[Dynamics of venous blood return in normal conditions and in patients with obstructive lung disease].

The venous blood flow in the jugular, cubital, and inferior cava veins was studied in 7 healthy individuals and in 22 patients with chronic obstructive bronchitis by means of bichamber Doppler ultrasonography and direct measurement of venous pressure. The diameter of the veins, blood flow rate, and venous pressure were found to be greatly determined by the intrathoracic pressure variations during the respiration cycle. It is suggested that distention of the peripheral veins, which is the commonly accepted sign of right-ventricular insufficiency, in patients with drastic bronchial obstruction is a consequence of disturbed mechanics of respiration, namely, increase of intrathoracic pressure during expiration, which impairs the return of venous blood to the right parts of the heart.