首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 968 毫秒
1.
To examine the waveforms of electrocardiograms, cardiac rhythm, heart rates at rest and during excitement, and the rate of increase of heart rate, electrocardiograms were recorded with standard bipolar limb leads from 79 free-living birds, including 19 species. The heart weights and heart-to-body weight ratios were obtained from an additional 96 free-living birds, including 20 species. In the majority of the electrocardiograms, lead I was of low amplitudes for all waves except the P wave, and leads II and II were very similar to each other with a predominant S wave and a very short or elevated ST segment. The P wave was often superimposed on the T wave when the heart rate increased to 330 beats/min. Four types of arrhythmia were observed in 50 of the 79 birds (63.3%): 48 sinus arrhythmias, four sinus arrests, two atrial premature contractions, and one ventricular premature contraction. The resting heart rate was negatively associated with the rate of increase, suggesting that a bird with a low resting rate might be able to maintain a greater capacity to increase its heart rate than one with a high resting rate. A negative correlation on a bilogarithmic scale was obtained between the heart weight and the resting heart rate, indicating that a bird with a high heart weight had lower resting heart rate than a bird with a low heart weight. When the heart-to-body weight ratios of free-living birds were compared according to their motility, the ratios of more active birds were greater than those of less active ones.  相似文献   

2.
Data on resting heart rates, pre-exercise heart rates, the anticipatory rises before exercise, the influence of speed of work and recovery heart rates have been presented. Some observations on differences in the heart rate response on slow and fast working days are also recorded. In conformity with other workers, a linear relationship between heart rate and working speed within the range of 400-800 metre/min was observed. When the speed of work was between 400-800 metre/min, horses with resting ECG's classed as abnormal had significantly higher heart rates than those regarded as normal. It was also observed that the abnormal animals showed lower heart rates than a small number classed as borderline. The significance of these findings is discussed and the need for further work indicated.  相似文献   

3.
The aim of this study was to determine the relationships between heart score (mean QRS interval), heart weight and body weight in Greyhound dogs. Highly significant correlations between these measurements have been observed and distinct sex differences have been demonstrated. The results of multiple regression analysis indicated that 66% of the variation in heart weight was due to variation in heart score and body weight. From the regression analysis, a formula for heart weight prediction with a standard deviation of 27.1 g was derived. The implications of these findings have been discussed briefly and emphasis has been placed on the need for good electrocardiographic technique, if the procedures outlined are to be used successfully. The positive correlation between heart score and heart size demonstrated here in Greyhounds is in accord with similar correlations reported previously in racehorses and human athletes.  相似文献   

4.
The heart of the bird is characterized by its enormous efficiency. Racing pigeons are bred for a long time for their flight performance. In the present study therefore the heart of 108 racing pigeons of the breed Bricoux were examined by means of echocardiography. The birds were either kept in aviaries (untrained) or as racing birds. The aim was to find out whether differences in the heart dimensions and/or the heart work occur between untrained and trained birds, like it is described already in humans and mammals (so-called athletic's heart). Significant differences between the two groups could be determined with different parameters, in particular with parameters, which affect the heart work. Thus it was for the first time possible to prove the formation of a athletic's heart in birds, and by that the adaptation of the avian heart to appropriate performance requirements.  相似文献   

5.
The purpose of this study was to determine whether the combination of dobutamine and atropine causes cardiac stress equivalent to treadmill exercise. Therefore, electrocardiography and echocardiography were performed on 10 warmblood horses before, during, and after different cardiac stress tests. Stressors consisted of a standardized treadmill exercise and combined administration of dobutamine (7.5 microg/kg/min) and atropine (5 microg/kg). Maxima heart rates were achieved during the treadmill exercise (175 +/- 10 bpm). After exercise, a rapid decrease in heart rate was observed. Subsequently, a stress echocardiography for which a heart rate >100 bpm was required could only be performed within 1 minute after exercise. The mean heart rate during echocardiography was 136 +/- 8 bpm after exercise. The combination of dobutamine and atropine also resulted in a significant increase in heart rate, up to 141 +/- 20 bpm. Maxima heart rate was significantly higher during the treadmill exercise, but the decrease in heart rate was significantly slower after dobutamine and atropine administration. Over a period of 7.9 minutes, the mean heart rate was 123 +/- 8 bpm during dobutamine and atropine administration. Consequently, the combination of both drugs offered sufficient time for detailed examinations. Overall, echocardiographic examination identified a decrease in left ventricular (LV) dimensions, an increase in LV wall thickness, and a decrease in stroke volume after the treadmill exercise and during pharmacologic stress testing compared with baseline. Changes in echocardiographic variables generally were more pronounced during dobutamine and atropine administration. Similar to stress echocardiography in humans, in horses the combination of dobutamine and atropine is useful to produce an increase in heart rate comparable with what is achieved with exercise but without the need of increasing dobutamine dosage.  相似文献   

6.
  相似文献   

7.
Cardioversion through varying quinidine sulphate treatments was achieved in 3 riding horses with auricular fibrillation. The horses were subjected to continual telemetric ECG registration before and after reversion in a uniform exercise-tolerance-test. A comparison of the heart rate curves showed a strong decline of the heart beat frequency during the exercise phase after synchronisation. The decrease in heart rate during exercise was greater than 30% in all 3 patients. Anti-arrhythmic treatment is, therefore, recommended for horses with auricular fibrillation and without concurrent heart disease.  相似文献   

8.
The objective of this prospective study was to determine the prevalence of echocardiographic evidence of heart disease in apparently healthy cats with heart murmurs. Thirty-two privately owned domestic cats were examined. All cats were considered healthy on the basis of history and physical examination, except for the finding of a heart murmur on auscultation. Cats on any medications (besides regular flea, tick and heartworm preventative) or that were pregnant or lactating were excluded from this study. The prevalence of echocardiographic evidence of heart disease in this population of cats was 53%. Therefore, identification of a heart murmur on routine physical examination in apparently healthy cats warrants further investigation.  相似文献   

9.
Knowledge of the competitive demands of different sports or activities is important for designing appropriate training programmes to ensure that animals reach a sufficient level of fitness to reduce the risk of overexertion and injury or illness and to achieve the best possible performance in relation to an individual's genetic potential. Whilst the physiological demands of many equestrian sports have been described, to the best of our knowledge the cardiovascular demands of polo have not. The aims of the present study were therefore to record heart rate during and after competitive polo games in a group of low-goal (non-elite) polo ponies in order to describe the absolute heart rates during play, the relationship of these heart rates to maximal heart rate and the characteristics of a typical chukka in terms of effort. Six low-goal polo ponies were studied during a total of 59 chukkas. Heart rate was monitored continuously before, during and after competition using a commercial heart rate monitor. Maximal heart rate was determined with field and treadmill incremental exercise tests and used to express work intensity in terms of time during play that each ponies heart rate was less than 75% HRmax, between 75 and 90% HRmax and greater than 90% HRmax. Mean maximum heart rate was not different during play or during field and treadmill exercise tests; 215+/-7 (mean +/- s.d.), 211+/-7 and 213+/-2 beats/min, respectively (P>0.05). Mean heart rate for all ponies over all chukkas was 166+/-6 beats/min with a mean chukka duration of 611+/-18 s. Of this time, 44+/-7% of the time was spent below 75% HRmax, 39+/-8% between 75 and 90% HRmax and 17+/-8% of time above 90% HRmax. When only one chukka had been played, there was a good correlation between mean heart rate during play and 3 min recovery heart rate (r = 0.63, P<0.001). Based on these observations, it is proposed that low-goal polo places moderate to high stress on the cardiovascular system.  相似文献   

10.
Gregory B.  Daniel  DVM  MS  Robert  DeNovo  DVM  MS  Anne  Bahr  DVM  MS  Gary T.  Smith  MD 《Veterinary radiology & ultrasound》2001,42(2):162-168
In this study, heart time-activity curve, created following intravenous injection of 99mTc-mebrofenin were used to quantify hepatic function in normal dogs and dogs with induced hepatic parenchymal cell damage. The results were compared to a direct measurement of hepatic extraction following mesenteric venous injection of 99mTc-mebrofenin. The heart time-activity curves were normalized and the area under the curve from 0-30 minutes and 0-60 minutes were determined. In addition, the half-time clearance rate of the heart time-activity curve was analyzed using a two-compartment model. Linear regression analysis was used to describe the relationship between the area under the normalized heart time-activity curve and hepatic extraction. There was good correlation between the area under the normalized heart time-activity curve and hepatic extraction. The best correlation was obtained from the 0-30 minute data (r2 = 0.92). A formula for calculating hepatic extraction was derived using linear regression analysis: Hepatic extraction = 1.092 - (0.0000308 x AUC0-30 minutes). There was good correlation between the half-time clearance rates from the heart time-activity curve and hepatic extraction. The best correlation was between the fast phase half-time clearance and hepatic extraction (r2 = 0.88). The area under a normalized heart time-activity curve can be used as a simple alternative to deconvolutional analysis for the determination of hepatic extraction as a measure of hepatic parenchymal cell function in the dog.  相似文献   

11.
Recent studies have demonstrated the benefits of nitric oxide (NO) on myocardial hypertrophy and myocardial fibrosis. It was suggested that NO has a protective effect on myocardial cell through the neurohormonal system. This effect serves to highlight the important role of NO in maintaining the function and form of heart with chronic heart failure. However, there are no known reports about on the effect of prolonged administration of nitrate on pressure over-load heart. This study was conducted to examine the long-term effect of oral nitrate therapy in rats with pressure-overloaded heart. An abdominal aorta constricted (AC) model of pressure-overloaded heart was created in male Wistar rats. Sustained release isosorbide dinitrate (sr-ISDN) (5 mg/kg once a daily) was administered to the rats once a daily for 12 weeks. The animals were euthanized during the study period, and the heart was collected and weighed. Histopathological examination was performed to evaluate the effect of sr-ISDN on myocardial hypertrophy and fibrosis. The ratio of heart to body weight increased significantly in AC rat and this increase was significantly prevented by sr-ISDN treatment. Histopathological examination showed significant increase in fibrotic area of AC rat compared to sham rat, this increase was inhibited by sr-ISDN treatment. Cardiomyocyte transverse diameter was significantly increased in AC rat compared with sham rat, but this increase tended to decrease by sr-ISDN treatment. In conclusion, intermittent administration with sr-ISDN has mild effect in inhibiting cardiac hypertrophy and marked effect in inhibiting fibrosis due to pressure-overload.  相似文献   

12.
In 37 healthy pups and seven pups with congenital pulmonic stenosis ECG were recorded and the heart rate determined. Between the first week of life in healthy pups (mean = 230/min) and the twelfth week of life the heart rate in both groups at six weeks was 195/min and 180/min. At the end of the investigation the averaged heart rate was 167/min or 166/min respectively. In single weeks during the investigation a slightly increased heart rate occurred in a few dogs between the fourth and sixth week of life owing to an increased restlessness during this time span. The heart rate of newborn pups at the first day (mean = 215/min) was a little lower than the average in the first week of life.  相似文献   

13.
Hypothesis/ObjectivesTo describe the therapeutic use of pimobendan in cats, describe the patient population to which it was administered, document potential side effects and report the clinical course following administration of pimobendan in conjunction with standard heart failure therapy. It is hypothesized that cats with advanced heart disease including congestive heart failure from a variety of causes will tolerate pimobendan with a minimum of side effects when used in treatment in conjunction with a variety of other medications.Animals, materials and methodsOne hundred and seventy client owned cats with naturally occurring heart disease, one hundred and sixty four of which had congestive heart failure. Medical records were reviewed and owners and referring veterinarians were contacted for follow-up data. Data collected included pimobendan dose, other medications administered concurrently, data collected at physical examination, presence or absence of heart failure, adverse effects, classification of heart disease, echocardiographic data and survival time. The data were analyzed for significance between the initial visit and any follow-up visits.ResultsAll cats were treated with pimobendan. The median pimobendan dose was 0.24 mg/kg q 12 h. Pimobendan was used in combination with multiple concurrent medications including angiotensin converting enzyme inhibitors, diuretics and anti-thrombotics. Five cats (3.0%) had potential side effects associated with pimobendan. One cat (0.6%) had presumed side effects severe enough to discontinue pimobendan use. Median survival time for 164 cats with congestive heart failure after initiation of pimobendan was 151 days (range 1–870).ConclusionPimobendan appears to be well tolerated in cats with advanced heart disease when used with a variety of concurrent medications. Randomized controlled studies need to be performed to accurately assess whether it is efficacious for treatment of congestive heart failure in cats.  相似文献   

14.
OBJECTIVE: To determine if Buchanan's vertebral heart scale can be applied to beagle dogs to establish reference values for this breed and to determine the possible influence of optimal lung inflation on the cardiac measurements. METHODS: The cardiac health of 19 beagle dogs was examined by echocardiography, electrocardiogram, non-invasive blood pressure measurement, complete blood count and serum chemistry profile. Right and left lateral recumbent radiographs of the thorax were obtained while the dogs were conscious and while under general anaesthesia with optimal lung inflation. The vertebral heart scale was measured in all radiographs. RESULTS: The mean (sd) vertebral heart scale in the beagle dogs was 10.3 (0.4) v, showing a significant difference from the mean vertebral heart scale of 9.7 (0.5) v in Buchanan's original study with dogs of different breeds. Degree of inspiration had no significant effect on the vertebral heart scale. CLINICAL SIGNIFICANCE: The vertebral heart scale provides the veterinarian with a possible way of objectively evaluating canine heart size without having to rely on echocardiography. However, the results should be interpreted critically and breed-specific differences should be taken into account, especially with values slightly above the reference range.  相似文献   

15.
对金黄地鼠Kcnq1基因进行分子克隆与鉴定以及在多种器官组织的表达差异进行分析,旨在研究Kcnq1基因在地鼠各组织器官中的功能。提取金黄地鼠心脏组织总RNA,根据大鼠Kcnq1的保守序列区域设计引物TK1,用RT-PCR的方法从金黄地鼠心脏组织中扩增出Kcnq1cDNA片段,并且以心脏cDNA片段为模板,将纯化后的cDNA在T4连接酶的作用下与pMD18-T载体特异性连接,转化感受态大肠杆菌DH5α中,筛选重组子并酶切鉴定,将鉴定后的重组子进行DNA测序。提取心、肝、脾、肺、肾各组织总RNA,并反转录,将各组织cDNA做荧光定量检测,检测各组织表达量的差异。结果显示克隆出金黄地鼠Kcnq1基因477bp的部分片段长度,推测出编码的159个氨基酸。与大鼠等物种Kcnq1基因比对,核苷酸和氨基酸序列均具有较高的同源性。荧光定量结果显示,Kcnq1在金黄地鼠心脏中表达量最高,在肺脏和肾脏中均有较高表达,在脾脏中低度表达,在肾脏中基本不表达。该研究结果为深入研究金黄地鼠Kcnq1基因功能奠定了基础。  相似文献   

16.
Previous studies have demonstrated evidence that normal reference ranges for radiographic vertebral heart scale values can vary among dog breeds. The purpose of this retrospective, observational study was to determine whether the normal vertebral heart scale values published by Buchanan and Bücheler for lateral radiographs are applicable to the Norwich terrier. Secondary objectives were to determine if clinical signs of respiratory disease, age, sex, weight, body condition score, recumbency, or thoracic depth‐to‐width ratio had any influence on vertebral heart scale measurements in this breed. The electronic medical record systems of two universities were reviewed and Norwich terriers were included in the study if they had orthogonal thoracic radiographs performed and no historical or radiographic evidence of cardiopulmonary disease. A vertebral heart scale was calculated for each patient. Sixty‐one client‐owned, Norwich terrier dogs with no clinical signs of cardiovascular disease were evaluated. The vertebral heart scale for Norwich terriers without evidence of cardiac disease (10.6 ± 0.6) was found to be significantly greater than the canine reference value of 9.7 ± 0.5 initially established by Buchanan and Bücheler. No significant correlation was found between clinical signs of respiratory disease, sex, age, thoracic depth‐to‐width ratio or lateral recumbency, and vertebral heart scale. Norwich terriers with a body condition score ≥6 had a significantly higher vertebral heart scale than those with a body condition score ≤5. Breed‐specific ranges and body condition scores need to be considered when interpreting vertebral heart scale values for Norwich terriers.  相似文献   

17.
A 15-day-old, 6.08 kg, lamb was injected subcutaneously with tilmicosin 15 mg/kg body weight. Approximately 15 min later, the lamb died. During necropsy, the heart was found to have multiple ventricular septal defects. Death was attributed to sudden heart failure due to the cardiac effects of tilmicosin in a heart having congenital defects.  相似文献   

18.
OBJECTIVE: To identify clinical signs, underlying cardiac conditions, echocardiographic findings, and prognosis for horses with congestive heart failure. DESIGN: Retrospective study. ANIMALS: 14 horses. PROCEDURE: Signalment; history; clinical signs; clinicopathologic, echocardiographic, and radiographic findings; treatment; and outcome were determined by reviewing medical records. RESULTS: All 14 horses were examined because of a heart murmur; tachycardia was identified in all 14. Twelve horses had echocardiographic evidence of enlargement of 1 or more chambers of the heart. Other common clinical findings included jugular distention or pulsation, crackles, cough, tachypnea, and ventral edema. Nine horses had signs consistent with heart failure for > 6 days. Underlying causes for heart failure included congenital defects, traumatic vascular rupture, pericarditis, pulmonary hypertension secondary to heaves, and valvular dysplasia. Seven horses were euthanatized after diagnosis of heart failure; 5 were discharged but were euthanatized or died of complications of heart disease within 1 year after discharge. The remaining 2 horses were discharged but lost to follow-up. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that congestive heart failure is rare in horses. A loud heart murmur accompanied by either jugular distention or pulsation, tachycardia, respiratory abnormalities (crackles, cough, tachypnea), and ventral edema were the most common clinical signs. Echocardiography was useful in determining the underlying cause in affected horses. The long-term prognosis for horses with congestive heart failure was grave.  相似文献   

19.
Objectives : The objective of the study was to examine the changes in vertebral heart scale, and left atrial and ventricular dimensions before and at onset of congestive heart failure in cavalier King Charles spaniels with mitral regurgitation. Methods : Records and radiographs from 24 cavalier King Charles spaniels with mitral regurgitation were used. Vertebral heart scale (24 dogs), and left atrial dimension and left ventricular end diastolic and end systolic diameters (18 dogs) and their rate of increase were measured at intervals over years to the onset of congestive heart failure. They were plotted against time to onset of congestive heart failure. Results : Dimensions and rates of change of all parameters were highest at onset of congestive heart failure, the difference between observed and chance outcome being highly significant using a two-tailed chi-square test (P<0·001). Clinical significance : The left heart chambers increase in size rapidly only in the last year before the onset of congestive heart failure. Increasing left ventricular end systolic dimension is suggestive of myocardial failure before the onset of congestive heart failure. Rate of increase of heart dimensions may be a useful indicator of impending congestive heart failure.  相似文献   

20.
In 18 horses, the pulmonary artery wedge pressure and the heart rate were measured during pharmacological stress load. 12 horses were healthy (4 trained, 8 untrained) and 6 horses had a heart disease (3 trained, 3 untrained). Pharmacological stress induction was carried out with the sympathomimetic drug dobutamine at a dosage rate of 7.5 microg/kg/min over 10 minutes of infusion. At the fourth minute, the parasympatholytic drug atropine was administered (5 microg/kg bw), and the heart rate and the pulmonary artery wedge pressure were continuously measured over 26 minutes. During sole dobutamine infusion, a significant decrease in heart rate and a significant increase in pulmonary artery wedge pressure were observed. After the application of atropine in the fourth minute, a significant increase in heart rate (from 35.7 +/- 6 up to 106 +/- 38/ min) and in pulmonary artery wedge pressure (from 15.7 +/- 3 up to 24 +/- 8.6 mmHg) were visible in the group of healthy horses. The horses with heart diseases had a significantly higher increase in both parameters (heart rate and pulmonary artery wedge pressure) with a significantly positive correlation (r = 0.7). The heart rate increased in the horses with heart diseases from 35.2 +/- 2,8 beats/min up to 132 +/- 45.7 beats/min and the pulmonary artery wedge pressure increased from 17.3 +/- 3,2 mmHg up to 32.7 +/- 13 mmHg. The cardiac status (healthy or heart disease) as well as the training level of the horses (untrained or trained) had a significant influence on the heart rate and the pulmonary artery wedge pressure. The untrained horses (healthy and heart disease) showed significantly higher values over a longer period of time than did the trained horses with the same cardiac status. Additionally the influence of pharmacological stress induction on echocardiographic parameters was investigated. The left atrial size (p = 0.015) and left ventricular diameter were significanly different in the systole (p = 0.008) and in the diastole (p = 0.001) between healthy horses and horses with heart diseases. All horses showed a positive correlation between the pulmonary artery wedge pressure and the left atrial size (r = 0.8), as well as between the left ventricular systolic (r = 0.6) and the diastolic diameter (r = 0.6). The correlation between the pulmonary artery wedge pressure and the left atrial size was nearly the same in the healthy horses (r = 0.74) and in the horses with heart diseases (r = 0.76). Regarding the training level, all untrained horses had a significantly higher correlation between the pulmonary artery wedge pressure and the left atrial size (r = 0.87) in comparison to the trained horses (r = 0.74). Particularly in the untrained horses with heart diseases, this correlation was remarcable (r = 0.99).  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号