[Evaluation of left cardiac function in chronic obstructive bronchopneumopathy. Correlation of the radiographic analysis of the thorax and hemodynamic data].

Chest radiographs, taken in the standing position, were reviewed in 47 hospitalised patients with chronic obstructive respiratory failure; the review was done retrospectively and the radiographs were examined for signs of left ventricular failure. Only interstitial and alveolar oedema were considered, upper lobe blood diversion was commonly seen in patients, probably reflecting pulmonary hypertension independent of any re-distribution of left ventricular origin. Interstitial oedema was seen in 9 patients (19.2%) of whom only one reached a pulmonary capillary pressure of 25 mmHg, traditionally considered as a threshold of interstitial oedema. In 8 other patients, the pulmonary capillary pressure was either moderately elevated between 15 and 25 mmHg (3 cases) or strictly normal (5 cases). The discordance observed between the radiological data and haemodynamics very probably reflects (bearing in mind the descriptions in valvular and ischaemic heart disease) a greater sensitivity of the radiograph when compared to measurements of pulmonary capillary pressure at rest in cases of left ventricular failure "fruste". The greater sensitivity of radiological analysis in patients suffering from chronic airflow obstruction contrasts with the classical notion, according to which the radiological expression of definite left ventricular failure was frequently poor in this kind of patient by reason of a destruction of the vascular bed, which limited the development of pulmonary oedema.