Primary Pulmonary Hypertension With Special Reference to Prognosis

Radiology of the right ventricle

RV changes may be generalized into dilatation and hypertrophy. Increased preload results in ventricular dilatation. Increased afterload causes hypertrophy. Change in the shape of the RV resulting from increased afterload and myocardial hypertrophy induces tricuspid regurgitation, which superimposes changes of chamber dilatation onto those of hypertrophy. Sustained ventricular dilatation and hypertrophy frequently progresses to RV failure. In these cases, RV systolic function decreases in association with elevation of RV and right atrial diastolic pressure. Changes in the wall thickness and shape of the RV are variable, and depend upon the severity of the volume or pressure load presented, as well as its duration and rate of progression. Because the RV is an anterior cardiac structure, it occupies little of any heart border. Therefore, the sensitivity of plain film examination to RV disease is limited. Inferential diagnosis of RV disease can often be made based upon identification of other radiographic changes, notably the state of the pulmonary circulation, and the position of the heart in the chest. Conventional contrast right ventriculography may be used to assess the size and position of the RV, as well as associated acquired and congenital lesions that result in RV dysfunction. Due to the unusual shape of the RV cavity, however, and the unpredictable manner in which it dilates, accurate quantitative analysis by this technique is limited. Furthermore, the common association between RV disease and pulmonary hypertension limits the applicability of this imaging technique for evaluating patients with RV disease. Multiplanar MR imaging allows direct demonstration of changes in RV size and wall morphology. Furthermore, application of Simpson's rule to tomographic slices acquired at ventricular diastole and systole allows direct, accurate, and reproducible quantitative analysis of ventricular volume and myocardial mass, allowing radiographic assessment in patients for diagnosis, as well as longitudinally during medical management or after surgical treatment for congenital and acquired diseases that result in RV dysfunction.

The effect of anticoagulant therapy in primary and anorectic drug-induced pulmonary hypertension

In a retrospective study, we tested the hypothesis that anticoagulant therapy with warfarin sodium (Coumadin) has a beneficial influence on the long-term prognosis in patients with primary pulmonary hypertension (PPH) and aminorex-induced plexogenic pulmonary hypertension. The study included a total of 173 patients from two European cities. One hundred four of these patients took the anorectic drug aminorex (Menocil), which was available in some European countries almost 30 years ago; 69 patients had pulmonary hypertension of unexplained etiology, ie, PPH. Fifty-six of the 104 aminorex-treated patients and 24 patients in the PPH group received warfarin after diagnosis was established. For analysis, patients were divided into four groups according to their history of aminorex intake and anticoagulant therapy. Survival time, changes in hemodynamics (pulmonary arterial pressure), and improvement in quality of life (scored by the New York Heart Association [NYHA] classification) were compared and analyzed. We found that aminorex-treated patients had a better long-term prognosis than those with PPH (7.5 vs 3.9 years; p < or = 0.001). The best mean survival time of 8.3 years was found in anticoagulated aminorex-treated patients, compared to 6.1 years in nonanticoagulated aminorex-treated patients. Moreover, aminorex-treated patients who received anticoagulant therapy soon after the onset of symptoms showed significantly better prognosis (10.9 years) than those who commenced treatment 2 years thereafter (5.9 years) (p < or = 0.05). In patients with PPH, systolic pulmonary pressure was shown to influence survival time significantly (p < or = 0.0005); however, this correlation was not found in aminorex-treated patients. An improvement of symptoms like dyspnea on exertion was seen in 44.8% of the anticoagulated aminorex-treated patients, while deterioration was evident in 72.2% of the nonanticoagulated aminorex-treated patients. In conclusion, our study has shown that anticoagulant therapy had a positive influence on long-term survival and a significant improvement in quality of life in patients with PPH, in particular in patients with a history of anorectic drug intake.

Clinical and pathologic manifestations of pulmonary vascular disease in the toxic oil syndrome

The toxic oil syndrome in Spain affected greater than 20,000 people. In the initial stages, it was characterized by a respiratory distress syndrome with myalgias and eosinophilia. Pulmonary hypertension developed in 20% of the patients and in many, it has spontaneously regressed. Nevertheless, in a small subgroup, it has progressed to a malignant course of cor pulmonale, leading rapidly to death. Clinical and pathologic features of 40 patients with severe pulmonary hypertension due to the toxic oil syndrome are presented (32 female and 8 male patients; mean age 26 +/- 13 years). The study began in June 1981, which was near the onset of the toxic oil epidemic, and ended in December 1987, greater than 6 years later. The pulmonary hypertension is clinically and pathologically indistinguishable from primary pulmonary hypertension. Direct endothelial injury by the toxic agent is proposed as the initial trigger of this type of pulmonary hypertension, but an interaction between the toxic agent and specific individual susceptibility is probably required in its pathogenesis.

Nitroglycerin therapy in the management of pulmonary hypertensive disorders

Vasodilator therapy has not been effective in patients with pulmonary hypertension because most of the drugs that have been utilized in treating this disorder do not exert selective effects on the pulmonary circulation. Nonselective agents may cause predominant systemic vasodilation and lead to severe hypotension; they may elicit reflex activation of the sympathetic nervous system and further elevate pulmonary artery pressures; or they may exert depressant effects on right ventricular function and aggravate right-sided heart failure. Nitroglycerin has theoretic appeal as a vasodilator drug in patients with pulmonary hypertension because it exerts a direct effect on the pulmonary circulation in doses that do not affect systemic resistance vessels or the myocardium and do not activate neurohumoral reflexes. Furthermore, the drug uniquely reduces pulmonary artery pressures in addition to pulmonary vascular resistance due to its ability to dilate venous capacitance vessels. Preliminary studies with sublingual and intravenous nitroglycerin in patients with pulmonary hypertension have shown that the drug produces marked hemodynamic improvement and that clinical benefits follow long-term therapy with transcutaneous or oral nitrates. However, treatment may provoke hypotensive events in some patients and systemic hypoxemia in others; still others may fail to benefit because the pulmonary vasculature is unresponsive to any vasodilator stimulus. Further work is needed to define the benefits and risks of nitroglycerin therapy in patients with pulmonary hypertension.

Long-term follow-up in primary pulmonary hypertension

Two patients with severe primary pulmonary hypertension, who are alive 38 and 27 years after the onset of the disease, were closely followed by the authors for 24 years. No previous report of such a long course has been found. Despite pulmonary artery pressures at systemic level, effort syncope disappeared and there were long intervals without symptoms during which the 2 patients were able to take part in physical activity with minimal discomfort. Severe primary pulmonary hypertension should not always be considered a malignant disease.

Familial primary pulmonary hypertension

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