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Biomedical subjects

J A Prieto

Publications and source records attributed to J A Prieto.

6 recordsLinked to original sources
PubMed1991

Success determining factors in percutaneous transluminal balloon valvuloplasty of pulmonary valve stenosis.

Twenty-two percutaneous transluminal balloon valvuloplasty procedures were performed on 21 patients with congenital pulmonary valve stenosis. The peak systolic pressure gradient was immediately reduced from 79.1 +/- 7.4 to 22.2 +/- 1.8 mmHg, (P less than 0.0001) and follow-up cardiac catheterization at 5.3 +/- 0.4 months in 19 patients revealed no further significant change in gradient (23.5 +/- 3.2 mmHg). The best results were obtained when balloons larger than the pulmonary annulus were used, i.e. an immediate residual transvalvular gradient of 22.0 +/- 2.2 mmHg with a balloon/annulus ratio greater than 1, as opposed to 44.2 +/- 5.4 with a balloon/annulus ratio = 1 (P less than 0.001). The angiographically determined cusp thickness of the stenotic pulmonary valves was significantly greater than that of the control group of 24 patients without pulmonary valve stenosis (1.21 +/- 0.09 vs 0.59 +/- 0.02 mmHg, P less than 0.00001). The relationship between this parameter and the residual transvalvular gradient at follow-up was found to be significant (r = 0.77, P less than 0.001). It is concluded that balloon size is a determinant factor in achieving good results with percutaneous balloon valvuloplasty although cusp thickness, a factor to which scant regard has hitherto been paid, also plays a significant role in the residual transvalvular gradient measured at follow-up.

Adolescent↗
PubMed1989

Positive modulators of muscle acetylcholine receptor.

A solution of succinic anhydride (SA) in buffer N-tris(hydroxymethyl)methyl-2-aminoethane sulfonic acid (TES), the SATES solution, potentiates the effect of carbonyl containing agonists on frog muscle (del Castillo et al., Br. J. Pharmac. 84: 275-288, 1985). Here we report that the main compound in the SATES solution is a monosuccinyl ester of TES (MST). This compound is not an agonist of the acetylcholine (ACh) receptor nor is it an inhibitor of ACh esterase, yet MST potentiates the ACh-induced tension and depolarization in frog muscle to a new maximum. It increases the amplitude of miniature endplate potentials but has no effect on the time course of miniature endplate currents. The acetylated analogue of MST (mono-acetyl-TES: MAT) had similar but more pronounced effects on frog muscle. Neither MST nor MAT affect [3H]Ach binding to receptor-rich membranes from the electric organ of Torpedo californica, or the affinity state transition induced by agonists. Radiolabeled MST does not bind to these membranes and MAT does not alter agonist-induced ion flux. Therefore, these compounds seem to act as positive modulators of muscle ACh receptor but are inactive in Torpedo vesicles.

Acetylcholine↗
PubMed1989

[Diverticulum of the right ventricle].

We report the case of a 38-year-old woman who underwent cardiac catheterization because of cyanosis from birth. This study revealed a right ventricular cavity hypoplasia, an atrial septal defect, and a diverticulum originated from the free right ventricular wall. Ventricular diverticuli, especially those in the right ventricle, are very rare malformations, usually associated with other cardiac defects. The right ventricular diverticulum is generally non-symptomatic, diagnosed by chance, and does not usually require surgical treatment.

Adult↗
PubMed1989

[Quantitative evaluation of the exercise test using discriminant analysis].

One hundred and twenty seven selected patients had treadmill tests and coronary angiograms. Eight variables were correlated by discriminant analysis to the presence and extent of coronary artery disease (CAD) in a two-way approach. In the first (43 patients without significant CAD versus 84 with significant CAD), two ergometric (maximal heart rate achieved and exercise time) and two common (age and sex) variables merged as predictors. In the second approach (65 patients without CAD or CAD with a little amount of myocardium at risk versus 62 with CAD and a greater extent of jeopardized myocardium), the two clinical variables were replaced by two new ergometric predictors: the level of ST depression and maximum systolic blood pressure reached. Comparatively with the conventional assay of exercise test, the second discriminant function (Z2) enhanced specificity (67 versus 84%) but impaired sensibility (82 versus 70%); nevertheless, this late index was preserved (93 versus 89%) in the 3-vessel CAD group. Moreover, the Z2 value decreased as the severity of CAD increased; the differences between groups were significant (p less than 0.01) up to the level of 2-vessel versus 3-vessel CAD where the trend persists but failed to be significant. Likewise, within the 1-vessel CAD group, the mean Z2 value was lower (p less than 0.01) when the narrowing was located in the proximal portion of the left anterior descending coronary artery. This quantitative approach to the exercise test was validated in a new series of 85 patients and, in our opinion, could be useful for making patient care decisions.

Angiocardiography↗