Electrocardiogram reference values for the buzzard in Spain.

Electrocardiographic reference values were established on apparently healthy buzzards (Buteo buteo) in Lugo (Spain) from March 1997 to June 1999. All birds were anesthetized with isofluorane and placed in dorsal recumbence. The standard and augmented unipolar limb leads electrocardiograms were recorded in 65 buzzards. The wave forms were analyzed in lead II at 50 mm/sec and at 1 cm = 1 mV to determine P, PR, QRS, T and QT durations and P, QRS 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 using leads II and III. The mean heart rate was 325.2 +/- 52.9 beats/min. In lead II, the P wave was positive, the dominant pattern of QRS complex was QS and the T wave was always positive. The average value of the MEA was -99.2 +/- 7.7 degrees. Establishment of normal electrocardiogram (EKG) values will facilitate a better understanding of EKG changes seen in many diseases of these birds.     

The electrocardiogram of unanesthetized cats fixed in a net

Electrocardiograms by standard limb lead, augumented unipolar limb lead and AB (Apex-Base) lead were recorded from 24 unanesthetized adult cats from a SPF closed colony. The unanesthetized cats were held in the sternal position or in the right lateral recumbent position by means of a net. The mean electrical axes of P, QRS and T waves were calculated on the basis of values of I, II and III leads. The ECG patterns and mean electrical axes were compared between the sternal position and the right lateral recumbent position. The results are summarized as follows. The mean values of RR duration, P wave duration, QRS complex duration, T wave duration, PQ interval and QT interval were 0.432, 0.033, 0.027, 0.101, 0.076 and 0.183 seconds, respectively. The values of duration, interval and amplitude were not prominently influenced by the change in posture. The ECG shape had a definite configuration on each lead except that leads I and a VL showed unstable patterns. Notches and R' waves appeared in every lead in many cases. There was a positive linear correlation between RR and QT duration: r = 0.798 in the sternal position and r = 0.525 in the right lateral recumbent position. The angle of QRS mean electrical axis on the horizontal plane was 66.90 degrees +/- 26.05 (SD) in the sternal position and 41.84 degrees +/- 75.23 (SD) in the right lateral recumbent position. The P and T mean electrical axes showed small variations.     

Electrocardiographic studies in the Japanese monkey (Macaca fuscata) with special reference to the effect of anesthesia with barbiturates

The electrocardiograms of 157 healthy Japanese monkeys (Macaca fuscata), covering a wide range of ages in both sexes, were recorded under light pentobarbital (Nembutal) anesthesia. Although results were generally similar to those reported for other macaque species, some quantitative differences were observed.The heart rate was about 160 per minute in all monkeys examined; the P-Q interval was 0.11±0.06 sec.; the duration of QRS was 0.04±0.01 sec.; the Q-T interval was 0.24±0.06 sec. The mean axis of QRS was +59° and the pattern of the QRS complex was qR type in most cases.The comparison with the human electrocardiogram shows that the heart rate ofM. fuscata is about twice that of man, while the P-Q, QRS, and Q-T intervals were about one-half of those found in human subjects. In the monkey, however, the P wave was sharp and the T wave flat.In order to estimate the effect of anesthesia on the electrocardiogram, the records of several monkeys before, during, and after intravenous administration of barbiturates were compared. Although some animals showed extrasystoles after barbiturate was administered, generally no essential changes were noted in the records, except for the retardation of the rate and proportional prolongation of intervals.This work was presented at the 10th Annual Meeting of the Primate Research Association held in Inuyama, March 13, 1966.     

正常家鸽的宽频带心电图时域值和功率谱

实验用南京新博公司生产的NHE-1000型宽频带心电信息检测分析仪,研究了正常家鸽宽频带心电图(WFB-ECG)的时域值和QRS波群的功率谱。主要结果如下:(1)Ⅱ、Ⅲ、aVF导联,QRS波群均为主波向下,形成rS或 rSr’型,无Q波,与人类相应导联的心电图波形相反;S波的升支均有一较大的切迹(无一例外),Ⅱ导联切迹幅度为 0.413±0.133mV,宽度为9.733±1.291ms;Ⅱ、Ⅲ、aVF导联T波直立,方向均与主波相反门(1例除外)。aVR导联,QRS波群主波向上,形成Rs型,T波倒置,与主波方向相反(无一例外),也与人类aVR导联的波形相反。(2)P波时程与P-R段之比值为0.8,而人的为1.0-1.6,小鼠的为0.4。(3)Ⅱ导联QRS波群的功率谱特点:以低频信号(低于80 HZ)为主,而高频频段的相对能量比小鼠的低,比人的高,其中高频频段100-1000 Hz的相对能量为(10.181±7.443)％,80-300HZ为(15.418±10.579)％。(4)QRS波群的额面心电轴为-118°±10°(-96°～-136°);(5)心电向量环的位置与人类的相反,位于-90°～-180°相限。这些现象的产生原因可能是由于家鸽心室 Purkinje纤维末梢延伸到心外膜下心肌,导致心外膜下心肌先除极化,心内膜下心肌后除极化而产生的。     

Electrocardiographic monitoring in the Göttingen minipig

The purpose of the study reported here was to determine conditions for electrocardiographic monitoring in the G?ttingen minipig in view of its use as a second non-rodent species in toxicology studies. Electrocardiograms were recorded from conscious minipigs (6/sex) maintained in a sling. The three standard bipolar limb leads (I, II, III), the three augmented unipolar limb leads (aVR, aVL, aVF), the triangular Nehb-Sp?ri leads (dorsal, axial, ventral) and their corresponding unipolar leads were recorded, and automated analysis of amplitudes and intervals was made. Major QRS patterns were not observed for any of the bipolar and unipolar leads. For triangular leads, the amplitude of waves was higher than that for limb leads, and the rS pattern dominated for dorsal, axial ventral and aV(F)-Ventral leads. The qR pattern dominated in the aV(R)-dorsal lead, whereas consistency and dominant patterns were not observed for the aV(L)-axial lead. For limb leads, the position of the electrode affected the ECG. Electrodes placed on the cubital and stifle joints were the preferred positions since the P- and R-waves were clearly identifiable with amplitudes > 0.2 mV. Also, the T-wave amplitude was (positive or negative) > 0.2 mV in at least two leads, making the determination of the QT-interval accurate. For the triangular leads, the position of the electrode had less influence on the amplitude of deflections. However, if the axial lead is to be used for calculation of intervals and amplitudes, the xyphoid process is the preferred position. In conclusion, the triangular lead system is recommended for recording ECGs in minipigs. Limb leads could be used in connection. The cubital and stifle joints for standard limb leads and the neck, sacrum, and xyphoid process for triangular leads are the preferred positions for electrodes.     

Electrocardiograms in five bipolar leads recorded from the body surface of three fish species (Cyprinus carpio, Oreochromis niloticus and Pagrus major) in fresh or sea-water

1. ECGs were recorded using five bipolar leads from the body surface of porgy Pagrus major and tilapia Oreochromis niloticus in fresh or sea-water, or held on a dry towel. 2. The maximum QRS amplitude was detected in lead V in both species being 54 +/- 25 microV in porgy and 241 +/- 78 microV in tilapia, respectively, when the fish were held on the dry towel. 3. Clear ECG waves could not be obtained from porgy in sea-water because of the porgy's small cardiac potential and leakage of the potential. However, clear ECG waves could be obtained in sea-water from the body surface of tilapia, with the average QRS amplitude being 35 +/- 8 microV. 4. The mean electrical P and QRS axes in tilapia were directed toward almost the same direction (frontal downward), whereas both P and QRS axes in most carp were in opposite directions. In porgy, the relationship between the P and QRS axes could not be identified due to the smaller amplitude of the P wave.     

Comparative studies on the wide frequency band electrocardiogram and vectorcardiogram in pigeon and mouse

Wide frequency band ECG and vectorcardiogram in anesthetized pigeon and mouse were studied from the standpoint of comparison. The key results were as follows: in pigeon, the direction of the main QRS was inverted in leads II, III and aVF, and upright in lead aVR, which was contrary to that in mouse. The T wave was upright in leads II, III and aVF, but inverted in lead aVR in pigeon, which was the same as that in mouse. In pigeon, there was a large notch on the upstroke of the S wave in lead II without exception, but there was no such notch in the corresponding lead in mouse. The QRS vector loop in the frontal plane lay between -90 and -180 degrees in pigeon, while that of mouse lay between 0 and 90 degrees. The relative power of high frequency range (80-1000 Hz) of the QRS in lead II was approximately 15% in pigeon, but 55% in mouse. The direction of the main QRS was contrary in pigeon and mouse because the subepicardial muscles were depolarized before the subendocardial muscles in pigeon, but the latter were depolarized before the former in mouse. The direction of the T waves was the same in both pigeon and mouse because subepicardial muscles were all repolarized before subendocardial muscles.     

不同类型心力衰竭患者心电图QRS波时限与血浆NT-proBNP水平的关系及其临床意义

目的：探讨不同类型心力衰竭患者心电图QRS 波时限与血浆N末端B型利钠肽原（NT-proBNP）水平之间的关系及其临床 意义。方法：选择我院2012 年7 月至2014 年6 月接收的慢性心力衰竭患者300 例,作为研究组,将患者分为收缩性心力衰竭组 （S组）和舒张性心力衰竭组（D组）;另外,选取我院非CHF 患者132 例,作为对照组。测定所有受试者的心电图QRS 波时限,及 血浆中NT-proBNP 水平,分析血浆NT-proBNP 水平与QRS 波时限及NYHA心功能分级关系。结果：与对照组相比,研究组QRS 波时限均延长,血浆NT-proBNP水平显著升高（P<0.05）,其中S 组比D 组明显延长,且S 组血浆NT-proBNP水平高于D 组 （P<0.05）。三组NYHA 分级对比发现,差异均具有统计学意义（P<0.05）;S 组患者血浆NT-proBNP水平与QRS 波时限及NYHA 心功能分级之间呈正相关;D 组患者血浆NT-proBNP水平与QRS 波时限及NYHA心功能分级之间无明显的相关性。结论：临床 上可以将NT-proBNP水平和QRS 波时限结合起来诊断慢性心力衰竭患者的类型,以便于之后的治疗。     

Aprotinin reverses ECG abnormalities induced by Mesobuthus tamulus concanesis, Pocock venom in adult rats

The kinins are implicated in the pathogenesis of scorpion envenomation. Therefore, this study was carried out to examine the involvement of kinins for the ECG abnormalities induced by M. tamulus concanesis, (BT) venom in anaesthetized rats. ECG was recorded using needle electrodes with limb lead II configuration. The PR interval, QRS wave pattern, QRS duration, ST segment and heart rate were examined in saline only, venom alone, and venom after aprotinin groups. BT venom (5 mg/kg) produced heart block of varying degree and ischemia-like changes in ECG wave pattern and the animals died within 30 min after exposure to venom. In aprotinin pretreated animals, the initial ECG changes produced by venom persisted, but after 15 min the ECG pattern improved and the animals survived for the entire period of observation (120 min). The results indicate that aprotinin protected the rats against the cardiotoxicity induced by BT venom.     

Somatosensory evoked potentials of median and tibial nerves in rhesus monkeys (Macaca mulatta) under captivity: influence of ontogenic status in neonatal, infant, young, adult, and senile stages

Background Somatosensory evoked potentials (SEPs) constitute a useful neurophysiologic tool commonly used to assess the functionality and developmental degree of the nervous system. Objective To analyze somatosensory pathways of the Macaca mulatta species throughout different ontogenetic statuses. Methods Twenty non‐human primates were divided into five age‐dependant groups. Recording of SEPs was executed by stimulation of lower limb at the tibial nerve and upper limb and recorded at the median nerve. Results Two wave series were observed for all groups for both limbs studied. Significant differences were found at the upper right limb at C4, C7 and also for the antecubital fossa site. The lower limbs showed a single significant right‐wing deflection. Conclusions Differences found in signals generated by the nervous system in response to somatosensory stimuli among the studied groups are thought to be developmental in origin, as the most remarkable deviations were seen in younger monkeys.     

Normal serum biochemical, hematological, and EKG parameters in anesthetized adult male Macaca fascicularis and Macaca arctoides

Selected serum enzymes, cholesterol, triglycerides, glucose, uric acid, protein, albumin, bilirubin, BUN, hematology, and electrocardiograms (EKG) were obtained from adult male cynomolgus (Macaca fascicularis) and adult male stumptailed (Macaca arctoides) macaques. Serum alkaline phosphatase, uric acid, albumin, bilirubin, mean corpuscular hemoglobin (MCH), mean corpuscular volume (MCV) and monocytes were significantly lower in the cynomogus monkeys. This relationship was reversed for serum levels of triglycerides, phosphorus, red blood cell counts and lymphocytes. EKG analysis revealed significantly increased PR interval and QRS wave duration in the cynomolgus species. However, there were no differences in heart rate. Right axis deviation was common in both species.     

Studies of heart disease and failure in aged female squirrel monkeys (Saimiri sp.)

Lesions consistent with heart failure were found in 23 of 88 adult squirrel monkeys that died between 1995 and 1999 at the Squirrel Monkey Breeding and Research Resource (SMBRR). This provided a rationale for a study surveying aged animals in the SMBRR for normal cardiac characteristics, using echocardiography (ECHO) and electro-cardiogram. In the pilot study, ECHO and electrocardiography were performed on 59 healthy female squirrel monkeys aged 10 years or older and 39 five-year-old monkeys. Parameters were heart rate, P-wave duration and amplitude, and PR, QRS, and QT intervals (electrocardiography), and ejection fraction. Two animals with cardiomyopathy were identified and received similar testing. Advanced-study animals had the same measurements, plus left ventricular internal diameter-systole (LVIDs) and -diastole (LVIDd), left atrial diameter-diastole (LADd) and aortic root diameter-diastole (AoRDd) by use of ECHO. Significant differences were found between groups in LADd, and P-wave and QRS interval durations. In a clinical context, these differences were not considered to be substantial. Normal aged female squirrel monkeys had significant increases in heart dimension and longer P- and QRS-wave durations than did monkeys of a five-year-old control group, although the increases were not considered clinically relevant. This study documents myocardial dynamics in healthy saimiri and those with cardiomyopathy.     

Experimental American leishmaniasis and Chagas'' disease in the Brazilian squirrel monkey: cross immunity and electrocardiographic studies of monkeys infected with Leishmania braziliensis and Trypanosoma cruzi

, and 1988. Experimental American leishmaniasis and Chagas' disease in the Brazilian squirrel monkey: cross immunity and electrocardiographic studies of monkeys infected with Leishmania braziliensis and Trypanosoma cruzi. International Journal for Parasitology 18: 1053–1059. Adult, laboratory-bred squirrel monkeys (Saimiri sciureus) previously infected with either Leishmania braziliensis braziliensis or L. b. panamensis were challenge infected with blood-form trypomastigotes of Trypanosoma cruzi (Brazil strain). Monkeys previously infected with T. cruzi were challenged with stationary phase promastigote forms of L. b. braziliensis. Monkeys were examined during the course of challenge for evidence of infection, electrocardiographic alterations and parasite-specific antibody responses. T. cruzi epimastigotes were cultured from the blood of monkeys up to 3 months after challenge with this parasite. Unulcerated cutaneous lesions appeared and persisted in monkeys challenged with L. b. braziliensis. The formation of satellite lesions was observed in one monkey. Increased QRS intervals were not observed in T. cruzi challenged monkeys without prior cardiac irregularities and QRS left axis shifts were observed in only two of these monkeys. Elevated titers of parasite binding IgM and IgG specific for both T. cruzi and L. braziliensis were observed in all monkeys following challenge. These results indicate that prior infection with T. cruzi or L. braziliensis does not protect against heterologous challenge infection with these organisms. However, prior infection with Leishmania parasites may provide some protection against chagasic cardiopathies.     

Serial Electrocardiograms Recorded on One Subject Over a Period of 42 Years (1923-1965)

A longitudinal study of the range of normal in the electrocardiogram was carried out, using the author as the subject: 18 records were made in the course of 42 years (1923-1965). Only minor differences were demonstrated which are believed to represent differences in posture or in relation to meals, because the electrocardiograms were not recorded under standard basal conditions. The QRS was wider in the precordial than in the limb leads. The amplitude of T-waves varied within a range of 1-11.5 mv.     

Morphometric and morphologic parameters of the heart in healthy Alouatta guariba clamitans (Cabrera, 1940)

Background

This study aimed at assessing the heart function of one neotropical primate (Alouatta guariba clamitans) kept in captivity using radiography, electrocardiogram (ECG) and Doppler echocardiography.

Methods

Ten adult healthy howler monkeys (A. g. clamitans) were evaluated under general anaesthesia. Vertebral Heart Scores (VHS) were obtained from radiographic studies. Ejection fraction, shortening fraction of left ventricle, left atrial/aortic root ratio, ascending aortic diameter, peak velocity of pulmonary, mitral, tricuspid and aortic blood flow and other values were measured by Doppler echocardiography. Heart rate, mean electrical axis of QRS complex, P, Q, R, S, T amplitude, P, PR interval, QRS, QT interval duration and ST segment unbalancing were measured by ECG.

Results and conclusions

Exam techniques were akin the ones used in humans. Doppler echocardiographic, radiographic, electrocardiographic and clinical parameters for howler monkey were described and correlated. The results have shown profiles of cardiovascular function and structure of A. g. clamitans.     

Electrocardiographic study of rat fetuses exposed to ethylene glycol monomethyl ether (EGME)

The widely used industrial solvent ethylene glycol monomethyl ether (EGME) is teratogenic to rats and mice, inducing a variety of heart and major vessel abnormalities. In the present study, electrocardiography was used to evaluate heart function in day 20 rat (Sprague-Dawley) fetuses from mothers treated on gestation days 7-13 (sperm = day 1) with 0, 25, or 50 mg/kg EGME by gavage in 10 ml/kg water. The increased incidence of fetuses with cardiovascular malformations (primarily right ductus arteriosus and ventricular septal defect) and abnormal electrocardiograms (EKG) was dose dependent. The most prevalent EKG abnormality was a prolonged QRS wave. Mean QRS intervals were not significantly increased by EGME exposure, but there were significantly more litters in the 50-mg/kg EGME group that had one or more fetuses with QRS complexes of 40 msec or longer. The enhanced duration and the appearance of the aberrant QRS's suggested the presence of an intraventricular conduction delay in these fetuses. Heart rate and other EKG characteristics such as the P wave or P-R and Q-T intervals were not significantly affected by exposure to EGME. There did not appear to be an association between abnormal EKG's and fetal heart dysmorphology.     

Hemodynamic responses to heat stress in the resting and exercising human leg: insight into the effect of temperature on skeletal muscle blood flow

Heat stress increases limb blood flow and cardiac output (Q) in humans, presumably in sole response to an augmented thermoregulatory demand of the skin circulation. Here we tested the hypothesis that local hyperthermia also increases skeletal muscle blood flow at rest and during exercise. Hemodynamics, blood and tissue oxygenation, and muscle, skin, and core temperatures were measured at rest and during exercise in 11 males across four conditions of progressive whole body heat stress and at rest during isolated leg heat stress. During whole body heat stress, leg blood flow (LBF), Q, and leg (LVC) and systemic vascular conductance increased gradually with elevations in muscle temperature both at rest and during exercise (r(2) = 0.86-0.99; P < 0.05). Enhanced LBF and LVC were accompanied by reductions in leg arteriovenous oxygen (a-vO(2)) difference and increases in deep femoral venous O(2) content and quadriceps tissue oxygenation, reflecting elevations in muscle and skin perfusion. The increase in LVC occurred despite an augmented plasma norepinephrine (P < 0.05) and was associated with elevations in muscle temperature (r(2) = 0.85; P = 0.001) and arterial plasma ATP (r(2) = 0.87; P < 0.001). Isolated leg heat stress accounted for one-half of the increase in LBF with severe whole body heat stress. Our findings suggest that local hyperthermia also induces vasodilatation of the skeletal muscle microvasculature, thereby contributing to heat stress and exercise hyperemia. The increased limb muscle vasodilatation in these conditions of elevated muscle sympathetic vasoconstrictor activity is closely related to the rise in arterial plasma ATP and local tissue temperature.     

Significance of fragmented QRS complexes for identifying culprit lesions in patients with non-STelevation myocardial infarction: a single-center, retrospective analysis of 183 cases

ABSTRACT: BACKGROUND: Fragmented QRS (fQRS) complexes are novel electrocardiographic signals, which reflect myocardial conduction delays in patients with coronary artery disease (CAD). The importance of fQRS complexes in identifying culprit vessels was evaluated in this retrospective study. METHODS: A 12-lead surface electrocardiogram was obtained in 183 patients who had non-ST-elevation myocardial infarction (NSTEMI) and subsequently underwent coronary angiography (CAG). On the basis of the frequency of fQRS complexes, indices such as sensitivity, specificity, positive and negative predictive values, and likelihood ratio were evaluated to determine the ability of fQRS complexes to identify the culprit vessels. RESULTS: Among the patients studied, elderly patients (age [greater than or equal to] 65 years) and those with diabetes had a significantly higher frequency of fQRS complexes (p = 0.005, p = 0.003, respectively). The fQRS complexes recorded in the 4 precordial leads had the highest specificity (81.8%) for indentifying the culprit vessel (left anterior descending artery). However, the specificity of fQRS complexes to identify lesions in the left circumflex and right coronary arteries was lower for the inferior and lateral leads than for the limb leads (65.5% versus 71.7%); however, the limb leads had higher sensitivity (92.3% versus 89.4%). And the total sensitivity and specificity of fQRS (77.1% and 71.5%) were higher than those values for ischemic T-waves. CONCLUSIONS: The frequency of fQRS complexes was higher in elderly and diabetic patients with NSTEMI. The frequency of fQRS complexes recorded in each of the ECG leads can be used to identify culprit vessels in patients with NSTEMI.