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Biomedical subjects

J Mugica

Publications and source records attributed to J Mugica.

At least 55 records · Page 3Linked to original sources
PubMed1982

Failure in the rate adaptation of the atrial refractory period: its relationship to vulnerability.

We evaluated the relationship of rate-dependent changes in atrial refractoriness to atrial vulnerability in 39 patients. Vulnerability was considered present when sustained atrial tachyarrhythmias, lasting longer than 1 minute, could be provoked with one to three extra stimuli. Adaptation of atrial refractory period duration to rate was defined as: normal: steep rate reduction with a linear correlation slope value of 0.08 or more; non-adaptation: absence of rate reduction, the slope value being 0 to 0.01; poor adaptation: slight reduction with rate, the slope having values of 0.02 to 0.07. Increased vulnerability was demonstrable in 16 of 17 patients with non-adaptation of the effective refractory period (ERP), and in 10 of 10 with a similar defect of the functional refractory period (FRP); in the intermediate category (poor adaptation) the results for ERP and FRP were 7/11 and 5/6. By way of contrast when both measurements showed normal adaptation, vulnerability was elicited in 2/9 patients. The significance between these groups showed P less than 0.005. Of 17 patients with atrial arrhythmia by Holter, 14 showed poor or non-adaptation of the ERP. It is suggested that poor or absent rate adaptation of the atrial refractory period, and a propensity to atrial fibrillation or flutter, constitute a clinical entity not previously described.

Adolescent↗
PubMed1982

[Computers in a center for cardiac stimulation].

The authors describe a computer system with details of the hard ware and filing organisation. The sophistication and originality of the programme makes it a multipurpose tool base on a condensed dictionary. Its uses may be summarised under three headings: --The upkeep of medical case notes, a very successful application, resulting in improved safety in the long term follow-up of pacemaker patients. Statistical analysis of multiple parameters in larger series of patients is possible, a task which could not be carried out without a computer. --The system has the advantage of providing secretarial help in the booking of follow-up appointments, automatic print-out of follow-up reports and letters to the referring physician. This leads to better efficiency in correspondence. --The third advantage is the stocking and treatment of numeric data on a wide range of materials, leading to the creation of its own data bank. The programme as described has been adopted for cardiology and, in particular, cardiac pacing. It could, however, be applied in all fields of medicine, especially those using other materials (valvular prostheses, orthopedic appliances, etc).

Adult↗
PubMed1981

Computer quantitated evaluation of cardiac arrhythmias.

The identification of a cardiac arrhythmia depends on the interpretation of both the QRS complexes and the P waves. P wave detection is unreliable and hence automated diagnostic systems are often imperfect. An alternative is a system which detects QRS only and which classifies the QRS events; the physician then has a detailed quantitated QRS analysis to aid in diagnosis. The ATREC system has an analog QRS detector, which suppresses the P wave and the T wave frequencies and feeds a minicomputer (Mitra 15/35) with signals for the RR interval, the QRS duration, and polarity. The computer classifies these signals as either narrow or wide complexes. The narrow complexes are analyzed for irregular rhythm, bradycardia, pauses, transient or continuous tachycardia, and fibrillation. The wide complexes are classed by their coupling interval, bi- or trigeminy, doublets, or salvos, and the number per hour. The system gives a trend of the 16 beat mean, and the minimum and maximum heart rate. The data is presented on several displays.

Analysis of Variance↗
PubMed1980

[Arrhythmia in patients with demand pacemakers caused by faulty conduction material in the electrode. 36 cases--Value of Holter monitoring].

36 cases of paroxysmal pacing failure in patients with demand pacemakers are reported. The possible causes of pacing lead problems, excluding inhibition by muscular contractions, are related to the distal extremity at the electrode itself, on the lead (rupture) or at the connection between the lead and the pulse generator. The recognition of the precise cause of the pacing failure leads to appropriate treatment. These arrrythmias are not always easy to detect and Holter monitoring is a very useful means of diagnosis.

Arrhythmias, Cardiac↗
PubMed1978

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↗