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At least 37 records · Page 2Linked to original sources
PubMed1998

[Implanted automatic defibrillator after ventricular fibrillation treated with semi-automatic defibrillation].

We report two cases of out-of-hospital ventricular fibrillation treated without delay, with basic life support practiced by the witness, followed by a successful defibrillation by paramedics with a semi-automatic defibrillator. In the subsequent month, a cardioverter-defibrillator was implanted. In one patient, a ventricular tachycardia occurring 10 months later and a ventricular fibrillation 9 months later in the other respectively, were successfully reversed by the implanted defibrillator. These two cases illustrate the value of the "survival chain" concept (undelayed alert, basic life support by witness, early defibrillation by paramedics with a semi-automatic defibrillator, advanced life support by a physician) as well as the benefit of the implanted cardioverter-defibrillator.

Adult↗
PubMed1975

Comparison of intravenous oxytocin and prostaglandin E2 for induction of labour using automatic and non-automatic infusion techniques.

A double blind trial of prostaglandin E2 and oxytocin given by intravenous infusion after amniotomy for induction of labour in 100 primigravidae with unfavourable induction features is reported. No clear-cut advantage of either drug emerged although PGE2 was perhaps superior when the cervix was highly unfavourable. Prostaglandin E2 appeared to produce less deleterious effects on the fetus but was associated with a higher incidence of maternal side effects. The automatic Cardiff Infusion apparatus was found to be a safe means of PGE2 infusion and to have advantages over the use of non-automatic techniques both for PGE2 and for oxytocin infusion.

Adolescent↗
PubMed1996

Italian experience with AutoCapture in conjunction with a membrane lead. Pacesetter Automatic Control of Energy and Membrane Automatic Threshold Evaluation (Pacemate) Study Group.

AutoCapture is a programmable feature of the Pacesetter Microny SR + 2425T VVIR pacemaker, which provides for the automatic capture verification, increase in output in the presence of noncapture and threshold searching, with adjustment of output settings. The effectiveness of this unit in conjunction with the Membrane models 1400T and 1401T bipolar endocardial leads was studied in 54 patients followed at 19 Italian Centers. The patients were randomized at the time of implantation to receive either the model 1400T or the 1401T lead. The electrodes in these leads are covered by a Nafion membrane, which was either impregnated (model 1400T) or not-impregnated (model 1401T) with steroid. This paper reports the data collected over the first six weeks postimplantation. The results of the automatic capture function was compared to the capture threshold measured using the Vario technique at the time of predischarge evaluations, and weeks 1,2, and 6 of postimplant follow-up. The reliability and effectiveness of the pulse generator-lead system allowed for consistent pacing at very low outputs and safety preserved at a programmed output only 0.3 V above the capture threshold.

Aged↗
PubMed2000

Is automatic mode switching effective for atrial arrhythmias occurring at different rates? A study of the efficacy of automatic mode and rate switching to simulated atrial arrhythmias by chest wall stimulation.

Automatic mode switching (AMS) is a useful means to avoid rapid ventricular response during atrial fibrillation (AF), but AMS cannot occur if the detected atrial rate during AF is below the mode switching criteria. This may be the result of antiarrhythmic medications, or when the atrial events fall within the atrial blanking period, or if the atrial amplitudes during AF are too small to be sensed. We hypothesize that the addition of an automatic rate switching (ARS) algorithm may complement AMS response during AF with different detected atrial rates. We studied the Marathon DDDR pacemaker (Model 294-09, Intermedics Inc.) with the AMS and ARS algorithms that are independently programmable but can also operate in combination. AF sensed above the AMS rate (160 beats/min) will lead to VDIR pacing, whereas AF below AMS rate will be tracked at an interim rate as dictate by the ARS, at a ventricular response that is 20 beats/min above the sensor indicated rate. Atrial tachyarrhythmias were simulated by chest wall stimulation (CWS). CWS was applied to 33 patients (16 men, 17 women, mean age 69 +/- 11 years) with a Marathon DDDR pacemaker using an external pacer to simulate AF occurring at two rate levels: above the AMS rate (programmed at 160 beats/min) at 180 beats/min and below the AMS rate at 120 beats/min. The maximum, minimum, and mean ventricular rates during CWS in DDDR mode with AMS alone, ARS alone, and their combination were compared. During CWS at 120 beats/min, the AMS plus ARS setting showed a mean ventricular rate of 79 +/- 3 beats/min and 124 +/- 14 beats/min in the AMS setting alone (P < 0.01). With CWS at 180 beats/min, the mean ventricular rate in the AMS plus ARS setting compared to the AMS setting alone was not significantly different. However, the variation in ventricular pacing rate was 7 +/- 14 beats/min in the AMS plus ARS setting and 40 +/- 42 beats/min in the AMS setting (P < 0.05). In conclusion, AMS is effective for simulated atrial tachyarrhythmias sensed above the AMS rate. Combined AMS with ARS is useful to handle simulated atrial tachyarrhythmia at a slower rate and to avoid rate fluctuation during AMS. There is also a possibility that this can be applied to the naturally occurring atrial tachyarrhythmias.

Aged↗
PubMed1992

Automaticity and cognitive anatomy: is word recognition "automatic"?

Recent progress in neural imaging technologies such as positron emission tomography and dense-array recording of event-related potentials has greatly increased the capacity for in vivo measurement of cognitively relevant processing activity within the human brain. Data from these neural imaging technologies can be combined with behavioral data from standard chronometric techniques to enhance computational modeling of human cognition. Applications of neural data to issues of attention and automaticity are illustrated in the domain of visual word recognition, addressing the question "Is word recognition automatic?"

Animals↗
PubMed1989

[Combination use of an automatic anti-tachycardia pacemaker and an automatic implantable cardioverter-defibrillator in sustained recurrent ventricular tachycardia resistant to drugs].

We used the combination of an antitachycardia automatic ventricular pacemaker with the automatic implantable cardioverter-defibrillator in two patients with sustained, recurrent, drug-resistant ventricular tachycardias in whom a surgical ablation was not indicated. The indications for the combined use of the two systems were the possibility to control: a) the ventricular tachycardias with ventricular programmed stimulation; b) the arrhythmias which might eventually degenerate into ventricular flutter or fibrillation (as a result of anti-tachycardia pacing) with the defibrillator. To avoid any possible interference between the two systems we used the following protocol: a) endocardial bipolar pacing; b) the sensing electrodes of the defibrillator were placed as far as possible from the endocardial one; c) a suitable programming of the pacemaker output; d) a careful selection of the anti-tachycardia pacing programme (burst rate inferior to the cut-off rate of the cardioverter-defibrillator and/or a duration of the burst pacing inferior to the arrhythmia sensing time of the defibrillator); e) use of cardioverter-defibrillators with a high cut-off rate. We never observed, during the follow-up (11 and 4 months, respectively), interference between the two systems. Both patients had ventricular tachycardia recurrences (51 and 3 episodes, respectively). The arrhythmias were correctly detected and interrupted by the pacemaker without the intervention of the defibrillator. These data confirm the feasibility of the combined use of the two systems in patients with ventricular tachycardias and, in selected cases, this approach is preferable. The anti-tachycardia pacemaker counteracts some limitations of the defibrillators available at present. It offers a protection against bradyarrhythmias and allows a more precise storage of arrhythmic events. The anti-tachycardia pacemaker often controls ventricular tachycardias without the intervention of the defibrillator, thus giving the same a longer life-span and allowing patients to avoid the shock.

Aged↗
PubMed1993

Anesthetics and automaticity in latent pacemaker fibers. IV. Effects of isoflurane and epinephrine or norepinephrine on automaticity of dominant and subsidiary atrial pacemakers in the canine heart.

BACKGROUND: Anesthesia and surgery may be associated with atrioventricular junctional or ventricular rhythm disturbances. These may be caused by alteration of automaticity of primary and subsidiary pacemakers. METHODS: The direct effects of isoflurane, alone or in combination with epinephrine (E) and norepinephrine (NE), as well as single effects of E and NE, were examined on automaticity of primary and subsidiary atrial pacemakers (SAP) using a perfused canine right atrial preparation (n = 29). Preparations were perfused with oxygenated Krebs' solution at a constant perfusion pressure of 87 mmHg and a temperature of 36.5 +/- 0.5 degrees C. Delivered concentrations of isoflurane of 1.4 and 2.8% corresponded to measured perfusate concentrations of 315 +/- 7 and 617 +/- 16 microM in experiments with E (n = 14), and 316 +/- 10 and 610 +/- 26 microM in experiments with NE (n = 15). Epinephrine or NE perfusate concentrations were 2 and 5 micrograms/l or 5 and 10 micrograms/l, respectively. To determine the site of earliest activation, extracellular recordings were made from the SA node region and distal sites (approximately 1, 2, and 3 cm) along the sulcus terminalis, the previously reported locations of SAP. Sites of earliest activation shifts from SA node to SAP were scored 1, 2, or 3 depending on the distance from the control pacemaker. The summed shift scores (magnitude score) were normalized by dividing by the total number of preparations for each experimental condition. RESULTS: Exposure to isoflurane, NE, or E alone did not produce a significant increase in the incidence of pacemaker shifts or normalized pacemaker shift scores. Only the high dose of E significantly increased the incidence of pacemaker shifts and normalized shift scores. Dysrhythmogenic potential of E and NE tended to be greater after earlier exposure to isoflurane. Every combination of isoflurane with E or NE produced a significant increase in the incidence of pacemaker shifts and normalized shift scores. CONCLUSIONS: It was concluded that isoflurane with E or NE acts synergistically to increase dysrhythmic potential in the arterial tissue.

Animals↗
PubMed1982

Concepts for automatic perimetry, as applied to the Scoperimeter, an experimental automatic perimeter.

The development of an experimental automatic perimeter, the Scoperimeter, is described. We use an oscilloscope as campimeter screen for the examination of the central 25 degrees of the visual field. The oscilloscope beam generates a homogeneous background luminance (0.1 cd/m2) and single stimulus static stimuli in any given position. The effective luminance-range of the stimuli is 3.0-3.5 log.unit. The visual field examination is controlled by a small computer system. Four examination programs written in Basic, are described. The screening programs using threshold related suprathreshold stimuli appear to be the most efficient compromise between speed and accuracy of the examination. The printout of these programs consists of a noninterpolated grey-scale presentation. Other programs perform static meridional perimetry or measure luminance threshold in 60 regularly distributed positions in the visual field. We have taken into consideration the factors that may influence the outcome of the examination: the presence of an instruction phase, the possibility to follow the progress of the examination and careful stimulus-timing. In a second paper we present clinical results we obtained using our instrument.

Humans↗
PubMed1998

The cost-effectiveness of automatic implantable cardiac defibrillators: results from MADIT. Multicenter Automatic Defibrillator Implantation Trial.

BACKGROUND: The recently reported Multicenter Automatic Defibrillator Implantation Trial (MADIT) showed improved survival in selected asymptomatic patients with coronary disease and nonsustained ventricular tachycardia. The economic consequences of defibrillator management in this patient population are unknown. METHODS AND RESULTS: Patients were followed up to quantify their use of healthcare services, including hospitalizations, physician visits, medications, laboratory tests, and procedures, during the trial. The costs of these services, including the costs of the defibrillator, were determined in patients randomized to defibrillator and nondefibrillator therapy. Incremental cost-effectiveness ratios were calculated by relating these costs to the increased survival associated with the use of the defibrillator. The average survival for the defibrillator group over a 4-year period was 3.66 years compared with 2.80 years for conventionally treated patients. Accumulated net costs were $97,560 for the defibrillator group compared with $75,980 for individuals treated with medications alone. The resulting incremental cost-effectiveness ratio of $27,000 per life-year saved compares favorably with other cardiac interventions. Sensitivity analyses showed that the incremental cost-effectiveness ratio would be reduced to approximately $23,000 per life-year saved if transvenous defibrillators were used instead of the older devices, which required thoracic surgery for implantation. CONCLUSIONS: An implanted cardiac defibrillator is cost-effective in selected individuals at high risk for ventricular arrhythmias.

Cost-Benefit Analysis↗
PubMed1977

[Automatic analysis of long-term EEG in epilepsy. First experiences with a new part-automatic analytic system (author's transl)].

A new equipment for automatic analysis of prolonged EEG derivations is demonstrated. Spikes, waves and SW-combinations are detected and counted separate; counted EEG signals are written with paper speed of 25 mm per sec. Results of a 3-channel-derivation with 1-channel-analysis are shown in a time compressed graphic demonstration. The method gives better information about pathological EEG-signals of one hour or more in epileptic patients, drug effects can be demonstrated easily, and detection of pathological EEG signals is simplified.

Diagnosis, Computer-Assisted↗
PubMed1976

[Automatic clinical electrocardiography laboratory of the Udine regional hospital. Considerations on 50,000 tracings automatically analyzed with computers].

Automatic ECG processing has now passed beyond the experimental stage into the realm of clinical practice. It offers the most advanced solution to the organisation problems faced by ECG laboratories, particularly in large hospitals. A centralised laboratory for this work was first set up in Italy in 1973 at the Udine Regional Hospital. Its instrumentation and organisation are described and a consecutive sample of 1000 ECGs culled from the 50,000 computerised since its inception are discussed.

Diagnosis, Computer-Assisted↗
PubMed1997

[Sensitivity S of film-screen systems and mode of operation of different automatic exposure systems in general practice conditions. II: Automatic exposure systems].

A new method is presented to check several automatic exposure control systems (AEC) for their suitability in radiological image production. It is based on measurements of dose and density with water as an absorbing and scattering medium. The characteristic curves of an AEC can be recorded, i.e., in what way is the dose K in the image receptor plane regulated by the AEC in dependence on the different radiation qualities and the specific water volume. These characteristics can be compared with several screen-film systems (SFS), i.e., which dose K is required by the SFS in dependence on the X ray tube voltage (kV) to get the net density of Dn = 1.00. It is possible to check the way of operating of an AEC with sufficient accuracy but less time and energy are needed. The disparity of the characteristics of AEC and SFS and their results on radiological examination are discussed.

Humans↗