Internal Medicine, Faculty of Veterinary Medicine, Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.
Internal Medicine, Faculty of Veterinary Medicine, Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.
Vet Parasitol. 2019 Sep;273:1-4. doi: 10.1016/j.vetpar.2019.07.008. Epub 2019 Jul 26.
Pulmonary endarteritis caused by Dirofilaria immitis and pulmonary hypertension (PH) are closely linked and the determination of PH could be validated to assess the severity and chronicity of the vascular damage, i.e. by the use of the Right Pulmonary Artery Distensibility (RPAD) Index. The aim was to evaluate the RPAD Index in dogs 10 months after the last dose of adulticide. The study included 23 client-owned dogs with heartworm brought for adulticide treatment. Echocardiographic exam was carried out to estimate worm burden, RPAD Index as well as other routine echocardiographic values on day 0 (diagnosis), day 120 (discharge), and 10 months after the last dose of adulticide. No significant differences were observed in the RPAD Index over time, neither when microfilaremic status and parasite burden were evaluated. An RPAD Index <29% was found in 52.2% of the dogs on day 0, day 120, and 10 months after the last dose of adulticide. Regarding other echocardiographic parameters, only significant differences were observed on tricuspid annular plane systolic excursion (TAPSE) values between day 0:day 120 (p = 0.008), and day 0:end of the study (p = 0.037). There was not significant improvement in pulmonary damage 10 months after the elimination of the parasites (p = 0.296), suggesting that, once the endarteritis has developed, the vascular changes are chronic and may not be reversible. The modifications of the TAPSE value suggest an improvement in the systolic function of the right ventricle after the disappearance of the worms, independently of the presence of PH. The endarteritis causes a decrease in the elasticity in the pulmonary vasculature and an increase in the resistance that, chronically, and depending on the severity, will cause the development of PH and later right heart failure. This complication of the disease is one of the most damaging and frequent, so it is necessary to adequately monitor PH in dogs undergoing adulticide treatment. Furthermore, knowing the pulmonary status could provide valuable information to help provide an objective prognosis and help assess the need to add additional treatments, once the worms have been eliminated.
由犬恶丝虫引起的肺血管炎和肺动脉高压（PH）密切相关，PH 的确定可用于评估血管损伤的严重程度和慢性程度，例如使用右肺动脉可扩展性（RPAD）指数。目的是评估在最后一次成虫杀灭剂给药后 10 个月时的 RPAD 指数。该研究包括 23 只接受心丝虫成虫杀灭剂治疗的患犬。在第 0 天（诊断）、第 120 天（出院）和最后一次成虫杀灭剂给药后 10 个月，进行超声心动图检查以评估虫体负荷、RPAD 指数以及其他常规超声心动图值。随着时间的推移，RPAD 指数没有变化，微丝蚴状态和寄生虫负荷的评估也没有变化。在最后一次成虫杀灭剂给药后 10 个月时，52.2%的犬 RPAD 指数<29%。关于其他超声心动图参数，只有三尖瓣环平面收缩期位移（TAPSE）值在第 0 天与第 120 天之间（p=0.008）和第 0 天与研究结束时（p=0.037）之间有显著差异。在消除寄生虫 10 个月后，肺损伤没有显著改善（p=0.296），这表明一旦发生血管炎，血管变化是慢性的，可能无法逆转。TAPSE 值的变化表明，在蠕虫消失后，右心室收缩功能有所改善，而与 PH 的存在无关。血管炎导致肺血管弹性降低，阻力增加，随着时间的推移，根据严重程度的不同，会导致 PH 及随后的右心衰竭的发展。这种疾病的并发症是最具破坏性和最常见的并发症之一，因此，在接受成虫杀灭剂治疗的犬中，有必要对 PH 进行充分监测。此外，了解肺部状况可以提供有价值的信息，有助于提供客观的预后，并帮助评估是否需要添加额外的治疗，一旦消除了蠕虫。
