The rectal electric activity or electrorectography was recorded transcutaneously in 24 healthy volunteers (mean age 39.6 years). A silver-silver chloride electrode was applied lateral to each of the two sacroiliac joints, and a third one was placed midway between the left greater trochanter and the ischial tuberosity. The reference electrode ...

To characterize the time course of intramuscular botulinum toxin-induced paresis, we serially performed electrophysiological measurements and recorded the sonographic size of an extensor digitorum brevis (EDB) muscle in 10 human subjects before and after injecting the EDB with 10 units of botulinum-A toxin. All EDB CMAPs decreased within 48 h, ...

A reversible cardiogenic shock model in pigs investigated shock-induced changes in the pharmacokinetics and tissue distribution of ampicillin-sulbactam and the efficacy of this antibiotic regimen in eliminating enteric bacterial translocation. Sixteen pigs were randomly allocated to 3 groups: group I (shock, ampicillin-sulbactam, n = 6), group II (no shock, ampicillin-sulbactam, ...

Six Jersey cows were implanted with 8 pairs of bipolar electrodes: 1 in the jejunum, 1 in the ileum, 3 in the cecum, and 3 in the proximal loop of the ascending colon (PLAC). Myoelectric activity was recorded at 2- to 3-day intervals, 3 times for 8 hours or 4 ...

Effects of electrical shocks on myocardium are important for defibrillation. We measured effects of shocks (5 ms, 1-40 V/cm) in isolated frog ventricular strips. We recorded contraction strength and intracellular action potential (AP) with a shock-voltage cancellation technique to allow recordings immediately after shocks. Shocks of > or = 5 ...

An In vitro comparison of the corrosion response of 316LVM stainless steel and MP35N (a CoNiCrMo alloy) electrodes under conditions appropriate to applications in functional electrical stimulation (FES) was made. Electrodes of both alloys were subjected to a cathodic 40 microC/cm2 charge injection protocol and the potential transient response was ...

Two hundred consecutive ulnar F wave latencies were evaluated in 30 healthy controls (C) and in 9 patients with mild neuropathy (N). The primary study objective was to determine the F wave sample size required to obtain a reliable F mean latency. A secondary objective was to explore the diagnostic ...

Changes in electrical impedance at the recording electrodes have been blamed for the failure of evoked electromyographic responses to return to baseline during the offset of neuromuscular block, but a relationship between electrode impedance and electromyographic responses has never been shown. In 50 fit adults, the resistive and capacitive (reactive) ...

This study determined the response of action potentials during ventricular fibrillation (VF) to timed monophasic and biphasic shocks. A floating glass microelectrode was used to record intracellularly from the anterior right ventricle in 10 open-chest dogs. After 10 seconds of electrically induced VF, 5-millisecond monophasic and 2.5/2.5-millisecond biphasic shocks or ...

Attempted cardioversion via the oesophagus (transoesophageal cardioversion) was compared with the transchest approach (transchest cardioversion) in a randomized trial of 100 consecutive patients with atrial fibrillation. For the transoesophageal group, 30, 50 and 100 J were delivered via an oesophageal electrode with subsequent 200 and 360 J transchest if required. ...

The use of artificial neural networks for classification of ST-T abnormalities of the electrocardiogram (ECG) was investigated. A training set of 356 lateral leads selected from 105 ECGs was visually classified as exhibiting one particular ST-T morphology (left ventricular (LV) strain) or not. Selected measurements, together with the classification, were ...

Several different piezoelectric lithotripters have been under clinical investigation for gallstones in the USA. Design differences in the different shock wave generators result in different characteristics for the three devices and different peak pressures at the focus of the lithotripters. Using gallstone families, we sought to study fragmentation in the ...

The fixing apparatus for a pulse transducer was improved to record continuously and stably the carotid artery pulse (CAP) during exercise on a bicycle ergometer. The CAP changed largely at the onset and at the end of exercise, oscillating during exercise. The contour of the CAP at exercise was different ...

Previous canine mapping studies of the transvenous defibrillation lead configuration of right ventricle (RV) to left R2 patch (P) revealed regions of low potential gradient in the left ventricular apex (A) and the right ventricular outflow tract (O). Thus 16 new lead configurations were tested in eight dogs, which incorporated ...

The congenital absence of pericardium is a rare condition which may determine electrocardiographic ST-T abnormalities. The case of a 16-year-old athlete who presented T-wave abnormalities at standard electrocardiogram performed during a physical checkup is reported. Ventricular repolarization tended to normalize during exercise and in right lateral decubitus. Chest x-ray and ...

It has recently been demonstrated that both biphasic and sequential pulse defibrillation shocks are superior to monophasic defibrillation shocks in animals and humans. There is little information directly comparing these two waveforms when pulse characteristics, subject, and total electrode surface area are kept constant. Pigs were randomized in a cross-over ...

We examined changes in P wave height in lead 2 of an ECG obtained during progressive exercise in 23 patients with COPD, and measured both P wave changes and pulmonary hemodynamics during exercise at a constant workload corresponding to approximately 50 to 60 percent of VO2 max in nine patients. ...

BACKGROUND: The purpose of the present study was to test the effects of lidocaine on the relation between the defibrillation threshold and the upper limit of vulnerability. METHODS AND RESULTS: The shock strength associated with a 50% probability of successful defibrillation (DFT50) and the shock strength associated with a 50% ...

A 13-year-old boy was admitted to hospital 45 min after the ingestion of approximately 750 mg of chloroquine base. A few minutes after gastric lavage with warm water he developed ventricular fibrillation from which he was promptly resuscitated. The plasma concentration of chloroquine was 4.2 mumol/l; significantly lower than the ...

Slow waves determine rhythm and polarity of spike bursts. We measured the variation of slow-wave frequency (swf) and locking (swl) in the canine jejunum during the various phases of the migrating myoelectric complex (MMC) and during induced phase III (erythromycin 125 micrograms/kg iv bolus or somatostatin 2.5 micrograms.kg-1.h-1 iv infusion), ...

STUDY OBJECTIVE: The aims were to develop a Langendorff rabbit heart model and to compare monophasic and biphasic defibrillation pulses. DESIGN: Hearts were perfused with a Krebs-Henseleit solution and two 1.4 cm2 Pt-Ir mesh patch electrodes were sutured onto the ventricles. A 5 ms monophasic or 10 ms biphasic pulse, ...

Many studies have been published concerning high-dose corticosteroids (HDC) in septic shock. Most of them have been criticized for not adhering to methodologic standards. Four studies were published during the 1980s taking into consideration the criticism of previous trials. The general conclusion following these trials was the HDC should not ...

The stability of the post-infarction simplified 29-point Selvester QRS score during maximal exercise testing was studied using both standard 12 and Mason-Likar (modified standard, M-L) ECG lead systems. Thirty-eight patients participated in the standard exercise test (mean interval after single infarction 4 months) and a total of 54 patients underwent ...

During the course of investigation for palpitations, a 62-year-old man underwent exercise testing using a MARQUETTE CASE 12 computerized exercise testing system. By stage III of the modified Bruce protocol, the computer-generated electrocardiogram appeared to show the development of exercise-induced preexcitation. Closer examination of the raw unfiltered data showed this ...

The paper deals with the problem of fiducial point detection in noisy exercise ECG signals. Performance of the averaging process depends on the detector's repeatability. The paper proposes an adaptive algorithm for optimization of the detector. The structure of the detector is well known and often used. Characteristics of the ...

The electrical impedance and its first derivative (dZ/dt) were measured at 100 kHz on 10 normal males in supine, sitting, and during upright bicycle exercise in order to compare the contribution of regional electrodes to the standard band electrode signal and to evaluate the possible use of spot electrodes for ...

The relationship between quantified pure-tone audiometric variables (namely, pure-tone audiometric slope and the degree of hearing loss) and the slope of the wave V L-I (latency-intensity) function of the ABR was investigated. The influence of loudness recruitment on the relationship between audiogram slope and the wave V L-I slope was ...

Three groups of rats were exposed to escapable shock, inescapable shock, or no shock using procedures known to induce learned helplessness effects. Twenty-four hours later, hippocampal electroencephalograms were recorded from freely moving subjects. A 5-s probe shock was delivered after 15 min, and recording continued. Frequency analyses revealed no differences ...

Changes of ECG due to long and intense -Gz acceleration was investigated in anesthetized Syrian golden hamsters. The R-R interval decreased (heart rate increased) slightly at the very initial phase of steady -Gz load. However, the R-R interval increased during the rest of the whole steady -Gz period. The P-R ...

This design allows generation of a wide range of waveforms from subaudio to ultrasonic directly via software. Waveforms may be calculated on the fly by suitable algorithms or produced from previously created lookup tables. The heart of the design is a fast 16-bit processor which directly executes the Forth programming ...

Conventionally, if an exercise electrocardiogram does not show evidence of ischemia, the patient must have achieved at least 85% of the predicted maximum heart rate for that test to be considered negative. However, no documentation of the validity of this practice exists. Thus, we evaluated the exercise electrocardiograms of 164 ...

Changes in the P wave, QRS complex, ST segment, and T wave during and after maximal exercise were quantitatively analysed in 116 healthy women with a mean age of 39. The corrected orthogonal Frank lead electrocardiogram was continuously recorded and computer processed during bicycle ergometry. With exercise, maximal spatial P ...

A detailed analysis of the exercise ECG was performed in 82 patients with right bundle branch block who underwent supine exercise equilibrium radionuclide angiography. The sensitivity and specificity of each individual electrocardiographic lead for the detection of a positive radionuclide angiogram was determined. Leads V5 and V6 had a sensitivity ...

Exercise electrocardiograms of 20 patients were analyzed using a customized software exercise electrocardiographic program and compared to measurements made by two cardiologists performing independent interpretations. The computerized program requires identification of the PQ junction, J point, and tracing of the ST-segment in three consecutive beats. The proportion of variance for ...

Radiofrequency current is a promising alternative to high voltage direct current defibrillator discharges for catheter ablation of arrhythmias. However, lesions produced with radiofrequency current are relatively small and use of high power is limited by the impedance rise that occurs with desiccation of tissue and coagulum formation. The effect of ...

To find the effect of exercise on the ECG, the electrocardiographic outlines in a training group of 7 two-month-old pigs (Landrace X White Belgian) were analyzed, compared with a nontraining control group of similar characteristics. In training animals a resting bradycardia was observed with a corresponding increase in the duration ...

Transthoracic resistance (TTR) and transmyocardial resistance (TMR) were measured during 10 minutes of uninterrupted ventricular fibrillation (VF) in a canine model. TMR was measured at 10- to 50-second intervals with two wire-mesh patch electrodes in 16 dogs. TTR was measured through two identical low-impedance electrodes. A monophasic exponentially truncated pulse ...

Biphasic waveforms reduce defibrillation threshold compared with corresponding monophasic waveforms. However, effects of fibrillation duration on relative efficacy of monophasic and biphasic waveforms are unknown. This study used a newly developed defibrillation model, the isolated right- and left-sided working rabbit heart, with epicardial defibrillation electrodes, to compare threshold for a ...

Exercise-induced changes in QRS voltage have been used to evaluate left ventricular function in adults, children, and adolescents. The purpose of this study was to investigate changes in QRS voltage with exercise in a population of healthy children and adolescents. Eighty-two normal subjects (61 boys and 21 girls) ages 4-18 ...

To investigate the cardiac function of WHHL rabbit (WHHL), an animal model of familial hypercholesterolemia, electrocardiography (ECG) and echocardiography (UCG) were taken from this species of homozygous type and normolipidemic Japanese White rabbits (controls). In WHHL, two of four had intraventricular conduction disturbances (IVCD) in ECG. UCG study showed that ...

More than 80 years after its discovery and nearly 70 years after its first being implicated in the mechanism of shock, the precise role of histamine (H) in the pathophysiology of the condition remains to be determined. The prevailing view over the decades has been that H is a noxious ...

We have developed and used a system for recording and analyzing the electrocardiogram (ECG) of the horse during exercise. The system consists of a commercial ECG transmitter telemetering a Z lead (base-apex) ECG from an exercising horse. The received data are then remodulated at an audio frequency and stored on ...

The problems of electrical phenomena striking the human body have been with us since early man observed the effect of lightning. The first generator was invented in the early 19th century, and commercial electricity generation began in 1849. By the early 1900s death from electric shock had been well described ...

The effects of maximal hyperventilation and submaximal exercise were studied on the unipolar, esophageal electrocardiogram recorded at ventricular level in 25 'normal' persons and 15 patients having ischemic heart disease with a positive exercise stress test. In normal persons, hyperventilation decreased the amplitude of the R and T waves in ...

Recent interest in sudden cardiac death during exercise in normal healthy people has highlighted the possible role of swings of extracellular potassium in arrhythmogenesis in conditions other than ischemia. Regional differences in action potential duration and conduction may be important. We have recorded monophasic action potentials (MAPs) from the endocardium ...

In order to minimize muscle noise in the exercise electrocardiogram, Mason and Likar proposed a new lead system where the limb electrodes are instead placed on the trunk. The Mason-Likar system is widely used for both the resting ECG before exercise and recordings during exercise. Several studies have, however, reported ...

Single bolus injections of hypertonic (7.5%) NaCl (H), hyperoncotic (6%) dextran-70 (D), or of their combination (HD) were given to severely bled (54.2 +/- 1.3 ml/kg) anesthetized dogs. Two shock procedures (30 or 60 min at 35 mm Hg) were tested. Survival was highest (11/12) after HD, lower (9/12) after ...

The effect of electrode polarity on defibrillation thresholds in humans is unknown. This prospective, randomized evaluation of electrode polarity on defibrillation thresholds was performed in 21 survivors of ventricular fibrillation (VF) undergoing cardiac surgery. Defibrillation was always performed with 2 identical large rectangular, wire mesh electrodes positioned over the anterior ...

Clinically available automatic implantable defibrillators use a monophasic truncated exponential waveform shock; after delivery the charge remaining on the device's capacitors is "dumped" internally and wasted. The efficacy of a monophasic and biphasic truncated exponential defibrillation waveform produced by a single capacitor discharge was compared in seven closed-chest, pentobarbital-anesthetized dogs. ...

A sixty-six-year-old man with severe aortic stenosis, in whom simultaneous and continuous monitoring of the electrocardiogram and arterial blood pressure was performed immediately before, during, and following recovery from exercise-induced syncope, is reported. During exercise the patient developed anginal pain associated with a gradual fall of arterial blood pressure followed ...