Clinical efficacy and safety of telmisartan 80 mg once daily compared with enalapril 20 mg once daily in patients with mild-to-moderate hypertension: results of a multicentre study.

The efficacy and safety of once-daily telmisartan 80 mg vs. once-daily enalapril 20 mg in the treatment of essential hypertension were evaluated in a multicentre, single-blind, placebo-controlled, randomised trial. In total, 68 patients (49 females, 19 males) with mild-to-moderate hypertension, defined as morning supine systolic blood pressure (SBP) 141-149 mmHg, diastolic blood pressure (DBP) 95-114 mmHg, were enrolled. After a 4-week placebo run-in phase, patients were randomly assigned to treatment with telmisartan or enalapril administered once daily in the morning for 8 weeks. No statistically significant differences were found in the baseline characteristics of patients in either group. Both SBP and DBP were decreased in both treatment groups, but the reductions were statistically different in favour of telmisartan (SBP, p = 0.013; DBP, p = 0.002). The incidence of adverse effects was lower in the telmisartan group, with the absence of cough. In conclusion, telmisartan is more effective and better tolerated than enalapril for the treatment of hypertension and has the advantage that it does not cause cough.

Clinical efficacy and safety of telmisartan 80 mg once daily vs. atenolol 50 mg once daily in patients with mild-to-moderate hypertension.

The objective of this open-label, parallel-group comparative study was to assess the clinical efficacy and safety of once-daily treatment for 8 weeks with telmisartan 80 mg in comparison with atenolol 50 mg on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in patients with mild-to-moderate hypertension (morning supine SBP 141-199 mmHg, DBP 95-114 mmHg). A total of 58 patients were enrolled. The comparability of the two treatment groups was statistically documented at the beginning of the study. Telmisartan was more effective than atenolol, with a decrease in SBP of 21.7 mmHg vs. 11.8 mmHg (p = 0.03) and a non-significant decrease in DBP of 14.7 mmHg vs. 10.1 mmHg. The safety profiles of both drugs were very similar; both drugs were well tolerated. In conclusion, once-daily telmisartan 80 mg is more effective than once-daily atenolol 50 mg in lowering SBP with no negative chronotropism. Furthermore, telmisartan was as well tolerated as atenolol in the treatment of mild-to-moderate essential hypertension in adults.

[The respiratory center in normal subjects at 2,240 meters above sea level. The ventilatory and occlusion pressure (P 0.1) responses upon CO2 stimulation]. / Estudio del centro respiratorio en sujetos normales a 2,240 metros sobre el nivel del mar. La respuesta ventilatoria y de la presión de oclusión (P 0.1) al estímulo del CO2.

Altitude hypoxia imposes acute changes and long term adjustments in the ventilation of human beings. Most of the present knowledge of the respiratory center behavior at high altitude derives from the studies of ventilatory response to both hypoxia and hypercapnea. Other indexes of respiratory center output such as the occlusion pressure (P 0.1) response to a variety of stimuli are at present being evaluated. We could not find, however, studies on the P 0.1 responses to CO2 at high altitude. In this study we analyze the ventilatory and P 0.1 responses to CO2 in a group of 32 normal subjects, all of them natives and residents of Mexico city (altitude of 2,240 meters) and we compared them with those reported at sea level. The slope of both, the ventilatory and P 0.1 responses to CO2 was found to be similar to that reported at sea level; 4.52 +/- 1.29 L. min. mmHg and 0.07 +/- 0.01 cm H2O/mmHg respectively. The crossing over of such responses, however, is shifted to the left of the reported at sea level. This means higher levels of both ventilation and P 0.1, for the same level of end-tidal PCO2, at high altitude. This finding might be explained in the basis of the so-called "acclimatization to hypocapnea".

[Pulmonary function in chronic ischemic cardiopathy]. / Estudio de la función pulmonar en la cardiopatía isquémica crónica.

Twenty patients with heart disease were prospectively studied. Seven of them had an old myocardial infarction and thirteen, ischemic symptoms without infarction. Pulmonary function was studied focusing on small airway disease and gas exchange abnormalities. Our results showed that a mild degree of abnormality exists as reflected by bronchial obstruction with origin in small airways, V/Q disturbed and hypoxemia. In 88% these seem to be related to left ventricular disfunction. Twenty four hours after pulmonary function test all patients underwent left heart catheterization with coronarography and ventriculography.

[Alveolar-arterial oxygen gradient in cardiopulmonary patients breathing ambient air at rest and during exercise]. / Estudio del gradiente A-a de oxígeno en pacientes cardiopulmonares, respirando aire ambiente, en reposo y en ejercicio.

The alveolar to arterial difference of oxygen [(A-a)DO2] depends on variables such as ventilation, cardiac output, respiratory exchange ratio and arterial PO2. The arterial PO2 itself depends on the ventilation to perfusion ratio (V/Q) pulmonary shunt, (a-v) O2 difference, and the metabolic status of the patient. When the alveolar-ventilation is normal, the (A-a)DO2 reflects gas exchange abnormalities and when the alveolar-ventilation is increased, the (A-a)DO2 can increase because of a decrease in PaCO2. The factors capable of altering the alveolar to arterial oxygen difference were investigated in ninety patients with pulmonary disease: (pulmonary embolism, lung fibrosis and chronic obstructive lung disease), both at rest and during exercise. At rest when alveolar ventilation was increased, the (A-a)DO2 broadened due to the decrease in PaCO2. During exercise the (A-a)DO2 also increased and the PaCO2 was not significantly modified, therefore admixture it is the result of an increase in the proportion of venous. The difference between the mixed venous and arterial PO2 decreased due to alveolar hypoventilation reducing in consequence the (A-a)DO2. We conclude that in the group studied the increase in the (A-a)DO2 is mainly due to V/Q imbalance at rest and during exercise.

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.

Estudio de la funcion pulmonar en la cardiopatia isquemica cronica. / Pulmonary function study in chronic ischemic heart disease

Se estudiaron 20 pacientes, 7 con infarto del miocardio de mas de un ano de evolucion y 13 con cardiopatia isquemica sin infarto. En el momento del estudio no mostraban evidencia clinica de insuficiencia cardiaca y ninguno era fumador. Se estudio la funcion pulmonar haciendo hincapie en aquellas alteraciones que traducen trastorno funcional de la via aerae menor y del intercambio gaseoso. En ellos, se encontraron signos de patologia pulmonar de poca cuantia, reflejada en broncobstruccion que se manifesto por trastorno funcional de la via aerea menor, desequilibrio de la relacion ventilacion/persfusion e hipoxemia. Estas alteraciones fueron poco importantes y en el 88% probablemente secundarias a congestion pulmonar por disfuncion ventricular izquierda. Veinticuatro horas despues del estudio de la funcion pulmonar en el laboratorio, todos los pacientes fueron estudiados en el gabinete de hemodinamica mediante estudio de cateterismo cardiaco, ventriculografia y coronariografia selectiva

[Pulmonary mechanics and small airways in patent ductus arteriosus and interventricular communication, in relation to pulmonary arterial flow and pressure]. / La mecánica pulmonary y la vía aérea menor en la persistencia del canal arterial y la comunicación interventricular, en relación al flujo y a la presión arterial pulmonar.

Eighteen patients with ventricular septal defect or patent ductus arteriosus were studied to investigate the effects of an increase of pulmonary hypertension. In general group II showed similar results as previously reported in patients with atrial septal defect without pulmonary hypertension. In group I, we found an increased frequency of functional abnormalities in the small airways. We do not have a definitive explanation for the origin of these differences.

[Effects of body posture on mechanical lung function in the obese patient]. / Los effectos de la posición corporal sobre la función mecánica del pulmón en el obeso.

The pulmonary mechanics of twelve obese patients were studied: the static and dynamic compliance, the maximum pressure of elastic recoil, and the expiratory flow curves breathing room air and a mixture of He-O2. Also analyzed were the closing capacity, the closing volume and the slope of the alveolar plateau (phase III), in the erect and supine positions. Our data confirm that the tests that explore the small airways are abnormal in the obese patients. The results obtained, allow us to assure that the pulmonary mechanics in the obese patients are affected by the change of position, as is shown by the closing volume and closing capacity when assuming the supine position when compared to orthostatism, as well as the decrease in vital capacity. These alterations were not found in non-obese patients which were used as controls.

[Arteriovenous shunting in obesity, its relation to lung volume]. / El corto-circuito venoarterial en al obesidad, su dependencia del volumen pulmonar.

Thirty-five patients with an average overweight of 67.1% were studied. Pulmonary restriction of a variable degree was found in 68.6/; in 60% due to reduction of respiratory reserve volume. Bronchial obstruction was detected in 57% as measured by forced midexpiratory flow (25-75%). In addition, 14% showed a decrease of 75-85% in forced expiratory flow, which suggested that the pathology was located in the small respiratory airways. The PaO2 while breathing room air and in a resting state was of 52.6 +/- 9.42 mmHg, and after breathing it increased to 69.07 +/- 11.01 mmHg. The PaO2 breathing inspiratory fractions of 99.6% O2 in a resting condition was 309.34 +/- 70.07 mmHg, and after deep breathing it rose to 354.0 +/- 64.27 mmHg. The mechanisms which produce hypoxemia in the obese were analysed and it was concluded that they were due fundamentally to alterations of the ventilation perfusion ratio and to an increase of the venous-arterial shunt. In some cases, alveolar hypoventilation contributed (Pickwick syndrome). By increasing the pulmonary volume with deep breathing, the ventilation perfusion ratio improves or becomes normal, likewise, the venous-arterial shunt can improve or persist as the only cause of hypoxemia.

El corto-circuito venoarterial en la obesidad, su dependencia del volumen pulmonar. / Arteriovenous shunt in obesity, its dependence to pulmonary volume

Se estudiaron 35 pacientes con sobrepeso corporal del 67.1% en promedio. El 68.6% tenian restriccion pulmonar de grado variable, en el 60% a expensas de reduccion del VER. Existio broncobstruccion en el 57% a juzgar por el FEF de 25-75%; ademas 14% tuvieron disminucion del FEF entre 75-85% lo que sugiere patologia de la via aerea menor. La PaO2 respirando aire ambiente en reposo fue de 52.6 mmHg +/- 9.42 y despues de realizar respiraciones profundas se elevo a 69.07 mmHg +/- 11.01. La PaO2 respirando O2 FI 99.6% en condiciones basales fue de 309.34 mmHg +/- 70.07 y despues de respiraciones profundas ascendio a 354.0 +/- 64.27. Se analizaron los mecanismos productores de hipoxemia en el obeso y se concluyo que eran debidos fundamentalmente a alteraciones de la relacion V/Q y al aumento del corto circuito v-a. En algunos casos contribuye la hipoventilacion alveolar (Sindrome de Pickwick). Al aumentar el volumen pulmonar con respiraciones profundas la relacion V/Q mejora o se normaliza; asimismo, el corto circuito v-a puede mejorar o persistir como unica causa de hipoxemia

Los efectos de la posicion corporal sobre la funcion mecanica del pulmon en el obeso / Effects of body position on the mechanical pulmonary function of the obese

Se estudio la mecanica pulmonar de doce pacientes obesos: su distensibilidad estatica y dinamica, la presion maxima de retraccion elastica y las curvas espiratorias de flujo-volumen, respirando aire ambiente y mezcla de HeO2. Se analizo, igualmente, la capacidad de cierre, el volumen de cierre y la pendiente de la fase III en ortostatismo y en decubito dorsal. Se confirma que todos los parametros que exploran la via aerea menor son anormales en el paciente obeso. Nuestros datos permiten asegurar que el cambio de posicion influye sobre la mecanica pulmonar del obeso, como lo demuestra el aumento del volumen de cierre y la capacidad de cierre al adoptar la posicion de decubito supino en relacion con el ortostatismo (p menor ou igual 0.001), asi como la documentada disminucion de la capacidad vital. Estos cambios no se prestaron en los sujetos normales que se usaron como testigos

[Pulmonary arteriovenous fistula and lateral decubitus anoxia]. / Fístula arteriovenosa pulmonar y decúbito-latero-deoxia.

The case of a female patient with Rendu-Osler-Weber disease associated with pulmonary arterio-venous fistula localized at the apical segment of the left inferior pulmonary lobe is described. A decrease in the oxygen arterial saturation (SaO2) at adopting the left lateral decubitus position (left-lateral-decubitodeoxia) was found, as well as an increase in the anatomical venoarterial short-circuit (Qs/Qt) in the same position. The resonsible factors of such changes in SaO2 and Qs/Qt related with the body position are analyzed, and the, exceptional in these patients, finding of alteration of pulmonary mechanics is commented.

[Pulmonary arterial hypertension of unknown etiology. Study of the cardiopulmonary function]. / Hipertensión arterial pulmonar de etiología desconocida. Estudio de la función cardiopulmonar.

Thirty two cases of pulmonary arterial hypertension of unknown etiology (PAH-UE) were studied. The diagnosis was established by exclusion after the results of hemodinamics studies. Ninety percent of cases had severe PAH (100 mmHg). The end diastolic right ventricular pressure was elevated in 46% of cases. The total pulmonary vascular resistance was increased in the order of the 1700 dinas. seg. cm-5. The cardiac index was 3.3 1/m2 with a right ventricular work index of 3.96 K gm min. The total lung capacity (TLC) was normal, with a vital capacity (VC) of 78% of the predicted value. The residual volume was increased. The mean value of the maximal midexpiratory flow rate (MMFR) was 78%. The A-a gradient of O2 was 30 mmHg, with a venous mixture expressed as a percentage ratio of the cardiac output (Qva/Qt) of 26%. The mean paO2 mmHg and the anatomical pulmonary artery to vein shunt (Qs/Qt) was 9%, with a DLco normal. The clinical hemodinamic correlation was in good agreement. Our results suggested that PAH-UE "per se" has effect in pulmonary function changing slight lung mechanics, and in a moderate degree lung gas exchange. The hipoxemia results meanly from V/Q imbalance.