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Biomedical subjects

R Chávez Domínguez

Publications and source records attributed to R Chávez Domínguez.

17 recordsLinked to original sources
PubMed1998

Diagnostic electrocardiography in epidemiological studies of Chagas' disease: multicenter evaluation of a standardized method.

An electrocardiographic recording method with an associated reading guide, designed for epidemiological studies on Chagas' disease, was tested to assess its diagnostic reproducibility. Six cardiologists from five countries each read 100 electrocardiographic (ECG) tracings, including 30 from chronic chagasic patients, then reread them after an interval of 6 months. The readings were blind, with the tracings numbered randomly for the first reading and renumbered randomly for the second reading. The physicians, all experienced in interpreting ECGs from chagasic patients, followed printed instructions for reading the tracings. Reproducibility of the readings was evaluated using the kappa (kappa) index for concordance. The results showed a high degree of interobserver concordance with respect to the diagnosis of normal vs. abnormal tracings (kappa = 0.66; SE 0.02). While the interpretations of some categories of ECG abnormalities were highly reproducible, others, especially those having a low prevalence, showed lower levels of concordance. Intraobserver concordance was uniformly higher than interobserver concordance. The findings of this study justify the use by specialists of the recording of readings method proposed for epidemiological studies on Chagas' disease, but warrant caution in the interpretation of some categories of electrocardiographic alterations.

Argentina↗
PubMedDate not supplied

[Reconstructive surgery of the mitral valve. Experience with 400 cases].

From january 1980 to december 1992 a total of 400 valvulopathies were subjected to conservative mitral procedures: 364 had rheumatic heart disease, 33 were congenital abnormalities and 3 probably myxomatous. Functional class and the cardiomegaly, were in grade III and IV in most cases. Different procedures were done; the most common one was commisurotomy, also subvalvular apparatus opening, annuloplasty ring and a newly designed procedure called "Tension Stitch". The results were satisfactory, with a reoperation rate of 9.2%, mostly caused by fibrosis which in turn caused dysfunction. A second cause were technical problems. The mortality rate was 2%, and was not caused by the procedure itself but because of bad clinical status of the patients. The follow up period was 13 years and showed an actuarial survival curve of 98%, with 90.8% free of reoperation and a very good post-op quality of life. We present this analysis in a effort to bring this procedure to the attention of cardiac surgeons, considering it as an alternative to prosthesis placement.

Adolescent↗
PubMedDate not supplied

[Dopamine in essential arterial hypertension: excretion of its metabolite homovanillic acid].

The results obtained in a group of 66 hypertensive patients in which the AHV values were 5.7 plus and minus 0.4 mM/24 hrs., were reported. These values were compared to those obtained in 42 healthy subjects: 7.0 plus and minus 0.5 mM/24 hrs. The difference was statistically significant P less than 0.05. The values of excretion of urinary dopamine in both groups were also presented. A value of 225.7 plus and minus 13.0 mug/24 hrs. was obtained for the hypertensives, while the value for the healthy groups was 361.2 plus and minus 16.5. The statistical study in this case showed a high significance p smaller or less than 0.001. There were no changes in the levels of adrenaline and noradrenaline nor in the metabolite of these two amines, that is, AVM.

Adolescent↗
PubMedDate not supplied

[Arterial blood pressure in various groups in the urban population of Morelia City].

Four groups from a urban population of Morelia were inquired, to determine frequency of high blood pressure and provide basic information of arterial hypertension in relation with other variables; 2638 persons were checked. Age ranged from 10 to 90 years, (771 men, 1867 women). Age, sex, weight and height were also measured. Evaluations were performed in the morning with mercury sphygmomanometer registering first and fifth korotkoff's sounds in orthostatic position with a second selective evaluation in sitting position. Availability of medical services and knowledge about presence of arterial hypertension were also evaluated. Blood pressure and prevalence of hypertension had similar behavior with regard to age: pressure recordings were higher in men before 40 years. After this age were higher in women. In general, 14% had high blood pressure, in the second evaluation this value dropped to 7%. For 11% of the studied population, high blood pressure had been previously recorded 7 out of 10 cases of hypertension did not have any control. Three of them had not information about this illness. We found a positive correlation between weight and blood pressure (p less than 0.001) specially among women.

Adolescent↗
PubMedDate not supplied

[Interobserver and intraobserver variation: a problem of validity in epidemiologic studies of arterial pressure].

In carrying out blood pressure epidemiologic studies there may be different factors that can affect internal and external validity and thus eliminate the inferential process. As part of the Hypertension and Risk Factors Associated Study conducted in March 1987 in Cuajimalpa de Morelos, Mexico City, 23 nursing students were standardized on the blood pressure auscultatory method using a sound picture and measuring intraobserver and interobserver agreement through intraclass correlation coefficient. Even though initial standardization sessions showed difficulties in the use of instruments and in the reading of blood pressure levels, final K (kappa) values measuring interobserver agreement increased from 0.25 to 0.86. Omega values measuring intraobserver agreement fluctuated between 0.86 and 0.98. This epidemiologic technique is proposed in order to improve internal and external validity of blood pressure studies.

Blood Pressure↗
PubMedDate not supplied

[Amiodarone keratopathy. Prospective longitudinal study].

In order to investigate the frequency of corneal micro-deposits of amiodarone and its relationship to age, sex, dose and treatment duration, we studied one-hundred-fifty consecutive patients from 1982 to 1986. The average age was 33.8 +/- 17.5 years for eighty woman and seventy men. The mean weekly dose was of 1.1 +/- 0.3 g and the duration was 23.7 +/- 15.3 months. A complete eye examination was performed in all cases. The corneal micro-deposits were classified in three levels according to their density. In one-hundred-fourteen cases there were corneal micro-deposits; sixty-nine had grade I, thirty grade II and fifteen grade III. None had visual disturbances. There was only a direct statistical correlation between age and micro-deposit levels. Nine cases had also deposits of pigment in the lens. Two cases presented atypical keratopathy which by their involution after withdrawal of the drug was considered to be amiodarone-related. Fifteen cases presented chronic blepharitis, and ten, chronic non-secreting conjunctivitis. Therefore, age is a determinant factor for corneal accumulation of amiodarone micro-deposits.

Adolescent↗
PubMedDate not supplied

[Arterial hypertension. Considerations on its current status in Mexico. In memory of Samuel Zajarias].

The present article summarises statistical information about the problem of hypertension in this country making reference to international and national epidemiological works, with the purpose of evaluating the problem in community. Includes information about the clino-pathologic experience acheived at the National Institute of Cardiology of Mexico. The data is analyzed and commented from the point of view of how worth might be to study hypertension in Mexico.

Adolescent↗
PubMedDate not supplied

[Predictive value of the increase in diastolic arterial pressure during the exercise test in ischemic cardiopathy].

There are few studies on the behavior of the diastolic blood pressure during the stress test. The purpose of this report is to present a simple, noninvasive technique of measuring the mean diastolic arterial blood pressure at rest, during maximal exercise testing and in the first minute of recovery (X delta DAP). We studied 132 patients with exercise testing (E/T) and coronariography (C). Of these, 116 had coronary artery disease and 16 did not. The following data were analyzed: Age (A) X delta DAP, X2, p value, sensitivity, specificity, positive predictive value (PV+), and negative predictive value (PV-). As we analyzed our patients with coronary arterial disease, we found that in 75% of the cases, the X delta DAP increased more than 15 mmHg, immediately after maximal effort, and 86% of these cases had poor myocardial contratility by angiocardiogram. We conclude that the increase of X delta DAP has a significant value in a ischemic heart disease.

Blood Pressure↗
PubMedDate not supplied

[Arterial hypertension: prevention and control at the community level. Model for a plan action].

This paper presents a model of care of the patient with the problem of systemic arterial hypertension, from the point of view of the organization of community service. The development of such a service should be closely linked with the existing community health services, specially those dealing with preventive medicine, but also with other resources and their particular needs. The paper gives, general recomendations considering the main needs brought by arterial hypertension as a pathologic process. The organization should be integrated by a multidisciplinary group and pointed out their objectives and goals. The task program should be made accordingly to the peculiar conditions of the community. Such type of community service has worked years ago in developed countries. Since the problem of hypertension in our environment is already a public health problem, it is becomming necessary to achive some experience in this type of organization, as well as having preliminary results with the community response to this service.

Community Health Services↗
PubMedDate not supplied

[Arterial hypertension and other coronary risk factors in primary care].

This paper is about the effort to measure the assistance load at the first level of attention given by arterial hypertension and care risk factors. It is been worked as a demonstration project to initiate activities within the setting of a Health Center. The risk factors are explored from the proportions of patients with the problems of obesity, smoking, hyperlipidemia, diabetes mellitus and alcoholism. The information was obtained from 395 consecutive cases out of 1100 persons who came to the center in a month period. They were 325 women (82.2%) and 70 men (17.2%) with a range of 18 to 85 years, average 40 +/- 17 and a median of 36. Obesity was encountered in 35.7% in men and 48.8% in women. Diabetes was found in 9.1% both sexes. Hypercholesterolemia > 200 mg/dl in 30.4% and > 240 mg/dl in 19.6%. Alcohol abuse was encountered in 14%, 9.2% in women and 37.7% in men. Smoking was present in 22.3% of them, 16.3% in women and 50% in men. High blood pressure > 140/90 mm Hg or hypertension history was present in 21% of the cases. Controlled cases were 6.6%. In the whole group 34% showed at least one risk factor, 57% showed two factors and 66% showed three factors. Therefore, the best estimate of assistance load, on the fight of risk factors associated to hypertension should not consider less than 70% among the regular subjects coming to this health center.

Adolescent↗
PubMedDate not supplied

[Diversity in studies of the prevalence of systemic arterial hypertension].

To evaluate the information about prevalence of hypertension at a national level, several articles published either within or outside Mexico from 1933 to 1995 were reviewed. Variables about criteria and methodology were considered: the BP readings, method used, cutting points to define hypertension, year for screen. There were 30 papers out of 7 states, 16 reporting the Federal District of Mexico, 3 from Jalisco, 3 from Yucatán and 2 from Tamaulipas, there was only one referring to the State of Mexico, one to Veracruz, one to Michoacán and another referring to Mexicans in USA; as whole population there were two, one by the Instituto Mexicano del Seguro Social and another by Secretaría de Salud. A wide variation in prevalence was found (0.47 to 30.9%) mainly attributed to different sampling, measurements and reporting methodology. Few information was disclosed regarding female and elderly populations. The trend is slightly increasing, as expected accordingly to other information sources, but the problem might actually be masked by bias interference. Most of the studies performed have contributed so far to explore the gross prevalence, but may not reach scientific evidence to base evaluations of preventive interventions. The problem may not just be happening in this country. Variability may be partially controlled following the international recommendations to record arterial blood pressure, but still, there is a lack of recommendations to uniform epidemiological reports. Otherwise the values of hypertension prevalence may not be useful for hypertension surveillance.

Adolescent↗