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At least 19 recordsLinked to original sources
PubMed1997

Pulmonary hypertension, pulmonary blood vessels and vasoactive drugs.

There is an urgent need for new drugs to treat pulmonary hypertension. Specific pathophysiological abnormalities, seen in both clinical pulmonary hypertension and experimental pulmonary hypertension in animals, suggest that potassium channel openers, endothelin antagonists and nitric oxide donors may be valuable in the future. Our own studies and those of others have shown that drugs from each of these groups have properties that are consistent with their potential therapeutic use in this disease. Use of the inhalational route of administration may be desirable, or even essential, if any of these drugs are to produce effects that are selective for the pulmonary circulation.

Animals↗
PubMed1996

Chronic infusion of nitric oxide in experimental pulmonary hypertension: pulmonary pressure-flow analysis.

Inhaled-nitric oxide (NO) is a selective pulmonary vasodilator in short-term clinical studies. Use of NO inhalation in chronic pulmonary hypertension is complicated by potential problems with ambulatory NO delivery. We hypothesized that long-term infusion of NO solution into the central venous circulation, which did not suffer from this drawback, might reduce chronic pulmonary hypertension. Saturated NO solution was infused in chronically hypoxic rats by implantable minipumps at a rate which was effective in reducing acute hypoxic vasoconstriction in isolated, Krebs' albumin perfused lungs (2.5 microL.h-1). Pulmonary haemo dynamics and the pressure-flow relationship were studied after 4 weeks of infusion. NO was still present in the minipumps at the end of the infusion period. Despite causing methaemoglobinaemia, NO infusion did not significantly attenuate pulmonary arterial pressure, pulmonary vascular resistance, right ventricular hypertrophy, or the parameters of the pulmonary vascular pressure-flow relationship. Pressure-flow curves, analysed with the nonlinear, distensible vessel model, indicated increased near-zero pressure resistance (Ro) in chronic hypoxia. The tendency of chronic NO infusion to reduce Ro did not reach statistical significance. Long-term infusion of nitric oxide solution is technically feasible but does not effectively reverse chronic pulmonary hypertension. The failure of infused NO to reduce pulmonary hypertension is explained by the fact that the inactivation of NO by haemoglobin is much faster than anticipated.

Animals↗
PubMed1992

Pulmonary hypertension: pulmonary flow quantification and flow profile analysis with velocity-encoded cine MR imaging.

Velocity-encoded cine magnetic resonance (MR) imaging provides two-dimensional velocity maps of a cross-sectional area of a vessel. Pulmonary flow and flow patterns in the main pulmonary artery were analyzed with velocity-encoded cine MR imaging and Doppler echocardiography in 10 patients with pulmonary hypertension (PH), one patient with a dilated main pulmonary artery, and 10 healthy subjects, and these findings were compared. Peak systolic velocity measured with velocity-encoded cine MR imaging was similar to that measured with Doppler echocardiography in healthy subjects and in patients with PH. Velocity-encoded cine MR imaging demonstrated substantial differences in velocity across the vascular lumen in PH. The flow pattern in healthy subjects was different than that in patients with PH; the latter had lower peak systolic velocity and greater retrograde flow after middle to late systole. The retrograde flow observed in patients with PH reflected hemodynamic events, since it was inversely proportional to pulmonary flow volume and directly proportional to pulmonary resistance and cross-sectional area of the vessel. Velocity-encoded cine MR imaging demonstrates an inhomogeneous flow profile in PH and may serve as a noninvasive method to estimate pulmonary vascular resistance.

Adult↗
PubMed1984

Pulmonary hypertension, pulmonary edema, and decreased pulmonary compliance produced by increased ICP in cats.

Cats, anesthetized with sodium pentobarbital, were cannulated to measure pulmonary, systemic, and left atrial pressures and pulmonary ventilation, compliance, and resistance. Intracranial pressure was elevated to 30 mm Hg by injecting silicone oil into the extradural space. After an average time of 56 minutes, pulmonary systolic and diastolic pressures more than doubled, systemic systolic pressure sometimes rose and sometimes fell, and diastolic pressure rose 5%. Left atrial pressure never exceeded 8 cm of saline. Pulmonary compliance decreased by one-half, but airway resistance was unchanged. Pulmonary edema was estimated from histological sections. The pulmonary hypertension may be the result of a sympathetic discharge confined to the lung, since no remarkable changes in heart rate or systemic blood pressure occurred. The decrease in pulmonary compliance followed the rise in pulmonary arterial pressure, and is interpreted as the result of interstitial edema. There was no evidence that left heart failure or elevated left atrial pressure caused the pulmonary edema.

Animals↗
PubMed1992

Primary pulmonary hypertension in association with human immunodeficiency virus infection. A possible viral etiology for some forms of hypertensive pulmonary arteriopathy.

Recent reports have suggested a possible association between HIV-1 infection and primary pulmonary hypertension (PPH), but most of the patients described to date have either had acquired immunodeficiency syndrome (AIDS) with concurrent lung infections or have administered Factor VIII intravenously for hemophilia. We report three human immunodeficiency virus type 1 (HIV-1)-positive homosexual white males with clinical and hemodynamic diagnoses of PPH. None of the patients had any opportunistic lung infections or other pulmonary pathology, nor were they hemophiliacs. They had no histories of intravenous drug use. Lung tissue from two of the patients revealed hypertensive arteriopathy consistent with PPH and no other pulmonary pathology. Attempts at localizing HIV-1 infection to the vascular endothelium with electron microscopy, immunohistochemistry, DNA in situ hybridization, and polymerase chain reaction techniques did not reveal direct pulmonary artery infection with the virus. These data and the finding of tubuloreticular structures on electron microscopy suggest that HIV-1 may play a role in the pathogenesis of these cases of PPH through mediator release associated with HIV-1 infection rather than by direct endothelial infection.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Recognition and management of pulmonary hypertension.

Pulmonary hypertension (mean pulmonary arterial pressure > 20mm Hg at rest or > 30mm Hg during exercise) occurs (i) as primary pulmonary hypertension (no known underlying cause), (ii) as persistent pulmonary hypertension of the newborn or (iii) secondary to a variety of lung and cardiovascular diseases. In the last 10 to 15 years there have been significant advances in the medical management of this debilitating and life-threatening disorder. The main drugs in current use are anticoagulants (warfarin, heparin) and vasodilators, especially oral calcium antagonists, intravenous prostacyclin (prostaglandin I2; epoprostenol) and inhaled nitric oxide. Calcium antagonists, (e.g. nifedipine, diltiazem) are used chiefly in primary pulmonary hypertension. They are effective in patients who give a pulmonary vasodilator response to an acute challenge with a short acting vasodilator (e.g. prostacyclin, nitric oxide or adenosine), and are used in doses greater than are usual in the treatment of other cardiovascular disorders. Prostacyclin, given by continuous intravenous infusion, is effective in patients even if they do not respond to an acute vasodilator challenge. The long term benefit in these patients is thought to reflect the antiproliferative effects of the drug and/or its ability to inhibit platelet aggregation. It is used either as long term therapy or as a bridge to transplantation. Inhaled nitric oxide, which is used mainly in persistent pulmonary hypertension of the newborn, has the particular benefit of being pulmonary selective, due to its route of administration and rapid inactivation. Anticoagulants have a specific role in the treatment of pulmonary thromboembolic pulmonary hypertension and are also used routinely in patients with primary pulmonary hypertension. Nondrug treatments for pulmonary hypertension include (i) supplemental oxygen (> or = 15 h/day), which is the primary therapy in patients with pulmonary hypertension secondary to chronic obstructive pulmonary disease and (ii) heart-lung or lung transplantation, which nowadays is regarded as a last resort. Different types of pulmonary hypertension require different treatment strategies. Future advances in the treatment of pulmonary hypertension may come from the use of drug combinations, the development of new drugs, such as endothelin antagonists, nitric oxide donors and potassium channel openers, or the application of gene therapy.

Anticoagulants↗
PubMed2006

[Contemporary prospects for the diagnostics and treatment of the chronic pulmonary hypertension].

Pulmonary hypertension is defined as the rise of mean pressure in the pulmonary artery over 25 mmHg at rest or over 30 mmHg during activity with accompanying increase of pulmonary vascular resistance over 3 WU (Wood's unit). According to the recent WHO classification from 2003 pulmonary hypertension can be categorized as pulmonary arterial hypertension, pulmonary venous hypertension, hypoxic pulmonary hypertension, chronic thromboembolic pulmonary hypertension and pulmonary hypertension from other causes. Because symptoms of the pulmonary hypertension are non-specific, the diagnosis is frequently late. Patients with higher risk of pulmonary hypertension require frequent echocardiographic examination. Treatment of the pulmonary hypertension is rather complex and economically demanding. It should be therefore centralized in specialized units. Decision on the pharmacotherapy is based on the acute pulmonary vasodilatation test. Only patients with the positive test (10% of patients) are indicated to the treatment with calcium channel blockers. In case of negative test, the treatment of choice in NYHA III stadium is bosentam per orally, in the NYHA IV stadium it is epoprostenol intravenously. In patients with chronic thromboembolic pulmonary hypertension, organized thrombotic material should be surgically removed together with the layer of the pulmonary artery (pulmonary endarterectomy) after preceding anticoagulation treatment lasting at least three months. Pulmonary hypertension center of the Cardiocenter of the General teaching hospital is the only unit in the Czech Republic which beside the complex therapy of the pulmonary arterial hypertension can employ also the surgical treatment of the chronic thromboembolic pulmonary hypertension.

Chronic Disease↗
PubMed1997

Effects of long-term infusion of prostacyclin (epoprostenol) on echocardiographic measures of right ventricular structure and function in primary pulmonary hypertension. Primary Pulmonary Hypertension Study Group.

BACKGROUND: Right heart failure is an important cause of morbidity and mortality in primary pulmonary hypertension. In a recent prospective, randomized study of severely symptomatic patients, treatment with prostacyclin (epoprostenol) produced improvements in hemodynamics, quality of life, and survival. This article describes the echocardiographic characteristics of participants in this trial; the relationship of echocardiographic variables to hemodynamic parameters, exercise capacity, and quality of life; and the echocardiographic changes associated with prostacyclin therapy. METHODS AND RESULTS: The 81 patients enrolled in this multicenter trial were randomized to treatment with a long-term infusion of prostacyclin in addition to conventional therapy (n = 41) or conventional therapy alone (n = 40) for 12 weeks. Echocardiograms and assessments of hemodynamics, exercise capacity, and quality of life were performed before and after the treatment phase. On baseline evaluation, patients had marked right ventricular dilatation and dysfunction, abnormal septal curvature, and significant tricuspid regurgitation with a high regurgitant velocity. Pericardial effusions were common. More pronounced abnormalities in right heart structure and function were associated with higher pulmonary arterial and mean right atrial pressures, lower cardiac index, and impaired exercise capacity but had no predictable relationship to quality-of-life indicators. The 12-week infusion of prostacyclin had beneficial effects on right ventricular size, curvature of the interventricular septum, and maximal tricuspid regurgitant jet velocity. CONCLUSIONS: The echocardiographic manifestations of severe primary pulmonary hypertension reflect abnormalities in hemodynamics and exercise capacity. Prostacyclin has beneficial effects on right heart structure and function that may contribute to the clinical improvement and prolonged survival observed with this drug.

Adult↗
PubMed1999

Isosorbide-5-mononitrate in the treatment of pulmonary hypertension associated with portal hypertension.

Pulmonary hypertension is uncommonly associated with portal hypertension. The current approach for the management of pulmonary hypertension involves the use of vasodilators in patients who show vascular responsiveness during an acute challenge. Since the association of portal hypertension with pulmonary hypertension is very seldomly presented, its optimal therapy has not been defined. Moreover, calcium-channel blockers, which are usually used in pulmonary hypertension treatment, may exert a deleterious effect on portal hypertension. Therefore, the search for drugs that may be active under both conditions has important clinical implications. This report presents the case of a patient with portal hypertension-associated pulmonary artery hypertension that was effectively treated with isosorbide-5-mononitrate (Is-5-Mn). The patient had severe portal hypertension (hepatic venous pressure gradient=14.5 mmHg) and pulmonary hypertension (mean pulmonary artery pressure (PAP)=50 mmHg). Acute administration of prostacyclin and nitric oxide elicited a significant reduction in both PAP and pulmonary vascular resistance (PVR), an effect that was also achieved with Is-5-Mn. The patient was treated with 40 mg Is-5-Mn twice daily and a haemodynamic study performed 6 months later showed that the reduction in both PAP and PVR persisted.

Female↗
PubMed2002

Haemodynamic evaluation of pulmonary hypertension.

Pulmonary hypertension is characterised by the chronic elevation of pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) leading to right ventricular enlargement and hypertrophy. Pulmonary hypertension may result from respiratory and cardiac diseases, the most severe forms occurring in thromboembolic and primary pulmonary hypertension. Pulmonary hypertension is most often defined as a mean PAP >25 mmHg at rest or >30 mmHg during exercise, the pressure being measured invasively with a pulmonary artery catheter. Doppler echocardiography allows serial, noninvasive follow-up of PAPs and right heart function. When the adaptive mechanisms of right ventricular dilatation and hypertrophy cannot compensate for the haemodynamic burden, right heart failure occurs and is associated with poor prognosis. The haemodynamic profile is the major determinant of prognosis. In both primary and secondary pulmonary hypertension, special attention must be paid to the assessment of pulmonary vascular resistance index (PVRI), right heart function and pulmonary vasodilatory reserve. Recent studies have stressed the prognostic values of exercise capacity (6-min walk test), right atrial pressure, stroke index and vasodilator challenge responses, as well as an interest in new imaging techniques and natriuretic peptide determinations. Overall, careful haemodynamic evaluation may optimise new diagnostic and therapeutic strategies in pulmonary hypertension.

Blood Pressure↗
PubMed1989

Isolated chronic mitral regurgitation with preserved systolic left ventricular function and severe pulmonary hypertension.

Pulmonary hypertension in chronic mitral valve disease has been related most commonly to left ventricular dysfunction or mitral stenosis; its association with chronic, isolated mitral regurgitation and preserved left ventricular systolic function is unclear. In 41 catheterized patients with chronic mitral regurgitation (known history of mitral regurgitation for greater than 18 months) and preserved left ventricular systolic function (ejection fraction greater than 0.55), historic, electrocardiographic, echocardiographic and hemodynamic variables were analyzed. Ten patients (Group I) had normal pulmonary artery systolic pressure (less than 30 mm Hg), whereas 31 patients had pulmonary hypertension. Pulmonary artery systolic pressure was mildly increased (30 to 49 mm Hg) in 13 patients (Group II) and was greater than or equal to 50 mm Hg in 18 patients (Group III). Univariate analysis showed the more frequent occurrence of male gender and ruptured chordae tendineae in the groups with pulmonary hypertension. Mean pulmonary capillary wedge pressure, size of the V wave in pulmonary capillary wedge pressure and pulmonary arteriole resistance were higher, whereas cardiac index was lower in the hypertension groups. Multivariate stepwise analysis revealed higher mean pulmonary capillary wedge pressure and pulmonary arteriole resistance as the only variables independently differing among groups. In conclusion, pulmonary hypertension occurs frequently (76% of cases) in patients with chronic, isolated mitral regurgitation with preserved left ventricular systolic function. In these patients, a severe increase in pulmonary capillary wedge pressure is associated with elevation in pulmonary artery resistance, a finding similar to that in mitral stenosis.

Echocardiography↗
PubMed2007

Therapeutic applications of sildenafil citrate in the management of paediatric pulmonary hypertension.

Pulmonary hypertension is characterised by a progressive increase in pulmonary vascular resistance and a poor prognosis. The exact underlying mechanisms are still poorly understood; however, it is hypothesised that pulmonary medial hypertrophy and endothelial dysfunction lead to impaired production of vasodilators such as nitric oxide (NO) and prostacyclin, and increased expression of vasoconstrictors such as endothelin-1. The current treatment modalities for pulmonary hypertension include conventional supportive therapies and more specific pharmacological therapies that are targeted at abnormalities of endothelial function. NO and phosphodiesterase type 5 (PDE5) inhibitors induce pulmonary vasodilation by increasing intracellular cyclic guanosine monophosphate (cGMP) concentrations. Sildenafil citrate is a highly selective inhibitor of PDE5. Investigations in animal models and recent clinical case reports with some studies in the paediatric population suggest that sildenafil may be a promising agent in treating pulmonary hypertension. The effect of sildenafil on pulmonary vasculature appears to be independent of the underlying cause, thereby providing a role in idiopathic pulmonary arterial hypertension (PAH), PAH associated with congenital heart disease, pulmonary hypertension secondary to lung disease or persistent pulmonary hypertension of the newborn. It may also be beneficial in postoperative pulmonary hypertension and in neonates who are difficult to wean from inhaled NO. It is easily administered and effective, and has minimal systemic adverse effects. Although the reported results in children with pulmonary hypertension are promising, it is an experimental drug and large-scale randomised controlled studies are required to validate the safety, efficacy and dosage in the paediatric population.

Animals↗
PubMed1993

Pulmonary hypertension as a fatal complication of extrahepatic portal hypertension.

Pulmonary hypertension is an uncommon complication of portal hypertension seen in cirrhotic as well as noncirrhotic patients. We report a 10-year-old girl who presented with extrahepatic portal hypertension and pulmonary hypertension in the absence of intrinsic liver disease. Further investigations revealed high serum concentrations of prostaglandin F2 alpha, thromboxane B2 in the inferior vena cava, and angiotensin I in the inferior vena cava and right ventricle. The increased levels of these vasoconstrictive substances strongly suggest that the possible mechanism for the pulmonary hypertension in such patients with extrahepatic portal hypertension include shunting of vasoactive agents from the splanchnic circulation to the pulmonary vascular bed.

Angiotensin I↗