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Biomedical subjects

S Furman

Publications and source records attributed to S Furman.

At least 199 records · Page 11Linked to original sources
PubMed1984

A registry for implantable antitachycardia devices.

Antitachycardia electrical stimulation involves significant problems of sensing the cardiac rhythm and determining whether a tachycardia exists. The simple algorithms developed for bradycardia pacing are inadequate for tachycardia pacing. Electrogram signal analysis and cardiac activation analysis with at least two leads will be required to make a device diagnosis of a tachycardia. Termination of a tachycardia reliably and consistently is difficult and has been accomplished reliably only by defibrillation. Further development of devices which are multimodal in termination capability is necessary. A registry for tachycardias and for tachycardia management is required to provide concentrated and analyzable data from a modality as yet infrequently used.

Electric Countershock↗
PubMed1984

Simultaneous atrial and ventricular electrogram transmission via a specialized single lead system.

No telemetrically monitorable pacemakers are capable of detecting and transmitting the complete electrogram (EGM) during normal and paced rhythms, although some are capable of detecting and transmitting either the P- or R-wave. A new lead and telemetry-pacemaker system has been developed that permits the transmission of the complete EGM and is not adversely affected by pacemaker outputs or after-potentials. Electrodes are placed in the right ventricle and atrium to optimize EGM detection. These A-V data probe electrodes are electrically separate from the pacing-sensing electrodes but are structurally part of a coaxial ventricular lead that is no larger than a conventional bipolar lead (2.3 mm). The telemetry system is also compatible with telephone monitoring systems. The system has consistently demonstrated its ability to detect accurately the EGM during normal sinus rhythms and does not affect atrial, ventricular, or A-V sequential pacing. In addition, this system can detect and transmit EGM abnormalities, including ectopic beats, retrograde conduction, and ischemic changes. A-V data leads with telemetry monitored VVI pacemakers have been implanted in dogs for over two years. This system will provide the means to detect and telemetrically record noninvasively the entire normal and abnormal EGM, even in pacer dependent patients. (PACE, Vol. 7, November-December, 1984).

Animals↗
PubMed1984

The role of the computer in cardiac pacemaker technology.

To satisfy the need for even higher performance and smaller size, pacemaker design makes use of the latest available technology. This high level of technology in pacemakers requires an even higher level of technology in the follow-up system. Present methods consisting of independent programmers for each pacer model are confusing to the operator and inadequate. The solution to pacer follow-up developed at Montefiore consists of a three step program: 1) computer-assisted program which guides the personnel interactively through the follow-up; 2) computer-controlled program which enables the person to send identical commands to various programmers and let the computer program identify the various pacer models; and 3) built-in program where the testing and the follow-up are performed internally to the pacer through stored programs. The system is developed in the MIIS version of the MUMPS language but was extensively modified to make conversion to other languages easy.

Arrhythmias, Cardiac↗
PubMed1984

Implantation of automatic cardioverter-defibrillators via median sternotomy.

15 AICD (automatic implantable cardioverter-defibrillator) Model B units were implanted in 10 patients. The median sternotomy is our preferred surgical approach using a right atrial patch electrode, a left ventricular apex patch electrode, and two closely placed epicardial sensing electrodes. Follow-up is 109 patient months and all patients are alive. AICD units discharged for ventricular tachycardia, ventricular flutter, and ventricular fibrillation. Discharges also occurred for sinus tachycardia and atrial fibrillation above the rate limit in three units. Premature pulse generator depletion has occurred in four AICD-B units 3 to 18 months postimplant and appears due to a defect in original battery design. Discharge of the AICD for supraventricular tachycardia is a problem that will remain until a better means of differentiating supraventricular tachycardia from ventricular tachyarrhythmias is found. The AICD appears to prevent sudden death from ventricular tachyarrhythmias.

Adult↗
PubMed1984

Programmed upper-rate limit dependent endless loop tachycardia.

In a patient with a VDD dual chamber pacemaker, an endless loop tachycardia (ELT) appeared spontaneously or could be provoked by magnet application and removal. The duration of the ELT was dependent on the programmed upper-rate limit of the pacemaker, ie, the higher it was set, the shorter the duration of the ELT. This was caused by the automatic variable pacemaker AV delay (the Wenckebach effect) which prolongs maintaining the programmed cycle length at each upper-rate limit during the tachycardia. This case illustrates the mechanism by which increasing the upper-rate setting of this unit prevents or restrains the ELT.

Aged↗
PubMed1984

Results of electrophysiologically guided operations for drug-resistant recurrent ventricular tachycardia and ventricular fibrillation due to coronary artery disease.

Over a 39 month period, 143 patients with coronary artery disease had programmed stimulation (PES) for recurrent ventricular tachycardia (VT) or ventricular fibrillation (VF). Twenty-two patients underwent operations. Ages ranged from 40 to 71 years; 20 of the 22 were men. All patients had coronary artery disease and 11 had left ventricular aneurysms. The mean ejection fraction was 31% (16% to 50%). Eighteen of the 22 patients underwent operations for drug-resistant ventricular arrhythmias (more than six different drugs plus drug combinations tested per patient). Nineteen patients had intraoperative mapping, endocardial resection, and/or an encircling endocardial ventriculotomy. Three patients with ischemia-related VT had coronary artery bypass (CABG) alone. The 30 day operative mortality was 14%. Thirteen of 19 (68%) operative survivors were effectively controlled with operation alone or a combination of operation and previously ineffective drug therapy. Of the six patients whose VT was inducible postoperatively, three have experienced episodes of sustained VT and one patient died suddenly. Three of these patients have the automatic implantable defibrillator. Operation guided by endocardial mapping is effective alone or in combination with drugs in this select group of patients. If the patients' VT was uninducible postoperatively with or without the addition of antiarrhythmic therapy, late deaths (3/19) were due to poor myocardial reserve and coronary artery disease, not the reemergence of sustained ventricular arrhythmias during a mean follow-up of 15 months.

Adult↗
PubMed1983

The telephone in family practice.

In a time-and-motion study in family practice it was found that 35,8% of all patient contact was per telephone. The study further revealed that 12,3% of total practice time was spent on the telephone, stressing its importance as a useful tool in family practice. The study supports others which suggest that 'telephone medicine' is worthy of careful examination in terms of cost-effectiveness. The implications for the doctor-patient relationship are also considered.

Family Practice↗
PubMed1983

Atrio-ventricular and ventriculo-atrial conduction times in patients undergoing pacemaker implant.

Pacemaker mediated reentrant tachycardias have been seen frequently during use of dual chamber sensing pacemakers and are dependent on the presence of intact retrograde (ventriculo-atrial) conduction. The status of a patient's retrograde (VA) conduction cannot be determined from the surface electrocardiogram. At the time of pacemaker implant the state of antegrade conduction should be determined at incremental atrial pacing rates, the exact timing measured from the intracardiac electrograms, i.e., from the intrinsic deflection of the intrinsic deflection of the ventricle. With this information obtained in 53 patients, it was possible to determine which patients could safely receive dual chamber sensing pacemaker devices, the appropriate pacemaker atrial refractory period setting to avoid pacemaker mediated tachycardias in those patients with intact retrograde conduction, and the optimal timing for programming the pacemaker's AV delay. Patients who have been studied in this manner and who were felt to be suitable for a dual chamber sensing device have not displayed pacemaker mediated reentrant tachycardias. Forty-seven percent of all patients who require pacemaker implant have VA 1:1 conduction; 67% of those with sinus node dysfunction and 14% of those with complete antegrade block have VA conduction at a mean interval of 235 +/- 50 ms (range 110-380 ms).

Atrioventricular Node↗
PubMed1983

Atrial lead malposition in a dual chamber (DDD,M) pacemaker.

A model 7000 pacemaker in the DVI mode emitted two stimuli, the first stimulating the right ventricle and the second 110 ms later. The atrial lead was found in the right ventricular outflow tract. The QRS complex produced by the atrial lead fell after the blanking period, and "committed" the ventricular stimulus 110 ms after the "atrial." Intracardiac electrography during the original implant would have enabled proper atrial lead position.

Aged↗
PubMed1983

Optimal resources for implantable cardiac pacemakers. Pacemaker Study Group.

In this document, the 1974 Inter-Society Commission for Heart Disease Resources (ICHD) report, Implantable Cardiac Pacemakers, has been revised and updated to emphasize the increased complexity of present-day pacing, to propose realistic guidelines for various aspects of pacing practivce, and to identify the resources needed for delivery of this important mode of health care. The first section of the report describes the several types of pacemakers currently available, how they function, and how and to what purpose they may be modified through noninvasive programming. Recommendations are given for a modified and updated version of the widely accepted ICHD code for identification of pacing modes. The emphasis of the second section of the report is on physical and personnel resources. Matters considered in some depth include the training and qualification of the various medical, technical, and paramedical specialists involved in an implantation procedure; requirements for, and methods of achieving, short and long-term surveillance of pacemaker patients; and the role of the hospital, the manufacturers, and the FDA in this new era of complex dual-chamber, multiprogrammable pacemakers.

American Heart Association↗