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Biomedical subjects

E Lupi-Herrera

Publications and source records attributed to E Lupi-Herrera.

At least 19 recordsLinked to original sources
PubMed1992

Effect of hydralazine on vascular mechanics in a canine lobar preparation of pulmonary embolism.

We studied the effect of hydralazine (H) on pulmonary vascular mechanics in an isolated, in situ, canine lobe model of normal and increased pulmonary vascular resistance (Rp) produced by Gelfoam embolization (GE). Pulmonary pressure-flow (P-Q) curves from 24 lobes were obtained at baseline and after each intervention. Hemodynamic parameters for analysis included: the mean critical closing pressure (Ppai), vascular conductance (1/Rp), lobar flow (QL), and the pulmonary inflow pressure (Ppa) at different levels (50, 100, 200, 400, and 600 ml/min) of a fixed flow. After the preparation was stabilized, the 24 lobes were classified into 2 groups. For group 1 (n = 8) we studied the effect of H on the normal pulmonary vasculature. In group 2 (n = 16) we studied the effect of GE. Following GE, this group was further divided in half. For group 2A (n = 8) we followed the natural history of GE with measurements at 15 and 60 min. For group 2B (n = 8) measurements were done 15 min after GE and repeated again 15 min after the infusion of H. For group 1 lobes, H promoted a significant decrease (p less than 0.001) in Ppa at fixed flows of 200, 400, and 600 ml/min compared to baseline, with no change in Ppa for flows below 100 ml/min. QL and 1/Rp increased (p less than 0.01), and there was not any significant change in Ppai. In group 2A lobes, GE produced an increase in Ppa at all levels of flow (p less than 0.01), QL and 1/Rp decreased (p less than 0.05), and there was an increase in Ppai (p less than 0.05). These changes remained stable over the 60 min of observation. For group 2B lobes, GE produced the same hemodynamic changes as in group 2A, and the infusion of H caused a decrease in Ppa at flows between 100 and 300 ml/min. (p less than 0.01) with no change in Ppa at flows below 100 ml/min. QL and 1/Rp increased (p less than 0.01) and Ppai did not change compared to 15 min after GE. We conclude that in the normal canine pulmonary vasculature as well as in the model of GE, H decreased Rp and did not affect mean critical closing pressure, all of which may be explained by an increase in vascular conductance due to an increase in vascular distensibility.

Animals↗
PubMed1991

Ventriculoatrial shunts for hydrocephalus and cardiac valvulopathy: an echocardiographic evaluation.

A group of 20 patients with ventriculoatrial shunts placed as surgical treatment for hydrocephalus were evaluated for cardiac lesions, particularly of the tricuspid valve. Patients with histories of septic or thromboembolic events were excluded. In each patient a clinical history, complete physical examination, electrocardiogram, chest x-ray film and M-mode, two-dimensional and pulsed continuous wave and color-coded Doppler echocardiography were performed. Eight patients were found to have cardiac abnormalities including tricuspid valve insufficiency, tricuspid stenosis and insufficiency, and the catheter passing through the foramen ovale into the left atrium. These findings demonstrate that tricuspid valvular lesions are frequent in patients with ventriculoatrial shunts, and that periodic echocardiographic evaluation should be performed routinely.

Adult↗
PubMed1991

Behavior of the pulmonary circulation at rest and during exercise in miliary tuberculosis.

We studied the hemodynamic behavior of the pulmonary circulation at rest and during exercise in six patients with MTB. As a group, in contrast to advanced fibrocaseous tuberculosis, these patients exhibited normal pulmonary hemodynamics at rest and during exercise. Only minor abnormalities in pulmonary vascular resistance at exercise (increased PAd-PWP gradient) were noted in two of the patients. The increase in Rp during exercise does not appear to be related to acute hypoxic vasoconstruction but rather to functional changes (compliance or recruitment or both) of the pulmonary microvasculature. In the genesis of these functional changes, chronic alveolar hypoxia and the inflammatory-fibrotic process might be interacting.

Adult↗
PubMed1988

PaO2 increases with coughing in patients with chronic lung disease.

We considered if the cyanosis frequently observed during a cough attack in patients with chronic lung disease was due to worsening hypoxemia. To investigate the effects of cough on PaO2, we measured arterial blood gases before and after a voluntary coughing period of 45 sec, in 11 patients with Interstitial Lung Disease (ILD) and 14 patients with Chronic Obstructive Lung Disease (COPD). All patients significantly increased (p less than 0.05) their PaO2 (COPD: from 49 +/- 2 to 60 +/- 2 mmHg; ILD from 44 +/- 2 to 51 +/- 3 mmHg, mean +/- SD) and decreased their PaCO2. We conclude that stable patients with COPD and ILD increase their PaO2 with coughing most likely due to hyperventilation. The cyanosis observed could be due to peripheral circulatory effects of coughing.

Adult↗
PubMed1986

Effect of hydralazine on intrapulmonary shunt.

We compared the acute effects of bilateral arteriovenous may be related to levels of PvO2. The hydralazine-associated (p less than .05) decrease in resistance. Mixed venous oxygen fistulas to those of hydralazine infusion on hemodynamics and pulmonary gas exchange in dogs with pulmonary edema induced by administration of oleic acid. Oleic acid significantly (p less than .01) increased intrapulmonary shunt (Qsp/Qt) and pulmonary and systemic vascular resistance, and reduced cardiac output. Once the lesion stabilized, both opening the fistula and infusing hydralazine produced a similar and significant (p less than .01) increase in cardiac output, and a significant (p less than .05) decrease in resistance. Mixed venous oxygen tension (PvO2) closely followed the changes in cardiac output; however, PaO2 did not change. Qsp/Qt significantly (p less than .01) increased with the fistulas open and with hydralazine infusion. Closure of the fistulas or bleeding the animal at the end of the experiment reversed the changes in cardiac output and Qsp/Qt. The comparable increases in cardiac output and Qsp/Qt produced by opening the fistulas or infusing hydralazine may be related to levels of PvO2. The hydralazine-associated PvO2 increase indicates that this drug increased oxygen transport to the tissues even as Qsp/Qt became larger.

Animals↗
PubMed1985

Hemodynamic effect of hydralazine in interstitial lung disease patients with cor pulmonale. Immediate and short-term evaluation at rest and during exercise.

Hydralazine was administered short-term to 13 patients who had stable interstitial lung disease (ILD), pulmonary arterial hypertension (PAH); mean pulmonary arterial pressure ( [PAP]=26 +/- 9 mm Hg), and cor pulmonale (CP). All patients were studied at rest and during exercise. After intravenous hydralazine at rest, there were statistically significant increases in cardiac index (CI) (p less than 0.001), arterial oxygen saturation (SaO2) (p less than 0.01), and mixed venous saturation (S-vO2) (p less than 0.01). Pulmonary vascular resistance (Rp) (p less than 0.005) and systemic resistance (Rs) decreased (p less than 0.001), and PAP did not change. During exercise, PAP did not change; however, CI (p less than 0.01), PaO2 (p less than 0.001), and S-vO2 (p less than 0.01) increased further. The increase in Rp was significantly reduced (p less than 0.01). After continuation of oral hydralazine therapy in 12 patients for 7 days, PAP at rest was not statistically different from control; Rp and Rs remained decreased (p less than 0.001). The same results were found for CI, PaO2, S-vO2, and Rs during exercise. Although PAP did not change from control values, the drug significantly reduced the increase in Rp (p less than 0.005). Vasodilator therapy with hydralazine could be useful in patients with stable ILD who have inflammation with minimal to moderate fibrosis and PAH and might be used as an adjunct to conventional therapy for ILD and CP.

Administration, Oral↗
PubMed1984

Hemodynamic effect of hydralazine in advanced, stable chronic obstructive pulmonary disease with cor pulmonale. Immediate and short-term evaluation at rest and during exercise.

Hydralazine was administered to eight patients (mean age, 69 +/- 2 years) who had stable, advanced chronic obstructive pulmonary disease (COPD), pulmonary arterial hypertension (mean pulmonary arterial pressure, 31 +/- 3 mm Hg), and cor pulmonale. All of the patients were studied at rest and during exercise. After intravenous administration of hydralazine at rest, there were statistically significant increases in pulmonary arterial pressure (p less than 0.05), cardiac index (p less than 0.005), arterial oxygen saturation (p less than 0.01), and mixed venous saturation (SvO2) (p less than 0.005). Pulmonary vascular resistance did not change, and systemic resistance decreased (p less than 0.005). During exercise, pulmonary arterial pressure increased in all patients, and this increase was not blunted by hydralazine; however, cardiac index (p less than 0.005), arterial oxygen pressure (p less than 0.005), and SvO2 (p less than 0.001) increased further during exercise. The increase in pulmonary vascular resistance was significantly blunted by hydralazine (p less than 0.005). Therapy with the drug was continued orally in seven patients because one patient showed a deleterious response in pulmonary hemodynamics. After seven days of oral hydralazine, pulmonary arterial pressure and pulmonary vascular resistance were not statistically different from control. There were statistically significant increases in cardiac index (p less than 0.005) and SvO2 (p less than 0.05), systemic resistance decreased (p less than 0.01). The same condition was found during exercise; however, only two patients showed pulmonary gas exchange and pulmonary hemodynamic benefit at rest and during exercise with hydralazine therapy. Our results suggest that it is unlikely that vasodilator therapy with hydralazine will be useful in patients with advanced stable COPD and cor pulmonale who seem to have fixed pulmonary vascular disease.

Aged↗
PubMed1983

Peripheral airways obstruction in idiopathic pulmonary artery hypertension (primary).

The mechanical properties of the lung were studied in ten nonsmokers with idiopathic pulmonary artery hypertension (IPAH) (mean pulmonary artery pressure 65.7 +/- 30 mm Hg). In the routine lung test, residual volume was found to be abnormal (greater than 120 percent of the predicted) in seven patients, and measured airway resistance was normal in eight out of the ten patients. A decreased FEF 75-85 percent, abnormal values for the helium-air flow ratios and increased closing capacities were documented in eight of ten patients in whom lung elastic recoil was normal (six of ten) or increased (four of ten). These features suggest peripheral airways obstruction (PAO) which was also supported by histopathologic findings in three cases (one biopsy and two necropsies). The observed changes in lung compliance could be related to the behavior of the coupling of the air-space and vascular compartments. The etiology of PAO in IPAH patients is not known, but our results indicate that both the peripheral airways and the pulmonary circulation are affected. The knowledge of PAO in IPAH patients could help to better understand the observed V/Q inequality in this entity.

Adolescent↗
PubMed1982

The role of hydralazine therapy for pulmonary arterial hypertension of unknown cause.

Hydralazine was administered acutely to 12 patients who had pulmonary arterial hypertension of unknown cause. All of the patients were studied at rest and nine during exercise. On the basis of hydralazine response at rest, the patients were divided in two groups. In six patients (group A), pulmonary arteriolar resistance (Rp) decreased from 8.4 +/- 1.4 to 4.8 +/- 1.4 U/m2 (p less than 0.001), cardiac index (CI) increased from 3.47 +/- 0.3 to 5.86 +/- 0.5 1/min/m2 (p less than 0.005) and systemic resistance (Rs) decreased from 25 +/- 4 to 14 +/- 2 U/m2 (p less than 0.01). The Rp/Rs ratio did not change significantly after hydralazine (0.32 +/- 0.03 vs 0.33 +/- 0.07, NS). In the other six patients (group B), Rs decreased from 25 +/- 2 to 17.0 +/- 1 U/m2 (p less than 0.01), but the other variables did not change significantly. Our results suggest that the pulmonary vasodilatory effect of hydralazine caused a marked reduction in right ventricular afterload in group A. In group B, a marked systemic vasodilatory effect occurred and right ventricular afterload was not reduced. On the basis of the previous hemodynamic response, only group A patients were treated with oral hydralazine (50 mg every 6 hours). Hemodynamic measurements were repeated 48 hours after hydralazine, both at rest and during exercise, as well as 8 months later in five of the six patients in whom the beneficial hemodynamic effects persisted. These data suggest that hydralazine can reduce Rp in selected patients (pulmonary arterial pressure less than 60 mm Hg, Rp less than 15 U/m2 and Rp/Rs ratio less than 0.7) with pulmonary hypertension of unknown cause.

Administration, Oral↗
PubMed1982

Behavior of the pulmonary circulation in chronic obstructive pulmonary disease. Pathogenesis of pulmonary arterial hypertension at an attitude of 2,240 meters.

The hemodynamics of the pulmonary circulation were examined in 28 patients with severe and stable chronic obstructive pulmonary disease (COPD) who were born and raised at high altitude (2,240 meters) (COPD-A). All patients had mean pulmonary pressures (PAP) greater than 16 mmHg. We observed: (1) a low correlation between pulmonary arterial diastolic pressure (PAd) and arterial oxygen saturation (r = 0.38, p less than 0.05); (2) similar PAP in patients with COPD living at sea level (COPD-S) and patients with COPD-A (COPD-S, 32 +/- 7 mmHg; COPD-A, 27.5 +/- 11 mmHg; p = NS), despite more unsaturation in patients with COPD-A (COPD-S, 84.6 +/- 6%; COPD-A, 77.5 +/- 9%; p less than 0.05) and similar arterial pH; (3) lower levels of PAP in COPD-A (COPD-S, 51.7 +/- 10 mmHg; COPD-A, 33.6 +/- 12 mmHg; p less than 0.001) for the same degree of unsaturation (COPD-S, 71 +/- 6%; COPD-A, 71 +/- 8%; p = NS) and a lower arterial pH in COPD-S (COPD-S, 7.34 +/- 0.03; COPD-A, 7.39 +/- 0.04; p less than 0.01). We conclude that pulmonary hypertension caused by chronic alveolar hypoxia is present in COPD-A, but it seems to be decreased when compared with that observed in COPD-S.

Adult↗
PubMed1982

The role of isoproterenol in the preoperative evaluation of high-pressure, high-resistance ventricular septal defect.

The experience we describe derives from the short-term administration of isoproterenol in 15 patients with ventricular septal defect (VSD) and severe pulmonary artery hypertension (PAH). For the whole study group, mean pulmonary artery pressure (PAP) was 68.5 +/- 2.6 mm Hg, pulmonary vascular resistance (Rp) was 11.6 +/- 0.9 U/m2, pulmonary vascular resistance/systemic vascular resistance ratio (Rp/Rs) was 0.9 +/- 0.03, and the pulmonary vascular gradient (PAd-PWP) was 45 +/- 3.5 mm Hg. Infusions of isoproterenol decreased PAP, Rp, Rp/Rs ratio, and PAd-PWP an average of 10.2 mm Hg, 2.88 U/m2, 0.13 and 6.6 mm Hg, respectively, for the whole group (P less than 0.001). On the basis of isoproterenol response, the patients could be divided into two groups: A (n = 4) and B (n = 11). In group A, the PAP decreased from 61.7 +/- 1 to 45 +/- 4 mm Hg, the Rp from 8.9 +/- 0.3 to 4.62 +/- 0.5 U/m2, the Rp/Rs from 0.84 +/- 0.02 to 0.55 +/- .05, and the PAd-PWP from 34.5 +/- 0.9 to 24 +/- 2 mm Hg (mean +/- 1 SE). In group B a less significant change in these measurements was observed. Group A patients underwent VSD repair, and the mean average postoperative decrease in PAP was 31 mm Hg (P less than 0.001). Our findings suggest that in patients with VSD and severe PAH, in whom surgical treatment is controversial, a trial with isoproterenol should be routinely attempted. If the preceding hemodynamic parameters improve significantly, the VSD repair should be performed.

Adolescent↗
PubMed1981

Extrinsic allergic alveolitis caused by pigeon breeding at a high altitude (2,240 meters). Hemodynamic behavior of pulmonary circulation.

The hemodynamic characteristics of the pulmonary circulation were examined in 10 patients with proved extrinsic allergic alveolitis caused by pigeons (EAA-P) raised at a high altitude. All patients had lung biopsies that showed an interstitial inflammatory response with vascular lesions. At rest, all patients had mean pulmonary pressures (PAP) greater than 16 mmHg; the average PAP was 22 +/- 12 mmHg for the whole group. Pulmonary vascular resistance was high and the mean for the whole group was 225 +/- 25 d.s.cm-5. The pulmonary artery diastolic-pulmonary wedge pressure (PAd-PWP) difference was elevated and averaged 8.5 +/- 2 mmHg. All patients were hypoxemic with elevated AaDO2. With exercise, both PAP and PAd-PWP increased abnormally. While breathing oxygen (FIO2, 99.6%) PAP decreased an average of 7 mmHg (p less than 0.05) and PAd-PWP decreased an average of 5 mmHg (p less than 0.05) without a significant change in PWP. The calculated compliance of the elastic pulmonary arteries in EAA-P was not different from that in normal subjects. Alveolar hypoxia produced mainly by EAA-P and presumably enhanced by living at a high altitude appeared to be the factors in the genesis of pulmonary hypertension, because pulmonary artery diastolic pressure and PAd-PWP difference were correlated with arterial oxygen saturation.

Adult↗
PubMed1981

The role of isoproterenol in pulmonary artery hypertension of unknown etiology (primary): short- and long-term evaluation.

The experience derived from the administration of isoproterenol in six patients with pulmonary hypertension of unknown etiology (PAH-UE) is presented. The diagnosis was made after exclusion of other known diseases capable of producing hypertension in the pulmonary circuit. Catheterization was performed, and basal cardiopulmonary parameters, mean pulmonary artery pressure (PAP), pulmonary arteriolar resistance (PAR), cardiac index (CI), alveolar-arterial oxygen tension difference P(A-a)O2, and PaO2 were investigated. The effect of infusing 3 micrograms/min of isoproterenol into the pulmonary artery was studied in five cases. Isoproterenol was given sublingually to one patient who had previously received it intravenously; in another case it was given only sublingually. Significant P values (P less than .05) as a group were obtained, in relation to heart rate, CI, PAR, and mean PAP after isoproterenol. A favorable effect on the heart and lungs was seen in two cases, maintained for three years with sublingual isoproterenol with a favorable cardiorespiratory effect. Use of isoproterenol in PAH-UE is justified at present in those cases with a favorable cardiopulmonary response while no specific therapy is available.

Adolescent↗
PubMed1980

Behavior of the pulmonary circulation in the grossly obese patient. Pathogenesis of pulmonary arterial hypertension at an altitude of 2,240 meters.

Twenty persons living at an altitude of 2,240 meters were studied in order to examine the relative roles of passive and active factors in the genesis of pulmonary arterial hypertension in obesity (overweight, 75 +/- 39 percent). Pulmonary arterial hypertension was present in 80 percent (16) of the patients (mean pulmonary arterial systolic pressure, 45 +/- 17 mm Hg). In 95 percent (19) of the 20 patients, resistance to pulmonary flow at the end of diastole was increased (estimated mean pulmonary arteriolar resistance, 210 +/- 144 dynes.sec.cm-5; mean pulmonary arterial diastolic-pulmonary wedge pressure gradient 7.86 +/- 1.40 mm Hg). The mean arterial oxygen pressure was 50 +/- 9 mm Hg, the arterial carbon dioxide tension was 37 +/- 6 mm Hg and the arterial pH was 7.42 +/- 0.08. Since the pulmonary arterial systolic pressure has been reasonably predicted (r = 0.91; P < 0.001), it would appear that the compliance of the elastic pulmonary arteries in obese patients follows a normal pattern. The behavior of the right ventricular end-diastolic pressure at rest (mean change, 4.6 mm Hg; P < 0.001) and of the pulmonary wedge pressure (mean change, 4.7 mm Hg; P < 0.001) during passive lifting of the legs was indirect evidence of the increase in pulmonary blood volume. The presence of an abnormal resistance to pulmonary blood flow at the end of diastole is suggestive of a decrease in the distention of the pulmonary microcirculation. The pulmonary arterial diastolic-pulmonary wedge pressure gradient and the pulmonary arterial diastolic pressure were related to arterial oxygen unsaturation (r = 0.70; P < 0.05) but not to the concentration of hydrogen ions; thus hypercapnic acidemia appears as a secondary factor in the genesis of pulmonary arterial hypertension at high atitudes. The explanation could be the relative hyperventilation of high altitudes, with a compensatory metabolic alkalosis. The increased pulmonary blood volume and the alveolar hypoxia are the main causes in the pathogenesis of pulmonary arterial hypertension in the grossly obese patient at this altitude.

Altitude↗
PubMed1977

Takayasu's arteritis. Clinical study of 107 cases.

The clinical experience derived from the retrospective study of 107 cases of TA over a 19 year period is presented. The disease predominated in females (8.5:1), with age of onset usually less than 20 years. In half of the cases an acute inflammatory phase was observed, characterized mainly by systemic and cardiovascular symptoms. Subsequently the natural course of TA was toward chronicity with gradual deterioration. The most frequent variety of TA (65 per cent of the patients) was Type III, in which the supra-aortic trunks and the abdominal aorta were involved. The predominant clinical features were reduction of amplitude of peripheral arterial pulses (96 per cent), vascular bruits (94 per cent), and raised blood pressure (72 per cent), mainly resulting from renal arterial involvement (62 per cent). Heart failure (28 per cent) is rarely the result of direct coronary arteritis. TA is most often confused with aortic coarctation, but usually the aortogram distinguishes these. The etiology of TA is discussed. The high incidence of previous and present active tuberculous (48 per cent) in the present series and previous experimental work suggest that tuberculosis may play an important role in the etiology of TA. Treatment for antihypertension and heart failure should be employed when indicated. Treatment with corticosteroids requires further evaluation. Treatment for tuberculosis is not justified in all cases until the exact role of tuberculosis is well established.

Acute Disease↗
PubMed1976

Effect of negative abdominal pressure on regional lung volumes in supine dogs.

Using 133Xe we measured regional lung volumes from apex to base in supine dogs during the application of negative abdominal pressure (-50 cm H2O). Changes in rib cage shape were monitored with magnetometers. Negative abdominal pressure caused a decrease of 5% in the cross-sectional area of the upper rib cage and a decrease of 19% in the cross-sectional area of the lower rib cage. These changes were similar to those observed when the dog was tilted to the erect position. Over the 10 cm of lung examined, control measurements showed a mean apex-to-base gradient of 1.4% TLC/cm, apical regions being more expanded than basal. Negative abdominal pressure increased this gradient to a mean of 2.1% TLC/cm. This change was in qualitative agreement with measurements of costal pleural surface pressure made in similar experiments by others. However, the changes we observed tended to be smaller than those predicted on the basis of costal pleural surface pressure. Since regional volumes represented the average of the pressures operating on lung regions, it was suggested that during negative abdominal pressure this average differed from pressure measured at the costal surface.

Abdomen↗
PubMedDate not supplied

Transesophageal echocardiography and right atrial infarction.

Transesophageal echocardiographic findings in right atrial infarction are described. In three patients with myocardial infarction of one or both ventricles, the association of right atrial myocardial infarction was suspected because of anatomic (two-dimensional) and hemodynamic (Doppler) alterations obtained from transesophageal images. Transesophageal interrogation may prove widely applicable in the evaluation of patients with suspected right atrial infarction.

Aged↗