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Biomedical subjects

R Melgares

Publications and source records attributed to R Melgares.

8 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

[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

[Transluminal angioplasty for aortic coarctation in newborns and infants].

It has been done transluminal angioplastic with catheter balloon in 14 patients who are under 1 year of age and who are affected by aortic coarctation. For this study, they were divided in two groups. The first one was formed by newborn children whose transcoarctation gradient was 52 mm Hg in average. The second group was integrated by 9 newborn children whose transcoarctation gradient was 59 mm Hg. After this experience was done the gradient descended to 9 and 15 mm Hg respectively. Twenty four hours later, two months later and over two more months, there were follow-up of the clinical situation, the evolution of the pulse, differential arterial pressure and the need of surgery. Of the first group only one of the patients, who is now 2 years old, is in good clinical condition; the others needed to be surgically intervened. Of the second group 4 patients, all of whom were over 3 months old at the time of the angioplastic had positive results. The rest needed surgical intervention.

Angioplasty, Balloon↗
PubMed1989

[Aortic stenosis with left ventricular systolic dysfunction: a severe disease but with good surgical prognosis].

From our series of 72 patients with severe valvular aortic stenosis, we identified 19 showing features of left ventricular systolic disfunction (ventriculographic ejection fraction less than 55% and/or fractional shortening less than 30% at M-mode echocardiography). In these patients, we found a significant inverse correlation between the fractional shortening and the systolic wall stress (r = 0.79, p less than 0.001). Clinically, 18 of the 19 patients were in NYHA class III (n = 11) or IV (n = 5), and two died before they could be operated upon. The remaining 17 had their aortic valve replaced (coronary artery bypass surgery was simultaneously performed in 2 patients). After a mean follow-up of 18 months, all patients are alive and show substantial symptomatic improvement (15 patients in class I and 2 patients in class II). Cardiothoracic index was reduced (61 +/- 5% preoperatively versus 52 +/- 5% postoperatively), and fractional shortening changed from 21 +/- 5% to 30 +/- 5%. The latter remains under normal limits in two thirds of the patients. Our results lend support to the idea that the systolic left ventricular dysfunction in aortic stenosis is due to the increased afterload, rather than to an intrinsic contractility defect. This explains the great functional improvement after the reduction of the systolic wall stress achieved by surgery.

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↗