Pulsatile Flow in Pulmonary Artery, Capillary, and Vein in the Dog'
Cardiovascular Research, 1974, 8, 330-337. Pulsatile flow in pulmonary artery, capillary, and vein in the dog' Downloaded from https://academic.oup.com/cardiovascres/article/8/3/330/298317 by guest on 25 September 2021 WARREN G. GUNTHEROTH, RICHARD GOULD, JOHN BUTLER, and EDWIN KINNEN~ With the technical assistance of Donald Breazeale, George McGough, and John Mendenhall From the Departments of Pediatrics and Medicine, University of Washington School of Medicine, Seattle, Washington 98195, USA AUTHORS' SYNoPsis The temporal relationship of flow pulses in the pulmonary artery, capil- laries, and veins was investigated in 10 chronic dog preparations with pulsed ultrasonic flowmeters and a nitrous oxide-body plethysmograph for capillary flow. Implanted pressure transducers in the left atrium provided reference to the conventional atrial pulses: A, C, X-descent, V, and Y-descent. Left atrial contraction produced an A-wave pressure transient followed by retrograde flow up the veins. The C-pressure pulse occasionally produced a minimal trough in the venous flow pattern. Early in ventricular systole, X-descent in left atrial pressure preceded a venous flow pulse of modest amplitude, which began prior to the onset of the pulse of capillary flow. On average, right ventricular ejection was followed in 37 msec by the major flow pulse in the capillaries, which in turn was fol- lowed 68 msec later by the onset of venous flow. This venous flow pulse was simultaneous with a rise in left atrial pressure, the V-wave. With the onset of diastole, the Y-descent in atrial pressure pre- ceded a major venous flow pulse. With accelerated heart rate, separation of the V and Y venous flow pulses was lost, and a monophasic pulse was found.
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