M.H.M.A. Larsson

Características eletrocardiográficas em eqüinos clinicamente normais da raça Puro Sangue Inglês

The determination of the electrocardiographic parameters of amplitude, duration, rhythm and electrical axis in the frontal plane from clinically healthy Thoroughbred foals, yearlings and pregnant mares was performed. Fifty foals and 50 yearlings, males and females, and 11 pregnant mares were used. It was concluded that the heart rate decreases with age and that foals and yearlings had intermediate values between reference values of neonates and adults. In yearlings, these values were more similar to the reference values of adults. In pregnant mares, the only difference observed when compared to reference values was the slight right displacement of the electrical axis.

Chronic valvular disease: correlation between clinical, electrocardiographic, radiographic and echocardiographic aspects in dogs

ABSTRACT Echocardiographic aspects of chronic mitral valvular disease were studied and compared to physical, radiographic and electrocardiographic aspects. Seventy dogs were used, and clinical examination, thoracic radiography, electrocardiogram and echocardiogram were performed. Correlations between regurgitation severity with cardiac failure functional class and murmur intensity were observed. The electrocardiogram showed a low sensibility in detecting cardiac chamber enlargement, caused by mitral regurgitation. All the dogs with severe mitral regurgitation showed cardiomegaly according to thoracic radiographies. Keywords: dog, heart, cardiac failure, echocardiography, cardiac valve RESUMO Avaliaram-se os aspectos ecocardiograficos da doenca valvar cronica, comparando-os com os aspectos clinicos, radiograficos e eletrocardiograficos em caes. Estudaram-se 70 animais, realizando-se exames fisicos, radiografias toracicas, eletrocardiograma e ecocardiograma. Observaram-se correlacoes entre a gravidade da regurgitacao, a classe funcional da insuficiencia cardiaca e a intensidade de sopro. O eletrocardiograma mostrou baixa sensibilidade para detectar aumento de câmaras cardiacas causadas por regurgitacao mitral. Todos os caes com regurgitacao mitral grave apresentaram cardiomegalia nas radiografias toracicas Palavras-chave: cao, coracao, insuficiencia cardiaca, ecocardiografia, valva cardiaca

Valores da pressão arterial em cães pelos métodos oscilométrico e Doppler vascular

Two noninvasive methods for blood pressure measurement, the oscilometric and the Doppler ultrasonic, were compaired aiming the establishment of parameters that can be helpful for the hypertension diagnosis. Forty-five dogs, males and females, were distributed in three groups, according to body weight: small, medium, and large sizes. In each animal, measurement of the blood pressure was performed, first by the Doppler ultrasonic, followed by the oscilometric method. No differences were observed in sistolic arterial pressure values obtained by both methods in none of the three animal groups. However, there was an important difference in diastolic arterial pressure values obtained by these methods, especially in small and medium size dogs. It was concluded that reliable results of sistolic blood pressure can be obtained both by the Doppler ultrasonic and the oscilometric method. Diastolic blood pressure results, however, showed no correlation between these two methods, mainly in small and medium size dogs.

Padronização da monitorização eletrocardiográfica por 24 horas em cães

The normal pattern for dynamic eletrocardiographic monitoring of Doberman, Boxer and Cocker Spaniel dogs, enhancing earlier diagnostic of dilated cardiomyopathy (DCM) was studied. For this, the technique of 24-hour electrocardiographic monitoring was standardized in 10 animals of each referred breeds. QRS complexes were more frequent in Cocker Spaniel than in Doberman and Boxer dogs. Ventricular premature beats were more common in Boxer dogs than in the other two breeds; however, all of then presented less than 1% of supraventricular ectopic beats in relation to the total of beatings. Cocker Spaniel dogs manifested the highest minimum, average and maximum heart rates and remained with heart rates equal or greater than 120bpm longer than Doberman and Boxer dogs otherwise, Cocker Spaniel dogs remained more time than dogs of the other two breeds with heart rate equal or lower than 50bpm. Cocker Spaniel dogs demonstrated, besides less frequently, shorter pauses than Doberman and Boxer dogs did. It was concluded that: a) clinically normal dogs of the studied breeds showed an evident variation of the heart rate; b) the isolate ectopic supraventricular and ventricular contraction were less than 50 during a 24-hour period of monitorization; c) in Boxer dogs, the number of isolated ectopic ventricular beats was less than 50 during a period of 24 hours; d) the periods of assistolia or pauses bigger than two seconds were frequent in Boxer and Doberman dogs and absent in Cocker Spaniel dogs; e) these pauses were commonly greater than three seconds; f) alterations of ST segment were not observed in clinically normal dogs of the three breeds studied.

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).

Avaliação ecocardiográfica do átrio esquerdo de cães sadios por meio do modo-M convencional e do modo bidimensional

The left atrium (LA) was evaluated through the bidimensional method (2-D) (short axis) and the relation left atrium:aorta (LA:Ao) in a group of 40 healthy adult dogs between 1.5 and 7 years of age and weights ranging from 3.2 to 38.3kg, and these values were compared to those in the conventional M-mode. Comparing the variable LA and Ao with the two methods and their respective indexes, significant statistical difference was observed (P<0,001), high positive correlation between the weight and LA-2D and LAM, between body surface and LA-2D and LAM. A difference between LA and Ao in both methods and these respective indicators were observed. The association was higly positive between weight and body surface area (BSA) and between M- mode LA (LAM) and 2-D mode LA (LA-2D). No correlation was observed between these indicators and weight and BSA, in both methods, so these indicators are weight and BSA-independent. Conclusions: LA-2D is bigger than LAM, the LA-2D:Ao-2D average index is 1,379 and the confidence interval is 1,337 to 1,422. The index in the 2-D method is, therefore, superior to the index in the M-mode.

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.

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.

Valor prognóstico da variabilidade da frequência cardíaca e da eletrocardiografia ambulatorial em cães Boxer com cardiomiopatia arritmogênica do ventrículo direito

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an important cause of sudden death in Boxer dogs. Validation of prognostic factors for this disease could help in detecting more severely affected animals and their exclusion from breeding programs. The aims of this study were to evaluate the prognostic significance of presence of symptoms, heart rate variability (HRV) indices and ventricular or supraventricular arrhythmias recorded by Holter monitoring on survival of Boxer dogs with ARVC at different stages. Symptoms, arrhythmias registered on Holter and five HRV indices were prospectively analyzed in 69 client-owned Boxer dogs divided into five groups: control Boxer dogs (CB group, 300 VPC/24 hours, n=19), Boxers with ARVC and systolic dysfunction without congestive heart failure (SDB without CHF group, n=6) and with CHF (SDB with CHF group, n=8). Statistical analyses consisted of an ANOVA test, Pearson correlation and Coxs proportional hazards regression. Compared to the CB group, no decrease in HRV indices was found in SB, ARVCB or SDB without CHF groups; otherwise, SDB with CHF group had impaired indices. No relation was found between HRV indices and cardiac-related death, but the presence of syncopes with or without clinical signs of heart failure and number of ventricular tachycardia (VT), were correlated with survival. These results allow us to conclude that the presence of symptoms of heart failure, presence of syncopes and number of VT on Holter examination seem to have prognostic value in Boxer ARVC.