Electrocardiogram Of Rabbits Research Articles

ST-Segment Alterations in the Electrocardiogram of Acute Pulmonary Thromboembolism: A Rabbit Model

In this study, we investigated the mechanism underlying electrocardiogram (ECG) alterations in a rabbit model of acute pulmonary thromboembolism (PTE). Twelve healthy adult New Zealand white rabbits were used, with eight in the experimental group (PTE group) and four in the control group. After developing the rabbit model of acute PTE, ECG and coronary angiography were performed. HE staining was conducted on the right and left ventricular tissues, and polymerase chain reaction (PCR) was used to determine brain natriuretic peptide (BNP), tumor necrosis factor-alpha (TNF-α), and Troponin I (TNI) mRNA expression in the myocardium. There were considerable changes in the ST segment of the ECG in the PTE group. Coronary angiography revealed the absence of spasm, stenosis, and occlusion. In the plasma of the PTE group, the levels of D-dimer, BNP, TNF-α, and TNI were significantly elevated, and these changes were statistically significant (P<0.05). PCR analysis of ventricular myocardial tissue indicated significantly higher levels of BNP, TNF-α, and TNI mRNA in the PTE group than in the control group. These differences were statistically significant (P<0.05). The ST-T variations on the ECG of rabbits with acute PTE correlate strongly with the temporary changes in right heart volume caused by acute PTE.

Singularity detection of the rabbit electrocardiogram: An evolutionary spectral method

The time–frequency characteristics of the spectral density of non-stationary signals (NSS) in the neighborhood of an instant time point can be determined using the evolutionary spectral analysis. An experimental rabbit model involving ligation of the left anterior descending coronary artery to simulate the physiology of early phase myocardial ischemia (EPMI) has been previously described. Clinically, EPMI derived from left coronary artery stenosis is the main symptom of coronary heart diseases including acute myocardial infarction. Here, we propose a new algorithm for estimating the evolutionary spectral density functions, which is an effective approach to determine the instantaneous frequency spectra (IFS) of NSS under the uncertainty principle in the time–frequency domain. The localization singularity information in the data recorded from a living system could be detected by means of the IFS. Electrocardiogram (ECG) data recorded from experimental rabbits were analyzed with the new algorithm. Results showed that the Q’s value of the evolutionary spectral quality number of the QRS-complex data was the characteristic parameter of ECG, and there was a matched connection between the time–frequency characteristics of QRS-complex data and the myocardial ischemia symptoms of the rabbits. These results provide valuable information regarding features of the EPMI for use in clinical diagnoses.

How to measure electrocardiographic QT interval in the anaesthetized rabbit

Many drugs prolong QT or QU intervals [QT(U)] in the electrocardiogram (ECG), and this may be associated with the generation of drug-induced torsades de pointes. Therefore, it is essential to assess the ability of the newly developed drugs to prolong QT(U) interval. For this purpose, both in vivo and in vitro rabbit models are frequently used. However, it is very difficult to locate the end of the QT(U) interval in most rabbit ECGs when repolarisation is delayed, as the shape of the T and U waves may be deformed. In addition, as the heart rate of the rabbit is very high, the T (or U) wave may overlap the P wave or even the QRS complex of the following sinoatrial beat. In these circumstances, application of the “extrapolation method” makes it possible to determine the length of the QT(U) interval. This article describes the extrapolation method, shows ECG examples of typical T and U waves in the anaesthetized rabbit, and makes an attempt to provide a useful guide for researchers to measure reliably and reproducibly the duration of the QT(U) interval in rabbit studies.

Effects of sesame oil on the rabbit electrocardiogram

Effects of sesame oil on the rabbit electrocardiogram

Spectral analysis of the normal electrocardiogram of rabbits.

A spectral analysis of the QRS complex of the rabbit's electrocardiogram was made. The amplified ECG signals were filtered through low-pass filters with cut-off frequency 500 Hz and steepness 12 dB/oct, and fed to a multichannel oscilloscope monitor. The images obtained were photographed. They were subjected to analog-to-digital conversion. The values were fed for processing to an EC 1035 computer. A standard discrete Fourier transformation was used. The spectral curve exhibited a considerable amplitude of the higher harmonics. Point -20 dB was at 164 Hz and point -30 dB was at 314 Hz. It was concluded that for accurate reproduction of the rabbit's ECG the recording electrocardiograph would have a bandwidth up to 225 Hz. An amplitude error not exceeding 10 per cent would be guaranteed.

Pharmacological Studies on Japanese “Sake” and Some Other Alcoholic Beverages

Toxicities of alcoholic beverages (Japanese “sake”, synthetic “sake”, “shochu”-a distilled alcoholic drink, “dakushu”-an unrefined “sake”, whisky and brandy) were pharmacologically studied using experimental animals. Lethal dose (LD50) in mouse, effects on respiration and blood pressure of dogs and rabbits, effects on the movement of the isolated heart of toads, electrocardiogram of rabbits and effects on the movement of the excised uterus and small intestine of rats and rabbits were studied.The pharmacological effects were much more obvious either in the brewed or distilled alcoholic drinks whose impurities were found to be much. The intensive effects were observed in the brewed Japanese “sake” and, in particular, the maximum toxicities were observed in the unrefined “dakushu”.The effects of the synthetic “sake” was in the same order as those of the alcohol-Ringer solution whose content of alcohol was the same as that of the synthetic “sake”.The toxic effects were not observed in the volatile fraction obtained by the distillation of the Japanese “sake”. On the contrary, the toxic effects of the congeners of the Japanese “sake” in the fraction of unvolatile extract were observed to be most intensive.

The electrocardiogram of rabbits in blast injury.

Summary.1. The ECG changes in blast injury have been studied in 194 rabbits, 62 of which were exposed to a detonating charge of TNT in the open field and the remaining 132 animals to a charge of PETN in a specially constructed detonation chamber.2. In the total material 65.5 per cent showed pathological ECG after the detonation, in the open field material 30.6 per cent and of the rabbits exposed in the detonation chamber 81.8 per cent. An inetantaneous, transient and often pronounced sinus brady cardia and a lowering of the voltage are found in almost every case, but these changes are not included in the pathological changes.3. Premature beats, depression of RS—T and T, injury potential, different kinds of heart block and auricular fibrillation are rather common findings.4. Some changes in ECG are not manifested until several minutes to some days after the detonation, and some are only of a transient type. The changes in the first stages after the detonation often differ from those occurring later on.

Genesis of respiratory and circulatory changes in blast injury.

ArticleGenesis of Respiratory and Circulatory Changes in Blast InjuryCarl-Johan Clemedson, and H. PetterssonCarl-Johan ClemedsonFrom the Medical Division, Research Institute of National Defense, Sundbyberg, Sweden, and H. PetterssonFrom the Medical Division, Research Institute of National Defense, Sundbyberg, SwedenPublished Online:01 Aug 1953https://doi.org/10.1152/ajplegacy.1953.174.2.316MoreSectionsPDF (925 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByDiabetes exacerbates brain pathology following a focal blast brain injury: New role of a multimodal drug cerebrolysin and nanomedicineModeling trauma in rats: similarities to humans and potential pitfalls to consider5 September 2019 | Journal of Translational Medicine, Vol. 17, No. 1Introduction to Blast in the Context of Blast-Induced TBI30 July 2019Management of Blast Related Injuries25 October 2016Alveolar macrophage depletion increases the severity of acute inflammation following nonlethal unilateral lung contusion in miceJournal of Trauma and Acute Care Surgery, Vol. 76, No. 4Blast Wave Loading Pathways in Heterogeneous Material Systems–Experimental and Numerical Approaches9 May 2013 | Journal of Biomechanical Engineering, Vol. 135, No. 6Brain injury risk from primary blastJournal of Trauma and Acute Care Surgery, Vol. 73, No. 4Brain Injuries from Blast20 October 2011 | Annals of Biomedical Engineering, Vol. 40, No. 1Survival Risk Assessment for Primary Blast Exposures to the HeadJournal of Neurotrauma, Vol. 28, No. 11Blast Injury19 January 2011Bilateral Vagotomy Inhibits Apnea and Attenuates Other Physiological Responses After Blunt Chest TraumaJournal of Trauma: Injury, Infection & Critical Care, Vol. 64, No. 6THE EVOLUTION OF ISOLATED BILATERAL LUNG CONTUSION FROM BLUNT CHEST TRAUMA IN RATS: CELLULAR AND CYTOKINE RESPONSESShock, Vol. 24, No. 2Exposure to sublethal blast overpressure reduces the food intake and exercise performance of ratsToxicology, Vol. 121, No. 1Die nervöse Steuerung der AtmungBlast injury of the chestClinical Radiology, Vol. 20, No. 4ACUTE INJURIES TO THE LUNGDie nervöse Steuerung der AtmungErgebnisse der Physiologie Biologischen Chemie und Experimentellen Pharmakologie, Vol. 54, No. 1THE EFFECT OF HIGH EXPLOSIVE BLAST ON THE CEREBRAL VASCULAR PERMEABILITY1 March 1957 | APMIS, Vol. 40, No. 2The Electrocardiogram of Rabbits in Blast InjuryActa Physiologica Scandinavica, Vol. 33, No. 2-3 More from this issue > Volume 174Issue 2August 1953Pages 316-320 Copyright & PermissionsCopyright © 1953 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1953.174.2.316PubMed13080453History Received 8 March 1953 Published online 1 August 1953 Published in print 1 August 1953 Metrics

The effect of trichlorethylene on the human, canine, and rabbit electrocardiogram

Although trichlorethylene has been used in the treatment of angina pectoris, 1, 2 its action on the cardiovascular system has not been extensively investigated. Only two short reports dealing with its cardiovascular effects are available, 3, 4 and both came from the same group of workers. Since trichlorethylene may be useful in the prevention and treatment of angina pectoris, an extensive study of its action was undertaken. In this paper the electrocardiographic changes produced by the administration of trichlorethylene to human, canine, and rabbit subjects are reported.

Spontaneous changes in the normal rabbit electrocardiogram

The rabbit electrocardiogram exhibits marked spontaneous changes in the form, voltage, and direction of many of its components. Transient reversal of the T wave in Leads I and II and in the chest leads is frequently observed. T 2 is constantly upright. Slight RS-T segment deviations, never exceeding 1 mm., are frequently encountered. The P-R interval never exceeds 0.10, and the duration of the QRS complex never exceeds 0.04, second. Abnormal rhythms are not seen in the normal, unrestrained, unanesthetized rabbit. Cognizance of these spontaneous changes in the rabbit electrocardiogram is essential to the intelligent appraisal of experimental studies on the rabbit heart.

The clinical significance of a persistent depression of the RS-T segment in the electrocardiogram

I N THE last ten years, since the electrocardiogram ceased to be a method of analyzing disorders of the cardiac rhythm only and became .an important aid in the diagnosis of other diseases of the heart, much stress has been laid on deviation of the RS-T segment from the isoelectric line. These deviations in acute coronary occlusion, as described by Pardeel and analyzed and classified by Parkinson and Bedford2 and Barnes and Whitten,” are well known. Similar changes have been described in transient myocardial ischemia. Depression of the RS-T segment with or without inversion of the T-wave has been seen both in attacks of spontaneous angina pectoris and that provoked by exercise (Feil and Siegel, 4 Parkinson and Bedford,5 Brow and Holman,6 Goldhammer and Scherf,? Hausner and Scherfs). It has been shown that general anoxemia induced by breathing of an oxygen-poor mixture causes a depression of the RS-T segment not only in patients with an insufficient coronary circulation, but also in normal subjects (Rothschild and Kissin,” Katz and HamburgerlO). Btichnerll found similar changes in the electrocardiogram of rabbits after an acute massive hemorrhage and demonstrated small areas of necrosis in the heart muscle of these animals. Electrocardiographic changes of this type were found in man in anemia,12 hypoglycemia,13 carbon monoxide poisoning and in other conditions, the common feature being a state of malnutrition of the heart muscle. Among other causes of RS-T deviation are certain drugs, especially digitalisI infectiond5 (acute rheumatism, diphtheria), pericarditis,16 and pulmonary embolism.17 There are, however, cases in which the deviation of the RS-T segment is permanent and progressive. PardeelS described this abnormality of the electrocardiogram and considers that the cause of it is unknown. He suggests that the contraction process may develop potential sooner after QRS because of the greater activity of the hypertrophied muscle. On the other hand, Weber and his associateslg accept a depression of the RS-T segment with or without an inverted T-wave as the most characteristic sign of an inadequate blood supply