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Biomedical subjects

S Botella

Publications and source records attributed to S Botella.

6 recordsLinked to original sources
PubMed1996

[Survival in patients with sick sinus syndrome and artificial pacemaker. Determining clinical factors].

INTRODUCTION AND OBJECTIVE: The hypothesis that ventricular pacing is the most important factor in the survival of patients with Sick Sinus Syndrome remains controversial. The aim of this report was to determine independent clinical variables to predict survival in paced SSS patients. METHODS: Retrospective, nonrandomized study of 153 patients with a mean age of 69 +/- 11 years, who received an initial pacemaker for Sick Sinus Syndrome between 1980 and 1994: 65 physiologic pacing (32 dual chamber, 33 atrial) and 88 ventricular pacing mode. After a maximum follow up of 177 months (median 57 months) the end point was total mortality. RESULTS: Total mortality was 21%. Using univariate analysis, single chamber ventricular pacing, age > or = 70 years and NYHA > or = 2, was associated with a higher risk for total mortality (4 times increased risk for ventricular pacing compared to other pacing modalities). Independent predictors using multivariate analysis were: 1) NYHA > or = 2 (p < 0.05). 2) Coronary artery disease (p < 0.01). 3) Chronic obstructive pulmonary disease (p < 0.05) and 4) Gender (p < 0.05). CONCLUSIONS: Mortality in patients with the Sick Sinus Syndrome is strongly predicted by preimplant baseline clinical variables. Our data indicate that the role of ventricular pacing mode remains inconclusive. A large, randomized study is necessary to confirm these results.

Age Factors↗
PubMed1994

[The incidence and significance of late potentials in patients with aborted sudden death].

BACKGROUND: Reentrant ventricular tachycardia and fibrillation probably have different electrophysiological bases. Regional conduction delay during sinus rhythm seems to be greatest in patients with spontaneous sustained ventricular tachycardia than in patients with spontaneous sustained ventricular fibrillation. We investigated the prevalence and significance of late potentials in patients with documented VT or VF in the setting of coronary diseases and other organic heart diseases. PATIENTS AND METHODS: Nineteen patients with a history of spontaneous sustained ventricular tachycardia (11 patients) or fibrillation (8 patients) were studied with signal-averaged ECG. All patients had been resuscitated of sudden cardiac death. All recordings were made in sinus rhythm in an antiarrhythmic free state following the recommendations of the Committee of the European Society of Cardiology for data acquisition and analysis of ventricular late potentials using Signal Averaged Electrocardiography. The relationship between this late potentials and tachyarrhythmia inducibility during electrophysiologic study were established. RESULTS: Abnormal late potentials were found in 79% of patients with sudden cardiac death. Patients with spontaneous ventricular tachycardia had a longer ventricular activation time in sinus rhythm than did patients with spontaneous ventricular fibrillation, but this difference did not reach statistic significance. The only analysis of late potentials could not discern the mechanism of sudden cardiac death. However when sudden cardiac death was caused by a spontaneous ventricular tachycardia, a good correlation between abnormal late potentials and induced ventricular tachycardia by programmed stimulation was found. Quantitative indices of late potentials did not correlate with ventricular tachycardia cycle length. CONCLUSIONS: 1) We have found and elevated incidence of abnormal late potentials in patients with sudden cardiac death, and 2) only when the mechanism of sudden cardiac death was a spontaneous VT, we were able to correlate abnormal late potential with provoked ventricular tachycardia during electrophysiologic study.

Aged↗
PubMed1992

Molinate decontamination processes in effluent water from rice fields.

The performance of aeration, photodecomposition and biological degradation processes as methods to reduce molinate contamination levels in effluent water from rice fields was studied. Aeration produced a molinate dissipation of 84%, as against 22% without aeration. Application of UV-light to clean water solutions achieved a molinate photodecomposition of 96% in 24 h. Maximal degradation obtained in algal cultures was 55% in 20 days and 78% in 40 days. In micro-organism cultures, kept in darkness and with a continuous flow of aqueous solution of molinate and inorganic salts, a degradation of 97% was achieved.

Azepines↗
PubMed1981

Function of atrioventricular node conduction: hyperbolic model.

Twenty four patients were subjected to an electrophysiologic clinical procedure. The conventional extrastimulus test was applied to verify the relation between conduction time increase through the atrioventricular node of the extrastimulus beat (delta AH), and its preceding interval (A1A2). Following the least square root method the parameters of the hyperbolic model delta AH.A1A2 = m . delta AH + n were adjusted. The correlation coefficients obtained and tested in all cases were very high and significant. From this hyperbolic equation it was possible to determine the equations for the effective refractory period (ERPe = m) and functional refractory period (FRPe = ERPe + n). The theoretical values for refractoriness approached very closely those of the actually measured ERP and FRP, in all cases. This model proved to be, in respect to adjustments and especially in calculating refractory periods, at least as good as the exponential model proposed previously by other authors.

Adolescent↗