Continuous monitoring of heart rate in healthy cats in the home environment
Sofia Hanas and others, Animal Clinic Djurdoktorn, Vasteras, Sweden
Sinus arrhythmia has been linked to a range of non-cardiac diseases in cats, including conditions affecting the respiratory tract and nervous system. However, heart rate measurements taken in a veterinary clinic setting may not provide a wholly reliable assessment of a patient’s cardiac status.
The authors examined the heart rhythm of 23 healthy cats in their own home environment for a full 24 hours using a Holter monitoring system. All animals produced good quality electrocardiographic recordings and had a normal sinus rhythm. However, intermittent cardiac arrhythmias occurred in 78% of these animals with a median number of three ventricular premature complexes occurring over the 24-hour period.
Older cats have significantly more of these events than those aged less than six years. There were also significant differences in heart rate according to age and gender.
Journal of Veterinary Cardiology 11 (1): 17-22.
Effect of manual lung inflation on cardiac silhouette in anaesthetised dogs
Natalie Webster and others, Animal Health Trust, Newmarket
Changes in bodily position and respiratory phase may affect the radiographic appearance of the canine thorax. Studies in calves have also shown that artificial lung inflation during anaesthesia can reduce the apparent size of the heart.
The authors performed a similar examination in dogs which revealed a significant reduction in the heart size on manual lung inflation compared with spontaneous breathing. So if serial radiographs are to be taken, they emphasise the importance of using the same radiographic technique in each one.
Veterinary Radiology and Ultrasound 50 (2): 172-177.
Predictive value of natriuretic peptides in dogs with mitral valve disease
Inge Tarnow and others, University of Copenhagen
Atrial and brain natriuretic peptides (ANP and BNP) are a group of hormones involved in regulating renal and cardiovascular function. Plasma levels are known to increase in dogs with congestive heart disease. The authors investigated whether they may also give an early indication of the onset of mitral valve disease. In Cavalier King Charles spaniels, plasma concentrations of the NT-proANP and NT-proBNP peptide fragments were shown to be positively correlated with the severity of the clinical signs of mitral valve disease.
The Veterinary Journal 180 (2): 195-201.
Doppler imaging of cardiac function in healthy and diseased geriatric cats
Kerry Simpson and others, University of Edinburgh
Pulsed-wave Doppler tissue imaging (pw-DTI) is a non-invasive method for assessing myocardial dynamics. The authors used this technique to look for changes in elderly cats with diseases, such as hyperthyroidism, that produce cardiomyopathies in humans and compare the findings with those of healthy geriatric cats and those with hypertrophic cardiomyopathy. They found evidence of diastolic dysfunction in untreated cats with hypertrophic cardiomyopathy and increased systolic function in hyperthyroid patients.
Journal of Feline Medicine and Surgery 11 (4): 293-304.
In vitro culture technique for canine valvular interstitial cells
Allison Heaney and others, Kansas State University
Chronic degenerative valve disease is the most common acquired cardiac disease in dogs. Valvular interstitial cells are the most prevalent cell type in cardiac valves and synthesise the extracellular proteins which determine the physical properties of the valve. The authors describe a method for harvesting and culturing these cells. The technique will allow the creation of large populations of valvular interstitial cells that can be used in cellular and molecular investigations into the causes and treatment of canine valve disease.
Journal of Veterinary Cardiology 11 (1): 1- 7.
Open patch grafting in the treatment of pulmonic stenosis in small dogs
R. Tanaka and others, Tokyo University of Agriculture and Technology
Pulmonic stenosis is a common congenital cardiac defect in dogs. Balloon valvuloplasty has been used to treat the condition in large breed dogs but is a difficult technique to perform in smaller patients. The authors describe the application of open patchgrafting as an alternative method in 10 small breed dogs. The method was effective in reducing the pulmonary pressure gradient in seven surviving dogs three months post-operatively but the method is highly invasive and should be used with caution in cases with severe stenosis.
Australian Veterinary Journal 87 (3): 88- 93.
Characterisation of systolic intervals in healthy, conscious sheep
Sergey Kharin and others, Institute of Physiology, Syktyvkar, Komi Republic, Russia
Measurements of systolic intervals are a useful tool for evaluating cardiac performance. There are few relevant data on this parameter in sheep and so the authors studied healthy sheep to investigate the relationship between systolic intervals and heart rate. They found that the total electromechanical systole, mechanical systole and ejection time varied inversely with heart rate, while there was no correlation with electromechanical delay and preejection period. However, a larger study would be needed to provide reference ranges.
American Journal of Veterinary Research 70 (3): 330-333.
Comparing three echocardiographic methods for assessing cardiac function in rabbits
Claudia Moura and others, University of Porto, Portugal
Traditionally, echocardiographic assessment of left ventricular diastolic function has relied on measurements of Doppler patterns of mitral inflow. However, in human medicine the myocardial performance index (Tei) has become widely used in assessing heart function in various disease states. The authors measured the myocardial performance index of the left ventricle using tissue Doppler imaging, pulsed wave Doppler and M-mode echocardiography in healthy rabbits. They found little agreement between the results with the three methods.
American Journal of Veterinary Research 70 (4): 464-471.
Double-outlet right ventricle in a 10-month-old filly
Laura Fennell and others, University of Melbourne
A Friesian filly presented with clinical signs suggestive of chronic left- and right-sided congestive heart failure. Echocardiography revealed cardiac chamber dilation and dextropositioning of the aorta while radiography showed an enlarged heart and interstitial infiltration. The horse was euthanased and a post mortem examination confirmed the diagnosis of a doubleoutlet from the right ventricle. The physiological consequences of this condition have not been described fully before in a horse but are similar to those in humans.
Australian Veterinary Journal 87 (5): 204- 209.
Chronic cor pulmonale secondary to pulmonary atherosclerosis in a parrot
Cassidy Sedacca and others, Colorado State University
A 20-year-old intact female African grey parrot presented with a threeweek history of lethargy, hyporexia, weight loss and ascites. Radiography revealed cardio- and hepatomegaly, and echocardiography showed changes in the right ventricle indicative of chronic cor pulmonale. After coelomocentosis, the parrot appeared to respond to medical treatment but was found dead 35 days after the initial consultation. A post mortem examination showed significant atherosclerosis of the large pulmonary arteries.
Journal of the American Veterinary Medical Association 234 (8): 1,055-1,059.
Ebstein’s anomaly with an atrial septal defect in a Korean dog
Ran Choi and others, Kangwon National University, South Korea
A seven-month-old intact jindo bitch presented with signs of severe ascites, exercise intolerance and cyanosis. Echocardiography showed evidence of an atrial septal defect and Ebstein’s anomaly,avariant of triscuspid valvular dysplasia characterised by downward displacement of the tricuspid valve leaflets into the right ventricle. The dog received medical treatment involving inotropics, diuretics and vasodilators for a 10- month period but then died suddenly of cardiac arrest. The owners refused to allow a post-mortem examination.
Canadian Veterinary Journal 50 (4): 405- 410.
