Pulmonary hypertension etiology

Primary pulmonary hypertension is a disease of unclear etiology that is characterized by abnormally high mean pulmonary arterial pressures, in the absence of a demonstrable cause. A wide variety of pulmonary and cardiac diseases can lead to secondary pulmonary hypertension. 

NO. A dose-response curve for inhaling 5-80 ppm was described, and full reversal of hypoxia-induced PAH was also reported in this paper. No dilatory effects were observed on the systemic circulation. Others confirmed (Girard et al., 1992) and extended (Fratacci et al., 1991) these findings in animal experiments with hypoxia- and thromboxane-induced pulmonary hypertension. These experimental observations initiated a new field of research activity examining the clinical and experimental effects of inhaled NO in states of pulmonary hypertension of varied etiology with or without concomitant hypoxemia. We review here some of this research. The field has grown so rapidly, however, that only original contributions are cited. 

Sudden, unexpected death is usually classified as cardiac in etiology, assumed to be due to ischemic heart disease or an arrhythmia. Death Irom asphyxia caused by acute bronchospasm could be erroneously classified as a cardiac cause of death. In addition, exacerbations of COPD can precipitate cardiac arrhythmias or myocardial infarction in patients with significant underlying heart disease (6,42). Severe COPD is often complicated by cor pulmonale, or chronic failure of the right ventricle caused by pulmonary hypertension and hypoxemia. Deaths caused by cor pulmonale may be misclassified as primary cardiac deaths, although the precipitating event may be a pulmonary insult. 

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