Metalloproteinase-9 in circulating monocytes in pulmonary hypertension.

The role of matrix metalloproteinases (MMPs) in pulmonary hypertension (PH) is complex as MMPs are involved in both the vascular and cardiac remodelling associated with PH. To gain insight into this problem, monocytes were isolated from pulmonary arterial blood in patients suffering from PH, related to chronic obstructive pulmonary disease (n = 6), chronic pulmonary thromboembolism (n = 3) or pulmonary arterial hypertension (n = 8). The severity of PH was associated with decreases in cardiac index (CI) and mixed venous blood oxygen saturation (SO(2)), and an increase in right atrial pressure ().

Interpretation of high wedge pressure on exercise in patients with chronic obstructive pulmonary disease.

In a retrospective review of patients subjected to right heart catheterization, case records from 109 consecutive patients with chronic obstructive pulmonary disease (COPD) and wedge pressure > or =15 mm Hg on exercise were analyzed. Patients were separated into group 1, resting wedge pressure (P macro w) <15 mm Hg and difference between P macro w and right atrial pressure (P macro ra) change on exercise <5 mm Hg (n = 54), group 2, same P macro w at rest but increase in macro on exercise > or =5 mm Hg, being higher than that of P macro ra (n = 34), and group 3, P macro w > or =15 mm Hg at rest (n = 21). The occurrence of left heart disease increased from group 1 to group 3 (19, 53 and 71%, respectively), and the slope of the P macro w/stroke index relationship was lowest in group 3.

Role of NO pathway, calcium and potassium channels in the peripheral pulmonary vascular tone in dogs.

Because hypoxic pulmonary vasoconstriction occurs mainly in the small pulmonary arteries, the authors investigated the effects of drugs acting on the nitric oxide (NO) pathway and the calcium and potassium channels in the peripheral pulmonary circulation, without interference with the overall pulmonary or systemic circulation. Mixed venous blood was infused in wedged areas to study the pressure/flow relationship and to compute peripheral pulmonary vascular resistance (PPVR). The authors studied the effects of Nomega-nitro-L-arginine methyl ester (L-NAME), an NO synthase inhibitor, sodium nitroprusside (SNP, an NO donor), the calcium channel blockers verapamil, nifedipine and nicardipine, and the potassium channel opener levcromakalim, during normoxia and acute mild normocapnic hypoxia.

Changes in peripheral pulmonary vascular resistance after ioxaglate infusion in anesthetized dogs.

The pulmonary vascular resistance in a peripheral portion of the pulmonary vascular bed can be determined with a catheter wedged in a peripheral branch of the pulmonary artery, from the pressure increase induced by infusion of mixed venous blood at known flow rates. The volume of the wedged vascular bed can be estimated during fluoroscopy, from the volume of a contrast agent infused until the corresponding pulmonary vein can be seen. The present work was undertaken to determine the possible influence of this maneuver on the peripheral pulmonary vascular resistance (PPVR).

Effect of acute hypercapnia on alpha atrial natriuretic peptide, renin, angiotensin II, aldosterone, and vasopressin plasma levels in patients with COPD.

Disturbances in hormonal systems involved in sodium and water homeostasis are common during respiratory insufficiency. To investigate the role of hypercapnia, we designed a study to examine the hormonal response to acute hypercapnia induced at constant cardiac filling pressures and without hypoxemia. Seven sedated patients with COPD receiving mechanical ventilation were studied during five successive periods.

Pulmonary arterial wedge pressure measurement can modify pulmonary haemodynamics in patients with chronic lung disease.

In 20 patients with chronic lung disease in stable condition, haemodynamic values were compared during wedging of a Swan-Ganz catheter, either in a distal branch of the pulmonary artery, or by balloon inflation (with 1 ml) in a proximal branch, mostly excluding right lower lobe perfusion. Average pulmonary arterial wedge pressure, systemic arterial pressure, transcutaneous and mixed venous oxygen saturation, cardiac output and pulmonary blood volume (PBV) were not statistically different during distal and proximal wedging, but systolic pulmonary arterial pressure and pulmonary vascular resistance were slightly higher during balloon inflation (P < 0.05).

Right ventricular pressure-volume relations in chronic lung disease.

Thirty-four patients with chronic lung disease in stable condition were studied at supine rest (RS), at rest with the legs raised (LR), and during two levels of exercise: E1, 0 or 20 W, E2, 20 or 40 W. Five patients had normal spirometry (group 1), six patients had normal vital capacity but FEV1/VC below 70% (group 2), and 23 patients had VC below 95% of normal and FEV1/VC below 70% (group 3); group 3 was subdivided into group 3a (n = 14) without, and group 3b (n = 9) with a history of right heart failure (RHF). Right ventricular end-diastolic (RVEDV) and end-systolic (RVESV) volumes were computed from stroke volume and right ventricular ejection fraction (RVEF).

Peripheral pulmonary vascular resistance.

The pressure-flow relationship has been studied in a peripheral portion of the lung vasculature in anesthetized dogs with use of a double-lumen catheter wedged in a distal pulmonary artery. One lumen was used to infuse mixed venous blood in the wedged area and the other to measure the corresponding perfusion pressure. Flow ranged from 0 to 9.

[Relationship between right ventricular ejection fraction and pulmonary pressure in man].

This clinical study analysed the changes in right ventricular ejection fraction induced by changes in right ventricular afterload using a new thermodilution catheter linked to a rapid response computer which allowed instantaneous measurements of the right ventricular ejection fraction. The first group comprised 16 patients referred for coronary angioplasty with single vessel disease (isolated proximal stenosis of one of the two main branches of the left coronary artery) and a normal left ventricular ejection fraction (> or = 55%) and mean pulmonary artery pressure of < 25 mmHg: right ventricular ejection fraction and mean pulmonary artery pressure were measured under basal conditions and after 60 seconds' coronary occlusion with the balloon catheter in order to assess the effects of the reactional increase in afterload on the right ventricular ejection fraction. The second group comprised 11 patients with dilated primary cardiomyopathy with decreased left ventricular ejection fraction (< 50%) and mean pulmonary artery pressure > or = 25 mmHg: the right ventricular ejection fraction and mean pulmonary artery pressure were measured under basal conditions and after intravenous trinitrin (performed to evaluate the pulmonary reaction to vasodilators) in order to analyse the effects of the reduction of afterload on right ventricular ejection fraction.

Pressure/flow relation in the peripheral pulmonary vascular bed in dogs: a preliminary study.

In order to test a technique for the determination of the pressure/flow relationship in the peripheral pulmonary vascular bed, the perfusion pressure changes with increasing and then decreasing flow in a small part of the lung (around 1 ml) were studied in anaesthetized supine dogs, after insertion of a specially designed double distal lumen Swan-Ganz catheter. One lumen was used for the pressure measurement, one for infusion of saline by a pump with variable flow, from 0.1 to 1.

Pulmonary blood volume and haemodynamic changes with legs raised in chronic lung disease patients.

Study Objective: The aim was determine the early effect of a posture change from supine (S) to legs raised 30 degrees above the table plane (LR) on haemodynamics in patients with chronic lung disease.

Study Design: Right heart catheterization was performed as part of a routine evaluation. Pulmonary arterial, pulmonary wedge, right atrial, and systemic arterial pressure were monitored at rest supine and during 8 min (steady values) after LR.

One year treatment with almitrine improves hypoxaemia but does not increase pulmonary artery pressure in COPD patients.

Almitrine bismesylate, a chemoreceptor agonist, improves hypoxaemia in a high percentage of chronic obstructive pulmonary disease (COPD) patients and its long-term use may thus be of interest in these patients. The course of pulmonary haemodynamics during a one year treatment was investigated in severe COPD patients (forced expiratory volume in one second FEV1 = 1,040 +/- 80 SEM ml) with persistent hypoxaemia (initial arterial oxygen tension (PaO2) in the range 6.6-8.

Differential effects on right ventricular function of transient right, left anterior descending and left circumflex coronary occlusions during percutaneous transluminal coronary angioplasty.

Right ventricular function was studied by means of a thermodilution catheter before, during and after percutaneous transluminal angioplasty of the proximal right (group 1, n = 8), left anterior descending (group 2, n = 8) or left circumflex (group 3, n = 8) coronary artery. All patients had evidence of myocardial ischemia, with single-vessel disease affecting the proximal segment of one of the three major coronary arteries; no patient had had a previous myocardial infarction and all had normal cardiac function at baseline study. Cardiac index decreased during balloon inflation.

AaDO2 as a predictor of pulmonary hypertension resulting from pulmonary emboli.

The authors examined the records of all patients referred for right heart catheterization between 1963-84 because of persistent dyspnoea after one or more episodes of pulmonary emboli. Patients with a history of congestive heart failure, angina, restrictive or obstructive pulmonary disease that could explain their symptoms were excluded. Catheterization was performed 15.

Circulatory response to repeated exercise in patients with chronic lung disease.

The pulmonary and systemic circulatory response to repeated exercise has been studied in 24 patients with chronic lung disease, mainly chronic bronchitis. The exercise consisted of supine bicycling at a constant low load (from loadless pedalling to 30 W) for 10 min with a 20 min rest period between exercises. Cardiac output was similar during the first (E1) and the second (E2) exercise periods, as well as pulmonary vascular resistance.

[Changes in right ventricular ejection fraction in right coronary angioplasty].

In order to analyse the response of the right ventricule (RV) to transient myocardial ischaemia, the RV ejection fraction was measured using a new rapid response thermodilution catheter in 15 patients (14 men and 1 woman: average age 58 +/- 7 years) referred for percutaneous transluminal coronary angioplasty of a dominant right coronary artery. Only patients with single vessel disease with a proximal stenosis of the right coronary without a visible collateral circulation who had no previous history of myocardial infarction were included. Right heart catheterisation was performed with a rapid-response thermodilution catheter which enabled measurement of heart rate, cardiac index, RV end-diastolic and end-systolic volumes and RV ejection fraction.

Inter- and intrasubject variability of the thermodilution measurement of right ventricular ejection fraction and volume in patients with chronic obstructive pulmonary disease.

Study Objective: To determine the spontaneous changes in volumetric indices of right ventricular function assessed by thermodilution.

Design: The study involved measurements of inter- and intraindividual variation of right ventricular function in human subjects at rest and at two different levels of low load supine bicycle exercise.

Subjects: The subjects were 23 patients with chronic obstructive pulmonary disease, referred for evaluation by right heart catheterisation.

Metabolic CO2 removal by dialysis: THAM vs NaOH infusion.

New methods of respiratory support are needed to reduce the high mortality rate of acute respiratory failure. To simplify the procedures of extracorporeal CO2 elimination under apneic oxygenation, one approach is to replace the membrane lung by a hemodialyzer and to administer an alkali, since hemodialysis requires a lower blood flow rate than blood-gas exchange. This study compared the effectiveness of trishydroxymethyl aminomethane (THAM) and NaOH in this procedure.

Pulmonary vascular resistance rises with lung volume on exercise in obstructed airflow disease.

There has been experimental evidence that lung distension produces an increase in pulmonary vascular resistance (PVR). To study this effect in patients, we measured functional residual capacity (FRC) by helium dilution at rest and during low-load supine exercise in 30 patients with chronic obstructive pulmonary disease. Pulmonary haemodynamics were studied in these patients under the same conditions.

Variability of the pulmonary vascular response to acute hypoxia in chronic bronchitis.

Hypoxic pulmonary vasoconstriction is considered as one of the factors leading to pulmonary hypertension in patients with chronic bronchitis, but the magnitude and the variability of the pulmonary vascular response to hypoxia in these patients have not been well established. We investigated the pulmonary hemodynamic changes induced by breathing two hypoxic mixtures (FIO2 = 0.15 and 0.

Local variations of pulmonary arterial wedge pressure and wedge angiograms in patients with chronic lung disease.

This study was undertaken in 23 patients with chronic lung disease to determine whether local wedge pressure variability is related to the state of the local perfusion as observed in distal wedge angiograms. We also compared the variability of the pressures obtained after distal (mechanical) and proximal (balloon inflation) wedging of a catheter in three to six different sites in each patient. When the wedge pressure measurements were repeated in the same site (n = 7), the mean of the absolute differences was below 1 mm Hg.

Natural variability of pulmonary haemodynamics.

In the interpretation of the effect of a drug or intervention in a single patient, it is desirable to know the spontaneous fluctuations of the variable under study. A few studies have determined pulmonary haemodynamic variability in acute and short-term intervals. It seems reasonable to adopt a confidence limit of 6 mmHg or 22% for PPA changes to be significant.