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Biomedical subjects

A Montero

Publications and source records attributed to A Montero.

At least 127 records · Page 7Linked to original sources
PubMed1987

Conservative operation for mitral stenosis with densely fibrosed or partially calcified valves. An eight-year evaluation.

Of 284 patients undergoing open mitral commissurotomy for mitral stenosis from January 1978 to December 1985, 81 patients had a densely scarred or partly calcified valve. In this study, we evaluated the postoperative results in these 81 patients. There were no operative or late deaths. Seventy-seven patients (95%) are in Functional Class I or II. Three patients required reoperation 3, 30, and 50 months after the initial procedure because of moderate or severe residual mitral regurgitation. After valvotomy there were four episodes of embolism. The actuarial rate of freedom from any complication (mortality, reoperation, congestive heart failure, and thromboembolic events) was 89.3% +/- 3.9% (mean +/- standard error of the mean) 8 years after operation. We conclude that for a follow-up period of 8 years, the stenotic mitral valve with anatomical deformities can be salvaged with satisfactory results. Therefore, we believe that this approach, at present, is a better alternative than prosthetic replacement with any type of valve presently available.

Adult↗
PubMed1985

Magnesium excretion in idiopathic hypercalciuria.

Given the parallelism in calcium and magnesium metabolisms, we have studied urinary magnesium in normal subjects and in patients with idiopathic hypercalciuria under conditions of basal and restricted diet, fasting, and after oral calcium overload. Serum magnesium values showed no differences between groups. Urinary magnesium levels are increased in absorptive hypercalciuria under free and restricted diet and calcium overload, returning to normal during fasting. Renal hypercalciuria patients maintain a high magnesium excretion under all conditions. This suggests that in idiopathic hypercalciuria there is an impairment of renal magnesium management, dependent on that of calcium because it normalizes when urinary calcium is normal.

Adult↗
PubMed1985

Intraoperative contrast two-dimensional echocardiography. Evaluation of the presence and severity of aortic and mitral regurgitation during cardiac operations.

We have used contrast two-dimensional echocardiography in the intraoperative evaluation of aortic and mitral regurgitation in 35 patients undergoing cardiac operations. All of them underwent previous cardiac catheterization in order to document the presence and severity of regurgitation. With the pericardium open, a catheter was introduced into the left ventricle (to document mitral regurgitation) or into the ascending aorta (to document aortic regurgitation). The two-dimensional echocardiographic probe was placed on the anterior surface of the right ventricle to obtain a basal image, equivalent to a conventional parasternal longitudinal view. Dextrose in water (5 ml) was rapidly hand-injected through the catheter, while echocardiograms were recorded on videotape. The observation of contrast medium (microbubbles) flowing in the retrograde direction through the incompetent valve was carefully evaluated with the same scoring system used in the hemodynamic laboratory. In 34 cases there was agreement between angiographic and echocardiographic evaluation of the presence and severity of mitral and aortic regurgitation. Only one case was evaluated as mild aortic regurgitation by angiography and moderate aortic regurgitation by echocardiography. There were no false positives or false negatives in the study. In view of the high degree of correlation between contrast two-dimensional echocardiography and hemodynamic data, we suggest that our method is an important tool for the cardiac surgeon. In addition, the present approach overcame the disadvantages of the conventional intraoperative methods, most of which are performed in a nonbeating or fibrillating heart.

Adult↗
PubMed1984

Respiratory muscle weakness in uremic patients under continuous ambulatory peritoneal dialysis.

The increasingly frequent use of continuous ambulatory peritoneal dialysis (CAPD) as substitutive therapy in terminal renal failure has induced the investigation of the advantages and disadvantages of this therapeutic modality. The effects of CAPD on pulmonary function are one of the aspects currently under study. Based on previous data suggesting the existence of extrapulmonary ventilatory restriction in uremic patients under CAPD, we have studied in these patients the respiratory muscle function as expressed in the maximal inspiratory pressure (MIP) and assessed the impact of the infusion of 2 liters of dialysis fluid into the peritoneal cavity on both MIP and the pulmonary volumes. Uremic patients evidenced significantly lower MIP values as compared with healthy controls. The filling of the peritoneal cavity induced, both in the supine and in the sitting position, a restrictive effect and an increase in the inspiratory capacity. We conclude that uremic patients under CAPD evidence a respiratory muscle dysfunction of as yet unclear cause. Our findings further suggest that the infusion of 2 liters of dialysis fluid into the peritoneal cavity induces not only a restrictive effect, but also an increase in the strength of the respiratory muscles, the latter effect being probably due to increased diaphragmatic contractility.

Adult↗
PubMed1984

Early disc dislodgement of a mitral Björk-Shiley prosthesis.

Because of its excellent durability, low-flow gradient and low incidence of valve-related complications, the Björk-Shiley prosthesis is one of the most widely used valve prostheses in the world. Component failures are rare with this prosthesis. The following report, however, described a case of early disc dislodgement of a mitral Björk-Shiley prosthetic valve.

Journal Article↗
PubMed1983

Outcome from severe head injury related to the type of intracranial lesion. A computerized tomography study.

The influence of the type of intracranial lesion on the final outcome in a consecutive series of 277 severely head-injured patients was analyzed. Patients were studied with computerized tomography (CT) and underwent continuous measurement of intracranial pressure. They received identical treatment according to a standardized protocol. Outcome of patients with either epidural hematoma (38 cases), subdural hematoma (56 cases), brain contusion (87 cases), or diffuse brain damage (96 cases) was rather heterogeneous, and serial CT scanning allowed the authors to outline eight consistent anatomical patterns in the whole series which have stronger prognostic significance than the four major lesion categories mentioned above. Patients with pure extracerebral hematoma (19 cases), single brain contusion (45 cases), general brain swelling (41 cases), and normal CT scans (28 cases) had a significantly better outcome than patients developing acute hemispheric swelling after operation for a large extracerebral hematoma (27 cases), patients with multiple brain contusion, either unilateral or bilateral (74 cases), and patients with diffuse axonal injury (43 cases). These anatomical patterns are interesting because, in addition to having clinical and physiopathological significance, they provide useful prognostic information and facilitate improved therapeutic decision-making in severely head-injured patients.

Adolescent↗
PubMed1983

[Our experience in heart surgery in early childhood (children less than 2 years old)].

We review 109 patients with congenital heart disease under (two year of life, surgically treated between June 1978 and October 1981; 44% were under six months and 71% were under one year. Fifty six patients were operated under cardio-pulmonary by-pass, in 41 we used deep hypothermia with total cardio-respiratory arrest, 21% of them were under three months of life an 53% under one year. We present the morbidity and mortality together with the pulmonary management. Eighty five percent of the cases remained intubated postoperative by for less than 12 hours. The postoperative pulmonary evolution was quite similar for different types of congenital heart disease, such as T. Fallot, A-V canal, transposition, etc., and there was no statistically significant difference between them in terms of respiratory assistance and pulmonary complications. Eleven patients died (19%), all of them under six months of life. In 53 patients operated, without extracorporeal circulation, 38 had total correction and 15 palliative procedures. The mortality in this group was 9% (5 cases), all of the under one month of life. The global mortality was 14%. We discuss our present surgical indications in view of our results.

Age Factors↗
PubMed1983

[Sternal cleft. Surgical treatment in the newborn].

The lack of total sternal fusion without other anomalies of the chest wall is extremely rare. We present the case of one 24 h. old female, clinically asymptomatic with complete sternal cleft without other symptoms. She was operated on within the first week of life, a sternal primary suture with costal condrotomy and alternate costal suture were performed. Good thoracic stability was obtained. We agree with other authors about the need for surgical correction during the neonatal period.

Female↗
PubMed1982

Effect of short-term infusion of sodium nitroprusside on mortality rate in acute myocardial infarction complicated by left ventricular failure: results of a Veterans Administration cooperative study.

Eight hundred twelve men with presumed acute myocardial infarction and left ventricular filling pressure of at least 12 mm Hg participated in a randomized double-blind placebo-controlled trial to assess the efficacy of a 48-hour infusion of sodium nitroprusside. The mortality rates at 21 days (10.4 per cent in the placebo group and 11.5 per cent in the nitroprusside group) and at 13 weeks (19.0 per cent and 17.0 per cent, respectively) were not significantly affected by treatment. The efficacy of nitroprusside was related to the time of treatment: the drug had a deleterious effect in patients whose infusions were started within nine hours of the onset of pain (mortality at 13 weeks, 24.2 per cent vs. 12.7 per cent; P = 0.025) and a beneficial effect in those whose infusions were begun later (mortality at 13 weeks, 14.4 per cent vs. 22.3 per cent; P = 0.04). Nitroprusside should probably not be used routinely in patients with high left ventricular filling pressures after acute myocardial infarction. However, the results in the patients given late treatment suggest that those with persistent pump failure might receive sustained benefit from short-term nitroprusside therapy.

Aged↗
PubMed1981

Renal tubular function and urinary acidification capacity in early juvenile diabetes.

Renal elimination of uric acid, calcium, phosphorus, sodium, potassium, chloride and magnesium and urinary acidification capacity were determined in ten insulin-dependent diabetics and in ten matched control subjects. The diabetics showed excessive excretion of uric acid, sodium, potassium, chloride and ammonia. Sodium, chloride and ammonia excretion fractions was also increased with respect to controls. The enhanced excretion of these substances in diabetics failed to relate to glomerular filtration rate, glycosuria or insulin requirements. These findings might be explained on the basis of glomerular filtration rate elevation, tubular response to this increment, and the underlying metabolic disturbances of diabetes.

Adolescent↗
PubMed1981

Serum level of alpha-N-acetyl-D-glucosaminidase in myocardial infarction in man.

alpha-N-acetyl-D-glucosaminidase, a lysosomal enzyme essential for the degradation of heparin sulfate, was measured in the sera of normal individuals and of 19 patients with myocardial infarction (MI). Normal individuals maintained a constant level of this enzyme from day to day. In contrast, patients with MI had a 2-3 fold elevation of this enzyme as early as 2 hr after MI. This elevation persisted at least until the creatine phosphokinase-MB had attained maximum activity, usually 6-23 hr after MI and then gradually decreased, returning to normal levels 3-5 days later.

Acetylglucosaminidase↗
PubMed1980

Complete proximal tubular acidosis (Type 2, RTA) in chronic active hepatitis.

Fifteen patients with chronic active hepatitis (CAH) were tested in order to ascertain the site of tubular dysfunction in renal tubular acidosis (RTA) associated with CAH. Renal plasma flow and GFR were reduced in the patients compared to controls (P < 0.005). Underbasal and acidification conditions, twelve patients showed normal acid-base balance and net acid excretion, while three patients had basal hyperchloremic metabolic acidosis while passing alkaline urine and showing bicarbonaturia. A sustained acidification test showed adequate urinary acidification in these three patients. Bicarbonate loading carried out in two of the three patients showed a proximal tubular acidifying defect (Type 2 RTA), Distal RTA (Type 1 RTA) complicating CAH is widely known, but these data suggest that CAH can also involve the proximal convoluted tubule in isolation.

Acid-Base Equilibrium↗
PubMed1979

The magnitude of exercise-induced ST segment depression and the predictive value of exercise testing.

The assess whether the magnitude of exercise induced ST segment depression improves the predictive values of symptom limited exercise tests, and helps in the recognition of patients with more severe coronary heart disease, 90 consecutive patients with positive treadmill tests who also underwent selective coronary arteriography were reviewed. The predictive value improved progressively with the increasing ST depression and was most reliable in a select group of patients with normal electrocardiographic baseline who were not receiving digitalis (73% with ST depression greater than or equal to 1 mm to 100% with ST depression greater than or equal to 4 mm). The incidence of 2 and 3 vessel disease increased from 61% with ST depression greater than or equal to 1 mm in the overall population to 100% with ST depression greater than or equal to 4 mm in the select group, and the incidence of left main trunk lesions increased, respectively from 6 to 30%. The prediction of 2 and 3 vessels disease was found to be significantly greater when patients were dichotomized into those with ST depression greater than or equal to 4 mm compared to less than 4 mm. It is concluded that the magnitude of ST segment depression definitely improves the predictive values of exercise tests as well as the ability to recognize the patients with more severe disease. However, the markedly positive exercise tests cannot be utilized to accurately predict the presence of 2 or 3 vessel disease in individual cases unless ST depression attains 4 mm or more in patients with normal electrocardiographic baseline who are not taking digitalis. In this group, the ability to predict left main trunk lesion is approximately 30%.

Coronary Angiography↗
PubMed1979

Surgery in active infective endocarditis.

Controversy persists concerning the role of early surgical intervention in severe infective endocarditis (IE). We therefore reviewed 163 episodes of well-documented IE in which 32 cardiac operations were performed during the active phase of IE. Congestive heart failure (CHF) was the principal indication for surgery in 88% (28/32); systemic emboli, 1/32; and persisting sepsis, 3/32. Staphylococcus and enterococcus were the most common infecting organisms in the operative group (44% and 16% respectively). Surgical mortality (11/32,37%) did not differ (p greater than 0.05) from medical mortality (26/131,20%). All 11 operative deaths occurred in patients moribund prior to surgery, including three with preoperative cardiac arrest. Surgical patients undergoing preoperative cardiac catheterization demonstrated marked CHF: a mean left ventricular end-diastolic pressure of 25.3 mm Hg. The mean cardiac index in 8/11 surgical deaths was lower (p less than 0.05) vs surgical survivors: 2.21/min/m2 vs. 3.21/min/m2. Postoperative complications were rare in the 21 surgical survivors. There were no episodes of continued infection, prosthetic dehiscence, or advanced heart block; only one paravalvular leak; and one systemic embolus. These findings emphasize the high medical and surgical mortality in patients with IE, suggest that delayed operative intervention may be a major causative factor resulting in a high surgical mortality, and justify an aggressive surgical approach in patients with valve dysfunction and heart failure. These data indicate that survivors of surgical intervention during active IE have eradication of infection and few postoperative complications.

Adult↗