Estimation of pulmonary artery wedge pressure from chest radiograph in patients with chronic congestive cardiomyopathy and ischaemic cardiomyopathy

Abstract

In order to define the relation between chest x-ray findings and the level of pulmonary artery wedge pressure in patients with chronic congestive cardiomyopathy, 82 patients had chest radiographs before undergoing 92 haemodynamic studies. The studies were divided into three groups according to the level of pulmonary artery wedge pressure (PAWP) (group 1: less than 15 mmHg, group 2: 15 to 24 mmHg, group 3: greater than or equal to 25 mmHg. Venous distribution, interstitial oedema, pleural effusions, left atrial enlargement, and right ventricular enlargement each occurred in less than 10 per cent of group 1 studies. Radiological abnormalities generally distinguished group 1 from group 2, but none except cardiothoracic ratio distinguished group 2 from group 3. Cardiothoracic ratio correlated best with pulmonary artery wedge pressure (r = 0.70). Alveolar oedema was uncommon when PAWP greater than or equal to 25 mmHg, occurring in 32 per cent of group 3 studies. Stepwise multiple linear regression analysis showed that cardiothoracic ratio, alveolar oedema, interstitial oedema, and left atrial size each contributed independently to the prediction of PAWP. The regression analysis improved the accuracy of the estimation of PAWP from the findings noted on standard chest radiographs.