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Results 751 - 800 of 995
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Frumin H - - 1985
In a patient with a dual chamber pacemaker that senses in both the atrium and ventricle (VDD, DDD), a ventricular depolarization temporally displaced from a P wave can cause retrograde atrial activation and initiate an endless loop pacemaker-mediated tachycardia. A case in which an endless loop tachycardia was initiated by ...
Luceri R M - - 1985
Cardiac pacemakers are now at the forefront of medical technology. The ability to provide pacing therapy adapted to the individual patient has resulted in significant patient benefit. Although the indications for cardiac pacing have changed little over the past decade, the types of pacemakers available for specific bradyarrhythmias have proliferated ...
Shade S K - - 1985
Transcutaneous electrical nerve stimulation units used in conjunction with cardiac pacemakers have traditionally been an absolute contraindication for these patients. In this case report, a patient successfully used a TENS unit in conjunction with a temporary cardiac pacemaker. No interference was noted by the ECG readout. This finding indicates that ...
Erdman S - - 1985
Pacemaker carriers are at risk when undergoing operations involving the use of diathermy. The Shaw Scalpel utilizes a method by which the cutting edge of the blade is heated to a selected temperature that seals blood vessels as they are cut. No electrical currents are passed to or through the ...
van Gelder L M - - 1985
Retrograde atrial activation during ventricular pacing has often been a cause of intermittent or persistent arrhythmias (pacemaker-mediated tachycardia) in AV universal pacemakers. We recently encountered two cases in which VA conduction was responsible for atrial malpacing in patients with an implanted AV universal pacemaker, one programmed in DDD and one ...
Medina R - - 1985
Great advances in pacemaker technology have produced devices capable of a vast array of physiologic adaptations formerly unimaginable, opening new possibilities in the pacemaker treatment of almost all rhythm disturbances. Nearly all units in use today are of the inhibited type, except for some antitachycardia applications. The AV-sequential mode (DVI) ...
Javelet J - - 1985
Bilateral vertical incisions were made in the maxillary and mandibular labial mucosa of eight young green vervet monkeys. Incisions were closed with either interrupted 4-0 black silk sutures or by the application of isobutyl cyanoacrylate. Mucosal specimens containing the incisions were examined histologically and scored for degree of inflammation at ...
Higgins J R - - 1985
Many investigators have reported the use of various permanent pacemaking modes in the long-term management of patients with recurrent ventricular tachycardia. The three general types of antitachycardic pacemakers are: (1) underdrive; (2) burst; and (3) scanning pacemakers. Such devices have been activated externally or have had automatic activation. Each antitachycardic ...
Grigorov S S - - 1985
Rhythm disturbances induced by endocardial pacing were studied in 15 patients. Atrial extrasystoles were found in 8, ventricular extrasystoles in 5, ventricular tachycardia in 1 and ventricular fibrillation in 1 patient. In all cases, an implanted pacemaker EKS-222 was used working in VVI regime. The connection of the above-mentioned rhythm ...
Nordlander R - - 1985
To evaluate the complication rate during AV universal pacing (DDD), 41 consecutive patients with complete heart block were studied and followed up for 2-30 (mean 10.8) months. The Cordis Sequicor Theta was used in 6 patients and the Siemens-Elema 674 in 35. Clinical problems related to the pacemaker treatment occurred ...
Müller C - - 1985
The author discusses whether post-partum psychoses are to be considered as a clinical entity per se. The studies conducted in Lausanne seem to demonstrate that the authors of DSM III were correct in excluding this possibility - of all the patients with a post partum episode, 65% had one or ...
Kamei K - - 1984
The effects of nitroglycerin (NTG) on cardiac function can be evaluated by echocardiography. In this paper, we discuss the effects of NTG on cardiac function in two groups of subjects, one with artificial pacemakers implanted with a fixed heart rate, and the other examined as the control group. Left ventricular ...
Przybojewski J Z - - 1984
A 48-year-old man with symptoms of presyncope and congestive cardiac failure had hypertrophic cardiomyopathy (HCM) without obstruction. Complete heart block (CHB), a rare complication of this disease, was preceded by complete left bundle-branch block. Right ventricular (RV) heart failure was a dominant clinical feature but improved dramatically after temporary transvenous ...
Nakamura R - - 1984
In reaction time (RT) experiments, shifts of arousal level induced by postural changes were examined in 10 normal subjects and 10 patients with SMON. Vocal RTs were recorded at neutral position (N) and facilitating position of the left arm (FA) or the left leg (FL). RT-ratios between two positions, FA/N ...
Seltzer J P - - 1984
Multiparameter programmable DDD pacemakers are said to have an uncountable number of possible parameter combinations. It is probable that a number of these combinations, particularly when triggered by one or more critically timed native events, will result in bizarre and unanticipated rhythms sustained entirely within the timing circuit of the ...
Harthorne J W - - 1984
The advent of dual chamber pacing systems that restore atrioventricular synchrony and allow rate variability in response to physiologic stress has provided a major advance in pacing therapy. Undesirable pacemaker-mediated tachycardias may arise when the atrial sensing amplifier of a VDD or DDD device detects a retrogradely conducted P-wave, ectopic ...
van Gelder L M - - 1984
A 67-year-old male, suffering from ventricular tachycardia unresponsive to drug therapy, received a universal AV sequential pacemaker (DDD,M). The pacemaker was programmed in the DVI mode, pacing rate 100 bpm, AV interval 250 ms. After implantation, the patient experiences two episodes of tachycardia that proved to be pacemaker tachycardia with ...
Repolski M - - 1984
Sinus node dysfunction may produce in some cases life threatening medical emergencies. From 138 patients with sinus node dysfunction followed up in our department, we present 8 cases in which emergency situations required special therapeutical approaches (precordial thump, atrial or ventricular pacing, permanent pacemaker implantation). These situations appeared spontaneously, during ...
Edhag O - - 1984
Eleven patients with bifascicular block complicating anteroseptal acute myocardial infarction were studied to determine the effect of prophylactic permanent pacing; eight of them also had transient high grade atrioventricular block during the acute phase of the infarction. One month after the infarction an electrophysiological study was performed and a bradycardia ...
Sedlacek R A - - 1984
Cardiac pacemakers may be utilized to maintain adequate heart rates, or in some cases, help slow rapid heart rates. Several types of pacemakers are available, from simple fixed rate generators to expensive programmable devices. New PPS regulations require approval before implantation of permanent pacemakers. Detailed information about those generators must ...
Perrins E J - - 1984
The spectrum of cardiac arrhythmias that may be encountered in paced patients is vast; as multiprogrammable and dual-chamber pacemakers have become more sophisticated, the problems of electrocardiographic interpretation have multiplied. The arrhythmias may be broadly classified as follows: those due to abnormal functioning of the device, those due to normal ...
Hayes D L - - 1984
Dual chamber (DDD) or "universal" pacemakers have had a significant impact on the advancement of artificial pacemakers by providing a more physiologic approach to cardiac pacing. However, with the early generation of DDD pacemakers (pacemakers that sense and pace in both the atrium and the ventricle), a significant number of ...
Castellanos A - - 1984
Annihilation and one-to-one entrainment of modulated parasystolic rhythms in humans has not been previously discussed. In 9 nonmedicated patients, it was possible to measure the intrinsic, parasystolic ectopic cycle length given by the intervals between 2 consecutive parasystolic beats without any interposed nonparasystolic beat. The corresponding values varied between 960 ...
Castellan R M - - 1984
Fifty-four healthy humans, selected for their acute airway responsiveness to cotton dust, had spirometric tests immediately before and after 6 hours of exposure to card-generated cotton dust from seven different cottons (of several grades and growing regions). During exposures, we measured airborne concentrations of viable fungi and bacteria (total and ...
Eriksson P - - 1984
Involvement of the heart is common in familial amyloidosis with polyneuropathy (FAP) and is manifested by disturbances of atrioventricular and intraventricular conduction and dysfunction of the sinus node. Pacemaker implantation was performed in 20 patients with FAP in northern Sweden between 1968 and 1983 for the following indications: complete heart ...
Halperin J L - - 1984
Skeletal myopotentials may inhibit the output of unipolar demand ventricular pacemakers, resulting in protracted episodes of asystole in susceptible patients. The new DDD-mode pacemakers have, in addition to a unipolar ventricular lead, a unipolar atrial lead to enable atrioventricular sequential or atrial synchronous function. During clinical investigation of a new ...
Loperfido F - - 1984
Multiform ventricular ectopic rhythm (MVER), i.e., at least two QRS configurations of ventricular ectopic beats (VEBs), was assessed by 24-hour ambulatory ECG recording in four patients with ventricular parasystole (VP). In two of these four patients, VEBs with fixed coupling to the preceding impulses coexisted with VP beats of different ...
Shahinian L L - - 1984
A scalloped line of tear film thinning (corneal valance), running horizontally across the top third of the cornea, was readily seen with slit lamp, fluorescein, and blue filter in 25 patients. Careful retrospective examination of these patients revealed barely discernible map and fingerprint lines corresponding to the areas of tear ...
Parsonnet V - - 1984
From the outset, the art and science of cardiac pacing has been beset with a variety of problems. With the passage of time and concentrated effort in the interrelated sciences, many have been solved. We no longer are concerned with premature battery failure or leaking pulse-generator capsules, but now focus ...
Harries M G - - 1984
A patient in whom a severe systemic illness was characterised by weight loss, arthralgia and breathlessness was exposed to her pet bird. This pragmatic approach reproduced the features of her illness. The changes that occurred in her pulmonary physiology and histology differed from those seen in extrinsic allergic alveolitis in ...
Samarel A M - - 1984
Rabbit cardiac cathepsin D exists as multiple isomeric forms of Mr = 48,000 within cardiac tissue. Their mechanism of formation and their functional role in cardiac protein degradation are unknown. We have previously demonstrated that cathepsin D is initially synthesized as an Mr = 53,000 precursor that is processed by ...
Quintal R - - 1984
Ventricular fibrillation has been only rarely observed as a complication of cardiac pacing after the advent of demand pacemakers. Automatic AV sequential pacing (DDD) may provide the setting for ventricular fibrillation in patients with junctional rhythms. In this report we present two patients with implanted DDD pacemakers in whom ventricular ...
Madigan N P - - 1984
The dislodgment rate of permanent pacing ventricular and atrial endocardial leads has significantly decreased with the incorporation of tines as a fixation device. In contrast, transvenous manual extraction of chronically implanted endocardial leads is, at times, clinically indicated, particularly when pacemaker system infection is present. The success rate of such ...
Bowman T A - - 1984
Pre-clinical studies of cardiac pacemakers and new electrodes, materials, and designs are for the most part conducted in dogs. Dogs, however, have electrophysiological differences which may preclude accurate translation to clinical trials. The purpose of this study was to develop normal electrophysiological parameters for an animal whose cardiovascular system more ...
Millar R N - - 1984
Atrial trigeminy was seen in a patient with a normally functioning DVI pacemaker (Byrel-5992). Atrial competition resulted from coincidence of sinus and atrial escape rates together with late ventricular sensing. This resulted in atrial output stimuli occurring within the QRS complex. Alternate impulses occurred late enough to conduct to the ...
Schiavone W A - - 1984
A transvenous left ventricular endocardial pacemaker catheter is a potential source of systemic arterial embolization. The case of a woman who presented with left-eye amaurosis fugax is reported. The patient had a history of contralateral carotid atherosclerosis; however, the digital subtraction angiography of the carotid arteries was not sufficiently abnormal ...
van Mechelen R - - 1984
To evaluate factors playing a role in initiation and perpetuation of pacemaker-mediated tachycardias (PMTs), 22 consecutive patients with symptomatic conduction disorders were studied after implantation of an AV universal (DDD) pulse generator (Cordis 233D). Patients were divided into two groups, depending upon the presence or absence of ventriculo-atrial (VA) conduction ...
van Gelder L M - - 1984
A 45-year-old man who had been implanted with a VVI pacemaker for sinus arrest complained of syncope, dizziness and throbbing in the neck. His pacemaker function was normal, but during ventricular pacing, retrograde V-A conduction was observed. This pacer was replaced by a DVI unit which caused periodic abdominal muscular ...
Fisher J D - - 1984
The possibility of adapting multimode dual-chamber pacemakers for programmed and burst stimulation was explored in a group of patients with ventricular tachycardia. The potential usefulness and pitfalls of these pacemakers were exemplified in one patient, presented in detail. The implanted DDD pacemaker was programmed to an all-synchronous mode (DDT), permitting ...
Amikam S - - 1984
A 3-beat episode of ventricular arrhythmia was recorded in a patient with an AV universal (DDD) pacemaker. This arrhythmia mimicked "endless loop" tachycardia (ELT) because it appeared following a ventricular premature contraction (VPC), its rate approached the preset upper-rate limit and the regular P waves disappeared during the episode. However, ...
Mészáros J - - 1984
The electrophysiological effects of bromobenzoyl - methyladamantylamine ( BMA ) were investigated in isolated electrically driven right ventricular papillary muscles of guinea pigs using conventional glass-microelectrode technique. BMA markedly increased the action potential duration, depolarized the membrane, reduced the maximum rate of depolarization (Vmax) and induced pacemaker-like action potentials. In ...
DiCola V C - - 1984
It has long been possible to prevent death from bradycardia by using single-chamber ventricular pacemakers. Important advances in dual-chamber pacemaker technology now make physiological control of cardiac output during pacing almost a reality. These pacemakers have properly timed atrial contraction and rate variability and have significant hemodynamic advantages over ventricular ...
Parsonnet V - - 1984
In April, 1973, a decade-long study was begun on nuclear-powered pacemakers. The first 15 of these were designed by the Numec Corporation under a contract from the United States Atomic Energy Commission. Altogether 151 units powered by the isotope plutonium 238 were implanted in 131 patients; the pacemakers of 4 ...
Quintal R - - 1984
This case report describes myopotential interference with an automatic AV sequential pacemaker (DDD) producing repetitive firing of the ventricular channel up to a rate of 160 and occasional suppression of the ventricular output. A silastic boot which covered the pacemaker did not prevent sensing of electromyopotentials. The problem was partially ...
Gold R D - - 1984
Progress in both the health sciences and engineering sciences has been necessary for the development of the cardiac pacemaker. From the invention of the vacuum tube triode amplifier in 1906 to that of the oscillator just a few years later; from the early electrocardiograph in 1906 and the first stimulation ...
Reddy C P - - 1984
A patient with recurrent sustained ventricular tachycardia that was resistant to both conventional and experimental antiarrhythmic agents was treated with a programmable automatic scanning extrastimulus pacemaker. The antitachycardia pacemaker was implanted only after many episodes of spontaneous and laboratory-induced ventricular tachycardia were reliably and reproducibly terminated with programmed ventricular extrastimuli. ...
Dangman K H - - 1983
The effects of overdrive stimulation were studied on preparations of isolated canine cardiac Purkinje fibers using standard microelectrode techniques. Preparations were made from false tendons, the subendocardial right bundle branch and 24 hour infarct zone Purkinje fibers. Three types of automaticity were recognized: high potential automaticity occurred in fibers with ...
Richards P - - 1983
The anatomical findings in 52 patients undergoing posterior fossa exploration for idiopathic trigeminal neuralgia are described. Anatomical abnormalities in the cerebello-pontine angle were found in 46. The commonest was an arterial loop indenting or distorting the nerve at the root entry zone. In view of this the operative procedure has ...
Sutton R - - 1983
Fifty-three patients have received 'physiological' pacemakers, 37 with atrioventricular (AV) block having atrial synchronous units (VAT or VDD) implanted and the remaining 16 patients with both AV block and sick sinus syndrome having 'universal' (DDD) pacemakers. Effort tolerance was assessed by serial bicycle ergometry and in 16 patients direct comparisons ...
Lerman B B - - 1983
A multiprogrammable automatic antitachycardia pacemaker (Cybertach-60), connected to a tined "J" wire electrode, was positioned in the right atrial appendage in three patients with recurrent supraventricular tachycardia (SVT). Mechanisms of SVT included atrioventricular (AV) nodal reentry (two patients) and reciprocating tachycardia using an accessory pathway (one patient). Indications for implantation ...
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