Assessment of left and right ventricular systolic function in dogs with multicentric lymphoma.

OBJECTIVE: Myocardial dysfunction in cardio-oncology is generally thought to be related to the cardiotoxicity of chemotherapy treatment. However, it is known that some tumors have direct effects on myocardial function. These effects have already been studied in man, but there are no publications of these of the effects in dogs. Novel advanced echocardiographic techniques may allow early detection of myocardial dysfunction when compared to conventional echocardiographic techniques. This study aims to assess myocardial systolic function in dogs with multicentric lymphoma prior to initiation of chemotherapy. ANIMALS: Fifteen dogs with multicentric lymphoma and nineteen healthy dogs. METHODS: Case-control study. Dogs with multicentric lymphoma and healthy control dogs underwent physical examination, electrocardiography, systolic blood pressure measurement, standard and speckle tracking echocardiography to assess biventricular systolic function. RESULTS: There were no differences between groups in terms of ejection fraction, fractional shortening, left ventricular systolic and diastolic diameter, tricuspid annular plane systolic excursion, mitral annular plane systolic excursion and fractional area change of the right ventricle (RV). However, there was a reduction in the values of global circumferential strain (p = 0.0003), RV strain (p = 0.01) and RV tissue motion annular displacement (p < 0.05) in the dogs with lymphoma when compared to the control group. CONCLUSIONS: Speckle tracking techniques appear to demonstrate early systolic dysfunction, primarily affecting the RV, in dogs with lymphoma prior to chemotherapy treatment.

64-Slice ECG-gated computed tomographic angiography for assessment of coronary arteries in brachycephalic dogs with pulmonary stenosis.

BACKGROUND: Brachycephalic dogs with pulmonary stenosis are known to have a higher incidence of concurrent coronary artery abnormalities than non-brachycephalic breeds, which increases risk when performing balloon valvuloplasty. The use of ECG-gated CT angiography has been reported for the evaluation of coronary arteries in normal dogs and dogs with pulmonary stenosis. The purpose of this study was to report findings of coronary artery origination and morphology of main branches using ECG-gated CT angiography in brachycephalic dogs with pulmonary stenosis. METHODS: An ECG-gated CT angiographic protocol was used to image coronary artery anatomy in nine brachycephalic dogs with pulmonary stenosis. Images were assessed for quality as well as coronary artery morphology by one veterinary radiologist, one veterinary cardiologist and one veterinary radiology resident. RESULTS: All nine dogs had good to excellent image quality. Coronary artery anomalies were identified in three of nine dogs: one R2A anomaly, one L2A anomaly and one L2C anomaly. Two dogs were assessed to be poor balloon valvuloplasty candidates based on CT angiographic images. LIMITATION: Coronary artery morphology was not confirmed via postmortem examination in all patients. CONCLUSION: ECG-gated CT angiography is a minimally invasive imaging modality capable of diagnosing various coronary artery anomalies in brachycephalic dogs with pulmonary stenosis and aiding in the determination of patient candidacy for balloon valvuloplasty.

The AliveCor KardiaMobile ECG device allows electrocardiogram assessment in awake bonobos (Pan paniscus).

OBJECTIVE: To determine the diagnostic utility of a smartphone-based ECG device (Alivecor KardiaMobile) in awake bonobos (Pan paniscus). ANIMALS: 7 adult bonobos in human care. PROCEDURES: Bonobos were trained with positive reinforcement to hold 1 finger from each hand onto the KardiaMobile sensors for 30 seconds to obtain an ECG reading. Ten ECG tracings were recorded from each bonobo and evaluated by a veterinarian, a veterinary cardiologist, and a human cardiologist for tracing quality, tracing length, heart rate, identification of P-waves, and presence and quantification of premature ventricular or atrial contractions. RESULTS: 6 of the 7 bonobos were trained within 21 weeks to allow the collection of 10 diagnostic quality ECG tracings. The average heart rate recorded was 87 bpm (range = 60 to 118 bpm). Potential abnormalities identified by the KardiaMobile included premature ventricular contractions in 2 male bonobos and 1 premature atrial contraction in another male. There was strong agreement by reviewers in all ECG parameters except for the identification of P-waves. CLINICAL RELEVANCE: The Alivecor KardiaMobile device has diagnostic utility as a screening tool for use in bonobos in human care. The training was accomplished to yield diagnostic ECG readings of acceptable duration in awake bonobos. Given the prevalence of cardiovascular disease in great apes, this technology may identify a subset of great apes who may benefit from early intervention and treatment in an effort to delay the progression of cardiac disease.

The next heartbeat: Creating dynamic and histographic Poincaré plots for the assessment of cardiac rhythms.

The rhythm of the heart is not a stationary phenomenon, and therefore, incorporation of the dynamic Poincaré plot and tachogram provides additional diagnostic information to complement and expand waveform (P-QRST) analyses from the electrocardiogram. Although pattern assessment of the Poincaré plot and tachogram can provide an appraisal for normal and abnormal rhythms and serve as a potential means for machine-learned rhythm diagnoses, time-selected windows of beat-to-beat variability permit more detailed examination. As such, expanded criteria for rhythm diagnoses, identification of arrhythmic triggers, global appreciation of rhythm changes, and recognition of patterns that provoke mechanistic questions may be gleaned from the use of the methods reviewed in this report. More specifically, these methods demonstrate that limitations exist in the reliance on traditional measures of heart rate variability in the dog due to the non-linear beat-to-beat rhythm of sinus arrhythmia in the species. Behavior of arrhythmias based on coupling intervals, repeating patterns, preceding triggers of beat-to-beat variability, and circumstantial evidence of atrioventricular nodal conduction during atrial flutter and fibrillation are a few examples of discovery founded in these techniques. The open access website, The Next Heartbeat (https://thenextheartbeat.com/), permits anyone to implement these methods in the assessment of long-term electrocardiographic examinations (Holter monitoring) so that, as yet to be revealed, features of the beating heart through time may be discovered.

Monitoring great ape heart health through innovative electrocardiogram technology: Training methodologies and welfare implications.

Assessing and treating cardiovascular disease (or heart disease) is a growing concern for institutions housing great apes, as it is a major cause of mortality in all four taxa managed in human care. As part of a proactive monitoring plan, zoological managers and veterinarians often elect to perform electrocardiograms (ECGs) on their great ape populations. ECGs noninvasively evaluate cardiac electrical activity, and are thereby capable of providing information regarding heart function. This electrical signature is transcribed as a visual display of waveforms, referred to as telemetry strips, and can detect irregularities in heart rhythm, also known as arrhythmia. While traditional 6- or 12-lead ECGs are recommended periodically as part of a thorough heart performance evaluation, here we discuss the KardiaMobile (KM) device as an additional primate welfare tool. KM is a small, Food and Drug Administration-cleared, clinical-grade mobile ECG monitor that requires only 30 s of pressure to flag heart rate or arrhythmic abnormalities. We detail the training process and applicability to great apes in human care.

Conventional and Holter Electrocardiographic Assessment of Dogs Infected Naturally With Acute Canine Monocytic Ehrlichiosis.

Canine Monocytic Ehrlichiosis (CME) is a disease of worldwide distribution caused by the bacteria Ehrlichia canis, appearing primarily in hot climates due to the massive prevalence of its vector, the tick Rhipicephalus sanguineus. Previous studies have shown that dogs afflicted by CME in the chronic phase can develop infectious myocarditis, arrhythmias, and alterations in heart rate variability (HRV), but there are few studies correlating cardiac diseases with the acute phase of CME. This study aims at assessing electric cardiac alterations and HRV in the time and frequency domains during the acute phase of CME. This study assessed 22 animals divided into 2 distinct groups: the control group, comprised by 10 healthy dogs, and the sick group, comprised of 12 dogs infected naturally with ehrlichiosis which presented clinical and hematological signs compatible with the acute phase of the disease. The animals underwent conventional and Holter electrocardiographic evaluations, systolic blood pressure measurement, complete blood count and biochemical assays (urea, creatinine, alanine aminotransferase (ALT), alkaline phosphatase (AP), and gamma glutamyl transferase (GGT)). The sick group presented higher activity in the sympathetic nervous system than in the parasympathetic nervous system, manifest as a significant increase in mean heart rate and a reduction in the HRV indexes for the time and frequency domains. The frequency-domain HRV indexes presented sympathetic prevalence during the sleep and vigilance states. Sinus tachycardia was the predominant heart rhythm in 58.33% of the animals. The mean systolic blood pressure diverged between the groups and no significant arrhythmias were observed during monitoring. The serum concentrations of urea, creatinine, AP, ALT, and GGT were within the established reference values for the species. We observed no indication that there was enough time during the acute phase for the disease to evolve in a way that resulted in arrhythmias, as is common in the chronic phase, but we observed that animals in the acute phase already present reduced HRV indexes.

Development and assessment of a novel precordial lead system for accurate detection of right atrial and ventricular depolarization in dogs with various thoracic conformations.

OBJECTIVE: To assess recording accuracy of right atrial and ventricular depolarization during 12-lead ECG when precordial lead V1 was positioned at each of 5 locations on the thorax of dogs with various thoracic conformations. ANIMALS: 60 healthy client-owned dogs. PROCEDURES: 20 dogs were allocated to each of 3 groups (brachymorphic, mesomorphic, or dolichomorphic) on the basis of thoracic conformation. Each dog remained unsedated and was positioned in right lateral recumbency for a series of five 12-lead surface ECGs, with V1 located adjacent to the sternum in the fifth intercostal space (ICS; control), at the costochondral junction (CCJ) of the right first ICS (1st-R), at the CCJ of the right third ICS, at the right third ICS where the thorax was the widest, and at the CCJ of the left first ICS. Electrocardiographic variables were compared among the 5 ECG tracings. RESULTS: When V1 was at the control location, the P wave was positive for all dogs; however, consistent recording of right atrial and ventricular depolarization (ie, R wave-to-S wave ratio [R/S] < 1) occurred more frequently for brachymorphic dogs (16/20) than for dolichomorphic (7/20) and mesomorphic (6/20) dogs. When V1 was at the 1st-R location, the P wave was negative for most dogs, and R/S was < 1 for the majority of dogs in the brachymorphic (19/20), mesomorphic (17/20), and dolichomorphic (16/20) groups. The median R/S for V1 at the 1st-R location was significantly lower than that for the other 4 V1 locations. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that placement of V1 at the 1st-R location provided correct evaluation of right atrial and ventricular depolarization in most dogs regardless of thoracic conformation.

Assessment of systolic and diastolic function in clinically healthy horses using ambulatory acoustic cardiography.

BACKGROUND: Assessment of cardiac electromechanical function in horses requires training, experience and specialised equipment and does not allow continuous monitoring over time. OBJECTIVES: The objective of this study was to establish the use of an acoustic ECG monitor (Audicor® ) in healthy horses. It provides noninvasive, examiner-independent, continuous analyses combining ECG and phonocardiography to calculate indices of cardiac mechanical activity and haemodynamics. Device usability was investigated, reference intervals calculated and reproducibility of analyses assessed. STUDY DESIGN: Prospective descriptive study. METHODS: Continuous overnight recordings were obtained in 123 healthy horses. ECG and acoustic cardiography analyses were performed. Electromechanical activating time (EMAT), rate-corrected EMATc, left ventricular systolic time (LVST), rate-corrected LVSTc and intensity and persistence of the third and fourth heart sound (S3, S4) were reported. Associations with age and reproducibility of analyses were assessed. RESULTS: Audicor® recordings of diagnostic quality were obtained in 116 horses, with an artefact-free recording time of 1:08-14:03 h (mean 10:21 h). 44.8% of the horses had atrial premature complexes (up to 0.18% of analysed beats), 4.3% had ventricular premature complexes (up to 0.021% of analysed beats). Reference intervals for acoustic cardiography variables were reported. S3 was significantly more often graded ≥5 (scale 0-10) in younger compared to older horses (P = 0.0036, R2  = 0.072). The between-day coefficient of variation ranged from 2.5 to 7.7% for EMAT, EMATc, LVST and LVSTc. MAIN LIMITATIONS: Audicor® algorithms are based on human databases. Horses were deemed clinically healthy without advanced diagnostics. Some data were lost because of technical difficulties, artefacts and noises. CONCLUSIONS: Overnight Audicor® recordings are feasible in horses. Combining ambulatory ECG and phonocardiography allows noninvasive, continuous assessment of variables representing systolic and diastolic cardiac function. ECG rhythm analyses require over-reading by a specialist, but acoustic cardiography variables are based on automated algorithms independent of examiner input. Further studies are required to establish the clinical value of acoustic cardiography in horses.

Diagnostic accuracy of electrocardiographic P wave related parameters in the assessment of left atrial size in dogs with degenerative mitral valve disease.

The purpose of this research was to compare the accuracy of newly described P wave-related parameters (P wave area, Macruz index and mean electrical axis) with classical P wave-related parameters (voltage and duration of P wave) for the assessment of left atrial (LA) size in dogs with degenerative mitral valve disease. One hundred forty-six dogs (37 healthy control dogs and 109 dogs with degenerative mitral valve disease) were prospectively studied. Two-dimensional echocardiography examinations and a 6-lead ECG were performed prospectively in all dogs. Echocardiography parameters, including determination of the ratios LA diameter/aortic root diameter and LA area/aortic root area, were compared to P wave-related parameters: P wave area, Macruz index, mean electrical axis voltage and duration of P wave. The results showed that P wave-related parameters (classical and newly described) had low sensitivity (range=52.3 to 77%; median=60%) and low to moderate specificity (range=47.2 to 82.5%; median 56.3%) for the prediction of left atrial enlargement. The areas under the curve of P wave-related parameters were moderate to low due to poor sensitivity. In conclusion, newly P wave-related parameters do not increase the diagnostic capacity of ECG as a predictor of left atrial enlargement in dogs with degenerative mitral valve disease.

Electrocardiogram assessment using the Einthoven and base-apex lead systems in healthy Holstein cows and neonates / Avaliação do eletrocardiograma utilizando os sistemas Einthoven e base-ápice em vacas e neonatos saudáveis da raça Holandesa

The objective aimed to describe the electrocardiographic behavior of parameters in Holstein pregnant cows and neonates during the perinatal period. The electrocardiograms were performed using a computerized electrocardiogram. The animals selected for the study were 23 cows and 18 neonates. Maternal electrocardiographic examinations were conducted in the 35, 28, 21, 14, 7 days and one-day pre -partum and the neonates were evaluated in six moments; at the time of birth, 7, 14, 21, 28 and 35 days after delivery. The evaluations were done in pre and post-delivery cows and into the group of neonates between female and male. For each electrocardiographic recording P-wave duration and amplitude, PR interval and the QRS complex duration, R, S-wave amplitude and polarity, QT and RR interval duration were examined. Changes in heart rate, ST segment and T wave polarity were recorded in leads of Einthoven and base-apex planes. The mean electrical axis of the QRS complex was calculated. In cows the results when comparing the two leads system, there are significant changes in the amplitude of the waves P, R, S, and T and the duration of the intervals PR, ST and QRS complex. The difference between primiparous and multiparous dairy cows was in the amplitude of the Twave. It was concluded that the base-apex system is a suitable lead for monitoring heart rhythm in Holstein cows and Einthoven in neonates. During the first month of life, no differences in P, Q, S and T waves, in PR, QRS, and ST intervals and in axis orientation was observed in neonates. There was a significant difference in duration of the QT interval. Among sexes, the difference was in the Q amplitude. This study incorporated the calves and Holstein cows in a single study in search of baseline information regarding the duration and morphology of the ECG parameters. In conclusion, it was proved that, with increasing age, there are changes in ECG components associated with variations in the distance between the recording electrode and the heart. The study contributes by providing Holstein reference values for clinical evaluations.(AU)

Tem como objetivo descrever o comportamento eletrocardiográfico de parâmetros em vacas da raça Holandesa grávidas e recém-nascidos durante o período perinatal. Os eletrocardiogramas foram realizados utilizando um eletrocardiógrafo computadorizado. Os animais selecionados para o estudo foram 23 vacas e 18 neonatos. Exames eletrocardiográficos maternos foram realizadas em 35, 28, 21, 14, 7 dias e um dia de pré-parto e nos neonatos foram avaliados em seis momentos; no momento do nascimento, 7, 14, 21, 28 e 35 dias após o parto. As avaliações foram realizadas em vacas pré e pós-parto e no grupo de neonatos entre fêmeas e machos. Para cada duração da gravação eletrocardiográfica analisou-se onda P e amplitude, intervalo PR e da duração do complexo QRS, R, S amplitude de onda e polaridade, QT e duração do intervalo RR. Mudanças na frequência cardíaca, segmento ST e polaridade da onda T foram registradas. A média do eixo eléctrico do complexo QRS foi calculada. Em vacas, há mudanças significativas na amplitude das ondas P, R, S, T, e a duração dos complexos QRS e intervalos PR e ST. A diferença entre as vacas leiteiras multíparas e primíparas estava na amplitude da onda T. Concluiu-se que o sistema base-ápice é adequado para monitorar o ritmo cardíaco em vacas da raça Holandesa e o Einthoven em neonatos. Nos neonatos durante o primeiro mês de vida, não houve diferenças nas ondas P, Q, S e T, em intervalos PR, QRS, e ST e na orientação do eixo. Houve diferença significativa na duração do intervalo QT. Entre os sexos, a diferença estava na amplitude Q. O presente estudo incorporou os bezerros e vacas da raça Holandesa em um único estudo, em busca de informações em relação a duração e morfologia dos parâmetros do ECG. Conclui-se portanto que, com o aumento da idade, ocorrem alterações nos componentes do ECG, associadas com as variações na distância entre o elétrodo de registo e o coração. O estudo contribui, fornecendo valores de referência de bovinos da raça Holandesa para avaliações clínicas.(AU)

Surgical implantation and functional assessment of an invasive telemetric system to measure autonomic responses in domestic pigs.

The first aim of this study was to establish a surgical procedure to implant a new telemetric device for the continuous recording of electrocardiogram (ECG) and blood pressure (BP) in freely moving pigs. A second aim was the functional assessment of cardiovascular parameters, including heart rate variability (HRV) and blood pressure variability (BPV), so that these data could be used as the basis for the objective evaluation of autonomic activity and balance in different behavioural contexts. Eleven domestic pigs (German Landrace) underwent surgery for the placement of a telemetric device. At day 15 after surgery, 512 consecutive inter-beat intervals and pressure waves were analysed using different detection methods (automatic and manually corrected) while the animals were resting or feeding, respectively. HRV and BPV were calculated. Incomplete datasets were found in four pigs due to missing ECG or BP signals. Technical and surgical issues concerning catheterisation and detachment of the negative ECG lead were continuously improved. In the remaining pigs, excellent signal quality (manually corrected data of 1%) was obtained during resting and acceptable signal quality (<10%) was obtained during feeding. Automatic triggering was sufficiently reliable to eliminate errors in BP recordings during active behaviour, but this was not the case for ECG recordings. Sympathetic arousal with accompanying vagal withdrawal during feeding was documented. The established surgical implantation and functional assessment of the telemetric system with the reliable registration of cardiovascular parameters in freely moving pigs could serve as a basis for future studies of autonomic regulation in context of stress and animal welfare.

Electrocardiogram assessment in non-anaesthetized clinically healthy agouti (Dasyprocta primnolopha, Wagler 1831) / Avaliação do eletrocardiograma em cutias (Dasyprocta primnolopha, Wagler 1831) não-anestesiadas clinicamente saudáveis

The agouti is one of the most intensely hunted species throughout the Amazon and the semiarid regions of north-eastern Brazil. Considering the current tendency of wild animal management in captivity, the objective of this study was to determine heart reference values for agouti raised in captivity, based on electrocardiographic assessments (ECG). Adult agouti were selected without clinical signs of heart disease (n=30). The animals were restrained physically and then the ECG was performed. Standardized measurements were taken to establish the statistical analysis of the data. Analysis of the QRS complex showed values compatible with previous reports in peer animals and the limited data available for other wild and exotic species, except for the T wave that showed similar amplitude to the R wave in all the animals studied. The data obtained provided the first reference values for ECG tracings in agouti, contributing to a better understanding of heart electrophysiology in identifying myocardial pathology in these animals.

A cutia é uma das espécies mais intensamente caçados em toda a Amazônia e as regiões semi-áridas do nordeste do Brasil. Considerando-se a tendência atual no manejo de animais silvestres em cativeiro, o objetivo deste estudo foi determinar os valores de referência para o coração cutia criadas em cativeiro, com base em avaliações do eletrocardiograma (ECG). Foram selecionadas cutias adultas e sem sinais clínicos de doença cardíaca (n=30). Os animais foram contidos fisicamente e, em seguida, o ECG foi realizado. Medições padronizadas foram tomadas para estabelecer a análise estatística dos dados. Análise do complexo QRS apresentou valores compatíveis com os relatórios pregressos em animais animais de companhia, assim como para os poucos dados disponíveis para outras espécies selvagens e exóticas, com exceção da onda T, que mostrou amplitude semelhante à onda R em todos os animais estudados. Os dados obtidos permitiram a aquisição dos primeiros valores de referência para os traçados de ECG em cutias, contribuindo para uma melhor compreensão eletrofisiologia cardíaca, na identificação de miocardiopatia nesses animais.

Echocardiographic assessment of cardiac structural and functional indices in broiler chickens treated with silver nanoparticles.

270 Ross broiler chickens of twenty days old were housed in 18-floor pens in a completely randomized design with six treatment groups and three replicate groups and fifteen chicks per each pen. The treatment groups (1-6) consisted of 0, 10, 20, 30, 50, and 70 ppm of nanocide in drinking water, respectively. At 26 days of age, 3 chickens were selected randomly for echocardiography using a 7.5 MHz linear probe, and the left ventricular internal diameter at the end of diastole (LVIDd), left ventricular internal diameter at the end of systole (LVIDs), left ventricular fractional shortening (LVFS), ejection fraction (EF), stroke volume (SV), interventricular septum thickness at the end of systole (IVSTs), and interventricular septum thickness at the end of diastole (IVSTd) were evaluated. LVIDd and LVIDs in group six were of higher rate than other groups and showed statistically significant differences with groups two, three, and four (P < 0.05). LVFS, percentage of EF, and IVSTd were minimum in group six and had significant difference with other groups (P < 0.05). The results of this study showed that prescription of high dosage of nanocide leads to cardiovascular problems with decrease in myocardial contractility and increase in the internal diameter of left ventricle.

Assessment of the electrocardiogram in dogs with visceral leishmaniasis / Avaliação do eletrocardiograma em cães com leishmaniose visceral

As myocarditis and arrhythmias have been shown to occur in both human beings and dogs with leishmaniasis, electrocardiograms of 105 dogs serologically positive for this disease were assessed for rhythm disturbances and changes in ECG waves. A few expressive alterations were seen, including sinus arrest, right bundle branch block, and atrial premature beats in 14.3%, 4.8%, and 4.8% of the studied subjects, respectively. Also, the analysis of ECG waves showed changes suggestive of left atrium and ventricle enlargements, and myocardial hypoxia in some animals. Although cardiac compromise has been previously reported in dogs with leishmaniasis, only a small subset of dogs showed any alteration in the electrocardiogram, which cannot support the occurrence of myocarditis in this investigation.

Devido à identificação prévia de miocardite e arritmias tanto em seres humanos quanto em cães portadores de leishmaniose, 105 cães com sorologia positiva para tal enfermidade tiveram seus eletrocardiogramas avaliados quanto à presença de distúrbios do ritmo e alterações nas ondas eletrocardiográficas. Poucas variações expressivas foram observadas, exceto parada sinusal, bloqueio de ramo direito e complexos atriais prematuros em 14,3%, 4,8%, e 4,8% dos pacientes estudados, respectivamente. Ademais, a análise do ECG demonstrou alterações sugestivas de sobrecarga do átrio e do ventrículo esquerdos e hipóxia do miocárdio. Embora o comprometimento cardíaco em cães com leishmaniose já tenha sido demonstrado anteriormente, apenas uma pequena parte dos cães avaliados apresentou alteração no eletrocardiograma, não sendo possível correlacionar com a ocorrência de miocardite nesta pesquisa.

Head-cloaca controlled current stunning: assessment of brain and heart activity and meat quality.

1. Behavioural and neural responses of 65 broilers to head-to-cloaca electrical stunning were evaluated and meat quality was assessed on two groups of 25 broilers stunned either head to cloaca, or in a conventional water bath method. 2. On the EEG recordings, a general epileptiform insult was observed when applying a current of 100 mA (100 Hz) or 70 mA (70 Hz) for 1·5 s. This general epileptiform insult shows a tonic, clonic and exhaustion phase followed by spikes of alpha, beta, theta and delta waves with duration of on average 34 ± 12 s and 39 ± 23 s respectively. These birds may have been unconscious for 20 s or longer, according to the correlation dimension analyses. 3. The heart rate decreased significantly (P < 0·05) after stunning and recovered after 60 s. 4. Within a confidence limit of 95%, taking into account the number of animals with a reliable EEG, the chance of an effective stun of all broilers lies between 0·9 and 1·0 with a current of 70 mA (100 Hz for 1·5 s; n = 28) and with 100 mA (100 Hz for 1·5 s; n = 27). 5. The shear force of breast fillets was slightly lower (P < 0·01) 4 d post mortem compared with the conventional water bath stunned group (set at 100 mA, 100 Hz for 10 s). The percentage of fillets and legs without blood splashes was higher, and the percentage with severe blood splashes lower-to-none, for carcases stunned head-cloaca. 6. It can be concluded that broilers are effectively stunned with the head-cloaca method by using a controlled current of 70 mA or 100 mA for 1·5 s. The fillets and legs of bird stunned head-cloaca showed fewer blood splashes in the muscles compared with birds stunned in a conventional water bath.

Cardiac assessment of African hedgehogs (Atelerix albiventris).

Cardiomyopathy is a common finding in captive African hedgehogs (Atelerix albiventris) at postmortem exam. To date, treatment attempts have been mostly empirical and unrewarding. The objective of this study was to determine reference cardiac values for captive African hedgehogs based on echocardiogram, electrocardiogram (ECG), and radiographs. Adult African hedgehogs with no clinical signs of cardiac disease (n = 13) were selected. Each animal was anesthetized with isoflurane via facemask and an echocardiogram, ECG, and radiographs were performed. Standard measurements were taken and the descriptive statistics performed. Values were comparable to limited data available in other hedgehog species and other similar-sized exotic species. Two animals were removed from consideration of reference values due to valvular defects that were considered significant. These data are the first establishing cardiac parameters in normal African hedgehogs using radiographic cardiac measurement, echocardiogram, and ECG. Evaluating animals with possible cardiomyopathy may allow for earlier diagnosis and more successful treatment.

Non-invasive telemetric electrocardiogram assessment in conscious beagle dogs.

INTRODUCTION: The primary objective of this investigation was to evaluate the sensitivity of a non-invasive telemetry system for the detection of drug-induced electrocardiogram (ECG) changes in conscious, freely moving dogs. A secondary objective was to compare, in the same set of dogs, ECG data acquired by a non-invasive system with data acquired from a surgically implanted telemetry device (invasive system). METHODS: Continuous beat-to-beat Lead II ECG data were simultaneously acquired from 6 male dogs using a non-invasive and an invasive telemetry system for 1h pre-dose and 6h following a sham control dose or single oral doses of (+/-) sotalol (4, 8 or 16 mg/kg). ECG parameters of heart rate, RR, PQ, QRS, QT and QT corrected for heart rate according to Van de Water (QTcV) and by an individual linear regression formula (QTcR), were determined. RESULTS AND DISCUSSION: Statistically significant dose-dependent reduction of heart rate, and increases in PQ, QT and QTc (V and R) were detected at all dose levels of (+/-) sotalol, with partial recovery during the 6-hour monitoring period. Statistically significant correlations for heart rate, RR, PQ, QT and QTc (V and R) were found between the two systems. QRS duration did not correlate. However, the difference between the two systems was consistent over the range studied. Based on these findings, the non-invasive system is quantitatively comparable to invasive telemetry, and can be used successfully to acquire continuous ECG data on a beat-to-beat basis from conscious freely moving dogs for at least 6h post-dose.

Long-term assessment of horses and ponies post exposure to monensin sodium in commercial feed.

REASONS FOR PERFORMING STUDY: Acute monensin intoxication in equids is well described; however, the long-term effects of sublethal intoxication and ability to return to previous use are less well understood. Long-term observations may allow improved estimation of prognosis in cases of sublethal intoxication. OBJECTIVES: To assess horses and ponies exposed to sublethal amounts of monensin for evidence of chronic sequelae and ability to return to prior/intended use. METHODS: Twenty-nine horses and 8 ponies were assessed utilising serum biochemistry, treadmill exercise stress testing, electrocardiography, and pre- and post exercise echocardiography > or = 6 weeks after ingestion of monensin-contaminated feed. Animals with evidence of monensin-induced cardiomyopathy were re-examined after a period of rest of > or = 11 months. Follow-up information was obtained by owner telephone interview > or = 52 months after exposure. RESULTS: During resting echocardiography, 11 animals had reduced/low-normal left ventricular fractional shortening (FS); an increase in FS in 8 of these animals was measured > or = 11 months later. Six animals had reduced or low-normal FS during post exercise echocardiography. Two horses had ventricular premature depolarisations during exercise. Follow-up information was available for 35 animals: 21 returned to athletic/reproductive use, 13 were retired immediately and one died. Mean FS increased significantly (P < 0.001) between initial and second examination in 15 animals that underwent resting echocardiography on 2 occasions. CONCLUSIONS: Some equids exposed to sublethal doses of monensin may not develop permanent myocardial disease and a return to athletic/reproductive use is possible. POTENTIAL RELEVANCE: Exercise stress testing, echocardiography and electrocardiography may be useful for detection and monitoring of cardiac dysfunction in equids exposed to monensin and determining whether a return to athletic/reproductive use is possible.

A low-cost telemetry system suitable for measuring mouse biopotentials.

The ability to generate specific genetic mutations in mice is a powerful tool to study normal and pathophysiological function. In order to determine the effects of a mutation, measurement of physiological variables, such as biopotentials, is often necessary. However, such measurements can be particularly challenging to obtain from an awake, unrestrained mouse. The goal of this study was to design and implement a telemetry system suitable for recording biopotentials from a mouse. A battery-powered system was fabricated from commercially available electronic components mounted on a small circuit board. The frequency response of the system was measured over a range of frequencies and found suitable for recording biopotentials in mice and larger animals. We affixed the circuit board externally to a mouse and connected surface electrodes to measure electrocardiograms (ECG). The size and weight of the board did not disturb normal behavior over 30-60 min. Recorded ECGs had easily identifiable components relevant to physiological parameters and had a similar frequency spectrum compared to recordings obtained from a commercially available measurement system. In conclusion, the telemetry system was low-cost due to the availability of the components, straightforward to implement, and provided biopotential recordings suitable for measuring physiological parameters in an awake mouse.

Diagnostic accuracy of electrocardiography and thoracic radiography in the assessment of left atrial size in cats: comparison with transthoracic 2-dimensional echocardiography.

BACKGROUND: Left atrial (LA) enlargement (LAE) is a morphologic expression of the severity and chronicity of left ventricular (LV) diastolic dysfunction, volume overload, and increased atrial pressure and has diagnostic, therapeutic, and prognostic importance in cats. The noninvasive gold standard for assessing LA size is 2-dimensional echocardiography (2DE). HYPOTHESIS: ECG and thoracic radiography may be used to predict LAE in cats. ANIMALS: Twenty-one healthy control cats and 31 cats with cardiomyopathy were prospectively studied. METHODS: 2DE studies, including determination of the maximum LA dimension (LAD) and area (LAA), were performed prospectively in all cats and compared to the assessment of LA size based on thoracic radiography and indices obtained from a 6-lead ECG. Results obtained from healthy cats were used to generate discrimination limits suggestive of LAE as defined by LAD > 1.57 cm and LAA > 2.75 cm2. RESULTS: In cats with LAE, P wave duration and PR interval were prolonged and radiographic LA vertebral heart size (LA-VHS) was increased (P < .05). P wave-related indices had low sensitivity (Se; range, 0.12 to 0.60) but high specificity (Sp; range, 0.81 to 1.00) for the prediction of LAE. Radiographic indices had low Se (range, 0.28 to 0.72) and high Sp (range, 0.74 to 0.95) for the prediction of LAE. Correlation analyses identified correlations between LAA and P wave duration (r = 0.47, P = .003) and LAD and LA-VHS (r = 0.70, P < .001). CONCLUSION AND CLINICAL IMPORTANCE: ECG and thoracic radiography are reasonably specific but less sensitive predictors of LAE in cats.