Risk factors related to the occurrence of silent myocardial ischemia in Mexicans.

BACKGROUND: Silent myocardial ischemia is a growing world health problem. It has been related to factors that promote an increase in myocardial oxygen demand or affect coronary vasomotor tone. Coronary artery disease has shown an increasing trend in Mexico in this century. HYPOTHESIS: The aim of the study was to estimate the strength of the association between some risk factors and the occurrence of silent myocardial ischemia. METHODS: A cross-sectional study was conducted and 249 individuals were screened by 24-h Holter electrocardiogram. Silent myocardial ischemia was diagnosed in patients with painless transient ST-segment depression. All subjects were interviewed for coronary risk factors and total serum cholesterol was measured. RESULTS: Silent ischemia was diagnosed in 115 patients (46%), who were older (59 +/- 9 vs. 57 +/- 11 years; p = 0.01). In a logistic regression analysis, a lower risk for silent ischemia was found in patients with thrombolysis [odds ratio (OR) 0.28; 95% confidence interval (CI 95%) 0.14-0.53], or those who followed their medical treatment (OR 0.16; CI 95% 0.04-0.68). The major risk factors were hypercholesterolemia (OR 1.6; CI 95% 0.9-2.9) and more severe coronary artery disease (OR 2.5; CI 95% 1.1-5.7). CONCLUSIONS: Some coronary risk factors are related to silent ischemia. It is still important to diagnose this entity, but modification of its related risk factors should be kept in mind to diminish its occurrence and its severe consequences.

[Comparative study between bisoprolol and metoprolol, combined with hydrochlorothiazide, as antihypertensive therapy]. / Estudio comparativo entre bisoprolol y metoprolol, asociados a hidroclorotiazida, como terapia antihipertensiva.

The main objective of this research was to compare the efficacy and security of bisoprolol (B), a new cardioselective beta-blocker, that does not have intrinsic sympathomimetic activity, and metoprolol associated to hydrochlorothiazide (HCTZ), in the treatment of patients with mild to moderate hypertension. Sixty-two hypertensive patients (47 females and 15 males) aged 20 to 70 years (mean 52.5 +/- 10.4) were included in a double-blind, placebo controlled and randomized clinical trial. After a two-weeks wash out period and a similar placebo phase, patients were randomly assigned to receive either a once-daily dosing of B (10 mg) with 6.25 mg of HCTZ, or M (100 mg) plus 6.25 mg of HCTZ during four-weeks. If there was no reduction below 90 mmHg at the end of this period, the dosing of either beta-blocker was doubled. After eight weeks of treatment, the mean decreases in systolic/diastolic blood pressures from baseline were 31.8/21.2 and 28.0/20.6 mmHg for B/HCTZ and M/HCTZ, respectively (p < 0.0001). There were no clinically significant changes from baseline in laboratory parameters in either group. Reduction in blood pressure with B/HCTZ is associated with adverse events and metabolic changes similar to those observed with other antihypertensive drugs.

[Predictive factors for survival and for a second coronary event in patients with a first acute myocardial infarct]. / Factores predictores de sobrevida o de un segundo evento coronario en pacientes con un primer infarto agudo del miocardio.

Prognosis after an acute myocardial infarction is closely related to the severity of coronary obstruction, and the residual functionality of left ventricle, which may be evaluated by the ejection fraction. To evaluate the utility of the ejection fraction and some cardiovascular risk factors, as predictors of a second myocardial infarction and delayed death, in those patients with a first acute myocardial infarction, 161 hospitalized patients were included in the study. The occurrence of a second myocardial infarction or death after the first month was evaluated. All patients were followed for 1 to 51 months, and the ejection fraction through a transthoracic echocardiogram was measured. 119 men and 42 women were included in the study, with a total of 3802 person-months of follow-up. The incidence rate for a second myocardial infarction was 0.01052 month,-1 and the mortality rate was 0.00342 month-1. In a Cox survival analysis model, ejection fraction was a major prognostic index and those subjects with an ejection fraction below 40% had a seven fold higher risk for a second myocardial infarction. Diabetes mellitus and hypertension were major predictors of a delayed death after a first myocardial infarction. Ejection fraction is the most related variable to the occurrence of a second myocardial infarction, and together with a history of diabetes and hypertension are good predictors of a delayed death after a first myocardial infarction. The identification of subjects with a poor prognosis may allow to establish specific preventive measures. Ejection fraction is useful to categorize patients according to their prognosis.

[Radiological findings in total abnormal drainage of pulmonary veins, not associated to other major cardiopulmonary abnormalities (isolated form)]. / Hallazgos radiológicos en el drenaje anómalo total de venas pulmonares (D.A.T.V.P.). No asociado a otras malformaciones cardiovasculares mayores (forma aislada).

Thirty patients with anomalous drainage total in the veins of the lungs (A.D.T.V.L.) not associated to greater cardiovascular deformations (in an isolated form) perfectly confirmated by a surgery or by a necropsic study, were examinated. In all of them there was a research to find out any radiologic sign which could make suspect about the anomaliation. The diagnosis could be established in eleven cases (36.6 per cent) with the thorax habitual radiologic study, owed to the recognition of some signs that have been cataloged as the characteristic; as it occurs in the A.D.T.V.L. in the level in the system in the upper left chamber that bring into existence a silhouette in "snowman" and in the drainage in the subphrenic level which makes appear a sign of the "scimitar". In the varieties of the A.D.T.V.L. it wasn't possible to discover any suggestive radiologic sign of the entity.