PubMed HealthSearch

Biomedical subjects

J Mugica

Publications and source records attributed to J Mugica.

14 recordsLinked to original sources

Noninvasive transcutaneous cardiac pacing: modern instrumentation and new perspectives.

Noninvasive transcutaneous cardiac pacing has evolved from a simple stand alone unit with no ventricular sensing to a complete cardiac arrest resuscitation system combining synchronous pacing and defibrillation capabilities and using a single set of multifunction electrodes. In current instrumentation, four configurations exist including stand alone unit, modular configuration, built-in monitor and recorder, and built-in monitor, recorder and defibrillator. In present day devices, ventricular sensing, extensive programmability, and large surface electrodes are general features. Capture monitoring requires specific integrated electrocardiographic capability. Future developments are expected to involve low threshold electrode technology, integrated mechanical monitoring, and interdevice electrode compatibility.

Cardiac Pacing, Artificial

Is polyurethane lead insulation still controversial?

A controversy arose some 10 years ago over the reliability of polyurethane lead insulation. On the basis of one of the longest standing and largest databanks worldwide, the authors compare the cumulative survival of several thousand polyurethane, standard silastic, and high-performance silastic electrodes as it pertains to the failure criterion described as insulation degradation. With the possible exception of the Medtronic 6972 (Medtronic, Inc.) electrode, polyurethane electrodes have a 100% reliability at 84 months, which is similar to silastic electrodes.

Databases, Factual

Lead failures.

Explore the source record for details and available documents.

Electrodes, Implanted

Methods for recording intermittent contact signals in demand pacemaker arrhythmias (11 cases).

This report describes some of the various techniques which may be used to demonstrate intermittent and/or incomplete fracture of a pacing lead. Eleven patients treated with an R-wave-inhibited demand pacer showed signs of paroxysmal arrhythmias. Intraoperative recordings of the ventricular electrogram showed the presence of spurious signals mimicking an R-wave. These signals varied from patient to patient but remained morphologically constant when a given technique was used in a given case. The most significant signals were picked up when pacing and recording on the same lead.

Arrhythmias, Cardiac

[Determination of first signs of pacemaker failure. Oscilloscopic study before and after removal].

An oscilloscopic study aimed at determining the first signs of pacemaker failure was carried out in vitro after removal in 95 cases. Using a differential apparatus with a 1 megahertz passing band, the following parameters were measured: interspike interval, amplitude, duration and morphology of the spike. During the course of the study, signs of pacemaker failure were seen in 66 cases. It may be concluded that the interspike interval represents the easiest and most precise measurement, making it possible alone to detect dysfunction in 70 per 100 of cases. However, in 30 per 100 of cases, represented by certain types of pacemaker, its alteration is preceded by a decrease in voltage. Whilst the latter may be precisely and easily measured in vitro, the same does not apply when the pacemaker is in situ and only large changes may be taken to be significant and interpreted in relation to the number of batteries in the model studied. Study of the vectrocardiogram should be added to the measurements mentioned above, any sudden change in axis of the spike being an argument in favour of a fault in the conductor. In the future, measurement of the area of the spike, a reflection of the energy delivered the histogram of the RR intervals giving an idea of the respective durations of function and of inhibition in demand models will provide additional information.

Humans

[Pregnancy in women with atrioventricular block. 13 cases].

Thirteen women aged between 18 and 37 years and suffering from atrio-ventricular block had 36 pregnancies. Foetal prognosis was excellent and the pregnancy quite unaffected by the block in 9 cases. In 4 women, Stokes-Adams attacks occurred. In one case from some time ago therapeutic abortion was necessary. Temporary pacing at the time of delivery was used in one case and a permanent pacemaker in one patient. The problems posed by the insertion of a pacemaker in a woman of childbearing age are discussed.

Abortion, Therapeutic

[Diagnostic value of closed thorax pericardial biopsy. 20 cases].

Twenty patients with sub-acute and chronic pericarditis under went closed thorax pericardial biopsy. In three cases the examination brought to light a diagnosis of tuberculosis and in one of a tumoural origin. In 16 cases in which the aetiology was that of a non-specific pericarditis, the value of this examination, integrated into the context, is discussed.

Adult

[Study of the cumulative survival of 1,697 cardiac pacemakers. Superiority of the totally hermetically sealed apparatus].

A comparison of the "cumulative survival" of 1073 totally sealed cardiac pacemakers with that of 624 unsealed models showed the marked superiority of the former group. Calculation of the "cumulative survival" is not only a method which allows a comparison of technological advantages, but also one which can yield the selective replacement time". This concept has direct implications for clinical practice for, once the "elective replacement time" is known for a particular model, it becomes possible to replace the pacemaker electively without having to wait for it to break down or run out, events which are in any case unpredictable and possibly sudden. Knowledge of the "elective replacement time" will also avoid changes being made too early, which is a source of unnecessary expense for the Social Security.

Evaluation Studies as Topic

Demand pacemaker arrhythmias caused by intermittent incomplete electrode fracture. Diagnosis with testing magnet.

This report describes how the testing magnet was used to diagnose intermittent and incomplete electrode fracture in two patients with an implanted demand pacemaker. During fixed-rate pacing the interval between two consecutive pacemaker spikes intermittently doubled in length, suggesting that the pulse generator was continuing to fire on time into a transiently disrupted circuit. Attenuated pacemaker spikes occurring at the anticipated time of pacemaker discharge also provided a diagnostic clue. Ventricular electrograms from the defective electrodes registered small false signals.

Adult

[Continuous electrocardiographic recording. Clinical, diagnostic and therapeutic value].

The interest of permanent electrocardiographic recording in ambulatory patients is not restricted to the demonstration of the cardiogenic origin of some functional disturbances. This method provides the proof of the often non fiable character of anamnesis for the diagnosis of arrhythmias. It shows the close relationship between "minor" (extra-systoles) and "major" (tachycardias) arrhythmias, and consequently the prognostic value of the former in relation with the latter. Continuous ECG follow-up affords in the assessment of anti-arrhythmic drugs efficiency a higher safety than that provided by the conventional simple clinical follow-up.

Anti-Arrhythmia Agents