Guilherme G. Pereira

Electrocardiographic Parameters of Captive Lions (Panthera leo) and Tigers (Panthera tigris) Immobilized with Ketamine Plus Xylazine

Abstract Twenty-seven healthy captive lions (Panthera leo) and 13 healthy captive tigers (Panthera tigris) from São Paulo Zoo (Fundação Parque Zoológico de São Paulo, São Paulo, Brazil) collection were selected for this study. They were anesthetized with ketamine (10 mg/kg) combined with xylazine (1–2 mg/kg) for physical examinations, hematologic and serum chemical analysis and electrocardiogram recording. The main aim of this research was to gather initial information about normal electrocardiographic parameters of large felids. Standard P-QRS-T deflections on leads described for domestic carnivores were analyzed, and they did not greatly differ from those of large felids, taking into account the greater weight and corporal mass of large felids. Heart rate of lions ranged from 42 to 76 beats per minute (bpm). Heart rate of tigers ranged from 56 to 97 bpm. In both species, the most common rhythm detected was normal sinus rhythm followed by sinus arrhythmia; wandering pacemaker was also observed with normal sinus rhythm or sinus arrhythmia. Mean electrical axis lay between +60° and +120°. QRS complexes were predominantly positive in leads DI, DII, DIII, and AVF, and negative in AVR and AVL. This study provides insights into normal electrocardiograms of large felids. Wider investigations on the same subject are necessary to establish criteria for the recognition of abnormalities in these species and should include other anesthetic drug(s) combinations and reports of electrocardiographic features of animals with cardiac disease and electrolytes disturbances.

Avaliação de alguns parâmetros ecocardiográficos do gato-do-mato (Leopardus tigrinus), mantido em cativeiro e submetido à anestesia com xilazina e quetamina

Some echocardiographic parameters in B, M-mode and Doppler of 27 Oncillas, Leopardus tigrinus, a wild little feline, kept in captivity and submitted to anesthesia with 1 to 2mg/kg of xilazine and 10mg/kg of ketamine, had been evaluated. Changes of the cardiovascular parameters were observed when the results were compared to non anesthetized domestic cat (Felis catus).

Parâmetros ecocardiográficos em modo unidimensional de cães da raca Poodle miniatura, clinicamente sadios

In Brazil, the canine population of the Poodle, mainly the Miniature variation, grows in geometric progression, beeing this breed frequently affected by congenital and adquired cardiopathies. The main objective of this study was the standardization and evaluation of the echocardiographic parameters in unidimensional (M) mode, from clinically normal Miniature Poodle dogs. Thirthy Miniature Poodle dogs, 09 males and 21 females ageing between 2 and 7 years old (3.87±1.55), and weight varying from 2.0 to 8.7 kilogram (4.49±1.38) were studied. To be included in this study, physical exam, hemogram, biochemical profile, urinalysis, detection of circulating microfilaries as well as ELISA test for Dirofilaria immitis, electrocardiographic, radiographic exams and meansurement of the blood pressure were performed. After the analysis of obtained echocardiographic results, reference values for the echocardiographic data, in healthy Miniature Poodle dogs, were determined. The statistical analysis also showed that factors, as weight and height, may have some influence on the echocardiographic parameters.

Avaliação dos fluxos das valvas aórtica e pulmonar com ecocardiografia Doppler pulsátil em cães clinicamente sadios

This study evaluated aortic (AO) and pulmonary (Pul) valves flow with pulsed-wave Doppler by qualitative (presence of valvar insufficiency and characteristic of flow profile) and quantitative analysis, and the following echocardiographic parameters were obtained: peak (PV) and mean (MV) velocities, velocity-time integral (VTI), acceleration (AT) and ejection (ET) time. Thirty dogs were studied, and to be considered normal, physical, laboratory, electrocardiographic, echocardiographic (uni and bidimensional mode) exams, thoracic radiography, and measurement of the blood pressure were accomplished, and the following echocardiographic parameters were obtained: AO PV= 1.22± 19.38m/s; AO MV= 0.72± 0.08m/s; AO VTI= 0.14± 0.02m; AO AT= 38.80± 11.29ms; AO ET= 197.90± 24.77ms; Pul PV= 0.95± 0.18m/s; Pul MV= 0.63± 0.10m/s; Pul VTI= 0.13± 0.02m; Pul AT= 70.97± 18.87ms; Pul ET= 203.70± 28.98ms. Heart rate presented negative correlation with AO VTI, AO ET, Pul VTI, Pul AT, Pul ET, and the variable weight had positive correlation with AO VTI, AO AT, AO ET, Pul VTI, Pul ET, differently from the gender, that had no influence on the evaluated parameters. The comparison of aortic and pulmonary valves flow demonstrated AO PV and AO MV higher than Pul PV and Pul MV, respectively, AO VTI higher than Pul VTI, and Pul AT higher than AO AT.

Padronização de parâmetros ecocardiográficos de cães da raça Golden Retriever clinicamente sadios

The Duchennes muscular dystrophy (DMD) in humans is a recessive X-linked neuromuscular disease, caused either by the absence or dysfunction of the dystrophin. Clinically it is characterized by severe alteration in the skeletal musculature, resulting in precocious death of the affected patient. In Golden Retriever dogs, the mutation that determines the muscular dystrophy occurs spontaneously and the extensive homology among the pathogenesis of DMD and of Golden Retriever muscular dystrophy allows to qualify the dog as the main substitute of humans in the clinical tests of new therapies. The deficient myocardium in dystrophin is more vulnerable to the pressure overload, and the patients with DMD can develop dilated cardiomyopathy as well as arterial hypertension; in echocardiography, diastolic function abnormalities are verified and systolic inadequacy can be observed in some old patients. In the present study, 41 healthy Golden Retriever dogs were evaluated by echocardiographic exam with the purpose to obtain parameters for the standardization of these cardiovascular characteristics in the refered breed, what hereafter can be used as reference in the identification of bearer or affected dogs by muscular dystrophy.

Serum determination of troponin I in dogs with ST deviation by chemiluminescent

In order to investigate myocardial cells injury, 38 dogs were evaluated, being 20 with a normal electrocardiogram (group 1) and 18 with ST segment elevation or depression (group 2), recorded in lead II, at paper speed of 50 mm/sec and N sensibility (1 mV = 1cm). Serum measurement of troponin I (cTnI) in group 1 was determined to obtain reference values (ng/mL). These values were compared to those obtained in dogs from group 2, to confirm or not myocardial injury. Mean cTnI values in groups 1 and 2 were 0.16ng/mL (SD±0.11ng/mL) and 0.20ng/mL (SD±0.11ng/mL), respectively. Three cTnI null values were found in group 1. cTnI was not related to age, mass, CK-T or serum potassium concentration in both animal groups, for each level varied in the group. There was no difference in cTnI values between groups 1 and 2. In conclusion, it is possible to use the human chemiluminescent immunometric assay kit in canine species and hypoxia/ischemia revealed by ST segment deviation does not mean significant myocardium injury.

Evaluation of left ventricular diastolic echocardiographic parameters in healthy dogs by pulsed-wave Doppler.

Left ventricular diastolic dysfunction plays an important role on heart failure progression. In order to obtain additional reference values of left ventricular diastolic parameters and investigate influence of common variables, peak E wave (peak E), peak A wave (peak A), E/A ratio (E/A), E wave deceleration time (EDT) and isovolumic relaxation time (IRVT) were studied in 40 clinically healthy dogs, by pulsed wave Doppler. The following values were obtained: peak E = 0.747 ± 0.117 m/s, peak A = 0.487 ± 0.062 m/s, E/A = 1.533 ± 0.198, EDT = 88.7 ± 9.2 ms and IRVT = 0.080 ± 0.009 s. Some parameters were influenced by heart rate (peak E, peak A and IRVT), by age (peak A and E/A) and by body weight (TRIV). Gender influence was absent. Values obtained can be used as reference for canine specimens but its interpretation should consider on the influence of related variables.

Monitorização eletrocardiográfica ambulatorial por 24-horas em cães com cardiomiopatia dilatada idiopática

This study aimed to characterize 24-hour ambulatory electrocardiographic monitoring (Holter monitoring) in dogs with idiopathic dilated cardiomyopathy. Physical examination and indirect (Doppler) blood pressure measurement, and also electrocardiography, thoracic radiography, echocardiography, and 24-hour ambulatory electrocardiographic exams were performed in 40 dogs with idiopathic dilated cardiomyopathy. Ventricular extrasystoles were detected in 97.5% of the animals, and ventricular tachycardia in 45%. No correlation between the number of ventricular extrasystoles and the shortening fraction was observed. Concerning the clinical symptoms, there was only association between the presence of ventricular tachycardia and past report of syncope. It was concluded that the incidence of ventricular arrhythmias is high in dogs with dilated cardiomyopathy, being ventricular tachycardia, mostly non-sustained, relatively frequent.

Survival and echocardiographic evaluation of dogs with idiopathic dilated cardiomyopathy treated with carvedilol

Sixty dogs with idiopathic dilated cardiomyopathy were randomly treated with traditional therapy - digitalis, diuretics, angiotensin-converting inhibitors - (group A) or treated with these drugs plus carvedilol (group B). Echocardiographic variables were measured before and after 3, 13, 26, and 52 weeks of treatment or until death. Comparisons between groups and time were performed. No significant differences between groups were found in the most of the echocardiographic variables. The left ventricular end-systolic diameter indexed to body surface area (LVESDi) increased significantly in the group A dogs compared to the group B animals. The survival of groups A and B dogs were not different (P-value=0.1137). In conclusion, the stability of the LVESDi observed in the group treated with carvedilol may represent the beneficial effect over the ventricular remodeling.

Myocardial velocities obtained by pulsed tissue Doppler in English Cocker Spaniels with dilated cardiomyopathy and congestive heart failure

ABSTRACT.- Pereira G.G., Goldfeder G.T., Yamaki F.L., Oliveira V.M.C. & Larsson M.H.M.A. 2016. Myocardial velocities obtained by pulsed tissue Doppler in English Cocker Spaniels with dilated cardiomyopathy and congestive heart failure. Pesquisa Veteri-naria Brasileira 36(9):851-856 . Departamento de Clinica Medica, Faculdade de Medicina Veterinaria e Zootecnia, Universidade de Sao Paulo, Av. Prof. Orlando Marques de Paiva 87, Sao Paulo, SP 05508-900, Brazil. E-mail: ggpereira2002@yahoo.com.brDilated cardiomyopathy (DCM) is characterized by systolic myocardial dysfunction which is identified by low myocardial velocities obtained by pulsed tissue Doppler (PTD). However, increased preload is known to increase myocardial velocities which could ove-restimate myocardial function and turn dysfunction characterization into a challenge in dogs with DCM and congestive heart failure. To test the hypothesis that increased preload could hamper identification of low myocardial velocities in dogs with DCM and congestive heart failure the present study prospectively evaluated 32 English Cocker Spaniel dogs, being 16 with clinical DCM and 16 healthy for control purpose. The PTD analysis of regional velocities were performed in both longitudinal and radial myocardial displacements and systolic (Sm), early (Em) and late diastolic (Am) velocities were obtained in left ventricu-lar free wall (LVFW) and interventricular septum (IVS). Peak radial subendocardial and subepicardial Sm velocities were lower in DCM group compared to control (0.065±0.018 vs. 0.102±0.020m/s and 0.059±0.014 vs. 0.094±0.025m/s respectively; p<0.001). Peak longitudinal Sm velocities were lower in basal and medial portions of LVFW (0.093±0.034 vs. 0.155±0.034m/s and 0.091±0.033 vs. 0.134±0.037m/s respectively; p<0.001) and IVS (0.063±0.021 vs. 0.136±0.039 and 0.066±0.026 vs. 0.104±0.032m/s respectively; p<0.001). Most of diastolic velocities were not significantly different between groups, although ad-vanced myocardial disease and dysfunction are expected in DCM group. Reduction in sys-tolic basal and medial longitudinal myocardial velocities and in radial myocardial velocities was the most significant PTD findings. Increased preload did not represent a problem to evaluate systolic dysfunction by PTD in English Cocker Spaniels with DCM, but influence of preload on assessment of diastolic velocities should be better elucidated.