PubMed Health⌕ Search

Biomedical subjects

M Guerreiro

Publications and source records attributed to M Guerreiro.

4 recordsLinked to original sources
PubMed1992

[Echocardiographic study of 53 patients with rheumatoid mitral stenosis].

In 53 patients with rheumatic mitral stenosis we performed echocardiographic study in order to define anatomic and functional alterations. We used 3.5 MHZ probe and obtained images from apical and parasternal windows. Determinations were performed by standards of the American Society of Echocardiography. Thirteen patients were men and forty women. Men's mean age was 43.5 years and women's mean age 40 years. In the men anatomic mitral valve area was 1.1 cm2 and in the women 1.3 cm2. Correlation anatomic to functional valve area was strong (r = 0.9). Mitral diastolic gradient had correlation with cardiac output, mitral valve area and ejection fraction. Pulmonary artery pressure had strong correlation with valve area and cardiac output. In conclusion, our study showed the usefulness of functional valve area in the graduation of mitral stenosis, the dependence of the mitral diastolic gradient of several cardiac events, the independence of the left atrium dimensions and also the strong dependence of pulmonary artery pressure of cardiac output and valve area.

Adult↗
PubMed1991

[Valve replacement with Macchi prosthesis].

OBJECTIVE: to evaluate the performance of a new ball valve prosthesis. DESIGN: set up of two groups of patients who underwent mitral valve replacement with two different prosthesis: the Macchi prosthesis under evaluation and the well known Starr-Edwards model prosthesis. The chi-square test was used to compare the results. PATIENTS: Patients referred for valvular surgery. INTERVENTIONS: One group of 98 consecutive patients who underwent isolated mitral valve replacement with a Macchi prosthesis from January 1984 to June 30 1986 was compared to a matched group of 49 patients who received a Starr-Edwards prosthesis in the same period of time. Follow-up data were available from 99% patients in the Macchi group 96% in the Starr-Edwards group, with a mean follow-up time of 35.2 (2-57) and 42.9 (4-62) months, respectively. RESULTS: There was no statistical difference in the incidence per 100 patients--month of prosthetic complications--thromboembolism, hemorrhagic events, prosthetic endocarditis, reoperation and mechanical failure. CONCLUSIONS: In our experience and with the available follow-up data the Macchi prosthesis is a good cost effective option when there is indication for a ball valve prosthesis.

Adult↗
PubMed1986

Postsynaptic alpha-adrenoceptor subtypes in the internal carotid, mesenteric, splenic, renal and femoral vascular beds of the dog.

Pressor effects of noradrenaline, phenylephrine and alpha-methylnoradrenaline and the inhibition of these effects by prazosin or yohimbine (or both) were studied in vivo in the renal, splenic, femoral, anterior mesenteric and internal carotid vascular beds of the dog. In all the vascular beds noradrenaline was more potent than alpha-methylnoradrenaline and alpha-methylnoradrenaline was more potent than phenylephrine. However, the ratios between the ED50 for phenylephrine and the ED50 for alpha-methylnoradrenaline in the mesenteric, in the femoral, in the splenic and in the renal circulations was 2.19, 1.89, 1.48, and 1.33, respectively, showing that the relative potency of phenylephrine increased in that order. In the internal carotid vascular bed it was not possible to determine any value. Furthermore, in the renal vascular bed, prazosin (100 micrograms/kg) inhibited pressor responses to all agonists more readily than yohimbine (250 micrograms/kg) and yohimbine was more potent than prazosin against all the agonists in the mesenteric and in the femoral vascular beds. Our results show that: there are both postsynaptic alpha 1- and alpha 2-adrenoceptors in the four vascular beds; the contribution of alpha 2-adrenoceptors to pressor responses to sympathomimetic agents is maximal in the mesenteric followed by the femoral, the splenic and the renal vascular bed, whereas the participation of alpha 1-adrenoceptors is maximal in the renal and progressively smaller in the splenic, in the femoral and in the mesenteric vascular bed, where it reaches the lowest value.

Animals↗