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PubMed1985

Monitoring at the University of California, Los Angeles.

Long-term EEG monitoring with radio or cable telemetry and video recording can be performed efficiently as an organized team effort involving physicians, nurses, technologists and other ancillary personnel. We use telemetry primarily for screening patients for possible surgical treatment of partial epilepsy. The technique is also used occasionally to define better the patient's type(s) of seizures or to differentiate seizures from pseudoseizures. Important technical points include precise correlation of EEG with clinical events, choice of recording montage, use of a 1 Hz low filter, and use of sphenoidal electrodes. Patients may need to be stressed, exercised or have medications reduced to bring about a sufficient number of seizures during monitoring. Care is needed to avoid or to identify atypical seizures due to medication withdrawal.

California↗

PubMed1979

[Biotelemetry in anesthesia and intensive care (author's transl)].

Biotelemetry and patient monitoring are two fields closely related, and should contribute to the contiuous measurement of physiological parameters from patients with little impediment. In anesthesia the requirement of minimal impediment is less important. Here wireless transmission has two advantages of great importance, namely: minimization of the risk of electricl shock by the incorporation of batteries and a complete separation of the patient and the recording equipment, and the possibility of connecting the patient to the measuring equipment before transporting him into the operating theatre. The telemetry of several parameters, especially of the cardiovascular and respiratory system is described, including the telemetry of blood-pressure, blood flow, cardiac output, ECG and arterial PO2, as well as respiratory flow, respiratory PO2 and its derived values, such as tidal volume, ventilation and oxygen uptake.

Anesthesia↗

PubMed1984

[Non-invasive diagnosis of tachycardial heart arrhythmias].

The exact recognition of arrhythmias (AR) is the basis for decision making weather to treat AR or not. During the past the field of non-invasive, diagnostic tools approached from a simple 12-lead-routine ECG to higher sophisticated methods. This paper deals with the advantages and disadvantages of those non-invasive methods for AR-detection. Exercise Stress Tests (ET) are of value for the detection of "exercise induced" ventricular arrhythmias and tachycardias frequently related to ischaemia or cardiac congestion. ECG-Telemetry recognizes AR during the postinfarction-period during moderate exercise. The transmission of the ECG via the public telephone net (ECG-Telephone-Telemetry) is used in symptomatic patients possibly related to AR. With the ECG-TTM AR can be excluded in one third and in another third confirmed as cause for the symptoms. The Long-term ECG recording (Holter Monitoring) is today a frequently used method in the daily routine to detect AR and to control therapeutic effects. To avoid misinterpretations of the analysis-results we should be familiar with the system used and we have to look with criticism on the results presented by a machine. A new method, the registration of Late Potentials using the averaging technique of a high amplified ECG seems to be promising for risk-stratification: Patients with such Late-Potentials develop frequently ventricular tachycardia or die suddenly. Prior the use of invasive diagnostic methods or therapeutic interventions it is possible to recognize AR with the above mentioned complementary methods successfully.

Death, Sudden↗

PubMed1981

Advances in sports medicine. Prevention of head and neck injuries in football.

Statistics on catastrophic head and neck injuries in football provide a more realistic indication of the incidence of serious injuries occurring on the football field than do the fatality figures. These statistics, however, provide no clues for preventing such injuries. Moreover, research using head models, anesthetized animals, cadaveric heads, and estimates of brain tolerance to impact based on studies of actual injuries to the heads of humans has produced conflicting data with respect to the goal of improving the safety record of the sport. To reconcile the data and to provide some solutions to the problem of serious injuries on the playing field, we reviewed the data collected in the laboratory and correlated it with the information obtained from telemetry studies. As a result of combining these two data sources, we concluded that injuries on the playing field occur at either end of the spectrum of offered resistance: when too much resistance is offered and when little or no resistance is offered. We demonstrated that, by avoiding either of these extremes, serious injuries to the head and neck can be reduced considerably. Finally, we discussed the importance of preprogrammed responses by the experienced, well-conditioned athlete. These allow the athlete to avoid either extreme of resistance and, thereby, protect him from injury. Clearly, the data obtained from laboratory and telemetry studies will prove instrumental in effecting changes in the sport of football. As a result of these studies, we can hope for alterations in the design of the helmet, enlightened coaching techniques, and rule revisions--all of which will serve to make football a safe sport.

Adult↗

PubMed1997

Managing a cardiac monitoring problem.

A multidisciplinary team initiated a plan of action to manage a consistently frustrating situation--telemetry utilization. Measurable criteria determined who needed telemetry and the length of time a patient would be monitored.

Heart Diseases↗

PubMed1998

Time to clinical stability in patients hospitalized with community-acquired pneumonia: implications for practice guidelines.

CONTEXT: Many groups have developed guidelines to shorten hospital length of stay in pneumonia in order to decrease costs, but the length of time until a patient hospitalized with pneumonia becomes clinically stable has not been established. OBJECTIVE: To describe the time to resolution of abnormalities in vital signs, ability to eat, and mental status in patients with community-acquired pneumonia and assess clinical outcomes after achieving stability. DESIGN: Prospective, multicenter, observational cohort study. SETTING: Three university and 1 community teaching hospital in Boston, Mass, Pittsburgh, Pa, and Halifax, Nova Scotia. PATIENTS: Six hundred eighty-six adults hospitalized with community-acquired pneumonia. MAIN OUTCOME MEASURES: Time to resolution of vital signs, ability to eat, mental status, hospital length of stay, and admission to an intensive care, coronary care, or telemetry unit. RESULTS: The median time to stability was 2 days for heart rate (< or =100 beats/min) and systolic blood pressure (> or =90 mm Hg), and 3 days for respiratory rate (< or =24 breaths/min), oxygen saturation (> or =90%), and temperature (< or =37.2 degrees C [99 degrees F]). The median time to overall clinical stability was 3 days for the most lenient definition of stability and 7 days for the most conservative definition. Patients with more severe cases of pneumonia at presentation took longer to reach stability. Once stability was achieved, clinical deterioration requiring intensive care, coronary care, or telemetry monitoring occurred in 1% of cases or fewer. Between 65% to 86% of patients stayed in the hospital more than 1 day after reaching stability, and fewer than 29% to 46% were converted to oral antibiotics within 1 day of stability, depending on the definition of stability. CONCLUSIONS: Our estimates of time to stability in pneumonia and explicit criteria for defining stability can provide an evidence-based estimate of optimal length of stay, and outline a clinically sensible approach to improving the efficiency of inpatient management.

Adult↗

PubMed2003

The alpha 2-adrenoceptor antagonist atipamezole potentiates anti-Parkinsonian effects and can reduce the adverse cardiovascular effects of dopaminergic drugs in rats.

The present experiments investigated the effects of the specific alpha(2)-adrenoceptor antagonist atipamezole, alone and in combination with a dopamine agonist, on motor function in rats with a unilateral 6-hydroxydopamine lesion of the nigro-striatal pathway and on exploratory behaviour and cardiovascular function in rats equipped with telemetry transmitters. Dexmedetomidine, an alpha(2)-adrenoceptor agonist and the alpha(2)-adrenoceptor antagonists idazoxan and yohimbine were used as reference compounds. In the unilaterally lesioned animals, direct dopamine agonists, such as apomorphine, induce contralateral turning behaviour. Indirect agonists, such as amphetamine, induce ipsilateral circling in the animals. Atipamezole (0.3 mg/kg s.c) potentiated and dexmedetomidine (10 micro g/kg s.c.) decreased contralateral circling evoked by apomorphine (50 micro g/kg s.c.) and by l-3,4-dihydroxyphenylalanine (L-DOPA, 5 mg/kg i.p.). Atipamezole also prolonged the duration of action of L-DOPA. Atipamezole dose-dependently induced ipsilateral turning behaviour and potentiated turning induced by amphetamine (1 mg/kg i.p.). The alpha(1)-adrenoceptor antagonist prazosin (0.1 mg/kg i.p.) partially antagonised the effect of amphetamine and had a strong inhibitory effect on the atipamezole-induced potentiation of the amphetamine response. Prazosin did not have any major effect on either the apomorphine response itself or on the potentiation of the apomorphine response by atipamezole. This suggests that atipamezole can modulate motor function both indirectly, by stimulating the release of noradrenaline and directly, by blocking postsynaptic alpha(2)-adrenoceptors in neurones other than noradrenergic nerves. The alpha(2)-adrenoceptor antagonists, when tested at comparably effective central alpha(2)-adrenoceptor antagonising doses in a rat mydriasis model: atipamezole 0.3 mg/kg s.c., idazoxan 1 mg/kg s.c. and yohimbine 3 mg/kg s.c., all induced ipsilateral turning behaviour and potentiated apomorphine-induced contralateral circling. The effects of the alpha(2)-adrenoceptor antagonists were in general similar in these experiments. In habituated non-lesioned rats equipped with telemetry transmitters, apomorphine (50 micro g/kg s.c.) decreased blood pressure in the home cage and in an open-field test. It also decreased spontaneous motor activity in the open field. Neither atipamezole (0.3 mg/kg s.c.) nor idazoxan (1 mg/kg s.c.) had any effect on blood pressure when given alone, but reversed the apomorphine-induced decrease in blood pressure. Atipamezole also diminished apomorphine-induced sedation in the open-field test. In conclusion, atipamezole improved the efficacy of L-DOPA and apomorphine in an animal model of Parkinson's disease and also reduced adverse dopaminergic effects on vigilance and on cardiovascular function. These results suggest that an investigation of the effects of specific alpha(2)-adrenoceptor antagonists in Parkinson's disease patients is warranted.

Adrenergic alpha-1 Receptor Antagonists↗

PubMed2001

Modification of d-amphetamine-induced responses by baclofen in rats.

RATIONALE: d-Amphetamine is known to have effects on heart rate, body temperature and locomotor activity. However, it is not known if GABAB receptor stimulation modifies these actions of d-amphetamine. OBJECTIVES: Using telemetry recordings, this study examined the interactions between the GABAB receptor agonist baclofen and d-amphetamine, on heart rate responses, body temperature and locomotor activity, and whether these effects could be blocked by the GABAB receptor antagonist SCH 50911. METHODS: Rats were prepared with telemetry implants, which allowed continuous monitoring of heart rate, core temperature and spontaneous locomotor activity. Drugs were subsequently administered subcutaneously to the animals for simultaneous recording over a period of 180 min. RESULTS: d-Amphetamine alone (0.3, 1.0 and 3.0 mg/kg) produced a dose-related increase in heart rate, but was without any effect on body temperature, whilst at 1.0 mg/kg, it significantly increased locomotor activity. Baclofen increased heart rate without affecting locomotor activity, and, at the highest dose of 10.0 mg/kg, it induced a significant reduction in body temperature. Graded doses of baclofen (3.0-10.0 mg/kg), when co-administered with d-amphetamine (1.0 mg/kg), did not modify the d-amphetamine-induced increase in heart rate, but the combination produced significant reductions of body temperature. The latter was only partially reversed by the GABAB receptor antagonist SCH 50911 (10.0 mg/kg). By contrast, the increase in locomotor activity by d-amphetamine was markedly blocked by baclofen in a dose-related manner, and this effect was abolished by SCH 50911 (10.0 mg/kg). SCH 50911 alone at doses of 3.0, 6.0 and 10.0 mg/kg had no effect on temperature or locomotor activity. Heart rate was increased significantly, but the magnitude of change was small. CONCLUSIONS: The results of the present study suggest that stimulation of GABAB receptors by baclofen completely blocks the locomotor stimulatory effects of d-amphetamine. Baclofen did not significantly modify the increase in heart rate produced by d-amphetamine and decreased body temperature, both alone and in combination with d-amphetamine. GABAB receptor ligands may well have potential as pharmacotherapies in the treatment of amphetamine abuse and dependence.

Animals↗

PubMed2003

Cardiac-directed expression of adenylyl cyclase and heart rate regulation.

Mice with cardiac-directed overexpression of AC(VI) show increased cardiac responsiveness to beta-adrenergic receptor stimulation but regulation of heart rate is unknown. Telemetry was used to test the hypothesis that mice overexpressing cardiac adenylyl cyclase type VI (AC(VI)) would have normal heart rate regulation. Mice overexpressing cardiac AC(VI) were generated using the alphaMHC promoter and studied 10 days after implantation of telemetry devices. Cardiac transgene AC(VI) presence and expression was verified using PCR, RT-PCR and immunoblotting. Ambulatory heart rates were assessed using time and frequency domain analysis over two 24 hour light-dark cycles. Heart rates then were assessed following pharmacological blockade. Time domain analyses showed ambulatory heart rates were unchanged (AC(VI): 597 +/- 15 (SEM) bpm, Control: 595 +/- 12 bpm; p = 0.92). Circadian heart rate variability was preserved and not different from control mice (ANOVA, p = 0.52). Frequency domain analysis of heart rate variability also was unchanged. No difference in heart rate response to pharmacological autonomic blockade was found (intrinsic heart rate: AC(VI) 622 +/- 17 bpm, control 616 +/- 16 bpm, p = 0.79). In conclusion, mice overexpressing cardiac AC(VI) have normal conscious ambulatory heart rates and normal heart rate variability. Overexpression of cardiac AC(VI) does not result in altered heart rate regulation in contrast to cardiac overexpression of other elements of the beta-adrenergic signaling pathway.

Adenylyl Cyclases↗

PubMed2006

Seizures and syncope: anatomic basis and diagnostic considerations.

Although pathophysiologically distinct, syncope and seizures share clinical characteristics which may make diagnosis difficult. Adding to diagnostic complexity are the facts that seizures and syncope may coexist in the same patient, syncope may be associated with seizure-like motor manifestations, and seizures may be complicated by cardiac arrhythmia and syncope. Combined EEG/ECG telemetry is sometimes necessary to establish the correct diagnosis. These techniques also provide an opportunity to study the role of certain cortical regions in the modulation of cardiac function. There is an increasing understanding of the central autonomic pathways involved in the genesis of the cardiovascular changes that occur during epileptic seizures. This article reviews the use of EEG/ECG telemetry in the evaluation of syncope and seizures, and the neuroanatomic circuitry involved in the production of the cardiovascular manifestations of seizures.

Aged, 80 and over↗

PubMed2006

Activity-based rate-adaptive pacemakers under hyperbaric conditions.

OBJECTIVES: The aim of this study was to test a variety of currently available activity-based rate-adaptive pacemakers under hyperbaric conditions. BACKGROUND: Sports divers with pacemakers can dive under certain circumstances. The rate response of activity-sensing pacing under hyperbaric conditions has rarely been evaluated. MATERIALS AND METHODS: We manufactured a miniaturized hyperbaric chamber. A pacemaker inside was kept close to the corresponding telemetry wand placed on top of the chamber. An inflation device for coronary balloon angioplasty was used to create hydraulic pressure. Group I pacemakers were exposed to a 30 msw/98 fsw/4 ATA and after a 1-month waiting period to 60 msw/197 fsw-depth/7 ATA. Group II was exposed to only one dive to 60 msw. The electrogram and event marker telemetry were used to monitor the pacing stimuli and measurements were made for case distortion. RESULTS: The baseline pacing rate did not change in 27 tests. Return to baseline was shown during 18 tests after transient sensor-driven rate. There was a sensor rate response to manual brief shaking during and following testing. A case distortion was shown in 15 of 29 tests at 60 m. CONCLUSIONS: Modern accelerometers showed no sensitivity to pressure on the pacemaker can at 30 msw/98 fsw and 60 msw/197 fsw but in some devices responded to pressure changes. There was no pacing dysfunction or suppression of the sensor response despite the high incidence of case distortion at 60 msw/197 fsw. As a general rule, diving should not be allowed at depths greater than 20 msw/65 fsw.

Diving↗

PubMed1987

Cellular telephone transmission of 12-lead electrocardiograms from ambulance to hospital.

Currently, only single-lead, serial telemetry rhythm strips can be transmitted from ambulances. Triage of patients with chest pain and administration of thrombolytic therapy in ambulances is limited by the lack of specific electrocardiographic (ECG) diagnosis. A new technique is described using cellular telephone transmission of simultaneous 12-lead ECGs from ambulance to hospital to overcome this limitation. A portable 12-lead ECG installed in an ambulance was connected via modern link to a cellular telephone and digitized ECG information was transmitted to an ECG device in the hospital emergency room. Paramedics in the field placed adhesive patch electrodes and attached ECG wires. Field ECGs from 23 patients were compared with corresponding transmitted ECGs. There were no differences in heart rate, PR interval, QRS duration, QT interval or R- and T-wave axes. Baseline and transmitted ECGs had identical morphologic characteristics. Differences in R-wave amplitude in 5 transmitted tracings compared with hospital-recorded ECGs resulted in computer diagnosis of left ventricular hypertrophy by voltage, possibly due to differences in patient position. Twelve-lead ECGs can be easily transmitted from a moving ambulance using cellular telephones. This allows diagnosis before hospital arrival, improves prehospital triage of patients and may facilitate prehospital therapy with lidocaine or streptokinase. In addition, the cellular telephone link can convey both verbal and digitized information and thus improve on current telemetry systems.

Ambulances↗

PubMed1977

Automatic noctural sleep sampling: a useful method in clinical electroencephalography.

The clinical usefulness of obtaining a sleep record in epileptic patients is well established. However, in many clinical EEG laboratories, it is difficult to obtain records at night during the patient's natural sleep. Thus, most sleep EEGs are recorded in the EEG laboratory during daytime and are induced by drugs. A 16 channel cable-telemetry system is described which automatically samples throughout the night the EEG of patients while sleeping in their room or ward without the aid of any medication. The electrodes and the cable-telemetry unit are applied to the patient in the afternoon and the system is checked. The patient is then instructed to plug the system into a wall box upon retiring and to disconnect it when he wakes up in the morning. The EEG samples are automatically written out during the night on one of the EEG machines located in the EEG laboratory to which the system is connected via spectral intra-hospital wiring. The duration of the samples and of the intervals separating them can be varied according to the circumstances. We have found this method to be very helpful in the investigation of epileptic patients, especially those considered for surgical treatment.

Electroencephalography↗

PubMed1977

New sphenoidal electrode assembly to permit long-term monitoring of the patient's ictal or interictal EEG.

A new sphenoidal wire electrode is described which greatly increases the clinical and diagnostic usefulness of sphenoidal electrode recordings. These very fine wire electrodes are easy to insert; they are comfortable and acceptable to the patient. In contrast to sphenoidal needle electrodes they expose the patient to no risk should he have a seizure during recording. These electrodes also allow one to extend the recording time to several days, thus increasing the chances of recording a spontaneous seizure, for instance while the patient's EEG is being recorded with a telemetry system. The extended recording time also allows for continuous automatic sampling of the interictal EEG over a period of several days. The quality and the reliability of the EEG record are also enhanced. The new sphenoidal electrodes have been used on over 100 patients and are now being used routinely on suspected temporal lobe epileptics recorded with conventional techniques, while 50 of the patients have also been recorded with a cable-telemetry seizure monitoring system which has captured 65 spontaneous seizures.

Electrodes, Implanted↗

PubMedDate not supplied

Focal cortical dysplasia in children with localization-related epilepsy: EEG, MRI, and SPECT findings.

A retrospective analysis was conducted of 9 children with focal cortical dysplasia and localization-related epilepsy who underwent epilepsy surgery. Focal cortical dysplasia includes malformed lesions with extensive abnormalities of neuronal morphology, architecture, and lamination. The patients were examined by EEG and video EEG telemetry, CT, MRI, and SPECT using 99mTc-HmPAO. EEG disclosed interictal localized epileptiform activity in 8 patients and nonepileptiform activity with slow waves in 1. Ictal EEG telemetry demonstrated a predominantly localized seizure onset in 8 patients and MRI demonstrated an abnormal loss of gray and white matter distinction in 6. Decreased regional cerebral blood flow (rCBF) was detected in 4 patients by interictal SPECT, and increased rCBF in the same epileptogenic focus in 2 by postictal SPECT. Pathologic analysis found focal cortical dysplasia in 8 patients. One had extensive focal polymicrogyria, pachygyria, and extensive white matter heterotopias. It is concluded that MRI can detect focal cortical dysplasia, which corresponds to the epileptogenic focus on EEG, and SPECT may help to detect a functional abnormality in the same region.

Adolescent↗

PubMed2005

The financial burden of emergency department congestion and hospital crowding for chest pain patients awaiting admission.

STUDY OBJECTIVE: We determined the additional cost of an extended emergency department (ED) length of stay for chest pain patients awaiting non-ICU, monitored (telemetry) beds. METHODS: This was a prospective cohort study of all ED chest pain patients aged 24 years or older and admitted to a telemetry bed in an urban university hospital during a 12-month period. Structured ED data collection included demographics, chest pain presentation, medical history, and laboratory test and ECG results. Hospital course was monitored daily, followed by a 30-day telephone follow-up. Risk severity scores (Goldman, Acute Cardiac Ischemia-Time-Insensitive Predictive Instrument, and Charlson) were calculated. Hospital charges, real costs, and revenues were obtained at discharge and 2 years later. The main outcome measure was risk-adjusted additional cost to the hospital of a delayed ED admission. Clinical outcome was a secondary measure. RESULTS: Of the 817 patients with chest pain presenting to the ED during the study period, there were 904 hospitalizations. Of these, 825 patients waited more than 3 hours for their bed (91%). There were 21 patient visits with a final diagnosis of acute myocardial infarction. ED length of stay was not associated with total hospital length of stay (r =0.01), hospital costs, or hospital or professional charges, revenues, or collection rates. The annual opportunity cost in lost hospital revenue for chest pain patients was 168,300 US dollars (204 US dollars per patient waiting >3 hours for a hospital bed). CONCLUSION: Extended ED length of stay demonstrated no association with total hospital costs or revenues or total hospital length of stay but imposed substantial ED opportunity costs, with decreased potential revenue. Interventions that reduce ED delays in hospital admissions have the potential to significantly increase hospital revenues.

Adult↗

PubMed2003

Critical illness at mass gatherings is uncommon.

Gatherings of large numbers of people at concerts, sporting events, and other occasions lead to an assembled population with a potential for a wide variety of illnesses and injuries. The collection of large numbers of people in a single location has led some authors to recommend the placement of resuscitation equipment or other medical services in close proximity to these activities. These recommendations not withstanding, data on the frequency of critical illness at mass gatherings (a group exceeding 1000 persons) are difficult to ascertain. Therefore, it was the purpose of this study to describe the incidence of critical illnesses among assembled populations at mass gatherings. An observational prospective study was conducted involving patient encounters at a large, multipurpose, indoor mass-gathering complex in Houston, Texas occurring between September 1, 1996 and June 30, 1997. Demographic, treatment, disposition and diagnostic data were analyzed in a computerized database. Of the 3.3 million attendants to the 253 events analyzed during the 10-month study period, there were 2762 (0.08%) patient encounters. Fifty-two percent were women. Mean age was 32 +/- 15.6 years. Of these patients, 51.1% were patrons and the remaining patients were employees or contractors of the facility. A wide variety of illness was seen with trauma (39.5%), headache (31%), and other medical complaints (29.5%) being most frequent. Disposition of the patients included 95.3% being discharged to go back to the event and 2.2% being counseled to seek other medical attention. One hundred twenty-nine patients (4.7%) were referred to the Emergency Department (ED); of these, 70 were transferred for abrasions, lacerations, or skeletal injuries and 13 for chest pain. Of those referred to the ED, 50 (38.7%) patients were transported by ambulance and only 17.4% were admitted to telemetry, with none admitted to an ICU. It is concluded that critical illness at mass gatherings is infrequent, as seen in this study, with very few being admitted to telemetry and none to an ICU. Careful consideration of cost-benefit should occur when determining allocation of resources for these activities.

Adult↗

PubMed2006

A novel approach based on nanotechnology for investigating the chronic actions of short-lived peptides in specific sites of the brain.

This review presents a novel experimental approach for investigating the chronic actions of short-lived peptides in specific sites of the brain. This method combines the advantages of three different techniques: liposome encapsulation, site-specific microinjection and telemetry. First, liposomes can be designed to remain located at the injection site for a long period of time, where they protect encapsulated peptide from rapid degradation and act as a sustained-release system. Secondly, microinjection allows the administration of peptides in specific sites of the brain with minimal side effects. Finally, using telemetry, it is possible to register physiological parameters and their circadian variations in undisturbed free-moving animals for several days. Angiotensin-(1-7) and angiotensin II were used as peptide models, in order to validate the proposed method. Following the unilateral microinjection of the liposome-encapsulated peptides into the rostral ventrolateral medulla (RVLM) of Wistar rats, long-lasting cardiovascular actions were elicited, for several days. Importantly, new physiological actions of angiotensin-(1-7) at the RVLM were unmasked: modulation of the circadian rhythms of blood pressure and heart rate. It is felt that this method can be applied to a wide variety of short-lived bioactive peptides and should encounter numerous applications in the field of neurosciences.

Angiotensin I↗