Search Results
Results 801 - 850 of 1172
< 12 13 14 15 16 17 18 19 20 21 22 >
Vera Z - - 1990
Elective cardioversion was undertaken in a patient with a VVI pacemaker and atrial tachyarrhythmia after converting the pacemaker to a VOO mode of function. The cardioverter output energy was unwittingly synchronized to the pacemaker output pulses that were falling randomly in various portions of the cardiac cycle. This resulted in ...
Das G - - 1990
Artificial pacemakers are electronic devices used primarily to control cardiac rate in patients in whom the intrinsic heart rate is inadequate for a normal life style. These devices automatically and rhythmically provide electrical impulses to stimulate the heart. Electrical stimulation of various organs of the human body was already in ...
Mori Y - - 1990
Practical method was devised for precise approach to hypothalamic nuclei in the Shiba goat. A stereotaxic instrument and a brain atlas with stereotaxic coordinates were developed. For an accurate placement of probes into specific hypothalamic regions a radiographic method was employed in which radio-opaque material was injected into the lateral ...
Evans L - - 1990
The effectiveness of air cushion restraint systems, or airbags, in preventing fatalities is estimated by assuming that they do not affect ejection probability, and protect only in frontal, or near frontal, crashes with impact-reducing effectiveness equal to that of lap/shoulder belts. In order to compute airbag effectiveness, lap/shoulder belt effectiveness ...
Garson A A - - 1990
A method is presented for obtaining data about a pacemaker from a routine ECG without any prior information about the type of pacemaker or the pacemaker parameters. The method begins with assessment of the mode of the pacemaker (AAI, VVI, VDD, DVI, or DDD) and the presence of physiologic sensing. ...
Theiss M - - 1990
Between May 1985 and July 1988, 11 patients with cardiac pacemakers were treated for renal or ureteral calculi by extracorporeal shock wave lithotripsy. During treatment and at follow-up no dysfunction of the pacemakers was noted. There were no cardiac complications during extracorporeal shock wave lithotripsy. All 11 patients were free ...
Tan U - - 1990
Paw preference assessed by a food-reaching test was studied in male and female cats. Of the total sample (N = 66), 34 (51.5%) were right-preferent, 24 (36.4%) left-preferent, and 8 (12.1%) ambilateral. In the total sample, there was evidence for an overall paw preference, general paw preference, right-, and left-paw ...
Björnström M - - 1990
Five saliva stimulants (Salivin, V6, Mucidan, Ascoxal-T and Nicotinamide) and three saliva substitutes (Saliment, Salisynt and an ex témpore solution) were evaluated in 106 patients with a low salivay flow rate and a long history of dry mouth. The study was carried out as a multi-centre study in collaboration with ...
Silver P J - - 1990
Cyclic nucleotide phosphodiesterase (PDE) isozymes isolated by DEAE-Sephacel or Mono-Q High Performance Liquid Chromatography from cardiac left ventricular tissue of normal subjects and patients with end-stage heart failure have been compared. With both separation techniques, four major peaks of PDE activity were evident in the soluble fractions; only one peak ...
Callaghan F J - - 1990
An overview of advances is presented. The focus is on automatic functions that have been developed to monitor the patient continuously and readjust the postventricular atrial refractory period, the atrioventricular (AV) delay, the ventricular refractory period, and the pacemaker stimulus intensity. The advent of automatic algorithms for the postventricular atrial ...
Marzocchi M - - 1990
Patients using diaphragm pacemakers have several respiratory-related problems placing them at high risk for death during sleep, including central hypoventilation, abnormal arousal responses, upper airway and/or tracheostomy obstruction, and, in the case of high quadriplegia, lack of motor response to airway obstruction. The recent death from airway obstruction of a ...
Chen D - - 1990
The use of transcutaneous electrical nerve stimulation (TENS) has increased in recent years for the management of chronic pain. One of its few contraindications is the presence of a cardiac pacemaker. Clinicians have recommended that cardiac monitoring be performed for a short interrupted period during the first application of TENS ...
Glazer H S - - 1989
The appearance of pneumothorax on lateral radiographs obtained with the patient erect were reviewed in 100 patients (122 total examinations). A pneumothorax could be seen on the lateral projection in 89% of the examinations (109 of 122). The displaced pleural line was most frequently identified anteriorly or posteriorly and was ...
Shandling A H - - 1989
The physiological benefit of rate responsive, single-chamber cardiac pacing is well documented. We studied the activity response of nine atrially placed Activitrax II pacemakers. Seven patients were noted to have an inadequate activity-rate response with maximal pacing rates of 85 to 101 beats/min. Marker Channel analysis revealed that the upper ...
Bocka J J - - 1989
The concept of transcutaneous external cardiac pacing has been present for approximately 200 years. However, it was not until the early 1950s that transcutaneous pacing was practical. Implantable pacemakers were introduced in the late 1950s, superceding the more cumbersome and uncomfortable external models. Recent technologic improvements and the development of ...
Rubio P A - - 1989
In the following simplified method for inserting temporary pacemaker electrodes, the cardiac pacing wire itself is used as a suture. This quick, atraumatic technique allows for extra-secure placement, provides excellent electrode contact, and prevents accidental dislodgement, even during cardiopulmonary resuscitation. Because removal of the electrodes is not necessary, complications associated ...
Van Hemel N M - - 1989
Transient programmed upper limit stimulation (150 bpm) was observed during repetitively utilized electrocautery in the beginning of an open-heart surgical procedure in a patient with a minute ventilation rate responsive ventricular pacemaker. This tachycardia caused severe hemodynamic deterioration, and was also initiated by internal heart massage and manual ventilation. Considering ...
Combs W J - - 1989
Investigation of dual chamber pacing and sensing interactions at high rates is becoming increasingly important with the advent of sensor driven dual chamber pacemakers. The present study was designed to investigate the pacemaker and lead interactions that will affect cross-talk during high rate atrial and ventricular pacing. The study was ...
Wallenhaupt S L - - 1989
The availability of external atrioventricular sequential pacemakers has improved the management of patients with sinus bradycardia, junctional rhythm, and atrioventricular block. However, these pacemakers are of less value in patients with postoperative heart block and accelerated atrial rhythms. The temporary use of a modified explanted dual-chamber demand pacemaker may counteract ...
Howard P J - - 1989
Dysphagia is a frequent cause of referral for oesophageal manometry although the motor response to eating is not routinely studied. We examined symptoms and oesophageal motor patterns in response to eating bread in 30 patients with either gastro-oesophageal reflux (n = 20), or normal oesophageal function tests (n = 10). ...
Madsen G M - - 1989
Pacemakers with a rate-responsive function, based on calculation of ventilatory minute volume, may induce tachycardia in patients who undergo hyperventilation during general anaesthesia. If hyperventilation is desired, it is recommended that the pacemaker is reprogrammed in order to avoid tachycardia. If the programming device is not available, a magnet may ...
Mickley H - - 1989
Runaway pacemaker is a rare, but still existing potential lethal complication in permanent pacemakers. Within 4 1/2 years, we saw two cases of runaway pacemaker in patients with multiprogrammable, VVI pacemakers (Siemens-Elema, Model 668). In both cases a pacemaker-induced ventricular tachycardia (rate 240-260 beats/min) was documented. One patient died. Runaway ...
Suzuki Y - - 1989
A noninvasive heart rate (HR) monitoring system for avian embryos has been developed based on the ballistocardiogram (BCG). The BCG was detected using a phonograph cartridge as a record of the velocity of the minute ballistic movements of the eggshell, which are generated by recoil and impact of heart contraction ...
Ahlfeldt H - - 1989
Modulation of ventricular parasystole by sinus beats has been shown to result in a biphasic phase response curve. Some reports also indicate that the modulation effect could be described by a triphasic response with an early phase of acceleration, which would correspond to the supernormal phase of excitability. Two cases ...
Ellestad M H - - 1989
Since July 1980, 90 patients have had 95 permanent pacemakers implanted via an iliac vein approach. An incision is made superior to the inguinal ligament and the iliac vein is cannulated with a single lead for the ventricle or two leads for the atrium and ventricle. The pulse generator is ...
Morris D C - - 1989
Using a percutaneous femoral vein approach under fluoroscopic control, a malpositioned ventricular pacemaker electrode was released from the right ventricular wall by hooking the lead with a deflecting wire inserted into a RIM catheter. A closed loop was formed by tightening the handle of the wire allowing the electrode to ...
Robles de Medina E O - - 1989
The electrocardiograms of 2 patients with frequent premature ventricular complexes characterized by variable coupling intervals and fusions with sinus activations were analyzed according to the modulated parasystole and reflection hypotheses of Moe et al. In addition, the ectopic activity was associated with couplets, tachycardia and ventricular fibrillation. Departures from the ...
McDeller A G - - 1989
It has been recognized for many years that the electromagnetic (EM) environment within aircraft presents a potential hazard to the subject with a pacemaker. Most of the information currently available is, however, several years old and may not be strictly relevant to modern pacemakers and the electromagnetic environment found in ...
Rosenqvist M - - 1989
Cardiac involvement in haemochromatosis includes development of congestive heart failure and/or cardiac arrhythmias. To elucidate the importance of this disorder among patients with severe cardiac bradyarrhythmias necessitating treatment with a permanent pacemaker, such patients were screened for evidence of iron overload. Serum ferritin was determined in 232 men treated with ...
Shen E Y - - 1989
One thousand normal Chinese full term neonates underwent prospective ultrasonography examination. Asymmetry of size between the right and left lateral ventricle was observed in a similar proportion of boys: 257/551 (47%) and girls: 183/449 (41%). The mode of delivery did not significantly influence the occurrence of ventricular asymmetry. We propose ...
Lafeber F P - - 1989
Hypocalcin, the major hormone with hypocalcaemic action in fish, was isolated from trout corpuscles of Stannius (SCs). The bioactivity of hypocalcin was assessed in a parathyroid hormone (PTH) bioassay involving bone resorption in embryonic mouse calvaria. Calcium and phosphate release and lactate production were stimulated in a dose-dependent manner by ...
Cornacchia D - - 1989
Twenty patients with advanced AV block and normal sinus node function underwent pacemaker implantation, randomly receiving a CPI 910 ULTRA II model VDD pacemaker. The first 13 patients received the implantation of a single lead with a screw-in positive ventricular fixation tip and a unipolar ring floating atrial electrode spaced ...
Horan L G - - 1989
A closed prolate ellipsoid was used to approximate the surface of the Rush torso model to permit recovery of the site and orientation of known dipoles in 15 cardiac locations. Localization was found to be reasonably close, usually within 2 cm. When body surface potential maps of 37 subjects with ...
Hariman R J - - 1989
To investigate the potential use of cryothermal mapping to localise the sites of the dominant and latent pacemakers of the sinus node, we compared the results of cryothermal and electrical mapping of the sinus node in 16 dogs. In all dogs, cooling (-5 to +5 degrees C) of a localised ...
Polak P E - - 1989
The Kearns-Sayre syndrome is a rare condition, characterized by progressive external ophthalmoplegia, retinal pigmentary degeneration and progressive impairment of cardiac conduction, which mainly determines the prognosis. Two young patients (aged 13 and 18 years) without symptoms of cardiac disease presented with an electrocardiogram showing sinus rhythm, a normal atrio-ventricular conduction ...
Smith P E - - 1989
Instant heart rate (R-R intervals) can be readily studied during spontaneous seizures recorded with ambulatory cassette AEEG/AECG techniques. Ninety-three seizures were recorded in 32 patients with complex partial epilepsy. Instant R-R interval plots showed that 74% of seizures were associated with a dominant tachycardia, the most characteristic features of which ...
Edelstam C - - 1989
A 65-year-old man, treated with the QT sensing rate responsive pacemaker required to manage high degree AV block, sustained a transmural inferior wall myocardial infarction 6 months after the pacemaker implant. The rate response of the pacemaker during the acute phase of the infarction was physiological as evidenced by increased ...
Griswold D E - - 1989
Myeloperoxidase (MPO) activity in postinfarction, dual-stained canine tissue in the presence of Evan's Blue (EB) and Triphenyltetrazolium chloride (TTC) was evaluated. Perfusion of EB and TTC allows quantification of the area of necrosis, area-at-risk of infarction and noninvolved, normal tissue postinfarction. EB in cardiac tissue has been reported to interfere ...
Nair C K - - 1989
One hundred seven patients with echocardiographically documented mitral anular calcium (MAC) and 107 age- and sex-matched control subjects without MAC were studied and followed for a mean of 4.4 +/- 2.4 (standard deviation) years. Fourteen (7%) patients were lost to follow-up. Compared with the control group, patients with MAC had ...
Drucker D E - - 1989
Transthoracic Nissen fundoplication was used for the correction of gastroesophageal reflux in five mentally retarded patients with severe kypho-roto-scoliosis. This deformity may result in a gastroesophageal junction so high above the left costal margin that transabdominal fundoplication is extremely difficult. Operative morbidity was minimal. One wrap disruption occurred that required ...
Epstein A E - - 1989
The automatic implantable cardioverter-defibrillator (AICD) effectively prevents death due to ventricular tachycardia or ventricular fibrillation. Some patients who need an AICD also require cardiac pacing to treat symptomatic bradycardia, bradycardia after defibrillation, or to provide a rate floor to reduce the frequency of bradycardia-related ventricular arrhythmias. Some patients also can ...
Ito K - - 1989
We investigated galvanic body sway of ten healthy adults and eight patients by using the averaging program for measuring T1 and T2, which were latencies at the onset and at the cutoff of galvanic stimulation, respectively, and the plotting program, which adopted 1.73 sec as T1 and 0.39 sec as ...
Deli Z - - 1989
The aim of this study was to investigate the sinus pacemaker shifts and its clinical significance. Spontaneous sinus pacemaker shifts and shifts after overdrive atrial pacing were assessed. A total of 43 cases, in whom stable sinus node electrograms (SNE) were obtained, were selected for the study, eight of the ...
Stoller M L - - 1988
A 73-year-old woman with a sick sinus syndrome and a 3-year-old ventricular demand pacemaker underwent extracorporeal shock wave lithotripsy without incident. There was no damage or malfunction of the pacemaker during or acutely after this therapy. The lithotriptor had no difficulty in sensing all paced or spontaneous ventricular complexes.
Sweesy M W - - 1988
Bipolar sensing pulse generators were thought to have eliminated crosstalk problems evident in unipolar systems. Crosstalk has been observed in the Model 284-02 bipolar sensing pacemakers. These intermittent problems were resolved by decreasing atrial output, decreasing ventricular sensitivity or increasing the ventricular blanking period. Three patients had pacemaker crosstalk, two ...
Greve H - - 1988
We implanted an "Automatic Implantable Converter-Defibrillator" (AICD) and as far as useful an antitachycardial pacemaker (Intertach) in addition in 11 patients suffering from malignant ventricular tachycardias via a median sternotomy. In eight cases a coronary artery disease and in three cases a dilatative myopathy was the intrinsic disease. During surgery ...
Hassett J A - - 1988
Patients with previously implanted dual chamber pacemakers (PM) may develop atrial flutter (AFL). The Siemens-Pacesetter AFP and Genesis PM have the capability of noninvasively synchronizing to a standard external electrophysiology (EP) stimulator. Any arrhythmia termination or induction protocol may be used with a refractory period limitation of approximately 127 msec ...
Foster C J - - 1988
Four permanent ventricular endocardial pacemaker electrodes which could not be removed via their insertion site have been retrieved via the femoral vein using a Dormier basket. Apart from short-lived ventricular arrhythmias no complications occurred in any case. Where removal of an otherwise unaccessible ventricular pacemaker electrode is considered essential the ...
Byrd C L - - 1988
A 44-month retrospective analysis was performed on 666 pacemakers implanted at Mt. Sinai Medical Center. Mapping techniques and endocardial waveform analyses were used during lead positioning to ensure the best electrical environment. The optimal pacing lead type was selected based on the clinical situation. Follow-up evaluations were rigorous. Patient population ...
Mugica J - - 1988
Recent developments in cardiac pacemaker electrodes have resulted in significant benefits to the group of pacemaker patients as a whole. The results of analysis of 2,818 chronic pacemaker electrodes are presented. These electrodes are divided into major categories according to their particularities: platinum iridium, elgiloy, carbon-tip, anodized platinum and granulated ...
< 12 13 14 15 16 17 18 19 20 21 22 >