40300+33870) when compared to the CG (T1:19090+23210 and T2:18810+22200) and within the group TG in T2 in relation to T0 (29340+20950). The proposed walking protocol is concluded to have increased the rMSSD and HF variables in TG, representing an increase of the parasympathetic tonus, justifying the indication of this therapy in B1 and B2 stages of MVD.

摘要
本研究旨在评估中等强度步行（最大心率的60%~80%）、每次30~50分钟、每周3次且隔日进行、持续8周的运动训练，对黏液瘤性瓣膜病（myxomatous valve disease, MVD）犬心率变异性的影响。为此，本研究纳入20只按美国兽医内科学会（American College of Veterinary Internal Medicine, ACVIM）分级标准处于B1（1只）、B2（14只）及C2（5只）分期的MVD患犬，将其分为未训练对照组（CG，n=9）与训练组（TG，n=11），并分别在基线（T0）、4周（T1）及8周（T2）时进行评估。最终仅1只B1级患犬与5只B2级患犬完成了全部训练方案。
在时域分析中，训练组在T1（155.5±42.07）与T2（199.8±83.54）时的连续正常窦性心搏间期差值均方根（root mean square of successive differences, rMSSD）均高于对照组（T1：91.17±35.79，T2：88.17±57.51）。在频域分析中，与对照组（T1：19090±23210，T2：18810±22200）相比，训练组在T1（30950±25810）与T2（40300±33870）的高频（High Frequency, HF）成分均显著升高；且训练组内T2时的HF成分相较于T0（29340±20950）亦有所提升。
本研究结果表明，上述步行训练方案可提升训练组的rMSSD与HF指标，提示副交感神经张力增强，因此该疗法可用于黏液瘤性瓣膜病（MVD）的B1与B2分期患犬。