[Pulmonary volume and cardiopulmonary function in acute myocardial infarction (author's transl)]

In order to evaluate alterations in lung mechanisms detected in patients with acute myocardial infarction (MI), changes in arterial oxygenation and pulmonary volume in relation to the hemodynamic status were measured in 19 patients with acute MI. Pulmonary volume was determined with spirometry and helium dilution closed technic at 24 and 72 hours and two months after acute MI. The first finding was decreased arterial PO2: 328 +/- 29 mm/Hg (mean +/- SE) which had significantly risen by the third day: 423 +/- 20 mm/Hg (p less than 0.02). This disturbance was accompanied by an increased pulmonary shunt (Qs/Qt) and VD/VT relation, which improved with time but did not return to normal. A manifest relationship was not found between the degree of hypoxemia and diminished functional residual capacity (FRC). During the acute phase lung volume was normal while patients were seated but upon assuming a supine position, vital capacity (VC), total lung capacity (TLC) and RV/TLC were altered considerably. The VC and RV/TLC alterations were significantly altered in patients with left ventricular dysfunction. No significant changes were found in pulmonary values during the acute phase and VC and TV/TLC had improved considerably two months later. It is probable that increased interstitial pulmonary edema bears the main responsibility for these alterations, including in uncomplicated acute MI.