Browsing by Author "RODRIGUEZ, JA"

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    ABNORMAL REGIONAL MYOCARDIAL FLOW IN MYOCARDIAL BRIDGING OF THE LEFT ANTERIOR DESCENDING CORONARY-ARTERY
    (1981) PICHARD, AD; CASANEGRA, P; MARCHANT, E; RODRIGUEZ, JA
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    ACUTE EFFECT OF SYSTEMIC VERSUS INTRACORONARY DIPYRIDAMOLE ON CORONARY CIRCULATION
    (1986) MARCHANT, E; PICHARD, A; RODRIGUEZ, JA; CASANEGRA, P
    Dipyridamole has been proposed as an ideal agent to evaluate coronary vascular reserve because it produces selective coronary vasodilation without systemic hemodynamic effect. The actions of intracoronary (IC) and intravenous (IV) dipyridamole on coronary blood flow and systemic hemodynamics were compared in 15 patients with chest pain syndrome and normal coronary arteries. They received IC dipyridamole, followed 10 minutes later by 0.5 mg/kg of IV dipridamole. IC dipyridamole produced a 73% increase in coronary sinus flow without hemodynamic changes, except for a slight increase in pulmonary systolic and diastolic pressures. IV dipyridamole administration produced an additional 88% increase in coronary sinus flow, reaching 172% over baseline; it was also associated with a significant (p < 0.01) increase in heart rate (78 .+-. 14 vs 102 .+-. 19 beats/min), cardiac index (4 .+-. 0.7 vs 6.3 .+-. 1.7 liters/min/m2), and pulmonary artery systolic (27 .+-. 5 vs 34 .+-. 7 mm Hg) and diastolic pressure (12 .+-. 4 vs 19 .+-. 7 mm Hg). These data suggest that the coronary vasodilatory effect seen after IV dipyridamole administration is related to mechanisms other than direct coronary vasodilation.
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    ADRENAL MACROTUMORS DIAGNOSED BY COMPUTED-TOMOGRAPHY
    (1990) LOPEZ, JM; FARDELLA, C; ARTEAGA, E; MICHAUD, P; RODRIGUEZ, JA; CRUZ, F
    Adrenal tumors larger than 6 cm are unusual but show a greater incidence of malignant etiologies than smaller adrenal tumors. The scarce information about adrenal macrotumors (AMT) induced us to study prospectively all patients who were seen in our clinic during the period 1984-1988 and were diagnosed by computed tomography (CT) to have an adrenal mass .gtoreq.6 cm. The clinical characteristics, including the main complaint, tumoral secretory activity, CT findings and histologic diagnosis from 18 patients are described; they represented a 0.3% of the total amount of abdominal CT studies performed. Seventy-two % of AMT resulted to be non cortisol or catecholamines secreting masses, and from them, a 38% corresponded to malignant etiologies characterized by marked and rapid weight loss. Four out of five hormone secreting AMT corresponded to pheochromocytomas, while the fifth one resulted to be a bilateral macronodular hyperplasia secreting cortisol. In two cases AMT did not correspond to a genuine adrenal mass, resulting to be a malignant histocytoma in one case and a hydatidic cyst in other one. When performed in two occasions, a percutaneous needle biopsy was a valuable diagnostic tool, permitting to diagnose a lymphoma and a tuberculoma. In conclusion: 1) AMT correspond mainly to non cortisol or catecholamines secreting tumors, often malignant; 2) not all AMT diagnosed by CT correspond to true adrenal masses; 3) percutaneous needle biopsy can be a helpful procedure for diagnosing nonfunctioning solid AMT.
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    EFFECT OF A CALCIUM INHIBITOR, NIFEDIPINE, ON EXERCISE TOLERANCE IN PATIENTS WITH ANGINA-PECTORIS - A DOUBLE-BLIND-STUDY
    (1981) CORBALAN, R; GONZALEZ, R; CHAMORRO, G; MUNOZ, M; RODRIGUEZ, JA; CASANEGRA, P
    The effect of nifedipine on exercise tolerance was studied in 30 patients with stable angina and positive graded exercise testing. Treadmill exercise testing was performed on each of 5 consecutive days. Placebo or nifedipine, 10 mg sublingually, was given 30 min before exercise on the 3rd day. The following day the intervention was reversed in a double-blind manner. Angina was abolished by nifedipine but not by placebo in 12 patients (40%). The time to onset of angina in the remaining patients increased from 4.1 .+-. 0.4 (SEM [standard error of mean]) to 6.7 .+-. 0.6 min (P < 0.001). Time to ST depression .gtoreq. 2 mm increased from 4.0 .+-. 0.3 to 5.4 .+-. 0.5 min, while duration of exercise increased from 6.3 .+-. 0.3 to 8.2 .+-. 0.4 min (P < 0.001). The maximum heart rate was 145 .+-. 3.3 with nifedipine and 122 .+-. 3.8 min-1 with placebo (P < 0.01). Resting systolic blood pressure decreased 30 min after nifedipine administration from 131 .+-. 3.4 to 106 .+-. 2.9 mm Hg (P < 0.01). Maximal systolic blood pressure during exercise was lower with nifedipine (127 .+-. 4.8 mm Hg) than with placebo (155 .+-. 8.6 mm Hg, P < 0.01). Nifedipine significantly improves the exercise tolerance of patients with stable angina pectoris by decreasing peripheral vascular resistance and myocardial O2 demand.
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    EFFECT OF ORAL POTASSIUM SUPPLEMENTS ON URINARY KALLIKREIN EXCRETION IN SHEEHANS SYNDROME
    (1988) LOPEZ, JM; MAHANA, D; RODRIGUEZ, JA; MICHAUD, P; ARTEAGA, E; FARDELLA, C
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    EFFECT OF THE COMBINATION OF DEXAMETHASONE AND SODIUM IPODATE ON SERUM THYROID-HORMONES IN GRAVES-DISEASE
    (1983) ARTEAGA, E; LOPEZ, JM; RODRIGUEZ, JA; MICHAUD, P; LOPEZ, G
    To investigate the effect of the combination of dexamethasone (Dex) and sodium ipodate (SI) on hyperthyroidism, 24 patients with typical Graves'' disease, divided into 4 groups of 6 persons each were studied. Three groups (Study I) were studied acutely (24 h) to determine the effects of Dex (5 mg every 12 h i.m.), SI (1 oral dose of 3 g) and both drugs at the same doses, upon T4, T3 and rT3 [thyroxine, triidothyronine and reverse triiodothyronine] at 0900 h before therapy was started and 24 h later. The group on Dex and that on SI had a similar T3 decrement of 25.9 .+-. 4.0% and 35.8 .+-. 5.0%, respectively, (P < 0.05), whereas the effect of both drugs combined was greater (64.2 .+-. 3.6%; P < 0.01, Dex, and P < 0.01, SI, respectively). The increment of rT3 was markedly greater in those patients on SI than in those on Dex (561 .+-. 149.2% and 58.9 .+-. 11%, respectively, P < 0.025). A 4th group (Study II) was studied for 7 days while receiving both Dex (1 mg orally 3 times per day) and SI (500 mg orally 3 times per day). Both T4 (from 18.8 .+-. 1.1 to 13.1 .+-. 1.1 .mu.g/dl, P < 0.02) and T3 (from 593 .+-. 41 to 136.3 .+-. 12.7 ng/dl, P < 0.001) decreased at day 8. The initial brisk increment of rT3 at 24 h (808 .+-. 149%, P < 0.005) then diminished concomitantly with the fall of its precursor, T4. The pulse rate correlated with plasma T3 concentration (r = 0.67, P < 0.001) and varied from 104.7 .+-. 3.9 on day 1 to 77.3 .+-. 3.0 beats/min (P < 0.001) on day 4 and then remained stable. Dex and SI have potent inhibitory effects at the level of peripheral conversion of T4 and on the thyroid gland itself and the combined use of these drugs significantly increases these effects. Considering the rapid clinical improvement of thyrotoxicosis achieved with both drugs, this regimen may be valuable in the initial treatment of some patients.
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    PLASMA-ALDOSTERONE RESPONSE TO ANGIOTENSIN-11 AND KCL INFUSIONS IN HYPOPITUITARY PATIENTS
    (1980) LOPEZ, JM; RODRIGUEZ, JA; MARUSIC, ET
    The acute adrenal response to KCl and angiotensin II (A II) infusions was studied in hypopituitary patients and compared with normal subjects. The peripheral plasma levels of aldosterone (PAC), cortisol, K and plasma renin activity, were measured at 0900 h and after 60 and 120 min of infusion. All subjects were recumbent and under balance conditions, receiving a daily dietary intake of 180 mmol of Na and 80 mmol of K. Basal PAC in hypopituitary patients was not significantly different from that observed in the control group. Both normal and hypopituitary patients respond to A II infusion with significant increments. Under KCl stimulus the PAC response in hypopituitary patients was only observed when cortisol (20 mg) was given 2 h prior to the infusion. When cortisol replacement was omitted the response to KCl was not detected. These results suggest a permissive role of cortisol on glomerulosa response to K.
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    RENIN-SECRETING TUMOR - CASE-REPORT
    (1980) VALDES, G; LOPEZ, JM; MARTINEZ, P; ROSENBERG, H; BARRIGA, P; RODRIGUEZ, JA; OTIPKA, N
    Renin-secreting tumor, though rare, should be considered in assessing severe hyperreninemic, hypertensive patients. An 18-yr-old girl with hypokalemic hyperreninemic hyperaldosteronism was studied. No angiographic lesion was detected. The plasma renin activity (PRA) of the right/left renal vein was 7.3. With a presumptive diagnosis of renin-secreting tumor (RST), the patient was operated on, and a cortical nodule was found on the right lower pole. Partial nephrectomy was followed by a rapid fall in PRA (half-life, 33-44 min) and normalization of blood pressure (BP). At 3 1/2 mo. postoperatively, the patient showed normotension, normopokalemia, normal aldosterone and slightly elevated PRA unresponsive to postural changes and furosemide treatment. Tumoral PRA secretion responded to postural stimulus, spironolactone use and nitroprusside-induced hypotension. Neither the high aldosterone excretion nor hyperreninemia decreased after 3 days of DOCA [deoxycorticosterone acetate]; this agrees with a previously reported case, suggesting the usefulness of this test in the diagnosis of RST.
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    ROLE OF PROGRAMMED ELECTRICAL-STIMULATION OF THE HEART IN RISK STRATIFICATION POST-MYOCARDIAL INFARCTION
    (1988) GONZALEZ, R; ARRIAGADA, D; CORBALAN, R; CHAMORRO, G; FAJURI, A; RODRIGUEZ, JA