bluuebunny/crossref_metadata_2025 huggingface dataset:
The Use of the Balloon‐Tipped Floating Catheter in Temporary Transvenous Cardiac Pacing
Authors: LANG ROBERTO , DAVID DANIEL , KLEIN HERMAN O. , DI SEGNI ELIO , LIBHABER CARLOS , SARELI PINCHAS , KAPLINSKY ELIESER
Published: July 2006

The effectiveness and safety of balloon‐tipped, flow guided, electrodes for ventricular pacing as opposed to the fluoroscopy‐guided semi‐rigid bipolar electrodes have never been compared in a controlled study. A prospective study was therefore undertaken to compare both techniques in semi‐elective and emergency procedures. Flow guided electrodes were inserted in 67 patients (group A) and semi‐rigid electrodes in 44 patients (group B). The results of group A were judged to be superior to those of group B in four aspects: a) shorter insertion time (6′45″ vs. 13′30″, p < 0.0005); b) lower incidence of catheter displacement (13.4 vs. 32.0 percent, p < 0.05); c) longer interval of time between implantation and catheter displacement (4.4 vs. 1.9 days, p < 0.0005); d) lower incidence of serious ventricular arrhythmias during insertion (1.5 vs. 20.4 percent, p < 0.005). Threshold at insertion was not significantly different (0.6 ± 0.3 vs 0.7 ± 0.2 milliampere). The superiority of flow‐guided electrodes over fluoroscopy‐guided electrodes persisted in the comparison of semielective insertions in groups A and B. We conclude that the flow‐guided insertion technique is safer, more expeditious and more stable than the fluoroscopy‐guided technique in semi‐elective as well as in emergency insertions. (PACE, Vol. 4, September‐October, 1981)
A Digital Timer for On‐Line Interval Measurement
Authors: KASELL JACK H. , GALLAGHER JOHN J.
Published: July 2006

A digital timer suitable for on‐line timing of cardiac intervals on a beat‐by‐beat basis is described in detail. The device expedites the process of on‐line data acquisition and analysis of mapping and timing of atrial and/or ventricular multiple data points for electrophysiologic surgery. An unusual feature allows interval measurement between a fixed reference point and varying data points to be expressed as a positive value regardless of whether the data point occurs before or after the reference. This low‐cost device is simple to operate and adds versatility to any existing analog recording system. (PACE, Vol. 4, September‐October, 1981)
Pacemaker Syndrome: A Non‐invasive Means to Its Diagnosis and Treatment
Authors: MILLER MURRAY , FOX STEWART , JENKINS RUSSELL , SCHWARTZ JON , TOONDER F. GEOFFREY
Published: July 2006

Vertigo, lightheadedness, syncope, and hypotension occurring after implantation of a ventricular pacemaker has become known as pacemaker syndrome. In one patient with this syndrome we have demonstrated an associated decrease in the pulse amplitude of the ophthalmic arteries during ventricular pacing by utilizing ocular pneumoplethysmography (O.P.G.). This non‐invasive technique was subsequently used intra‐operatively lo test the presence of ophthalmic artery pulse amplitude changes after implantation of the ventricular electrode. An A‐V sequential pacemaker was then implanted and eliminated all symptoms of pacemaker syndrome. (PACE, Vol. 4, September‐October, 1981)
Observations on Mechanisms of Circus Movement Tachycardia in the Wolff‐Parkinson‐White Syndrome. Role of Different Tachycardia Circuits and Sites of Block in Maintenance of Tachycardia
Authors: BRUGADA PEDRO , BAR FRITS W.H.M. , VANAGT EDDY J. , WELLENS HEIN J.J.
Published: July 2006

Different mechanisms of block of impulse propagation in several re‐entrant circuits resulted in a major discordance between the “echo‐zone” and the “tachycardia‐zone” in a patient with intermittent Wolff‐Parkinson‐White syndrome, dual atrioventricular nodal pathways, and bundle branch re‐entry. This case illustrates the delicate balance in electrophysiologi‐cal properties required between the tissues incorporated in a re‐entrant circuit to initiate and sustain the arrhythmia. It also shows how the presence of several reentrant pathways can lead to refractoriness in the circuit responsible for the circus movement tachycardia.
Temperature Dependent Pulse Generator Dysfunction
Authors: ABRAHAMSEN ARNE M. , AARSLAND TORBJØRN
Published: July 2006

Malfunction of a lithium‐powered R‐wave inhibited unipolar pulse generator (CPI* Model 0505) necessitated removal 15 months after implantation. Examination of the pulse generator in a water bath revealed abnormal function at temperatures above 31.5°C and normal function at temperatures below 31.5°C. CPI suggested that the failure was caused by the 10 kHz timing crystal in the generator. (PACE, Vol. 4, September‐October, 1981)
Technique of Insertion of Transvenous Atrial Pacing Leads—The Value of Lateral Fluoroscopy
Authors: THURER RICHARD J.
Published: July 2006

The value of positioning the atrial lead while viewing the patient in the lateral position is pointed out. Satisfactory lead position is rapidly achieved with this technique. (PACE, Vol. 4, September‐October, 1981)
Atropine‐Induced Multilevel Block in Acute Inferior Myocardial Infarction A Possible Indication for Prophylactic Pacing
Authors: CASTELLANOS AGUSTIN , GARCIA HUGO G. , ROZANSKI JOHN J. , ZAMAN LIAQAT , PEFKAROS KYRIACOS , MYERBURG ROBERT J.
Published: July 2006

The degree of A‐V block increased after intravenous administration of atropine in 10 nondigi‐talized patients with acute inferior myocnrdial infarction who had narrow QRS complexes during periods of 1:1 A‐V conduction. Short episodes of 3:1. 4:1 and 5:1 A‐V block were seen to emerge: (a) in 6 patients, directly from Wenckebach periods; (b) in 3 patients, from alternating Wenckebach periods; and (c) in 1 patient, from a 3:2 Wenckebach period which led to a short‐lived alternating Wenckebach period. Apparently, the predominance of the chronotropic effects on the sinus node over the dromotropic effects on the A‐V node led to a tachycardia‐dependent (more ischemic than vagail process, exposing or producing multi‐ (two, three or four) level block involving the A‐V node (and perhaps the His bundle). Subsequently, therapeutic pacing was instituted in 9/10 patients because they developed spontaneous symptomatic advanced A‐V block. Therefore, it is possible that the early effects of atropine identified a narrowly‐defined subset of patients in whom prophylactic pacing may be indicated. However, more studies are necessary to corroborate these assumptions, (PACE, Vol. 4, September‐October, 1981)
A Programmable Pulse Generator with High Output Option
Authors: Sloman Graeme , SMYTH NICHOLAS P.D. , SAGER DIANE , KESHISHIAN JOHN M.
Published: July 2006

A new puise generator, with a programmable high output option, was implanted m fifteen patients and studied for eight to ten months postoperatively. This feature is designed to combat exit bloch. Il was useful in one pati ent who developed a form of exil block following a silenl myocardial in‐farction. Muscle stimulation was rare, even though the system is unipolar. The high output option seems to be a desirable feature and shouldprobabJy be available in all multiprogrammable puise generators, (PACE, Vol. 4, September‐October, 1981)
Pacemaker Failure Following External Defibrillation
Authors: GOULD LAWRENCE , PATEL S. , GOMES G.I. , CHOKSHI A. B.
Published: July 2006

An 81‐year‐old female with the sick sinus syndrome had a permanent pacemaker implanted. She subsequently developed ventricular fibrillation and was successfully defibrillated. However, the defibrillation paddle was placed on the pulse generator which led to a complete Joss of function of the pulse generator. External defibrillation can produce varying degrees of damage to the implanted pulse generator. The resultant abnormalities are discussed and recommended defibrillation procedures are also outlined in this report. (PACE, Vol. 4, September‐October, 1981)
Externally Induced Irreversible Runaway Pacemaker
Authors: VAN GELDER L.M. , EL GAMAL M.I.H.
Published: July 2006

An implanted ventricular demand pulse generator started firing at a rate of 1200 ppm during routine pacemaker follow‐up utilizing the Vitatron VA 1000 pacemaker analyzer. This resulted in complete Joss of capture; fortunately the patient had an intrinsic heart rate of 50 bpm and remained asymptomatic. Emergency replacement of the pulse generator resulted in re‐establishment of effective ventricular pacing. An artificial origin of the impulses from the measuring equipment was excluded. To the best of our knowledge this is the first report of an externally induced irreversible runaway pacemaker. (PACE, Vol. 4, September‐October, 1981)
An Unusual Cause of Pacemaker Current Leakage Causing Muscle Stimulation
Authors: RADCLIFFE P.J. , JONES S. , WARD D.E.
Published: July 2006

Stimulation of skeletal muscle is a fairly common complication of permanent cardiac pacing. The usual cause is direct apposition of the anode of a unipolar pacemaker with muscle surrounding the pocket,1 Other causes include electrode insulation defects2 and electrode displacement,1‐3 In this report we describe an unusual cause of muscle stimulation related to direct current leakage from the pacemaker. (PACE, Vol. 4, September‐October, 1981)
Mid‐systolic Click and Echocardiographic Evidence of Mitral Valve Prolapse During Electrical Pacing
Authors: KLEIN HERMAN O. , DI SEGNI ELIO , DAVID DANIEL , LANG ROBERTO , LEVI ALEXANDER , LIBHABER CARLOS , SARELI PINHAS , KAPLINSKY ELIESER
Published: July 2006

A mid‐systolic click was present in a patient during three years of follow‐up after implantation of a permanent transvenous pacemaker. Echocardiography revealed posterior motion of the anterior leaflet which resembled mitral valve prolapse. Both the click and echocardiographic evidence of prolapse disappeared simultaneously with resumption of sinus rhythm and during supraventricular tachyarrhythmias. With spontaneous change in the position of the electrode three years after initial implantation, both the click and the posterior motion of the mitral valve disappeared. The association of mitral valve prolapse with electrical pacing is most unusual and appears to have a distinct pathophysiological mechanism. (PACE, Vol. 4, November‐December, 1981)
Spontaneous Heart Activity in Pacemaker Treated Patients with High‐grade Atrioventricular Block A Holter Monitor Study
Authors: BREIVIK KJELL , OHM OLE‐JØRGEN
Published: July 2006

A Holter monitor study. A Holter monitor study was performed to assess the occurrence of spontaneous heart activity in 70 pacemaker treated patients (mean age 72.1 years) with high‐grade atrioventricular (AV) block, who had been treated with permanent pacemakers for a mean of 60 months (range 5‐161). Nineteen patients had asynchronous (VOO), and 51 QRS‐inhibited (VVI) pacemakers. The patients were monitored for a mean of 23 hours (range 15.5‐26). Twenty‐five patients were re‐studied for day‐by‐day variations in spontaneous heart activity. At clinical observation, thirty‐eight patients had pacemaker rhythm only. During monitoring, all patients studied had some kind of spontaneous cardiac activity, mostly ventricular ectopic beats. Three patients had short episodes of sinus rhythm of more than 70 beats/min. Patients in functional class III‐IV (NYHA) or with an enlarged heart had the most spontaneous heart activity; those with asynchronous pacemakers had the least spontaneous cardiac activity. No tachyarrhythmias precipitated by interference between intrinsic heart beats and asynchronous pacemakers were seen. Twenty patients studied twice had a relatively stable occurrence of spontaneous heart activity, while five (20%) varied considerably. On the basis of these long‐term observations it is difficult to predict when interference rhythm will occur, and asynchronous pacemakers therefore cannot be recommended for the first implantation. (PACE, Vol. 4, November‐December, 1981)
Short‐Term Threshold Behavior of Human Ventricular Pacing Electrodes: Noninvasive Monitoring with a Multiprogrammable Pacing System
Authors: SCOBLIONKO DAVID P. , ROLETT ELLIS L. , DeTurk Susan
Published: July 2006

Twenty‐two patients were studied for 8 to 12 weeks following pacemaker implantation. A unipolar multiprogrammable pacing system was used to assess and compensate for early post‐implant changes in pulse width threshold (PWT). Changes in PWT were estimated by noninvasive measurements of the lowest pulse width required for 100% capture at constant voltage. All patients showed an early increase in PWT. The magnitude of this change was unpredictable and ranged from 2‐ to 10‐fold. For pacing, we selected an appropriate margin of safety to be a pulse width three times the PWT. During the study period, 4 patients showed critical increases in PWT, requiring reprogramming to an increased pulse width as above, whereas only one patient required lead repositioning. The majority of patients achieved a stable low PWT and were reprogrammed to a reduced pulse width. The programmable pacing system provides a safe accurate technique for monitoring early changes in PWT, defines the need for appropriate alterations in programmable functions, decreases the risk of early pacemaker failure, and offers promise for improved pacemaker longevity in many patients. (PACE, Vol. 4, November‐December, 1881)
A New Orthogonal Lead for P Synchronous Pacing
Authors: GOLDREYER BRUCE N. , OLIVE ARTHUR L. , LESLIE JAMES , CANNOM DAVID S. , WYMAN MILFORD G.
Published: July 2006

P synchronous pacing has long been identified as advantageous for patients with atrioveniricular conduction defects and intact sinus node function. Prior endocavitury systems have been infrequently employed, because of unreliable P wave sensing from standard ring electrodes in the atrium or the requirement for a second atriaJ sensing lead. A single endocardial lead employing a unipolar ventricular stimulating electrode and an orthogonal P wave sensing design was developed and tested in 22 patients undergoing electrophysiologic study or pacemaker implantation. Thirteen centimeters from the stimulating tip of a standard permanent pacing lead, three or four electrodes with a surface area of one millimeter squared, equidistant from the tip, were placed circumferentially about the catheter. With the catheter tip normally placed in the right ventricular apex, atrial sensing eJectrodes were positioned in the mid‐high lateral right atrium, adjacent to, but not affixed to, the right atrial wall. Bipolar orthogonal leads X and Y were obtained. In 22 patients, during sinus rhythm, atrial electrogram voltages in the X axis of 2.47 plus or minus 1.6 millivolts and 2.32 plus or minus 1.6 millivolts in the Y axis were recorded. QRS voltages of 0.078 millivolts and 0.073 millivolts, respectively, allowed dramatic ability to discriminate P from QRS complexes (P/QRS equals 32/1). There was no change in QRS voltages recorded during spontaneous premature ventricular contractions, bipolar or unipolar ventricular pacing. A single catheter designed for P synchronous pacing empJoying circumferentially placed atrial sensing electrodes has demonstrated unique atrial sensing voltages with excellent QRS signal rejection. (PACE, Vol. 4, November‐December, 1981)
Diffuse Conduction Abnormalities in an Adolescent with Familial Sinus Node Disease
Authors: TAN ARTHUR T.H. , EE BERNARD K.H. , MAH P.K. , CHOO MAURICE H.H. , CHIA B.L.
Published: July 2006

We report a case of familial sinus node disease with associated conduction abnormalities in the atrioventricular node and distal conducting system. Spontaneous atrial pacemaker activity was absent though the atrium could be depolarized. The pacemaker activity of the heart resided in the atrioventricular junction. The AV node showed impaired automaticity and abnormal conduction properties which partially improved after vagal blockade. (PACE, Vol. 4, November‐December, 1981)
Limitations of Pacemaker System Analyzers for the Evaluation of Implantable Pulse Generators
Authors: HAUSER ROBERT G. , EDWARDS LYNN M. , GIUFFRE VERLIN W.
Published: July 2006

A variety of commercial pacemaker system analyzers have been used to evaluate the electrical performance of pulse generators prior to implant or at the time of reoperation for pacemaker malfunction. We evaluated the ability of seven commercially available pacemaker system analyzers to provide the data required to determine if a given pulse generator was operating according to its manufacturer's specifications. While all pacemaker system analyzers provided accurate data for rate and pulse duration, values displayed for amplitude and sensitivity were inconsistent due to the methods each pacemaker system analyzer employed to measure these parameters. Overall, 22% of representative test sequences yielded data which would have resulted in the inappropriate rejection of the subject pulse generators for implantation. These observations suggest that pacemaker system analyzers are not suitable for evaluating all pulse generators. Moreover, physicians must be aware of these deficiencies in order to avoid the pitfalls of relying exclusively on pacemaker system analyzer data when troubleshooting pacemaker malfunction. (PACE, Vol. 4, November‐December, 1981)
Treatment of Chronic Ventricular Dysrhythmias in the Young
Authors: GARSON ARTHUR , GILLETTE PAUL C.
Published: July 2006

The decision to treat chronic ventricular dysrhythmias in o young patient is based upon the potential for eJectrophysioIogic or hemodynamic instability. We have treated 51 young patients (mean age 13.4 years; range 1 week to 30 years) with chronic ventricular dysrhythmias according to the following guidelines: multiform premature ventricular contractions (PVCs), couplets and ventricular tachycardia were treated in all patients; frequent uniform PVCs were treated in patients with an abnormal heart. All patients were admitted to the hospital and continuous 24‐hour electrocardiograms (ECGs) were performed. Drug serum concentrations were measured every six hours. A drug was considered “effective” if there were less than 10 uniform PVCs per hour. Drug dosages were increased until clinical signs of mild toxicity developed or the serum concentration was above the therapeutic range. Drug treatment was begun in each patient with phenytoin: 32 received an oral loading dose and 19 an intravenous loading dose. If this was ineffective, other drugs were added or substituted: propranolol, quinidine sulfate and disopyra‐mide. Patients were divided into three groups according to their hemodynamics. The ages and types of ventricular dysrhythmias were similar for the three groups. Group I had 25 patients with severely abnormal hemodynamics; drugs were effective in 92%. Group II had 22 patients with moderately abnormal hemodynamics; drugs were effective in 68%. Group III had four patients with normal hemodynamics; drugs were effective in 50%. Phenytoin was the most effective drug in 39/51 (76%) followed by propranolol in 3/7 (43%) and quinidine in 1/7 (14%). We conclude: (1) chronic ventricular dysrhythmias can be controlled in 76% of children with standard drug regimens. (2) The response to drugs was significantly related to hemodynamic status: the most effective control was in patients with severely abnormal hemodynamics and the least effective was in patients with a normal heart. (3) Phenytoin is the drug of choice for children with ventricular dysrhythmias, especially those with abnormal hemodynamics. (PACE, Vol. 4, November‐December, 1981)
Atrioventricular Dissociation During Paroxysmal Junctional Tachycardia
Authors: KO PATRICK T. , NACCARELLI GERALD V. , GULAMHUSEIN SAJAD , PRYSTOWSKY ERIC N. , ZIPES DOUGLAS P. , KLEIN GEORGE J.
Published: July 2006

We describe the rare occurrence of atrioventriculor dissociation in three patients during paroxysmal functional tachycardia. The mechanism of tachycardia was atrioventricular nodal reentry in two patients. The third patient had reentrant tachycardia that utilized the A V node for at least part of the reentrant circuit. This patient also had a nodoventricular pathway that may have participated in the reentrant circuit. In two patients, ventricular tachycardia was diagnosed prior to electrophysiologic assessment and medication to prevent tachycardia was not successful. After electrophysiological studies, treatment directed at suppressing AV nodel reentry prevented recurrent tachycardia. These case studies demonstrate the importance of detailed electrophysiological assessment of tachycardia in patients whose arrhythmia does not respond to empirical antiarrhythmic therapy. (PACE, Vol. 4, November‐December, 1981)
External Electrical Stimulation in the Management of Acute Tachyarrhythmias
Authors: WIRTZFELD A. , SCHMIDT G. , KLEIN G. , WORZEWSKI W.
Published: July 2006

For the management of acute tachyarrhythmias various methods of electrical temporary pacing are available which offer advantages over other forms of treatment such as use of antiarrhythmic agents or electrocardioversion. This paper gives a survey of the different pacing methods foverdrive pacing, rapid rate stimulation, overdrive suppression, underdrive pacing and programmed stimulation) and discusses their application, indications, effectiveness and possible complications. (PACE, Vol. 4, November‐December, 1981)
Subtle EGG Sign of Acute Infarction: Prominent Reciprocal ST Depression with Minimal Primary ST Elevation
Authors: Barold S. Serge , GOLDBERGER ARY L. , ERICKSON RICHARD
Published: July 2006

In most cases of acute transmural infarction, the reciprocal ST segment depressions observed in contraiateral leads are less marked than the primary ST segment elevations. Two unusual cases are presented where reciprocal ST depressions were the predominant findings due to the orientation of the injury current vector. Failure to recognize this pattern may impede the diagnosis and localization of acute infarction. Furthermore, these cases illustrate the principle that “hyperacule” T waves may only appear as a slight, relative increase in T wave posltivity rather than as a marked absolute increase in T wave amplitube. (PACK, Vol. 4. November‐December, 1981)
Pseudo‐fracture of Pacemaker Lead Due to Securing Suture: A Case Report
Authors: WITTE ALBERT A.
Published: July 2006

With improved pacemaker lead design and materials, complications caused by lead problems have decreased.4,5 There have been isolated reports of leads severed by suture material but they have been rare. Presented is a case of suture‐induced “pseudo‐fracture” in a urethane‐insulated ventricular lined endocardial lead (Medtronic Model #6971‐58). No loss of capture or sensing function has been encountered eight months following initial implantation. It is felt that the softer, stronger urethane permitted compression and resulted in a radiographic suggestion of a fractured lead, but lead integrity does not seem to have compromised. Although (his may be an inconsequential radiographic finding, it could lead to an inappropriate lead removal unless it is properly interpreted. (PACE, Vol. 4, November‐December, 1981)
Multiple Conduction Delays within the His Bundle
Authors: REDDY C.V. RAMANA , GOULD LAWRENCE
Published: July 2006

His Bundle recordings in a 75‐year‐old male with complete heart block exhibited split His Bundle potentials with three components thus demonstrating multiple conduction delays within the bundle of His.
Electrophysiologic Characterization of Surgically Induced His Bundle Rhythm in Man
Authors: GONZALEZ ROLANDO , SCHEINMAN MELVIN , THOMAS ARTHUR , DESAI JAWAHAR , PETERS ROBERT , DZINDZIO BARRY
Published: July 2006

Seven patients who had His bundle section and permanent ventricular pacemaker insertion for intractable recurrent supraventricular tachycardia underwent electrophysiologic studies 4–6 months postoperatively. The permanent pacemaker was inhibited to assess the His bundle recovery time (HBRT) and spontaneous His bundle rate (SHBR) (tenth postinhibition cycle). In addition, in five of the seven patients, the HBRT and SHBR was also assessed during mild supine exercise and after administration of intravenous atropine followed by lidocaine. There was no significant difference in HBRT or SHBR before exercise (2695 ± 1056 ms; 1435 ± 75 ms), during mild supine exercise (2220 ± 1564 ms; 1379 ± 42 ms), or after atropine (2152 ± 544 ms; 1379 ± 117 ms) or lidocaine (3943 ± 3198; 1487 ± 139 ms, respectively). Only one patient showed consistent lengthening of both HBRT and SHBR after lidocaine. On a separate day, programmed ventricular extrasiimuli were induced during ventricular overdrive pacing. In three of the seven patients, programmed ventricular extrastimuli resulted in typical bundle branch reentrant depolarizations. Four of the seven patients underwent maximal exercise treadmill testing. In none of these four patients did the His bundle rate exceed that of the implanted pacemaker. We conclude that prolonged pauses often follow pacemaker inhibition in these patients; therefore, careful follow‐up of pacemaker function is required. Surgically induced His bundle rhythms in man are characterized by spontaneous rates of 38.7 to 45,5 beats/min and do not increase their rate after vagolysis or during mild exercise. In addition, the atrioventricular node is not required for bundle branch reentry in man.
Delayed Pulse Generator Malfunction after D.C. Countershock
Authors: PALAC ROBERT T. , HWANG MING H. , KLODNYCKY MARY L. , LOEB HENRY S.
Published: July 2006

Immediate pacemaker malfunction following defibrillation or cardioversion has been reported. In this paper we report one patient whose pacemaker appeared to be functioning normally after D.C, countershock but malfunctioned 13 days later manifested by changing from an R‐wave inhibited to an R‐wave synchronous mode.
The Mechanism of Flutter Electrical Alternans
Authors: ROZANSKI JOHN J. , ZAMAN LIAQAT , LUCERI RICHARD , PASTORIZA JORGE , KLEINFELD MORRIS , CASTELLANOS AGUSTIN , MYERBURG ROBERT J.
Published: July 2006

We have had the opportunity to observe the occurrence of flutter electrical alternans in which two distinct populations of flutter waves are present and which alternate in 1:1 and 2:1 patterns. The flutter alternans whether 2:1 or 3:1, was concordant with the pattern of preceding ventricular conduction (ventriculophasic variation). This concordance occurred reproducibly and remained consistent. Our example of flutter allernans probably represents mechanical artefact caused by catheter movement during ventricular mechanical systole. We reproduced this pattern consistently at a slower rate during coronary sinus pacing. These findings appear to suggest an explanation for certain types of so‐called atrial flutter electrical alternans.
A Digital Module for Cardiac Pacemaker Assessment
Authors: BILITCH MICHAEL , MORTARA DAVID W. , SARMA J.S.M.
Published: July 2006

The accuracy of a digital pacemaker testing module incorporated into a digital recording electrocardiograph has been tested against two other methods of waveform recording. Measurements of rate (pulse interval), pulse width, pulse amplitude and ratio of trailing edge to the leading edge amplitude were found to be highly accurate. The pulse shapes were faithfully recorded. The practical clinical use of the method is discussed.
Problems Encountered during Insertion of Permanent Endocardial Pacing Electrode
Authors: GILLMER DAVID J. , VYTHILINGUM SHANMUGAM , MITHA ABDUL S.
Published: July 2006

Case reports of two potential problems arising during permanent endocardial pacemaker electrode insertion are described. They are cannulation of a persistent left‐sided superior vena cava, and unsuspected subclavian vein thrombosis. A left‐sided superior vena cava may be recognized clinically and avoided; but, if necessary, it can be employed as a route to the right ventricular endocardium. Subclavian vein thrombosis appears to be a complication of previous cephalic vein pacemaker insertion and prohibits further access on the implanted side. It may present with a painful, swollen arm or with the symptoms of multiple pulmonary emboli; occasionally it is not clinically suspected unless abnormal venous distension is sought.
Atrioventricular Block in Childhood Caused by Mesothelioma
Authors: HELLEMANS I.M. , van HEMEL N.M. , KOOYMAN C.A.
Published: July 2006

The case of a girl who was first seen at 3.5 years of age with longstanding asymptomatic heart block is reported. Electro‐physiological study disclosed a block proximal to the His bundle. She grew up normally until the age of 11.5 years, when a syncopal attack occurred. Before a pacemaker could be inserted, she suffered a second fatal attack. Necropsy revealed a tumor of the atrioventricular node diagnosed as mesothelioma. Our findings are compared to the 38 cases already described in the literature.
Non‐invasive Analysis of Simulated Pacemaker Failure Available in Multiprogrammable Pulse Generators
Authors: DALY JAMES E. , WITTE ALBERT A.
Published: July 2006

Non‐invasive analysis of muscle fascicuhtion using selected sensitivity settings is described This case report demonstrates trouble‐shooting methods afforded by the multi‐parameter programmable pulse generator while avoiding invasive generator and lead analysis Multiple pacing modes and sensitivities allow simulation of apparent generator malfunctioning as well as variable programming modes best suited to pacing needs
Myocardial Stimulation with Ultrashort Duration Current Pulses
Authors: PEARCE J.A. , BOURLAND J.D. , NEILSEN W. , GEDDES L.A. , VOELZ M.
Published: July 2006

In order to identify a practical short‐duration limit for stimulating myocardium, theoretical and experimental studies were carried out using dog and turtle hearts The strength‐duration curves for current, charge and energy were derived from the standard excitable membrane model which employs a parallel resistance and capacitance. From these derivations, the predicted duration for minimum energy was identified. The experimentally measured strength‐duration curves for two types of myocardium followed the predicted vaiues cioseiy The duration for minimum energy was calculated to be 1.25 times the membrane time constant. The practical short‐duration limit for a pacemaking stimulus is about 30% of the membrane time constant. For dog myocardium the average time constant was 2.4 ms Therefore, a practical stimulus duration for minimum charge in the dog should be no longer than about two‐tenths of a millisecond, although shorter duration stimuli are equally effective This minimum charge criterion provides the minimum drain on the stimulator power supply
Acute and Chronic Clinical Performance Comparison of a Porous and a Solid Electrode Design
Authors: BERMAN NEIL D. , DICKSON SHARON E. , LIPTON IRVING H.
Published: July 2006

The long‐term performance of porous and solid ring‐tipped electrodes was compared in clinical use over a one‐year period Each of the two electrode designs was implanted in 22 patients in conjunction with an output‐programmaWe pacemaiter. Implant evaiuation included impedance, height of sensed R wave, and a strength‐duration curve. Threshold determination by pulse‐width programming was performed at the time of implant and at one week, two weeks, two months, six months, and one year. There were no dislodgements with either electrode. No significant differences were noted in the acute parameters or in chronic thresholds.
Recent Advances in Antiarrhythmic Drug Research: Studies in Chronic Canine Myocardial Infarction‐Ventricular Tachyarrhythmia Models
Authors: Dreifus Leonard S. , MICHELSON ERIC L.
Published: July 2006

Several chronic canine myocardial infarction‐ventricular tachyarrhythmia models are now available for the evaluation of new antiarrhythmic drugs The available models ful‐fill many, but not all of the requirements for an ideal chronic arrhythmia model Sustained arrhythmias can be initiated in these animals using routine methods of programmed pacing. Presumably, the mechanism for these arrhythmias is localized re‐entry, similar to that in patients with previous myocardial infarction and chronic coronary artery disease However, these models are not suitable for determining whether a new drug will abolish spontaneously‐occurring ventricular extrasystoies In addition, these models are of unproven value in the study of acute spontaneously‐occurring sudden death, although recently initiated, provocative work may shed further light on this subject Most important, the available models do seem well‐suited to the evaluation of new drugs intended for use of chronic coronary artery disease patients at risk for sustained re‐entrant ventricular tachycardia or fibrillation Notably, the results of preliminary electropharmacologic studies in these canine models parallel closely those findings reported in human patients with sustained life‐threatening ventricular tachyarrhythmias. Therefore, increased use of these chronic models for new antiarrhythmic drug testing appears promising
Automatic Detection of Pacemaker Pulses in Ambulatory ECG Recording
Authors: Sloman Graeme , TRANESJÖ JUSSI , FÅHRAEUS THOMAS , NYGÅRDS MATS‐ERIK , WIGERTZ OVE
Published: July 2006

This paper discusses the problem of pacing pulse detection in electrocardiograms (ECG) recorded from ambulatory patients It is concluded that for optimal performance a device for automatic pulse detection must be implemented as a preprocessor prior to the record/reproduce system The accuracy of such a detector, realized as a bandpass filter followed by a threshold eiement, has been evaluated in 12 patients with artificial pacemakers
Two‐Dimensional Echocardiographic Identification of Pacing Catheter‐Induced Thrombosis
Authors: Nanda Navin C. , SCHUSTER ALLAN H. , ZUGIBE FREDERICK , NANDA NAVIN C. , MURPHY GERALD W.
Published: July 2006

We describe a case in which pacing catheter‐induced thrombosis of ihe great veins is demonstrated by two‐dimensional real‐time echocardiography
Damaging Effect of Therapeutic Radiation on Programmable Pacemakers
Authors: ADAMEC R. , HAEFLIGER J.M. , KILLISCH J.P. , NIEDERER J. , JAQUET P.
Published: July 2006

Two series of present‐day pacemakers were tested in vitro with pulsed x‐ray radiation. The first series of 12 pacemakers consisted of 10 different types and models of demand pacemakers (VVI). The second series of 13 pacemakers had 9 different types and models of programmable pacemakers. Unlike the first series which showed only mild changes in frequency and pulse width, all but four of the programmable pacemakers presented sudden complete failure after different radiation doses. We conclude that direct pulse radiation at therapeutic levels of programmable pacemakers should be avoided. (PACE, Vol. 5, March‐April 1982)
X‐ray Effects on Pacemaker Type Circuits
Authors: BLAMIRES N.G. , MYATT J.
Published: July 2006

Queries have been raised concerning the potential hazards of X‐ray irradiation on patienls using the new generation of heart pacemakers based on digital circuitry. The present study was undertaken to provide some answers to these queries. The work was conducted in two parts. First, a literature search was done and, second, circuits using current “state of the art” digital technology were irradiated with X‐rays. Watch circuits were chosen because of their availability and built‐in facilities by which their function could be tested. Doses up to 330 rods were administered to them using energies of 46.114, and 141 KeV. The conclusion drawn from both parts of the study was that X‐rays used for diagnostic purposes were uniikeiy to affect the performance of this type of circuit in any way. It was accepted that for therapeutic purposes doses far in excess of this are administered and circuit malfunctions are likely to occur. To assess the probability of a digital pacemaker malfunctioning, samples of that particular type would have to be irradiated at the reievent dose. (PACE, Vol. 5, March‐April, 1982)
Pacemaker Failure Due to Radiation Therapy
Authors: KATZENBERG CHARLES A. , MARCUS FRANK I. , HEUSINKVELD ROBERT S. , MAMMANA ROBERT B.
Published: July 2006

Pacemaker malfunction occurred after a patient was given 3000–3600 rads to an area occupied by an A‐V sequential pacemaker. Analysis of the removed generator showed that there was malfunction of the large scale integrated circuit and the type of damage was consistent with radiation‐induced effects. The newer muJtiprogram‐mable units may be more sensitive to ionizing radiation than those previously available. (PACE, Vol. 5, March‐April, 1982)
Malignant Ventricular Arrhythmias in Chronic Chagasic Myocarditis
Authors: CHIALE PABLO A. , SUSANA HALPERN M. , NAU GERARDO J. , PRZYBYLSKI JULIO , TAMBUSSI ANA M. , LÁZZARI JULIO O. , ELIZARI MARCELO V. , ROSENBAUM MAURICIO B.
Published: July 2006

We studied 28 cases of chronic chagasic myocarditis (CCM) with frequent ventricular arrhythmias. Two‐hundred and three conventional ECGs recorded during 3 months showed ventricular extrasystoles (VE) ranging between 0.2 and 6 per ten beats in 100%; multiform VE in 97.04%; couplets in 79.31%; ventricular tachycardia (VT) in 42.85%; and R on T in 21.67%. A 24‐hour continuous recording showed that VE ranged between 3780 and 61733 (mean 16618 ± 2627); muitiform VE and couplets were present in 100% of patients, and VT was present in 78.5%. In 16 patients (group I) the frequency of VE was persistently high, without diurnal variation; 11 patients showed sustained reduction during sieeping hours and only one showed an increase during night sleep (group II). Even in group II, VE never disappeared for periods longer than 10 minutes. In five patients, four 24‐hour recordings were obtained at weekly intervals, and in five other patients a second 24‐hour recording was performed 10 to 24 months later. The remarkable frequency, persistence and low variability of ventricular arrhythmias in CCM suggest that such arrhythmias can be used as a most stable, reliable, but highly demanding model for testing the efficacy of antiarrhythmic drugs. (PACE, Vol. 5, March‐April, 1982)
Rapid AV Nodal Re‐entrant Tachycardias Presenting with Syncope or Pre‐syncope: Use of Eiectrophysioiogicai Studies to Select Therapy
Authors: WIENER ISAAC , RUBIN DAVID , PITCHON ROBERTA , BOCCARDO DANIEL
Published: July 2006

Five patients with recurrent syncope or pre‐syncope due to rapid supraventricular tachycardias underwent electrophysiological study. In each patient, an AV nodal re‐entrant tachycardia could be induced. By leaving a coronary sinus catheter in place, the effects of drugs on the ability to induce tachycardia could he tested on sequential days. Drug effects were highly variable, but in each patient it was possible to determine a drug which prevented induction of tachycardia. Patients treated with this drug have had no recurrent symptoms or tachycardias with a followup of 4–21 months. Although AV nodal re‐entry is highly dependent on autonomic tone, electrophysiological study appears to be a useful means of selecting therapy in patients with severe, symptomatic tachycardias. (PACE, Vol. 5, March‐April, 1982)
The Use of Active Fixation Electrodes for Permanent Endocardial Pacing Via a Persistent Left Superior Vena Cava
Authors: HELLESTRAND K.J. , WARD D.E. , BEXTON R.S. , CAMM A.J.
Published: July 2006

Two patients underwent permanent endocardial pacing for complete atrioventricular block. In each case a persistent left superior vena cava was either suspected or known to be present. An active fixation electrode was passed down the left superior vena cava and the tip positioned in the apex of the right ventricle. Stable ventricular pacing was achieved for the follow‐up period of approximately six months. With the availability of such active fixation electrodes the presence of a persistent left superior vena cava no longer mandates insertion of an endocardial electrode via the right superior vena cava. when present, or implantation of an epicardial pacing system. (PACE, Vol. 5, March‐April, 1982)
Late Unheralded Pacemaker Pocket Infection Due to Staphylococcus epidermidis: A New Clinical Entity
Authors: WOHL BARRY , PETERS ROBERT W. , CARLINER NATHAN , PLOTNICK GARY , FISHER MICHAEL
Published: July 2006

Late pacemaker pocket infections in the absence of predisposing factors such as multiple pacemaker related procedures, skin erosion, chest wall trauma or generalized sepsis have been rarely reported. In the past year, we have seen three late pocket infections (18, 32 and 47 months post‐implanlafion) due to Staphylococcus epidermidis (S. epidermidis). All three patients with late S. epidermidis infections presented with painless swelling over the pulse generator site and had been well until shortly before admission. The patients denied febrile illnesses or chest trauma in the preceding year and no skin erosion was evident. All had been seen regularly in clinic and bimonthly transtelephonic recordings had shown normal pacemaker function. Local drainage, antibiotics and removal of the pacing system was successful in all three patients. We conclude that late pacemaker pocket infections due to S. epidermidis may become an imporlanf clinical problem in this era of long‐lasting pulse generators. In light of the insidious nature of S. epidermidis infections, regular inspection of the pocket area by both patient and physician is mandatory. (PACE, Vol. 5, March‐April, 1982)
Ventricular Fibrillation After Intravenous Atropine in a Patient with Atrioventricular Block
Authors: LÁZZARI JULIO O. , BENCHUGA ELÍAS G. , ELIZARI MARCELO V. , ROSENBAUM MAURICIO B.
Published: July 2006

A 69‐year‐old black woman with complete AV block developed ventricular fibrillation following an IV injection of 1 mg of atropine sulphate. After a successful DC countershock, the ECG showed a polymorphous ventricular tachycardia which subsided spontaneously. Cardiac catheteriza‐tion revealed a small left ventricular diverticulum and normal coronary arteries. This seems to be the first reported case of atropine‐induced ventricular fibrillation in a patient with complete AV block. The fact that this occurred without previous change of the ventricular rate suggests that the adverse action of atropine was mediated through a mere vagolytic effect at the ventricular level (PACE, Vol. 5, March‐April, 1982)
Clinical Evaluation of an Adaptive Tachycardia Intervention Pacemaker with Automatic Cycle Length Adjustment
Authors: NATHAN ANTHONY , HELLESTRAND KEVIN , BEXTON RODNEY , NAPPHOLZ TIBOR , SPURRELL ROWORTH , CAMM JOHN
Published: July 2006

An exlernal version of a new pacemaker designed for automatic tachycardia termination is described. In response to a tachycardia, defined as four successive beats occurring at a rate faster than a variable preset value, a number of stimuli (1–15) are generated. The initial coupling interval and subsequent pacing cycle intervals (where applicable) are always the same. Failure to terminate tachycardia results in the reduction of the pacing cycle length by 6 ms before termination of tachycardia is re‐attempted. Pacing cycle length reduction may be repeated up to 16 times. If all coupling intervals of a single extrastimulus fail to achieve tachycardia termination, a second stimulus is scanned with the first through the same range of decrements. Additional stimuli, to a total of 15. could be used. A memory function is incorporated to retain and re‐use a successful sequence. The pacemaker was evaluated in 16 patients with recurrent “supraventricular” (atrioventricular and intra A‐Vnodal) tachycardia, using right ventricular pacing. Termination was successful in all patients. More than two stimuli were necessary in only two patients, one of whom required five, and the other six stimuli. No unwanted arrhythmias were induced. (PACE, Vol. 5, March‐April, 1982)
The Use of Atrial Pacing to Evaluate Patients with Definite or Suspected Wolff‐Parkinson‐White Syndrome
Authors: BASSAN MAYER M. , GANNEM JIHAD
Published: July 2006

Four patients with definite or suspected WPW syndrome are presented in order to show that valuable clinical information can be obtained via simple atrial pacing. In three cases with a questionable resting ECG, atrial pacing produced pathognomonic changes in the QRS complex, eslablishing the diagnosis of WPW syndrome. In the fourth case, atrial pacing provoked the associated tachyarrhythmia, which had not previously been documented. In all four cases, functional properties of the accessory pathway could be assessed, and in three cases, the induction of atrial fibrillation allowed estimation of the risk of ventricular fibrillation. For evaluating patients with definite or suspected WPW syndrome, the technique of atrial pacing is recommended as an alternative to sophisticated electrophysiological studies which are costly and require special expertise and equipment. Airial pacing is easier, cheaper, and less traumatic, and for many patients will provide most, if not all, the necessary information. (PACE, Vol. 5, March‐April, 1982)
“Invisible” Pseudo‐Pseudofusion Beats
Authors: CASTELLANOS AGUSTIN , ZAMAN LIAQAT , MYERBURG ROBERT J.
Published: July 2006

Three simultaneous leads (I, II and VI) were recorded in a patient with a normally functioning bipolar AV sequential (DVI) pacemaker. Superimposition of the ineffectual atrial spikes upon the early part of the QRS complexes resulted in pseudo‐pseudofusion beats, clearly identified in lead II, However, the small spikes were hardly seen in lead I and not seen at all in lead VI. Therefore, the pseudo‐pseudofusion beats were “almost invisible” and “invisible,” respectively, in these leads. Delivery of atrial spikes within the beginning of the QRS complexes was possible because sensing of the ventricular electrogram occurred after the onset of ventricular depolarization in the surface leads. (PACE, Vol. 5. March‐April, 1982)
Transvenous Physiological Pacing—A New Atrioventricular Electrode
Authors: Sloman Graeme , Sloman Graeme , LAJOS THOMAS Z.
Published: July 2006

Twenty‐eight patients were paced physiologically by transvenous atrioventricular electrodes since 1968. Fourteen of the twenty‐eight patients received the new modified atrioventricular electrode (Mark 11). Technical details of the electrode and recent modifications are elaborated. Pacing threshold characteristics, indications and method of introduction are discussed. (PACE, Vol. 5, March‐April, 1982)
Electrophysiological Properties of a New Permanent Endocardial Lead for Uni‐ and Bipolar Pacing
Authors: Sloman Graeme , BREIVIK KJELL , ENGEDAL HOGNE , OHM OLE‐JØRGEN
Published: July 2006

BRElVIK, K., ENGEDAL, H., and OHM, O.‐J.; Ehctropbysiological properties of a new permanent endocardial lead for uni‐ and bipolar pacing. Unipolar and bipolar electrode systems were compared for electrogram amplitudes and slew rates, signal source impedance, and myocardial stimulation threshold and resistance in 15 consecutive patients who received a new endocardial electrode (Cordis 325–161). The bipolar electrograms showed the highest amplitude in nine of the patients (60%). The unipolar and bipolar electrograms were equal in four patients (26.7%), whereas the unipolar electrograms were highest in only two patients (13.3%). The difference in mean amplitude between bipolar (11.1 mV) and unipolar (10.1 mV) electrograms was statistically significant (p 0.05). Mean slew rates were almost equal (1.7 versus 1.6 V/s; p > 0.1). The bipolar electrode system always gave somewhat higher signal source impedance than the unipolar system (p 0.001). The current threshold was significantly lower during bipolar pacing (0.59 mA) in constant current pacing mode, than during unipolar pacing (0.65 mA) (p < 0.05). No significant differences were found during constant voltage pacing. Stimulation resistance was highest in the bipolar electrode system (p < 0.001). We conclude that the bipolar eiectrode system is as good as, or better than, the unipolar system both for ventricular sensing and for pacing. (PACE, Vol. 5, March‐April, 1982)