[Contribution of the mechanocardiography to the study of obstructive chronic bronchopneumopathy]. / L'apporto della meccanocardiografia allo studio delle broncopneumopatie croniche ostruttive

Kinetocardiography, ECG and radiography, were compared as ways of obtaining early diagnosis of chronic cor pulmonale in two series of patients (81 in all) with chronic obstructive bronchopneumopathy. Kinetocardiography proved markedly superior in this respect. It revealed right ventricular pressure overload in a higher percentage of cases and at an earlier stage, i.e. when PAP values were little above normal resting values, of even when their increase appeared only during physical effort.

[Early changes of respiratory function in mitral valve stenosis]. / Alterazioni precoci della funzione respiratoria nelle stenosi mitraliche

In order to detect early changes of respiratory function in patients affects by pure mitral valve stenosis, the authors selected 12 patients-non smokers, without symptoms of respiratory disease, of I and II NYHA class. In all subjects right and left cardiac catheterization and conventional spirometric measurements were performed. Then maximal mid-expiratory flow (MMEF), maximal expiratory flow at 50% of vital capacity (MEF 50%), maximal expiratory flow at 25% of vital capacity (MEF 25%), closing volume (CV) and closing capacity (CC) were determined, to find a small airways (bronchi of caliber inferior to 2 mm) disease. Whereas conventional spirometric measurements showed normal values, the small airways disease was proved by MEF 50% and MEF 25% measurements. The small airways obstruction observed by the authors may be due to: a) dilatation of pulmonary vessels because of venous congestion resulting in the compression of adjacent small airways; b) partial bronchiolar obstruction because of congestion of submucous venous plexus; c) interstitial oedema due to increase of extravascular pulmonary water because of pulmonary venous congestion.

Regional lung perfusion and pulmonary artery pressure in chronic obstructive lung disease.

In 22 chronic bronchitics with or without emphysema, the authors measured regional pulmonary perfusion in the supine position and calculated the ratios of radio-active tracer (131I-MAA) concentrations in the lung apices and bases (U/L ratio). This ratio was found to be normal in the right lung and tendentially high (though not to a statistically significant degree) in the left lung, this being probably due to the presence of an enlarged heart (13 patients showed evidence of right ventricle hypertrophy and/or overload). The correlation between the U/L ratio and functional impairment of respiration expressed spirometrically failed to reach statistical significance and the same was true of the correlation between the U/L ratio and mean pulmonary arterial pressure at rest.

Heart volume determination with phase synchronization in normal subjects and postinfarct patients.

The authors investigated the influence of the systole-and-dyastole cycle upon the cardiac volume measured radiologically with ECG phase synchronization in prone subjects. Measurements were made in 30 healthy subjects and 27 patients with a history of myocardial infarction, all of them ambulatory. As expected, the mean cardiac volume relative to body surface was greater in postinfarct patients than in normal subjects to a high degree of statistical significance. Conversely, the differences between end-systolic and end-diastolic cardiac volumes fell short of statistical significance both in healthy subjects and in postinfarct patients. Accordingly, radiological measurements of cardiac volume without phase synchronization seem justified in the functional evaluation of postinfarct patients.

Can pulmonary artery pressure be predicted without right heart catheterization in chronic obstructive lung disease?

We have investigated the dependance of observed pulmonary artery mean pressure (PAP) on body surface, age, PaO2, pH, PaCO2, hematocrit, and spirometric data (VC, FEV1/VC, RV/TLC) in 70 patients with chronic obstructive lung disease (COLD). After elimination of all variables that failed to correlate with PAP, multifactorial analysis showed that only two of nine independent variables, namely PaO2 and body surface, correlated significantly with PAP. According to our calculations, 28.9% of total PAP is predictable by PaO2, 1.5% by H+ concentration, 2.8% by RV/TLC, and 2.5% by body surface. Fully 64.2% of total variability was not accounted for by our regression analysis; thus the error of predicted PAP was so great (+/- 17 mm Hg for P = 0.05) as to invalidate the method. We also recalculated our subjects' PAP values by applying Enson's and Grassi's equations to our own lung function and biochemical data, and compared the predicted PAP values thus obtained with those measured directly in our subjects. Both equations proved imprecise and/or inaccurate in the individual case. From this we conclude that whereas available equations may be suitable for predicting the mean PAP value of a large population sample, the same equations cannot give a reliable prediction in individual cases.