Peripheral glucose metabolism in human hyperthyroidism.

The present study was designed to determine the effect of spontaneous hyperthyroidism on the forearm muscle glucose uptake and oxidation during the postabsorptive state and after an oral glucose challenge. Ten normal subjects and 11 hyperthyroid patients were studied after an overnight fast (12-14 h) and for 3 h after ingestion of 75 g glucose. Peripheral glucose metabolism was analyzed by the forearm technique to estimate muscle exchange of substrate combined with indirect calorimetry. Increased forearm glucose uptake was observed in the hyperthyroid patients compared to that in the normal subjects (1286 +/- 212 vs. 677 +/- 88 mumol/100 mL forearm.3 h) with enhanced glucose oxidation (443 +/- 40 vs. 147 +/- 29 mumol/100 mL forearm.3 h). Nonoxidative glucose metabolism was also greater in hyperthyroid patients than in normal subjects (842 +/- 234 vs. 529 +/- 90 mumol/100 mL forearm.3 h). Basal serum FFA levels were significantly higher in hyperthyroid than in normal subjects (0.252 +/- 0.025 vs. 0.182 +/- 0.022 g/L), as were the basal lipid oxidation rates in the forearm muscles of the thyrotoxic individuals (0.290 +/- 0.066 vs. 0.088 +/- 0.016 mg/100 mL forearm.min). After glucose ingestion, serum FFA levels and lipid oxidation rates declined significantly to equivalent values in both groups of subjects, and the similar basal insulin concentrations increased to significantly higher levels in the hyperthyroid patients. In conclusion, spontaneous human hyperthyroidism increases glucose uptake by the forearm muscles in the postabsorptive state and during an oral glucose challenge, with augmented fluxes of glucose through the oxidative and nonoxidative pathways.

Distribution and properties of endo-oligopeptidases A and B in the human neuroendocrine system.

The thiol activated endo-oligopeptidases A and B were studied in the soluble fraction of human hypothalamus and various endocrine glands. For the identification, characterization and purification of the enzymes, Z-Gly-Pro-NH-Np and bradykinin were used as substrates. Endo-oligopeptidase B showed a molecular mass ranging from 55.5 to 65.5 kDa and isoelectric point from 4.7 to 4.95. Its activity in tissues was highest in the testis, with intermediate levels in the thyroid, neurohypophysis, adenohypophysis and hypothalamus and the lowest activity in the pineal gland. Endo-oligopeptidase A, 467-fold purified by immunoaffinity chromatography, exhibited a molecular mass of 65.5 kDa in the adenohypophysis but 58.5 kDa in other tissues. The isoelectric point ranged from 5.22 to 5.50. High endo-oligopeptidase A activity was observed in the adenohypophysis, testis and hypothalamus with lesser activity in the neurohypophysis and thyroid and the lowest in the pineal gland. Endo-oligopeptidase A cleaved the bonds Phe-Ser of bradykinin, Met-Arg of BAM-12P and Arg-Arg of neurotensin as described for rabbit brain and heart and bovine brain enzymes. This work shows that endo-oligopeptidase A also hydrolysed the bonds Tyr-Gly of LH-releasing hormone, Pro-Phe of angiotensin I and Tyr-Ile of angiotensin II.

Short report: comparison of the effects of sublingual nifedipine and isosorbide dinitrate on oesophageal emptying in patients with Chagasic achalasia.

The effects of sublingual nifedipine and isosorbide dinitrate on oesophageal emptying were compared in 11 patients with Chagasic achalasia. The oesophageal emptying of a radiolabelled test meal was assessed three times in each patient by a scintigraphic technique. No treatment preceded one of the studies (basal study). Nifedipine (20 mg) by the sublingual route 30 min before the meal, preceded one study. Isosorbide dinitrate, 5 mg by the sublingual route 5 min before the meal, preceded the third study. The order of the studies was allocated randomly for each patient. Oesophageal retention at the completion of the meal was significantly less (P less than 0.01) after isosorbide dinitrate (median: 54%, range: 5-87%) than after sublingual nifedipine (median: 78%, range: 7-99%) or after the control study (median: 83%, range: 5-100%). This difference persisted up to 20 min after the meal. Values measured in the control study and after sublingual nifedipine were not different (P greater than 0.10). These results show that isosorbide dinitrate, but not sublingual nifedipine, enhances oesophageal emptying in Chagasic achalasia.

Treatment of diabetic gastroparesis with oral clonidine.

BACKGROUND/AIMS: Clonidine, a specific alpha-2-adrenergic receptor agonist, has been suggested to improve symptoms of gastroparesis in diabetics with diarrhoea. The aim of this study was to investigate the effects of clonidine on gastric emptying and symptoms suggestive of gastroparesis in patients with longstanding diabetes mellitus and evidence of autonomic neuropathy. METHODS: Six diabetics with chronic, refractory symptoms of bloating, nausea and vomiting were studied. Gastric emptying of a liquid nutrient meal (250 mL; 430 kcal) was evaluated by scintigraphy and symptoms were scored. Patients were treated with clonidine (median dose: 0.3 mg/day) for 2-12 weeks (median: 4 weeks), after which symptoms and gastric emptying were re-evaluated. Treatment was then sustained for a median follow-up period of 7 weeks (range: 2-56 weeks). RESULTS: Gastric emptying half-time values in diabetic patients ranged from 16 to 180 min (median: 100 min) and four patients had abnormally delayed emptying before treatment. In all patients, half-time values decreased during treatment (median: 35 min; range: 14-106 min, P < 0.025 vs. pre-treatment values) and in three of the four patients with abnormal gastric retention, half-time values returned to the normal range. During clonidine treatment, a substantial decrease in the score for symptoms was observed (median and range: 7.5; 2-9 vs. 0; 0-9). In four patients, symptoms virtually disappeared, an effect that was maintained throughout follow-up (6-56 weeks). CONCLUSIONS: These findings suggest that impairment of adrenergic influences on gastrointestinal motility control may play a role in the pathophysiology of diabetic gastroparesis and that clonidine may be a useful alternative for treating patients with this condition.

Multiple pulmonary thromboembolism diagnosed by two-dimensional echocardiography.

A 55-year-old man was admitted to our hospital because of progressive dyspnea, orthopnea and hemoptysis. Two-dimensional echocardiography multiple echo-dense images 1-4 mm in diameter were consistently seen crossing the tricuspid valve. A hypothesis of multiple pulmonary thromboembolism was raised. Clinical and postmortem evidence were later obtained to confirm this diagnosis.

Radionuclide angiographic evidence for early predominant right ventricular involvement in patients with Chagas' disease.

Radionuclide angiography was used to study biventricular function in 11 noncardiac (group 1) and eight chronic cardiac chagasic patients (group 2). Results in chagasic patients were compared to those obtained in 10 normal subjects. Global ejection fraction and the standard deviation of peak (SDP) phase histogram were determined for each ventricle and qualitative evaluation of regional wall motion in both anterior and left anterior oblique projections was performed. Left ventricular dysfunction was markedly predominant in group 2, mean +/- SD ejection fraction 39.7 +/- 13.1% and SDP 29.8 +/- 15.6 degrees, as compared to group 1, in which these values were 56.7 +/- 9.9% (P less than 0.01) and 18.3 +/- 7.1 degrees (P less than 0.05), respectively. In contrast, severe right ventricular impairment was found equally in both groups: ejection fraction averaged 31.8 +/- 12.7 and 31.0 +/- 9.1%, and the mean SDP was 29.3 +/- 8.6 and 23.7 +/- 6.7 degrees, in groups 2 and 1, respectively. The qualitative analysis of segmental wall motion also showed apical and/or free-wall right dysynergy in all patients of group 1, while the same abnormalities were detected in six out of eight patients in group 2. These findings indicate that severe functional impairment of right ventricular performance is by far the most significant abnormality detected by radionuclide angiography in chagasic patients who are asymptomatic and have no other clinical sign of heart disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Age-related reduction in 99Tcm-DTPA alveolar-capillary clearance in normal humans.

Age is known to reduce the efficacy of body organs and systems, even in the absence of disease. The alveolar-capillary clearance (ACC) rate is representative of the alveolar-capillary barrier's functional state. We studied 29 healthy non-smokers, who were selected after clinical and radiographic evaluation. The patients were divided into three groups based on age: Group I, < or = 30 years (n = 10); Group II, 31-55 years (n = 9); Group III, > or = 56 years (n = 10). Each patient inhaled 750 MBq 99Tcm-diethylenetriamine pentaacetate (99Tcm-DTPA) aerosol generated by a Venticis nebulizer (particles with a mean diameter of 1.1 microns) for 5 min. Forty frames of 30 s duration each were acquired and the ACC rates for the right and left lungs determined using a computer program. The mean ACC rates for the three groups were as follows: Group I, 1.31% min-1; Group II, 1.08% min-1; Group III, 0.76% min-1. The differences between Groups I and III (P < 0.001) and Groups II and III (P = 0.03) were shown to be significant. There was no significant difference between Groups I and II. Possible explanations for an age-related reduction in ACC rates include a reduction in the internal alveolar surface, the closure of the small airways, a reduction in the lung blood capillaries and a reduction in cardiac output. We conclude that there appears to be an age-related reduction in ACC rates in healthy non-smokers, even in the absence of clinically and radiographically detectable lung disease. However, larger studies are required.

Scintigraphic study of the gastrointestinal transit of a liquid meal in patients with chronic Chagas' disease.

Gastric emptying and small bowel transit of a liquid meal (isotonic dextrose) were assessed by a scintigraphic technique in 16 patients with Chagas' disease involving the esophagus and/or the colon, including one case with mega-jejunum, and in 10 control subjects. Initial gastric emptying was faster in the Chagas' disease group than in controls (gastric retention at 15 min, median and (range): 52% (15-86) vs 71% (43-97), P < 0.01) although there was no significant difference in total gastric emptying (T1/2: 20 min (4-132) vs 31 min (13-280), P > 0.05). Both the front (time to reach the proximal small bowel: 2.5 min (2.5-8) vs 15 min (5-40), P < 0.01) and the bulk of the meal (geometric center values at 15 min: 1.8 (1.2-2.4) vs 1.6 (1.2-1.8), P < 0.05) travelled faster through the proximal small bowel in Chagas' disease patients than in control subjects. There was no difference between the two groups concerning the time taken by the front of the meal to arrive to the caecum (110 min (15-180) vs 90 min (60-140), P > 0.20), but a precise delineation of this region was possible in only less than half of the patients and controls. In the patient with mega-jejunum, a remarkable delay in the intestinal progression of the liquid meal was found. These results suggest that the diffuse lesion of the enteric nervous system in chronic Chagas' disease mainly affects the control of gastric emptying and leads to accelerated proximal small bowel transit of a liquid meal.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of test meal temperature on the gastric emptying of liquids.

The effect of test meal temperature on the gastric emptying of 500 ml of 5% dextrose containing 12 MBq of 99mTechnetium-sulfur colloid was studied in eight healthy volunteers using a quantitative scintigraphic technique. Four different temperatures, 4, 20, 37 and 55 degrees C, were investigated in random order. Gastric emptying of the test meal at each temperature was mono-exponential and measurable as a half-life. The half-life of the meal at 20 degrees C (median, 35.6 min; range, 21.7-62.6 min) did not differ significantly (P greater than 0.10) from that obtained at 37 degrees C (median, 34.3 min; range, 20.1-60.5 min). In comparison to 37 degrees C, the half-life was longer for meals at 4 degrees C (median, 48.9 min; range, 20.9-77.5 min) and at 55 degrees C (median, 60.7 min; range, 33.5-79.0 min) although statistically different only at 55 degrees C (P less than 0.01). These results confirm the view that liquid meals, colder or warmer than body temperature have an inhibitory effect on gastric emptying and show that a significant delay in gastric emptying of liquids is obtained only with a warmer meal.

Effects of hemidecortication on the regulation of rat thyroid function.

1. Thyroid function in hemidecorticate and control rats was studied by the measurement of oxygen consumption (under basal conditions and after cold exposure) and radioiodine (131 I) uptake by the thyroid after a low-iodine diet for 30 days. 2. The oxygen uptake of male and female hemidecorticate rats under basal conditions (29 degrees C) did not differ significantly from that of the controls. The values observed for both experimental groups were relatively constant, ranging from 40 to 75 kcal h-1 m-2 for 2 to 50-day-old animals. 3. When hemidecorticate and control rats, age 60-65 days, were exposed to 7-8 degrees C for 5-6 h, the oxygen consumption of the hemidecorticate rats increased (83-84 kcal h-1 m-2) but to a lower extent than that of the controls (105-106 kcal h-1 m-2). 4. The rate of radioiodine (131 I) uptake by the thyroid gland of hemidecorticate rats was also lower than that of controls when the animals were maintained on a low-iodine diet. 5. These results show that, under basal conditions, the hypothalamic-pituitary-thyroid axis of hemidecorticate rats does not differ from that of control rats. However, when exposed to cold the hemidecorticate animals were not able to increase their oxygen consumption to the extent achieved by the control groups.

Spermatogenic and steroidogenic testicular function in hypothyroid pubertal rats.

The reproductive system of immature rats is held to be more influenced by thyroid dysfunction than that of adult animals. The effect of hypothyroidism on the spermatogenic process of the rat has not been reported previously. The objective of the present study was to investigate the spermatogenic and steroidogenic functions of pubertal hypothyroid rats. Hypothyroidism was induced by ad libitum ingestion of a 0.05% solution of propylthiouracil for 60 days, and confirmed by reduced plasma thyroxine levels in treated rats. Plasma testosterone level, the histological features of the testis and cauda epididymis and the concentration of spermatozoa stored in the cauda epididymis were unchanged by hypothyroidism.

Hypothyroidism affects pulsatile LH secretion in pubertal orchiectomized rats.

The present study evaluated the effect of hypothyroidism on the pituitary-testicular axis in rats rendered hypothyroid on the beginning of puberty. Rats were treated with propylthiouracil for 8 weeks and killed for determination of hormonal status and body parameters. For determination of pulsatile LH secretion other animals were orchiectomized two weeks before sampling. Analysis of the results led us to conclude that although the absolute weight of sex organs tended to decrease in hypothyroid animals, the relative weights were equal or higher than control, suggesting that the development of these organs were not affected by hypothyroidism; the androgenic activity of hypothyroid rat testes were preserved; basal plasma levels of pituitary hormones were similar in control and hypothyroid groups; the pulsatile LH secretion showed a decrease in the number of pulses, nadir mean and total LH secretion in hypothyroid animals. Our results demonstrate that although hypothalamic-pituitary axis of hypothyroid pubertal rats displays an abnormal pulsation LH release, no evidences of abnormalities in the reproductive system functions were found.

An improved mouth-piece to prevent environmental contamination during radioaerosol inhalation procedures.

The literature suggests that environmental contamination is common during labeled aerosol inhalation procedures in nuclear medicine. We have tested an adherent mask to prevent environmental contamination in 70 procedures. Two groups of patients were evaluated. Group 1 (60 inhalation cases in which the mask was used) presented no environmental contamination in 95% of the procedures (means of 553 dpm and 596 dpm before and after inhalation, p > 0.05, mean of the differences before/after inhalation 6.95, SD = 21.2 dpm) and the only 3 cases in which contamination did occur concerned bearded men; Group 2 (10 inhalation cases in which the mask was not used) showed large increases of environmental radioactive levels in 70% of the procedures (means of 601 dpm and 2,756 dpm before and after inhalation, p < 0.05, mean of the differences 3,066, SD = 2,98 dpm). We conclude that such a mask is very helpful in avoiding environmental contamination during radioaerosol inhalation procedures.

[Paracoccidioidomycosis assessed with 4 isotopic studies]. / La paracoccidioidomycose évaluée par quatre études isotopiques.

Paracoccidioidomycosis (south-american blastomycosis) is a consumptive granulomatous disease that is found in all Latin-America. The ethiological agent is a fungus (Paracoccidiosis brasiliensis) and mechanisms of disease transmission are not clear. Affection is frequent in the lungs, liver, spleen, ganglia, oropharynx and brain. Disease's response to therapy (Amphotericin, Ketoconazole) is good but recurrence is frequent. We have studied 12 patients with gallium-67, bone scintigraphy, bone marrow scintigraphy and lymph-scintigraphy. Six of these patients were re-studied after variable time of therapy. Gallium-67 accumulated in all patients's lungs. Other abnormal areas included ganglia, liver, spleen and bone. Bone scintigraphy was abnormal in all bone sites that were abnormal at the gallium study. Bone marrow scintigraphy showed expansion to the periphery in 6/12 cases and lymph nodes accumulated the radiopharmaceutical in 5 patients. Patients re-studied after the beginning of therapy presented decreased degrees or normalization of the radio-pharmaceutical's uptake (gallium and MDP), a regression of the bone marrow periphery expansion (bone marrow scintigraphy) and normalization of the lymph node aspects. These four radioisotopical studies may be useful for staging and for therapy follow-up. The sensitivity of the method is greater than the one noted for the conventional radiological studies.

[Scintigraphic study of gallbladder emptying in chronic Chagas' disease]. / Estudo cintilográfico do esvaziamento da vesícula biliar na doença de Chagas crônica.

Previous studies on gallbladder motility in Chagas' disease, which is known to be associated with diffuse destruction of intramural neurons, have produced conflicting results. In the present study we reevaluated this question by submitting chronic chagasic patients (n = 18) and controls (n = 12) to a cholescintigraphic study of gallbladder emptying in response to a single intra-venous injection of 60 ng/kg cerulein 90 min after administration of 99mTC-HIDA. Five min. before and immediately before carulein injection, as well as every 5 min. up to 45 min. after the stimulus, images of the gallbladder were obtained with a gamma-camera coupled to a computer. The counts obtained for regions of interest corresponding to the gallbladder, permitted the calculation of the ejection fraction of the organ and the construction of individual gallbladder emptying curves. The ejection fractions values for the total sample of chagasic patients (median 67.8%; variation, 4.0 to 99.0%), although higher than those for the control group (median: 34.2% variation, 13.1 to 88.0%), were not statistically significant (p greater than 0.05). However, analysis of the individual curves for the chagasics permitted identifying 2 subgroups, one of which (n = 9) showed values very similar to those for the controls, whereas the other (n = 9) showed a very rapid and intense gallbladder emptying. It is concluded that impairment of the gallbladder innervation in Chagas' disease may lead to heterogeneous patterns of gallbladder emptying, with some patients being definitely hypersensitive to an exogenous cholecystokinetic agent.

[Increased intestinal permeability to 51 Cr-EDTA among children with persistent diarrhea]. / Aumento da permeabilidade intestinal ao 51Cr-EDTA em crianças com diarréia persistente.

Persistent diarrhea, a condition highly prevalent in developing countries, causes different morphological and functional alterations of the mucosa of the small intestine, including increased permeability to different test molecules. In the present study we investigate for the first time the intestinal permeability to 51Cr-EDTA of Brazilian children with persistent diarrhea. The test of 51Cr-EDTA absorption was performed in 13 control children and in 14 children with persistent diarrhea by offering 50 microCi of the test substance by the oral route, with later detection of radioactivity excreted in 24-hour urine. There was a statistically significant difference between the control group (median = 1.26; range = 0.20-3.31%) and the group with persistent diarrhea (median = 4.68; range = 1.40-10.29%). Using the minimum and maximum values detected in the control group as the normal reference standard for the test of urinary 51Cr-EDTA absorption, we observed that 61.5% of the patients with persistent diarrhea showed altered results. Among the patients with persistent diarrhea, 51Cr-EDTA excretion was significantly higher in the group fed a protein hydrolysate diet and/or total parenteral nutrition than in the group that did not receive this diet. In four patients with persistent diarrhea, the test was performed after clinical recovery, with a fall in the excretion levels in all cases. On the basis of these data, we may conclude that: 1) in persistent diarrhea there must be alteration of intestinal permeability that might permit an increased entry of local alimentary antigens, with subsequent sensitization and allergic enteropathy, contributing to the perpetuation of the diarrhea, malabsorption and malnutrition cycle; 2) the 51Cr-EDTA test may be useful as an indicator of severity in persistent diarrhea; 3) alteration of intestinal permeability is a secondary phenomenon in persistent diarrhea, with normalization occurring after reconstruction of the intestinal barrier.

[Assessment of intestinal permeability using 51 CrEDTA: clinical usefulness in the detection of small bowel epithelial structural abnormalities]. / Estudo da permeabilidade intestinal pelo teste do 51CrEDTA: utilidade clínica na detecção de alterações estruturais do epitélio do intestino delgado.

Intestinal permeability tests have been increasingly used in the clinical management of small bowel diseases. Nevertheless, the application of such tests in Brazil is still limited. In this study we report the results of the application of 51Cr-EDTA for assessment of intestinal permeability in 13 healthy volunteers, 10 control patients with miscellaneous disorders, but without evidence of small bowel involvement, 11 patients with well characterized diseases affecting the small bowel, and five patients with inflammatory conditions affecting exclusively the colon. Urinary radioactivity levels in the 24 h following the ingestion of 51Cr-EDTA, expressed as the percentage of the ingested dosis, ranged from 1.99 to 5.93% (median: 3.14%) in healthy volunteers and was not significantly different from the results obtained in control patients (range: 1.48-3.98%; median 3.32%). Based on data from these two control groups, an upper limit of the normal range was set at 5.17% (95% confidence interval). Among patients with diseases of the small bowel, results ranged from 1.58 to 14.85% (median: 8.07%) and were significantly different from those observed in the control groups. Only two out of the 11 patients in this group had abnormal results. In the group of patients with diseases of the colon, results ranged from 3.48 to 5.13% (medium: 4.54%) and were not significantly different from the results obtained in control subjects. All patients in this group had results within the normal range. Data from control subjects and patients with diseases of the small bowel were used for the calculations of sensitivity (81%), specificity (96%), as well as false-positive (4.3%) and false-negative (18.1%) rates. Taken as a whole, the results of the present study indicate that the 51Cr EDTA test of intestinal permeability is accurate and may be useful in the clinical management of small bowel diseases in Brazilian patients.

[Protein-losing gastroenteropathies in children. Clinical, laboratory and therapeutic observations in 13 patients]. / Gastroenteropatia perdedora de proteínas na infância. Observações clínicas, laboratoriais e terapêuticas em 13 pacientes.

Thirteen children carrying protein-losing gastroenteropathy confirmed by the excretion fecal 51Cr albumin are presented. The ages ranged from 3 months to 12 years old, and the mean age of onset of symptom was 6 years 11 months old. Symptoms initiated between 3 to 7 years old in 11 patients. First and second grade malnutrition were detected within 10 cases. The most frequent clinical observation was diarrhea, found in 11 patients, followed by peripheral edema (10), anorexia (10), paleness (10), muscular hypotrophy (9), abdominal distension (8), ascite (7), wasted (7) and vomiting (5). The serum albumin level was below 2.5 g/100 ml in 12 patients, with and average of 1.7 g/100 ml. The gammaglobulin fraction was below 1.0 g/100 ml in 8 patients and lymphocytopenia in 5. Tests have shown a compromised fat absorption, thus, 7 among 8 lipiodol's test were negatives. The etiologic diagnosis were: paracoccidioidomycoses (5 patients), primary enteric lymphangiectasia (1), stronglyoidiasis (1), constrictive pericarditis (1), rheumatic carditis with double mitral lesion (1), Ménétrier's disease (1), short gut malabsorption syndrome (1), celiac disease (1) and cow's milk allergy (1). The responsible mechanism for the great loss of proteins to the digestive tube as well as diagnose and therapeutic aspects of the patients are commented. A report of 4 cases was done, as a way to show the pathology more characteristically due to protein losing gastroenteropathy.

[The effect of isosorbide dinitrate on esophageal emptying in chagasic megaesophagus]. / Efeito do dinitrato de isossorbitol sobre o esvaziamento esofagiano no megaesôfago chagásico.

The effect of 5 mg of sublingual dinitrate isosorbide (DNI) on the esophageal emptying of a semi-solid test meal labeled with 99mTc-sulfur colloid was studied by a scintigraphic technique in 18 chagasic patients with megaesophagus. DNI significantly reduced the esophageal retention measured at 0, 5, 10, 15, and 20 minutes after the end of the test meal ingestion. Five minutes after the meal not preceded by DNI the esophageal retention was always higher than 10% whilst 5 minutes after the meal preceded by DNI the retention was lower than 10% in 10 patients. These results indicate that DNI may be useful to reduce esophageal retention in chagasic megaesophagus.

[Ventricular function in mitral valve prolapse: effects of beta adrenergic blockers with and without intrinsic sympathomimetic activity]. / Função ventricular no prolapso de valva mitral: efeitos do bloqueio beta-adrenérgico com e sem atividade simpatomimética intrínseca.

A corollary of the "cardiomyopathy therapy" implies that mitral valve prolapse may cause intrinsic myocardial depression. The impairment of ventricular function may not be detected in basal conditions, but could be unmasked by superimposing depressant factors. The use of beta-blockers constitutes the first choice treatment for the symptomatic management of patients with mitral valve prolapse. Therefore, we tested the hypothesis that myocardial depression could be shown during beta-blockade in the uncomplicated primary form of mitral valve prolapse. The results of echocardiographic and radionuclide angiographic evaluation of left ventricular function during basal conditions, as well as under beta-blockade with propranolol and pindolol, do not lend support to the cardiomyopathy hypothesis of the pathogenesis of primary mitral valve prolapse. However, significant decreases of heart rate, left ventricular ejection fraction and peak velocity of left ventricular systolic emptying were seen with propranolol, but not with pindolol. Beta-blockade with intrinsic sympathomimetic activity may be preferable therapeutic option for patients with mitral valve prolapse.