bluuebunny/crossref_metadata_2025_split huggingface dataset:
Physiological Benefits of Atrial Synchrony in Paced Patients
Authors: SUTTON RICHARD , MORLEY CHRISTOPHER , LU CHAN SIEW , PERRINS JOHN 
Published: July 2006

Au cours ?une période de cinq ans, nous avons comparé la stimulation ventriculaire et la stimulation. “physiologique” chez 50 malades. Dans 17 eas de stimulation de type DVI, le débit systolique était plus éevé que dans la stimulation VVI, (P < 0.005), de même la pression télédiastolque du ventricule gauche était plus basse (P < 0.05). Chez 44 maJades la performance au cours de ľexercice était meilleure avec la stimulation VDDJDDD (P < 0.01). Ces effets se sont confirmés à long terme. La dyspnée était moindre (P < 0.01) et ľimpression de “bien‐être”était confirmée (P < 0.01) avec la stimulation physiologique. Nous concluons que la stimulation cardiaque synchrone àľoreillette est le mode de choix en ľabsence de contre‐indications.Over a five‐year period, hemodynamic exercise capacity studies and a randomized controlled trial have been performed in a total of 50 patients. DVI vs. VVI pacing showed an increase in stroke work index (P < 0.005) and a fall in left ventricular filling pressure (P < 0.05) in 17 patients. VDDJDDD pacing vs. VVI showed an exercise capacity benefit in 44 patients (P < 0.01) including 8 patients with sinus node disease and a lower peak heart rate (P < 0.02). Maintenance of benefit was also shown of VDDJDDD pacing in the longer term (13 months) vs. acute (P ‐ NS). The controled trial VDDJDDD vs. VVI showed benefit in shortness of breath (P < 0.01) and general well being (P < 0.01). It is concluded that atrial synchronous ventricular pacing (VDDJDDD) is the mode of choice in suitable patients.
Physiologic Benefits of Rate Responsiveness
Authors: SHAPLAND J.E. , MACCARTER D. , TOCKMAN B. , KNUDSON M. 
Published: July 2006

Ľaugmenfation du besoin métabolique ou cours de ľexercice est fournie par une hausse du débit cardiaque et de ľapport ?oxygène. Les malades porleurs ?un stimuluteur à fréquence fixe ne peuvent pas augmenter la fréquence cardiaque dont dépend ľaugmentation du débil systolique. Nous décrivons un stimulateur capable ?augmenter sa fréquence suivant ľuctivité auriculaire. Par cette méthode nous avons observé un meilleur débit cardiaque, de ľordre de 55 ± 3.7%. Ce stimulafeur améliore donc la performance cardiaque pendant ľexercice.Increases in metabolic demand in response lo routine activities and exercise are met througb grealer cardiac output ond oxygen delivery. Putienls with fixedrate pacemakers cannot increase heart rate and must rely solely on increases in stroke volume to provide the necessary adjustments in cardiac output. These compensatory strofte volume increases limit the fixedrate pacemaker patient's ability to meet the demand of their daily routine. A physiological, rate responsive pacemaker was studied and it was found to increase maximum exercise tolerance from 4.4 ± .62 METS paced VVI at 65 ppm to 8.1 ± .71 METS when the same patients were paced rate responsively at an average rate of 91 ± 3.8 ppm. Animal studies were used lo quantify the limitation in stroke volume reserve. Maximum increases of 55.8 ± 3.7% over resting vulues were seen in animals in complete heart block at pacing rates of 100 ppm during strenuous exercise. Higher pacing rates increased cardiac output at the same exercise intensity, from 4.94 ± .72 Ipm at 100 ppm lo 7.66 ± 1.02 Ipm at 250 ppm. A pacemaker that increases pacing rate in response to grealer metabolic demand will maintain stroke volume and enddiastolic volume at near normal voiues while providing significant improvement in cardiac output and work capacity.
Management of Tachyarrhythmias with Dual‐Chamber Pacemakers
Authors: MEDINA‐RAVELL VICTOR , CASTELLANOS AGUSTIN , PORTILLO‐ACOSTA BOLIVAR , MADURO‐MAYTIN CASTOR , RODRIGUEZ‐SALAS LUIS , HERNANDEZ‐ARENAS MANUEL , LA SALLE‐TORO RAUL , MENDOZA‐MUJICA IVAN , ORTEGA‐MALDONADO MANUEL , BERKOVITS BAROUH V. 
Published: July 2006

Des stimulaleurs multiprogrammables AV séquentiels de type “double‐demande” (DVI, MN) ont été implantés chez 23 patienls porteurs ?anomalies variées de tachycardies supraventriculaires. De plus, des stimuloteurs AV séquenfiels à paire “nonobligée” (DVI, MN e(DDD, M) ont été utilisés pour le traitement de lachyarhythmies ventriculaires. Nous avons observé que ľexpérience avec ee type de stimulateur multiprogrammable est favorable chez les patients sans fibrillation auriculaire chronique, qui ont besoin ?un stimutafeur et qui nécéssitent un froilement anti‐tachycardique. Ľévolution des stimulateurs du type DDD contribuera sans doute à un traitement encore plus éfficace.Multi‐programmable dual‐demand AV sequential (DVI, MN) pacemakers were implanted in twenty‐three potients (in one of them a DVI, MN unit was used as a VVI, MN with the aid of an atrial plug) with suproventricular tachycardias after electrophysiological studies revealed a great voriety of AV reentry circuits. The latter included tachycardios involving accessory pathways of the Kent type, manifest or concealed Wolff‐Parkinson‐White syndromes, nodo‐ventricular (Mahaim) tracts, “enhanced” AV node for extra AV nodal) pothwaysand dual AV pathways. In addition, multiprogrammable “non‐committed” AV sequential (DVI, MN and DDD, M) pacemakers were permanently implonted to treat different forms of ventricular tachyarrhythmias that included: torsode de pointes in the Romano‐Ward syndrome and Chagas' cardiomyopathy, ventricular tachycordia which is bradycardia‐dependent (in Chagas' cardiomyopathy) and reciprocal beats indueed by, and producing severe hemodynamic derangements in a patient with a conventional VVI unit. With smallsize multiprogrammable units, arrhythmias may be treated by changing parameters non‐invasively. By temporary inhibition, one may analyze the underlying rhythm and pacemaker dependency. In potients without chronic atrial flutterJfibrillation who require pacing and possibly tachyarrhythmia control, our experience with multiprogrammable “non‐committed” AV sequential pacing has been very satisfactory. The evolution toward newer pacing modes which provide atrial sensing and trackmg (DDD), and thus preserve AV synchrony over a wider range of atrial rates, may contribute even further to successful patient management. This may be applicable to pediatric patients as well.
Principles of Multimode Pacing
Authors: TARJAN PETER P. 
Published: July 2006

En dépit de la proliferation des systémes de stimulation dits physiologique, ľanalyse de leur fonction par ľéléctrocardiogramme est restée complexe. Une meilleure méthode ?analyse est done necessaire pour aider le clinicien à mieux comprendre les systemes DDD. Le dialogue entre fabricant et clinicien doit done rester toujours ouvert.Although physiologic pacing systems have multiplied recently, their functional evaluation by ECG analysis remains an area of relative complexity. More thorough and detailed specifications of operation are necessary to aid the clinician in his effort to understand and assess the function of a DDD pacer. Elimination of cross‐talk via various available methods should simplify interpretation. Awareness by physicians will provide the necessary feedback to the designers to create more physiologic systems in the future.
Detection and Characteristics of Retrograde P Waves
Authors: RIPART A. , PIOGER G. 
Published: July 2006

Le systéms de détection de ľactivité auriculaire present dans les stimulaleurs actuels VDD ou DDD ne permet pas de faire avec certitude to distinction entre ľactivit? aurieulaire normale et rétrograde. Il apparait done nécessaire de mettre au point un systéme efficace de détection et de prévention des tachycardies induites par les stimulateurs, qui ne limitera pas les bénéfices hémodynamiques apportés par ces appareils.Clinical evaluation performed on an external prototype of a programmabie VDD pacemaker showed a high risk of induction of pacemaker‐mediated tachycardia. In these tests tachycardia was observed following magnet removal, premature atrial and ventricular complexes, myopotential oversensing, detection of electri‐cal interference and other events. The high risk and poor predictability of pacemaker‐mediated tachycardia suggest that VDD (or DDD) pacemakers should provide automatic means to control this kind of tachycardia without undue loss of the hemodynamic benefits which can be provided by these units.
Prevention of Pacemaker Mediated Arrhythmias
Authors: ELMQVIST HAKAN 
Published: July 2006

Les tachycardies de type réentrée induites par les stimulateurs à deux chambres sont présentées. Les méthodes utilisées pour prévenir ces arythmies sont énumérées. La méthode la plus efficace consiste à reprogrammer la période refractaire de la détection ouriculaire alin ?éviter la stimulation ventriculaire induite par une onde P rétrograde.Pacemaker mediated re‐entry tachyarrhythmias and their causes are discussed. Several methods to prevent these arrhythmias are presented. It is shown that the most efficient method incorporates a long refractory period of the atrial detection after ventricular depolarization. The benefits of a short A‐V delay after atrial sensing are discussed.
Dual‐Chamber Committed Mode Pacing
Authors: CALFEE RICHARD V. 
Published: July 2006

La prolifération de slimulateurs AV séquentiels est responsable de ľexistence de plusieurs modes de stimulation DVI. La distinction entre “paire obligée” et “paire non‐obligée” est expliquée. En plus, un mode di (“hybride” a élé mis en production. C'est le mode des paires demi‐obligées. Ce mode de stimulation divise ľintervalle AV en deux: une partie non‐physiologique suivie ?une partie physiologique oúľinhibition ?un stimulus ventriculaire est possible aprés un recueil de ľactivité ventriculaire.The proliferation of dual‐chamber pacemakers has resulted in several different modalities of DVI pacing. A distinction is made between “committed” and “noncommitted” modes, and the differences are presented. In addition, a new hybrid mode has been developed which has been termed “semi‐committed” and is currently being introduced. The semi‐committed mode divides the AV interval into an early non‐physiologic interval and a later “physiologic” interval which enables inhibition of ventricular output following a sensed ventricular event.
Comparison of Pacing Electrodes of Different Shape and Material—Recommendations
Authors: IRNICH WERNER 
Published: July 2006

Plusieurs suggestions pour la comparaison des différenles électrodes de stimulation sont énumérées. Dans Ja majorité des rapports cités, ces comparaisons n'atteignent pas leur but, parce que les paramètres de mesure utilisés ne sont pas constants. Un calendrier pour les mesures de seuil aigu et chronique est proposé rheobase et chronaxie est aussi expliqué. EnFin le rôle de la polarisation ?électrode est disculé.Recommendations for comparing different pacing electrodes to one another are presented. In most reported studies, such comparisons fall short of the intended gool because they are made with eiectrode parameters that are not constant. The suggestions presented include timetables for acute and chronic threshold measurements, conditions for measuring lead impedance, and the relationship between rheobase and chronaxie. In addition, the effects of polarization of the electrodes are discussed.
Porous Electrodes: Concept, Technology and Results
Authors: MacCARTER DEAN J. , LUNDBERG KATHLEEN M. , CORSTJENS J.P.M. 
Published: July 2006

Ľélectrode poreuse a été déVelopée pour améliorer le recueil ainsi que la qualité de la stimulation. Ces électrodes créent une interface au niveau de ľendocarde qui a pour but (1) de diminuer les seuils de stimulation chronique, (2) de faciliter la pénétration de la fibrose dans ľélectrode afin ?éviter les déplacements et (3) de présenter une surface électrolytique importante de contact pour réduire le voltage de polarisation. Les résultats cliniques actuels sonl favorables. Les avantages de ľéiectrode poreuse à long terme restent à décrire.Porous electrodes were designed and implanted to optimize sensing and pacing performance of the cardiac pacemaker. These eJectrodes were manufactured to create an effective, atraumatic endocardial interface in order to (1) decrease chronic stimulation thresholds and pacemalter current drain; (2) facilitate fibrous protein tissue ingrowth for reduced electrode displacement; and (3) to create a large electroiytic surface area of contact for reduced polarization voltage, thus improving impulse and electrogram transmission. Thus far, clinical results demonstrate reduced long‐term threshold and decreased current drain. Long‐term advantages of porous electrodes remain to be determined.
The Carbon Tip Electrode
Authors: ELMQVIST HAKAN , SCHUELLER HANS , RICHTER GERHARD 
Published: July 2006

Le developement de ľelectrode au carbone et les seuils de stimulation à long terme sont presentés. En comparaison avec les matériaux ?électrodes usuels, ľélectrode au carbone permet des seuils de stimulation à long terme plus bas. Chez 43 patients, il a été possible de diminuer le voltage des stimulateurs lorsque ľélectrode au carbone était utilisée. Ce matériau favorise done ľutilisation des stimulateurs à basse énergie.The development of the carbon tip electrode and its low chronic threshold behavior are described. Compared to presently used electrode material, carbon tip electrodes result in lower chronic stimulation thresholds. In a group of 43 patients, chronic pulse generator output has been favorably reduced in association with this type of electrode. Thus the use of activated carbon tip electrodes may result in the routine implantation of low output pacemakers.
Polyurethane Leads: Facts and Controversy
Authors: SCHEUER‐LEESER MARION , IRNICH WERNER , KREUZER JOACHIM 
Published: July 2006

Une comparaison des électrodes de stimulation en polyuréthane et en silicone est présentée. Lorsq́ue ľon compare tes qualités mécaniques et électriques, les qualités de friction et la stabilité hydrolytique, les deux matériaux paraissent capables ?être utilisés comme game des sondes ?électrode. Néanmoins, en raison des craquelures de surface observé'es avecle polyuréthane il est nécessaire ?obtenir des surfaces aussi précises et parfaites que possible. De plus, les manoeuvres de torsion et de courbure doivent être évitées lors de ľimplantation. Enfin, la surveillance à long terme doit être assurée ?une façon routiniere.A comparison of polyurethane and silicone cardiac pacing leads is presented. In comparing mechanical and electrical properties, friction coefficient and hydrolytic stability, both are highly qualified for use as electrode sheaths. The occurrence of surface cracking of polyurethane leads is examined. Several suggestions are proposed for dealing with the manufacture of new leads, the technique of implantation, and the follow‐up required for successful surveillance.
Orthogonal Electrogram Sensing
Authors: GOLDREYER BRUCE N. , KNUDSON MARK , CANNOM DAVID S. , WYMAN MILFORD G. 
Published: July 2006

Le recueil de ľéléctrogramme intracardiaque donne ľinformation nécessaire aux systèmes de stimulation à la demande. Les troubles du recueil surviennent dans près de 50% de stimulateurs unipolaires, ceux de ľoreillette sont encore plus fréquents. Le recueil par électrode orthogonale ne demande pas de contact avec le myocarde et on obtient de hauts potentiels ?origine auriciilaire avec rejection totale des pontentiels ventriculaires. Ce système permet la sequence ?activation aussi bien que la vérification de la capture.Intracardiac electrogram sensing is the afferent limb of demand pacing systems. Under‐ and over‐sensing at the ventricular level has been demonstrated in almost 50% of implanted unipolar pulse generators, and atrial eJectrogram sensing problems are more common. A unique dedicated sensor employing noncontacting and circumferentially placed orthogonal electrodes was tested at both the atrial and ventricular levels. Electrograms demonstrated voltages similar to those recorded from contacting electrodes, but with complete far‐field rejection of signals from the opposite chamber. Orthogonal electrograms allowed for activation sequencing and capture verification as well.
“Crown of Thorns” Single Pass Lead ‐ Clinical Results
Authors: SOWTON EDGAR , WAINWRIGHT R.J. , CRICK J.C.P. 
Published: July 2006

Vingt‐quatre patients ont ete tracés pendant une période ne dépassant pas deux ans (14 mois en moyenne) àľaide ?une sonde auriculo‐ventriculaire unique. Les récents progrès de fabrication permettpnt ľinsertion percutanée dans la veine sousclavière. Les seuils de stimulation et le recueil pour ľoreiilette et pour le ventricule restent satisfaisonts pour plusieurs types de stimulateurs. Aucune complication liée à cette sonde n'a été observée chez 277 mois/patients. Nous concluons donc que cette sonde auriculoventdculaire unique est utilisoble pour ľimplantation à long terme des stimulateurs physiologjques.Twenty‐four patients have been treated for periods of up to two years (mean 14 months) with this single pass electrode for physiological pacing. Manufacturing refinements now allow percutaneous insertion into the subclavian vein. Pacing thresholds and sensing signals from both atrium and ventricle have remained satisfactory for a wide variety of different physiological pacemakers. No complications specifically related to the lead have occurred in a total of 277 patient months. We conclude that this single pass electrode is suitable for long‐term implantation and can provide physiological pacing with present day stimulators.
Results, Problems and Perspectives with the Autoregulating Pacemaker
Authors: CAMMILLI L. , ALGIDI L. , SHAPLAND E. , OBINO S. 
Published: July 2006

Ces variations peuvent être utilisées pour réguler la fréquence de stimulation op‐timale. Des recherches continues sont nécessaires pour perfectionner ce système; surtout en ce qui concerne la surface de ľélectrode et ľamelioration du contrôle et de la réponse du capteur.Experi‐mental in vitro testing coupled with animal and clinical studies have shown that a pH sensor may sense acute changes in pH occurring in response to exercise. This signal may in turn be used as a determinant for optimal pacing rate. Further investigation into membrane coating of electrodes and algorithm testing is necessary to maximize sensor response and control.
Wide QRS Tachycardia: Multiple Mechanisms in a Patient after Myocardial Infarction
Authors: YEE RAYMOND , KLEIN GEORGE J. 
Published: July 2006

A 34‐year‐old man was hospitalized for extensive antero‐apical myocardial infarction. Eight weeks after discharge from the hospital, he had intermittent rapid palpitations. During several episodes, a rapid, regular, wide‐QRS‐complex tachycardia with left bundle branch (LBB) morphology was recorded. All antiarrhythmic agents administered to the patient were unsuccessful in alleviating his symptoms, which were thought to be due to supraventricular tachycardia (SVT) with aberration. An electrophysiologic study was performed and revealed three morphologically distinct types of wide complex tachyarrhythmias: 1) Tachycardia 1 was determined to be A‐V re‐entry with antegrade conduction utilizing the normal A‐V conducting system and retrograde conduction over a concealed accessory pathway located in the left A‐V groove; 2) tachycardia 2 was identified as ventricular tachycardia (VT); and 3) tachycardia 3 was considered to be a second morphologic type of ventricular tachycardia as the morphology was identical to some of the episodes documented clinically. The patient was treated with oral amiodarone which was unsuccessful until combined with quinidine; this regimen has suppressed recurrence of VT during a four‐month period of follow‐up.The occurrence of wide‐QRS‐complex tachycardia in this patient immediately suggested the diagnosis of VT, but our other findings were unexpected. This case illustrates the need for considering all possible mechanisms when seeking to manage tachyarrhythmias, even if the diagnosis appears obvious.
Long‐Term Follow‐up of Pulse Width Threshold of Transvenous and Myo‐epicardial Leads
Authors: HENGLEIN DAGMAR , GILLETTE PAUL C. , SHANNON CATHLEEN , BURNS GINA 
Published: July 2006

Postoperative pulse width thresholds were measured at a constant of 5 volts in 140 patients. In 41 patients, transvenous atrial and/or ventricular leads were implanted at a median age of 13 years (3–78 yrs). Myo‐epicardial leads were implanted in 99 patients at a median age of 8 3/4 years (1 wk to 76 yrs). The initial rapid rise of threshold was found to persist not longer than to the third follow‐up period of 11 days to 5 weeks in all atrial and transvenous ventricular leads; in myo‐epicardial ventricular leads it persisted until the period of more than 5 weeks to 6 months. During initial rise, pulse width threshold m + sem did not exceed 0.45 ms. We therefore suggest that a pulse width setting of 0.5 ms at 5 V is a safe setting for this period. In only one patient did a late rise of threshold occur.The comparison of pulse width thresholds of transvenous versus myo‐epicardial leads showed lower mean values for transvenous atrial leads in each follow‐up period, but the difference was not statistically significant. The pulse width thresholds of transvenous ventricular leads were significantly lower than those of myo‐epicardial leads in some follow‐up periods. We therefore conclude that transvenous leads have a slight advantage with regard to postoperative pulse width threshold.
Electrical Termination of Tachyarrhythmias by Discrete Pulses
Authors: GERMAN LAWRENCE D. , STRAUSS HAROLD C. 
Published: July 2006

Reentrant tachycardias can often be terminated by discrete pacing stimuli that penetrate the reentrant circuit. The ability of discrete stimuli to terminate an arrhythmia depends on the timing of the stimulus, the distance from the site of reentry where the stimulus is applied, the electrophysiologic properties of the myocardium between the site of stimulation and the site of reentry, and the size of the reentrant circuit.Modes of pacing used to terminate tachycardia have included single or multiple timed extrastimuli, overdrive pacing, burst pacing and competitive asynchronous (underdrive) pacing. Patient‐triggered devices that deliver asynchronous pacing stimuli are routinely available. Newer devices have been developed that automatically sense the onset of tachycardia and respond with pacing stimuli. These devices have been highly effective in selected patients with supraventricular tachycardia. The seriousness of occasional pacing‐induced acceleration of ventricular tachycardia or conversion to ventricular fibrillation has limited the application of these devices in patients with ventricular arrhythmias. Pre‐implantations electrophysiologic studies are necessary to document arrhythmia mechanisms and to determine the feasibility of various pacing modalities in treating the tachycardia. The potential for complicating arrhythmias (atrial fibrillation/flutter or ventricular fibrillation) must also be tested.Future devices designed for terminating tachycardias with discrete pulses should be capable of being programmed to respond with one or more of the various modalities available. These devices should automatically and reliably sense both tachycardia onset and termination, and should adjust their responses appropriately if initial stimulation sequences fail to terminate the arrhythmia.