The normal electrocardiogram of four species of conscious raptors

Age and Sex Determine Electrocardiogram Parameters in the Octodon degus

Cardiovascular diseases represent the leading cause of mortality and morbidity worldwide, and age is an important risk factor. Preclinical models provide supportive evidence toward age-related cardiac changes, as well as allow for the study of pathological aspects of the disease. In the present work, we evaluated the electrocardiogram (ECG) recording in the O. degus during the aging process in both females and males. Taking into account the age and sex, our study provides the normal ranges for the heart rate, duration and voltage of the ECG waves and intervals, as well as electrical axis deviation. We found that the QRS complex duration and QTc significantly increased with age, whereas the heart rate significantly decreased. On the other hand, the P wave, PR and QTc segments durations, S wave voltage and electrical axis were found to be significantly different between males and females. The heart rhythm was also altered in aged animals, resulting in an increased incidence of arrhythmias, especially in males. Based on these results, we suggest that this rodent model could be useful for cardiovascular research, including impacts of aging and biological sex.

Heart Disease in Pet Birds - Diagnostic Options

Cardiovascular diseases are common in pet birds. Diagnosis is often made postmortem only. In any case, suspicious for cardiac disease, a full diagnostic work up should be applied. First indications are given by the anamnestic data. Relative predisposition to cardiovascular diseases is associated with the species, breed, age, gender, lifestyle, and diet. Clinical signs and examination can reveal further indications of cardiovascular diseases, but may be unspecific or even without any pathologic finding. Diagnostic imaging, at least radiography, and echocardiography are always recommended. Advanced imaging methods, especially angiocardiography, can be valuable but is also more invasive and expensive.

Normal Electrocardiographic Pattern in Conscious Healthy Domestic Geese (Anser anser)

The aim of this study was to describe the reference intervals of electrocardiographic patterns and values in conscious healthy domestic geese (Anser anser). Standard bipolar and augmented unipolar limb lead electrocardiograms with a direct writing electrocardiograph were recorded in 14 domestic geese. The durations of PR interval, QRS complex, ST and QT intervals, the net of the QRS complex, and the P and T amplitudes were determined at 50 mm/s and at 1 cm = 1 mV. The polarity waveform was examined. The mean electrical axis in the frontal plane was determined in leads II and III. Data are expressed as means and standard deviations. The mean (SD) heart rate was 153.8 (22.4) beats/min. The QRS complex was mainly negative in leads II and III; it was positive in the augmented vector right, augmented vector left, and augmented vector foot leads. The T wave was positive in leads II, III, and the augmented vector foot lead and was negative in the augmented vector right and left leads. The mean electrical axis ranged between -30° to -140°. Electrocardiogram recordings were well tolerated by the geese. The reference intervals provided here can be used to assist in the interpretation of electrocardiographic patterns in geese.

High heart rate associated early repolarization causes J-waves in both zebra finch and mouse

High heart rates are a feature of small endothermic—or warm‐blooded—mammals and birds. In small mammals, the QT interval is short, and local ventricular recordings reveal early repolarization that coincides with the J‐wave on the ECG, a positive deflection following the QRS complex. Early repolarization contributes to short QT‐intervals thereby enabling brief cardiac cycles and high heart rates. We therefore hypothesized high hearts rates associate with early repolarization and J‐waves on the ECG of endothermic birds. We tested this hypothesis by comparing isolated hearts of zebra finches and mice and recorded pseudo‐ECGs and optical action potentials (zebra finch, n = 8; mouse, n = 8). In both species, heart rate exceeded 300 beats per min, and total ventricular activation was fast (QRS < 10 ms). Ventricular activation progressed from the left to the right ventricle in zebra finch, whereas it progressed from apex‐to‐base in mouse. In both species, the early repolarization front followed the activation front, causing a positive J‐wave in the pseudo‐ECG. Inhibition of early repolarization by 4‐aminopyridine reduced J‐wave amplitude in both species. Action potential duration was similar between ventricles in zebra finch, whereas in mouse the left ventricular action potential was longer. Accordingly, late repolarization had opposite directions in zebra finch (left‐right) and mouse (right‐left). This caused a similar direction for the zebra finch J‐wave and T‐wave, whereas in the mouse they were discordant. Our findings demonstrate that early repolarization and the associated J‐wave may have evolved by convergence in association with high heart rates.

Bilateral Anterior Uveitis in a Northern Saw-whet Owl (Aegolius acadicus) With a Metastatic Pectoral Malignant Mesenchymoma

A captive, adult, male northern saw-whet owl (Aegolius acadicus) was examined for blepharospasm of the left eye. The owl was diagnosed with bilateral anterior uveitis and a corneal ulceration in the left eye. It was treated with oral and topical nonsteroidal anti-inflammatory medications and a topical antibiotic. Multiple recheck examinations and medication adjustments were performed over the next 4 months, at the end of which time the bilateral anterior uveitis was controlled with a topical nonsteroidal anti-inflammatory applied 3 times per week to both eyes. The owl was re-examined 2 months later after 2 suspected neurologic episodes. On physical examination, the owl was quiet and had difficulty standing and ambulating. Five firm multilobular and immobile masses were identified overlying the pectoral muscle and sternum. Fine-needle aspiration from 1 mass revealed neoplastic cells consistent with a sarcoma. The owl was euthanatized. On the basis of results of histopathologic examination, the mass was diagnosed as a pleomorphic spindle cell sarcoma with features of rhabdomyosarcoma, liposarcoma, and osteosarcoma. Numerous tumor cells were immunopositive for myoglobin and desmin, indicating striated muscle origin. Although a metastatic lesion was present in 1 adrenal gland, lesions of inflammation or neoplasia were absent in either eye on histopathologic examination. This report describes an apparent ocular manifestation of systemic disease in an avian species with clinically diagnosed recurrent anterior uveitis.

ELECTROCARDIOGRAM ANALYSIS OF THE GOLDEN ( CHRYSOLOPHUS PICTUS) AND SILVER ( LOPHURA NYCTHEMERA) PHEASANTS

The aim of this study was to describe normal electrocardiogram patterns and values in two species of conscious pheasants (golden and silver). The standard bipolar and augmented unipolar limb leads electrocardiograms were recorded in the birds. The wave forms were analyzed in all leads at 50 mm/sec and at 10 mm = 1 mV to determine PR, QRS, ST, and QT durations and P, net QRS complex, and T amplitudes. The polarity of each wave form was tabulated in all leads. The mean electrical axis for the frontal plane, calculated using leads II and III, was mostly negative in two species (-43 ± 28.0° in golden and -92 ± 10.0° in silver pheasant). The P wave was predominantly positive in most of the leads. The pattern of wave forms of the QRS complexes were different (Rs, QS, rS, R, RS, QR, qR). The T wave was almost positive in leads I, II, III, and aVF. The heart rates of the birds were mean (± SD) of 320 ± 36 beats/min (golden) and 314 ± 31 beats/min (silver). Description of normal electrocardiogram parameters will facilitate a better understanding of electrocardiogram changes of unhealthy birds.

Analysis of the Normal Electrocardiogram in Wild Rooks ( Corvus frugilegus )

To describe the normal electrocardiographic (ECG) patterns and values in unanesthetized rooks ( Corvus frugilegus ), standard bipolar (I, II, and III) and augmented unipolar limb (aVR, aVL, and aVF) lead ECGs were recorded from 10 clinically healthy wild rooks. Wave forms were analyzed in all leads at 50 mm/s and at 10 mm = 1 mV to determine PR, QRS, ST, and QT durations; the net QRS complex; and P and T amplitudes. The polarity of each waveform was tabulated in all leads. The mean electrical axis (MEA) for the frontal plane was counted by using leads II and III. The mean heart rate was 340 ± 18 beats/min. The P wave was mainly positive in the most leads. The dominant pattern of waveforms of the QRS complexes was QS in leads II, III, and aVF, whereas in leads aVR and aVL, the patterns were rS and R, respectively. The T wave was positive in leads II, III, aVF, and aVL and negative in lead aVR. The mean of the heart MEA was -93 ± 2.2. Interpretation of the ECG values and patterns in rooks may facilitate a better realization of ECG changes of abnormalities in this species.

Computerized electrocardiography in healthy conscious guinea pigs (Cavia porcellus)

ABSTRACT: The purpose of this study is to evaluate healthy conscious guinea pigs as a model for electrophysiology assessment and to describe normal electrocardiographic patterns in controlled laboratory environment, establishing the best QT formula for this method. Electrocardiographic recordings of fifty adult conscious guinea pigs were obtained using a computerized electrocardiography. The electrocardiographic measurements of three different tracings were analyzed. The results obtained established normal mean and range values for the parameters: heart rate, waves and intervals of P-QRS-T deflections, as well as the mean cardiac axis. Groups were separated by body weight: group 1 gathered animals with 500-699g and group 2 with animals 700-900g. No differences were found when measurements were compared between groups, showing no significant difference between weight/body sizes to the electrocardiographic parameters (P<0.05). The mean corrected QT values (QTc) obtained using diverse formulae were significantly different (P<0.05), were the most consistent was Van der Water (QTcV). QTcV values were strongly correlated (r=98) and 95% confidence interval 185.7 to 195.2ms.Considering its simplicity and reliability, the QTcV was deemed the most appropriate to be used for the correction of QT interval in conscious guinea pigs.The results of this study also suggest that the values found can be used as reference for the species.

Atrioventricular Dissociation and Congestive Heart Failure in a Ring-Necked Pheasant ( Phasianus colchicus )

The aim of this clinical report was to describe a case of complete atrioventricular dissociation in a 9-month-old, male ring-necked pheasant ( Phasianus colchicus ). The case was incidentally determined during the evaluation of electrocardiograms recorded from pheasants. There were no observed clinical symptoms in the bird before or after the electrocardiogram. The PR interval varied, and there was no association of the P waves and QRS complexes in the electrocardiogram. Although the ventricular rhythm was regular (130 beats/min), atrial rhythm was irregular (approximately 91 beats/min). Pathological examination showed there was left ventricular hypertrophy with degeneration of the mitral valve of the heart and well-marked congestion in the liver and lung.

Normal electrocardiogram patterns and values in Muscovy ducks (Cairina moschata)

To describe normal electrocardiographic parameters in conscious Muscovy ducks (Cairina moschata), standard bipolar (I, II, and III) and augmented unipolar limb (aVR, aVL, and aVF) lead electrocardiograms were recorded in 10 clinically healthy birds. Wave forms were analyzed in all leads at 50 mm/s and at 10 mm= 1 mV to determine PR, QRS, ST, QT durations; the net QRS complex; and P and T amplitudes. The polarity of each waveform was tabulated in all leads. The mean electrical axis (MEA) for the frontal plane was calculated by using leads II and III. The mean (SEM) heart rate calculated from lead II was 146.6 - 6.8 beats/min. The P wave was predominantly positive in all leads. The dominant pattern of waveforms of the QRS complexes was rS in leads II, III, and aVF, whereas, in leads aVR, and aVL, the pattern was R. The T wave was positive in leads II, III, and aVF and was negative in leads aVR and aVL. The mean (SEM) of the heart MEA was -91.2 2 1.8. The electrocardiographic values and patterns tabulated in these clinically normal Muscovy ducks should provide a means of comparison to aid in the diagnosis of pathologic abnormalities in this species.

Normal electrocardiogram of the laughing dove (Spilopelia senegalensis)

The aim of this study was to describe the normal electrocardiographic patterns and values in conscious laughing dove (Spilopelia senegalensis). The standard bipolar (I, II, and III) and augmented unipolar limb (aVR, aVL, and aVF) leads' electrocardiographs were recorded in 10 clinically healthy laughing doves. The wave forms were analyzed in all leads at 50 mm/sec and at 10 mm = 1 mV to determine PR, QRS, ST, and QT durations, the net QRS complex, and P and T amplitudes. The polarity of each waveform was tabulated in all leads. The mean electrical axis (MEA) for the frontal plane was calculated using standard bipolar leads II and III. The mean heart rate (calculated from the lead II) was 357 +/- 12.5 beats/min. The P wave was positive in all leads except for the aVR lead. The dominant pattern of waveforms for the QRS complexes was rS in leads II, III, aVR, and aVF, whereas in leads I and aVL, the patterns were R and Rs, respectively. The T wave was positive in leads II, III, aVF and negative in leads I, aVR, and aVL. The average value of the heart MEA was -89.7 +/- 1.30 degrees. The electrocardiogram values and patterns tabulated in these clinically normal laughing doves provide a means of comparison to aid in the diagnosis of pathologic abnormalities in this species.

Electrocardiogram analysis of the normal unanesthetized green peafowl (Pavo muticus)

The aim of this study was to describe normal electrocardiogram (ECG) patterns and values in unanesthetized green peafowl (Pavo muticus). The standard bipolar and augmented unipolar limb leads ECGs were recorded in the birds. The waveforms were analyzed in all leads at 50 mm/sec and at 10 mm = 1 mV to determine P, PR (segment and interval), QRS, ST, QT durations, P, net QRS complex and T amplitudes. The polarity of each waveform was tabulated in all leads. The mean electrical axis (MEA) for the frontal plane was calculated using leads II and III. The mean heart rates were calculated from lead II that was 257.5 ± 5.33 beats/min. The P wave was dominantly positive in all leads. The dominant pattern of waveforms of the QRS complexes were QS in leads II, III, and aVF. In leads I, aVR and aVL, the R pattern was dominant. The T wave was almost positive in leads I, II, and aVF. The average value of the heart MEA was -96.75 ± 3.31°. Description of normal ECG parameters will facilitate a better realizing of ECG changes of unhealthy green peafowls.

Analysis of electrocardiographic parameters in helmeted guinea fowl (Numida meleagris)

The goal of this study was to describe normal electrocardiographic (ECG) patterns and values in conscious helmeted guinea fowl (Numida meleagris). Using 8 clinically healthy birds, 4 males and 4 females, standard bipolar and augmented unipolar limb lead ECGs were recorded. Wave forms were analyzed in all leads at 50 mm/s and at 10 mm = 1 mV to determine PR, QRS, ST, QT durations; the net QRS complex; and P and T amplitudes. The polarity of each wave form was tabulated in all leads. The mean electrical axis (MEA) for the frontal plane was calculated by using leads II and III. The mean (SD) heart rate calculated from the lead II was 338.4 +/- 19.0 beats/min. The P wave was predominantly positive in all leads. The dominant pattern of wave forms of the QRS complexes was RS in leads II, III, and aVF; R in lead I; QR in lead aVR; and qR in lead aVL. The T wave was predominantly positive in leads I, II, III, and aVF. The mean (SD) of the heart MEA was -60.2 degrees +/- 24.0 degrees. The ECG values and patterns tabulated in these clinically normal helmeted guinea fowl should provide a means of comparison to aid in the diagnosis of pathologic abnormalities in this species.

The normal electrocardiogram of conscious golden eagles (Aquila chrysaetos)

The aim of this study was to describe the normal electrocardiographic patterns and values in conscious golden eagles (Aquila chrysaetos). The standard bipolar and augmented unipolar limb leads' electrocardiograms were recorded in the golden eagles. The waveforms were analyzed in all leads at 50 mm/sec and at 10 mm = 1 mV to determine P, PR (segment and interval), QRS, ST, and QT durations and P, net QRS complex, and T amplitudes. The polarity of each waveform was tabulated in all leads. The mean electrical axis for the frontal plane was calculated using standard bipolar leads II and III. The mean heart rate was 346.7 +/- 14.29 beats/min. The P wave was predominantly positive in standard bipolar leads I and II and augmented unipolar limb leads aVL and aVF. The dominant pattern ofwaveforms of the QRS complexes were QS in leads I, II, III, and aVF, whereas in leads aVR and aVL, the pattern was always R. The T wave was slightly positive in leads I, II, and aVF. The average value of the heart mean electrical axis was -85.9 +/- 7.50 degrees. Establishment of normal electrocardiogram values will facilitate a better understanding of electrocardiographic changes seen in many avian diseases.