- 著者
- Prapawadee PIRINTR Nakkawee SAENGKLUB Vudhiporn LIMPRASUTR Suwanakiet SAWANGKOON Anusak KIJTAWORNRAT
- 出版者
- 公益社団法人 日本獣医学会
- 雑誌
- Journal of Veterinary Medical Science (ISSN:09167250)
- 巻号頁・発行日
- pp.17-0016, (Released:2017-07-17)
- 被引用文献数
- 9
Myxomatous mitral valve degeneration (MMVD) causes an imbalance of sympathovagal activity resulted in poor cardiac outcomes. Phosphodiesterase-5 inhibitors have been revealed cardioprotective effect in patients with heart diseases. This study aimed to 1) compare the heart rate variability (HRV) between asymptomatic MMVD and healthy dogs and 2) assess long-term effects of sildenafil and enalapril on time- and frequency-domains analyzes. Thirty-four dogs with MMVD stage B1 or B2 and thirteen healthy dogs were recruited into the study. MMVD dogs were divided into 3 subgroups: control (n=13), sildenafil (n=12) and enalapril (n=9). HRV was analyzed from 1-hr Holter recording at baseline (D0) in all dogs and at 30, 90 and 180 days after treatment. The results showed that MMVD dogs had significant higher heart rate (HR), systemic blood pressures, the ratio of low to high frequency (LF/HF) and had significant decreased standard deviation of all normal to normal RR intervals (SDNN) and the percentage of the number of normal-to-normal sinus RR intervals with differences >50 msec computed over the entire recording (pNN50) when compared with healthy dogs (P<0.05). Neither time nor frequency domain parameters were different among subgroups of MMVD dogs at D0. After treatment with sildenafil for 90 days, both time- and frequency-domain parameters were significantly increased when compared with control and enalapril groups. This study demonstrated that sildenafil improves HRV in asymptomatic MMVD dogs suggesting that sildenafil should be used in the MMVD dogs to restore the sympathovagal balance.
- 著者
- Nakkawee SAENGKLUB Brad YOUNGBLOOD Carlos DEL RIO Suwanakiet SAWANGKOON Robert L. HAMLIN Anusak KIJTAWORNRAT
- 出版者
- 公益社団法人 日本獣医学会
- 雑誌
- Journal of Veterinary Medical Science (ISSN:09167250)
- 巻号頁・発行日
- pp.15-0481, (Released:2016-02-26)
- 被引用文献数
- 4
Dronedarone is a multichannel blocking antiarrhythmic drug that has been used for management of atrial fibrillation in humans, but the data in veterinary medicine are inadequate. The objective of this study was to determine the short-term effects of oral dronedarone on cardiac inotropy and lusitropy, blood pressure and electrocardiogram (ECG) in healthy dogs. A total of 6 beagle dogs were instrumented with telemetry units and sono-micrometry crystals to obtain left ventricular pressure-volume relationship, mean blood pressure (MBP) and ECG. Dogs were given orally dronedarone (20 mg/kg, twice per day) for 7 days. All parameters were obtained hourly at 4–8 hr after the first dose and at 12-, 96- (day 4) and 168-hr (day 7) after dosing. The results showed that dronedarone had no effect on inotropy and lusitropy, while it significantly lengthened PQ interval (P<0.001) and lowered MBP (P<0.05). Dronedarone also tended to reduce cardiac output (P=0.237) and heart rate (P=0.057). These results suggested that short-term effects of oral dronedarone administration at a dose of 20 mg/kg, twice per day, produced negative dromotropy with minimal effect on cardiac function in conscious dogs.
- 著者
- Nakkawee SAENGKLUB Vudhiporn LIMPRASUTRL Suwanakiet SAWANGKOON Chollada BURANAKARL Robert L. HAMLIN Anusak KIJTAWORNRAT
- 出版者
- 公益社団法人 日本獣医学会
- 雑誌
- Journal of Veterinary Medical Science (ISSN:09167250)
- 巻号頁・発行日
- pp.15-0413, (Released:2015-09-04)
- 被引用文献数
- 1 8
Dronedarone is a class III antiarrhythmic that has been used for management of atrial fibrillation in humans, but limited information was found in dogs. The objective of this study was to determine the acute effects of escalating concentrations of dronedarone on electrocardiograms (ECG), hemodynamics and cardiac mechanics in healthy dogs. A total of 7 beagle dogs were anesthetized with isoflurane and instrumented to obtain lead II ECG, pressures at ascending aorta, right atrium, pulmonary artery and left ventricle, and left ventricular pressure-volume relationship. Five dogs were given vehicle and followed by escalating doses of dronedarone (0.5, 1.0 and 2.5 mg/kg, 15 min for each dose), and two dogs were used as a vehicle-treated control. All parameters were measured at 15 min after the end of each dose. The results showed that all parameters in vehicle-treated dogs were unaltered. Dronedarone at 2.5 mg/kg significantly lengthened PQ interval (P<0.01), reduced cardiac output (P<0.01) and increased systemic vascular resistance (P<0.01). Dronedarone produced negative inotropy assessed by significantly lowered end-systolic pressure-volume relationship, preload recruitable stroke work, contractility index and dP/dtmax. It also impaired diastolic function by significantly increased end-diastolic pressure-volume relationship, tau and dP/dtmin. These results suggested that acute effects of dronedarone produced negative dromotropy, inotropy and lusitropy in anesthetized dogs. Care should be taken when given dronedarone to dogs, especially when the patients have impaired cardiac function.