Objective—To assess the effectiveness of the vertebral heart scale (VHS) system to differentiate congestive heart failure from other causes of dyspnea in cats.
Design—Retrospective case series.
Animals—67 cats with acute respiratory distress.
Procedures—Medical records of client-owned cats evaluated on an emergency basis because of acute respiratory distress during a 1-year period were reviewed. For study inclusion, cats must have undergone evaluation with echocardiography and thoracic radiography within 12 hours after hospital admission. The VHS was calculated for each cat by 2 investigators. Signalment, physical examination, and echocardiographic findings were reviewed for each patient.
Results—There was 83% agreement overall between the 2 investigators in assessment of cardiomegaly in cats with dyspnea (κ = 0.49). The VHS cutpoints were the same for both observers in terms of optimizing sensitivity and specificity. A VHS of > 8.0 vertebrae was the best cutpoint when screening for heart disease, whereas a VHS of > 9.3 vertebrae was very specific for the presence of heart disease. Measurements between 8.0 and 9.3 vertebrae suggested the cause of dyspnea was equivocal (ie, secondary to congestive heart failure or respiratory disease), in which case echocardiography would be most useful in providing additional diagnostic information.
Conclusions and Clinical Relevance—Results suggested that the VHS system may be a useful tool to help differentiate cardiac from noncardiac causes of respiratory distress in cats in an emergency situation when an echocardiogram is not available or is not plausible in an unstable patient.
Objective—To compare mitochondrial complex I and complex IV activity in myocardial mitochondria of clinically normal dogs, clinically normal dogs exposed to inhalation anesthesia, and dogs affected with dilated cardiomyopathy.
Sample—Myocardial samples obtained from 21 euthanized dogs (6 clinically normal [control] dogs, 5 clinically normal dogs subjected to inhalation anesthesia with isoflurane prior to euthanasia, 5 dogs with juvenile-onset dilated cardiomyopathy, and 5 dogs with adult-onset dilated cardiomyopathy).
Procedures—Activity of mitochondrial complex I and complex IV was assayed spectrophotometrically in isolated mitochondria from left ventricular tissue obtained from the 4 groups of dogs.
Results—Activity of complex I and complex IV was significantly decreased in anesthetized dogs, compared with activities in the control dogs and dogs with juvenile-onset or adult-onset dilated cardiomyopathy.
Conclusions and Clinical Relevance—Inhalation anesthesia disrupted the electron transport chain in the dogs, which potentially led to an outburst of reactive oxygen species that caused mitochondrial dysfunction. Inhalation anesthesia depressed mitochondrial function in dogs, similar to results reported in other species. This effect is important to consider when anesthetizing animals with myocardial disease and suggested that antioxidant treatments may be beneficial in some animals. Additionally, this effect should be considered when designing studies in which mitochondrial enzyme activity will be measured. Additional studies that include a larger number of animals are warranted.
Objective—To generate reference ranges for echocardiographic variables in clinically normal adult chimpanzees (Pan troglodytes).
Design—Retrospective cohort study.
Animals—88 clinically normal adult chimpanzees.
Procedures—Echocardiographic data obtained between 2002 and 2011 from chimpanzees at the Alamogordo Primate Facility were reviewed (263 echocardiograms obtained from 158 individuals). Data from clinically normal individuals (33 females and 55 males) were analyzed. Basic cardiac parameters measured in all individuals included aortic root diameter and left atrial diameter in the short and long axis during diastole. Left ventricular measurements included left ventricular internal diameter in systole and diastole and diastolic septal and posterior wall thickness. The E point to septal separation was also measured. Spectral Doppler measurements included the peak flow velocity of the pulmonary artery and aorta and diastolic transmitral flow. The presence of arrhythmias was also noted.
Results—Standard echocardiographic findings for a large group of adult female and male chimpanzees were obtained. Female and male chimpanzees were grouped by age in 10-year blocks, and echocardiographic findings were analyzed statistically by 10-year block. In male chimpanzees, cardiac arrhythmias were noted to increase with age.
Conclusions and Clinical Relevance—Cardiovascular disease is an important cause of morbidity and death in captive chimpanzees; however, basic echocardiographic measurements from a large cohort of clinically normal animals have not previously been reported. The number of animals in the present study was insufficient to generate reference ranges; however, data from a large cohort of clinically normal animals are presented. This information will be useful for veterinarians working in clinical and research settings with this species.
Objective—To determine whether measurement of blood cardiac troponin I (cTnI) concentrations with a cage-side analyzer could be used to differentiate cardiac from noncardiac causes of dyspnea in cats.
Design—Prospective, multicenter study.
Animals—44 client-owned cats with dyspnea and 37 healthy staff-owned cats.
Procedures—Affected cats were examined because of dyspnea; treatment was administered in accordance with the attending clinician's discretion. Cats were judged to have a cardiac or noncardiac cause of dyspnea on the basis of results of physical examination, thoracic radiography, and echocardiography. Blood cTnI concentrations were determined with a cage-side analyzer on samples collected within 12 hours after admission of affected cats. Concentrations for healthy cats were obtained for comparison.
Results—5 enrolled cats were excluded from the study because of concurrent cardiac and respiratory disease. Of the remaining 39 cats with dyspnea, 25 had a cardiac cause and 14 had a noncardiac cause. The 25 cats with a cardiac cause of dyspnea had a significantly higher blood cTnI concentration than did the 37 healthy cats or the 14 cats with a noncardiac cause of dyspnea.
Conclusions and Clinical Relevance—Measurement of cTnI concentrations with a cage-side assay in emergency settings may be useful for differentiating cardiac from noncardiac causes of dyspnea in cats.
Objective—To determine whether echocardiographic variables differed between successful (elite) and less successful (nonelite) Arabian endurance horses.
Animals—34 Arabian horses that competed in endurance racing.
Procedures—Horses were assigned to either an elite or nonelite group on the basis of results of a previous competition, and a standardized echocardiographic examination was performed on each horse within 1 to 4 weeks after that competition. Multivariable logistic regression with backward stepwise elimination was used to create a prediction model for the determination of horse status (elite or nonelite) as a function of the measured echocardiographic variables.
Results—The elite and nonelite groups consisted of 23 and 11 horses, respectively. One horse in the nonelite group had a frequent ventricular dysrhythmia that could have negatively affected its performance and rider's safety, whereas none of the horses in the elite group had remarkable cardiac abnormalities. The left ventricular internal diameter during systole and diastole and left ventricular mass and stroke volume were significantly greater for horses in the elite group, compared with those for horses in the nonelite group. The final logistic regression model correctly predicted the horse status for all of the horses in the elite group and 8 of 11 horses in the nonelite group.
Conclusions and Clinical Relevance—Results indicated that heart size was significantly associated with performance for Arabian endurance horses in a manner similar to findings for Thoroughbred and Standardbred racehorses in active competition.
Objective—To identify risk factors potentially associated with the development of bacterial endocarditis in dogs and determine whether periodontal disease and surgical procedures (oral and nonoral) were associated with bacterial endocarditis.
Design—Retrospective case-control study.
Animals—76 dogs with (cases) and 80 dogs without (controls) bacterial endocarditis.
Procedures—Medical records were reviewed for information on signalment, physical examination findings, recent medical history, and results of echocardiography, clinicopatho- logic testing, and necropsy.
Results—None of the dogs with endocarditis had a history of undergoing any dental or oral procedure in the 3 months prior to the diagnosis of endocarditis, and no significant difference was found between groups with regard to the prevalence of oral infection. Dogs with endocarditis were significantly more likely to have undergone a nonoral surgical procedure that required general anesthesia in the preceding 3 months or to have developed a new heart murmur or a change in intensity of an existing heart murmur. Preexisting cardiac dis-ease (congenital or acquired) was not found to be a risk factor.
Conclusions and Clinical Relevance—Results did not provide any evidence of an association between bacterial endocarditis in dogs and either dental or oral surgical procedures or oral infection. Findings suggested that the routine use of prophylactic antimicrobial administration in dogs undergoing oral procedures needs to be reevaluated.
Objective—To determine whether plasma cardiac troponin I (cTnI) concentrations can be used to discriminate cardiac from noncardiac causes of dyspnea in cats.
Design—Prospective, multicenter study.
Animals—Client-owned cats with dyspnea attributable to congestive heart failure (D-CHF; n = 31) or to noncardiac causes (D-NCC; n = 12).
Procedures—For each cat, plasma cTnI concentration was analyzed by use of a solid-phase radial partition immunoassay; values in cats with D-CHF and D-NCC were compared. A receiver operating characteristic curve was analyzed to determine the accuracy of plasma cTnI concentration for diagnosis of D-CHF.
Results—Median plasma concentration of cTnI in cats with D-CHF (1.59 ng/mL; range, 0.20 to 30.24 ng/mL) was significantly higher than in cats with D-NCC (0.165 ng/mL; range, 0.01 to 1.42 ng/mL). With regard to the accuracy of plasma cTnI concentration for diagnosis of D-CHF, the area under the receiver operating characteristic curve was 0.84. At plasma concentrations ≥ 0.2 ng/mL, cTnI had 100% sensitivity but only 58% specificity for identification of CHF as the cause of dyspnea. At plasma concentrations ≥ 1.43 ng/mL, cTnI had 100% specificity and 58% sensitivity for identification of CHF as the cause of dyspnea.
Conclusions and Clinical Relevance—On the basis of the derived diagnostic limits, CHF as the cause of dyspnea could be ruled in or ruled out without additional diagnostic testing in > 50% of the study cats. Measurement of plasma cTnI concentration may be clinically useful for differentiation of cardiac from noncardiac causes of dyspnea in cats.