Effects of pimobendan on survival time in cats with congestive heart failure
Yamir Reina-Doreste and others, North Carolina State University
Pimobendan is a positive inotropic and vasodilatory drug which has become a standard part of the care of dogs with congestive heart failure, secondary to dilated cardiomyopathy and chronic mitral valve disease. However, in cats with cardiac disease the use of this drug has not gained widespread acceptance and some veterinarians have even suggested that it is contraindicated.
The authors carried out a case control study examining the effects of pimobendan in 27 cats with congestive heart failure secondary to hypertrophic cardiomyopathy or hypertrophic obstructive cardiomyopathy and 27 matched controls which received a treatment regime which did not involve this agent.
Their results indicate that cats receiving pimobendan had a significant benefit in survival time. Their median survival was 626 days from initial diagnosis compared with 103 days in the matched controls. There were no significant differences in any of the other parameters examined, which included echocardiographic data and serum biochemistry. The drug was well tolerated in this patient population.
Journal of the American Veterinary Medical Association 245 (5): 534-539.
24-hour holter monitoring of dogs with myxomatous mitral valve disease and syncope
Caroline Rasmussen and others, University of Copenhagen, Denmark
Syncope is a transient loss of consciousness which occasionally occurs in dogs with advanced myxomatous mitral valve disease. The authors used holter monitors to record electrocardiogram changes during syncopal episodes in small breed dogs with advanced disease. They also compared the pattern of arrhythmias in dogs with this condition, with and without a history of syncope. Dogs with MMVD and a history of syncope had a comparable frequency of arrhythmias to those with the disease but no history of syncope. But they did have fewer sinus arrhythmias, decreased overall heart rate variability, decreased parasympathetic and increased sympathetic modulation of heart rate.
Journal of Veterinary Internal Medicine 28 (2): 363-370.
Echocardiographic findings in cats with acromegaly
Jennifer Myers and others, Triangle Veterinary Referral Hospital, Raleigh, North Carolina
Cardiovascular abnormalities are a consistent finding in human patients with acromegaly and are a major cause of morbidity and mortality. Acromegaly due to a pituitary hyperplasia is increasingly recognised in cats. The authors used echocardiography to look for possible abnormalities in the hearts of 11 cats with this condition. In seven of the 11 cases, there was evidence of left ventricular concentric hypertrophy, six had left atrial enlargement and seven had abnormal diastolic function. Indeed, all 11 cats had evidence of structural or functional heart disease and so a complete cardiac evaluation should be considered in such patients.
Journal of Veterinary Internal Medicine 28 (4): 1,235-1,238.
Comparison of direct blood pressure measurements and ultrasonic doppler flow detectors
Anderson da Cunha and others, Louisiana State University
Blood pressure measurements are essential for monitoring patients receiving general anaesthesia and in monitoring response to therapy of critically ill animals. The authors assessed whether measurements with an ultrasonic Doppler flow detector were in agreement with direct blood pressure measurements in anaesthetised cats. Their findings show that there was poor agreement between Doppler values and directly measured blood pressures. The use of Doppler technology could be misleading and any readings should be interpreted with caution in a clinical context.
Veterinary Emergency and Critical Care 24 (3): 272-278.
Cardiac MRI findings in a dog with a diffuse pericardial mesothelioma
Ricardo Guillem Gallach and Wilfried Mai, University of Pennsylvania
Pericardial effusion is a common acquired cardiac disease in dogs and may result from a range of conditions, which on rare occasions may include a mesothelioma. The authors used the relatively new technique of veterinary cardiac MRI to assess a case in which the echocardiographic findings were equivocal. The technology demonstrated diffuse thickening and enhancement of the pericardium.
A pericardiectomy was performed and histopathology revealed a diffuse pericardial mesothelioma. The case demonstrates the potential value of cMRI in the management of patients with pericardial effusion.
Journal of the American Animal Hospital Association 49 (6): 398-402.
Technique for measuring heart rate variability in anaesthetised cats
Kuan Hua Khor and others, University of Queensland
Analysis of heart rate and heart rate variability are powerful tools for investigating cardiac disorders but current methods such as holter monitoring are cumbersome and can be compromised by movement artefacts. The authors used a standard laboratory recording system to monitor heart rate and heart rate variability in anaesthetised cats during pharmacological manipulation of that rate using atenolol and epinephrine.
They conclude that the method is a highly sensitive and repeatable model for investigating heart rate variability in a laboratory setting for investigations into cardiovascular disease and to study subtle responses to pharmacological agents.
The Veterinary Journal 199 (2): 229-235.
Assessment of mitral valve regurgitation by doppler colour flow mapping
Marco Di Marcello and others, Cellatica Veterinary Medical Centre, Brescia, Italy
Diagnosis of mitral regurgitation in dogs with degenerative mitral valve disease is usually straightforward but there is no reliable way of measuring its severity. The authors used Doppler colour ow mapping to investigate the vena contracta width in 279 dogs with different levels of mitral regurgitation severity. The median values of VCW were 2.9mm in those dogs classified as having mild to moderate and 4.6mm in those with moderate to severe disease. Although this cannot be regarded as a validation study, it did show that the method was easy to use and provided an additional tool in quantifying disease severity.
Journal of Veterinary Internal Medicine 28 (4): 1,206-1,213.
Mural endocarditis caused by Corynebacterium mustelae in a dog with a VSd
Randolph Winter and others, Texas A&M University, College Station
Infective endocarditis is a relatively rare condition in dogs but one associated with considerable morbidity and mortality. The authors describe the case of a six-year-old female spayed Munsterlander with a three-week history of lethargy, inappetence, intermittent fever and a change to the timing of a previously diagnosed heart murmur. Echocardiography revealed a large, mobile, vegetative lesion in the right ventricular out ow tract associated with a ventricular septal defect. Corynebacterium mustelae was isolated from a pooled blood culture. Treatment of infective endocarditis was begun alongside supportive care and the patient was discharged after nine days.
Journal of the American Animal Hospital Association 50 (5): 366-372.
Serum fatty acid concentrations in cats with hypertrophic cardiomyopathy
Daniel Hall and others, Tufts Cummings School of Veterinary Medicine Massachusetts
Plasma n-3 fatty acid concentrations are reduced in dogs with congestive heart disease and there is evidence that dietary supplementation is beneficial. However, there have been no comparable published studies in cats. The authors measured serum fatty acid concentrations in healthy cats and those with hypertrophic cardiomyopathy.
The latter group had higher concentrations of palmitic acid, docosahexanoic acid and total n-3 acids and lower concentrations of linolenic acid concentrations than healthy cats. However, in the cats with cardiomyopathy there was no correlation between serum fatty acid concentrations and left atrial dimensions.
Journal of Feline Medicine and Surgery 16 (8): 631-636.
Effect of body position on electrocardiographic recordings in dogs
Joshua Stern and others, Ohio State University
There is some controversy over the optimum position for recording an accurate and reproducible electrocardiogram in a dog. Although the Academy of Veterinary Cardiology recommends placing the dog in right lateral recumbency, ECGs in research and clinical practice are taken with a number of different methods. The authors recorded ECGs in 65 sled dogs with the animal either standing or in right lateral recumbency.
They conclude that right lateral recumbency improves the quality of the recording by decreasing muscle tremor artefacts, alters the amplitude of P, R and S waves in specific leads and results in a rightward shift in the mean electrical axis, relative to standing recordings.
Australian Veterinary Journal 91 (7): 281-286.
