Browsing by Author "CASANEGRA, P"

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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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    ACTIN-DEFICIENT CARDIOMYOPATHY COEXISTING WITH CELIAC-DISEASE - A CHANCE ASSOCIATION
    (1986) CHUAQUI, B; GARRIDO, J; CASANEGRA, P
    A case of idiopathic congestive cardiomyopathy associated with celiac disease is presented. The ultrastructural and electrophoretic examination of myocardial samples showed a selective loss of actin. Electron microscopy revealed the characteristic alterations of enterocyte microvilli seen in celiac disease. The involvement of the microfilament system both in the myocardial sarcomere and in the enterocyte may indicate a pathogenic relation between these alterations. Ultrastructural examination of skeletal muscle tissue showed a good preservation of the cell contractile apparatus.
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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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    ASSOCIATION OF CORONARY-ARTERY DISEASE AND VALVULAR HEART-DISEASE IN CHILE
    (1983) MARCHANT, E; PICHARD, A; CASANEGRA, P
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    CARDIOVASCULAR MANAGEMENT OF PREGNANT-WOMEN WITH A HEART VALVE PROSTHESIS
    (1975) CASANEGRA, P; AVILES, G; MATURANA, G; DUBERNET, J
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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 INTRAVENOUS DIPYRIDAMOLE ON REGIONAL CORONARY BLOOD-FLOW WITH 1-VESSEL CORONARY-ARTERY DISEASE - EVIDENCE AGAINST CORONARY STEAL
    (1984) MARCHANT, E; PICHARD, AD; CASANEGRA, P; LINDSAY, J
    The effects of i.v. dipyridamole were studied in 9 patients with isolated total left anterior descending coronary artery (LAD) obstruction, in 6 patients with isolated 90-99% diameter reduction of the LAD and in 10 patients with normal coronary arteries and normal left ventricular function. Coronary sinus and great cardiac vein flows were determined by continuous thermodilution. Flows were measured at rest and 1, 3, 5 and 10 min after i.v. dipyridamole. Great cardiac vein flow represents the venous outflow from the LAD territory. In the presence of coronary steal from the LAD territory, great cardiac vein flow is expected to decrease while coronary sinus flow increases. I.v. dipyridamole induced a similar flow increase in the coronary sinus and the great cardiac vein in all 3 groups (P < 0.001 between rest and dipyridamole, difference not significant among groups), suggesting that no coronary steal was induced. The maximal increase in great cardiac vein flow was 118 .+-. 74% in the control group, 86 .+-. 74% in the group with 90-99% LAD obstruction and 102 .+-. 29% in the group with total LAD obstruction (difference not significant). Evidently, i.v. dipyridamole produces a similar increase in coronary flow in ischemic and nonischemic areas and an increase in collateral flow is the underlying mechanism for increased flow to the ischemic area.
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    EFFECTS OF CAPTOPRIL VERSUS MILRINONE THERAPY IN MODULATING THE ADRENERGIC NERVOUS-SYSTEM RESPONSE TO EXERCISE IN CONGESTIVE HEART-FAILURE
    (1990) CORBALAN, R; JALIL, J; CHAMORRO, G; CASANEGRA, P; VALENZUELA, P
    The potential adverse consequences of increased adrenergic nervous system activity in patients with heart failure are now recognized. Modulation of the plasma noradrenaline response to submaximal exercise should be desirable. The long-term (9 weeks) effects of milrinone (10 mg 4 times a day) or captopril (50 mg 3 times a day) compared to placebo were evaluated in a double-blind crossover study, in 16 patients with stable, congestive heart failure receiving digoxin and furosemide. After treatment, clinical status (score range 0 to 14 points) improved significantly with both milrinone (4.4 .+-. 0.5, p < 0.01) and captopril (4.1 .+-. 0.4, p < 0.01). Plasma noradrenaline at rest was similar with both drugs and not significantly different from placebo. During submaximal exercise it increased significantly to 1,295 .+-. 174 pg/ml with milrinone; this response was reduced significantly with captopril, to 820 .+-. 100 pg/ml (p < 0.01). Thus, long-term therapy with both captopril and milrinone improved the clinical score, but only captopril reduced the plasma noradrenaline response to submaximal exercise. These findings suggest that angiotensin-enzyme inhibition with captopril will modulate the adrenergic system response to daily activities in patients with chronic congestive heart failure and therefore could have additional salutary effects beyond vasodilatation.
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    EFFECTS OF NIFEDIPINE DURING LOW, NORMAL AND HIGH INTAKES OF SODIUM IN PATIENTS WITH ESSENTIAL-HYPERTENSION
    (1982) VALDES, G; SOTO, ME; CROXATTO, HR; BELLOLIO, T; CORBALAN, R; CASANEGRA, P
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