EFFECTS OF GRADED-EXERCISE ON PULMONARY AND SYSTEMIC HEMODYNAMICS IN HORSES

Exercise-induced pulmonary hemorrhage (EIPH) is a common occurrence in racehorses and it is being increasingly recognized that pulmonary cir culation is the likely source of blood in racehorses experiencing EIPH . in order to understand the pathophysiology of EIPH and the interacti ons of pulmonary and systemic hemodynamic variables during exercise, w e studied changes in heart rate, right atrial pressure, pulmonary vasc ular pressures, phasic and mean aortic pressure, cardiac output, strok e volume, and pulmonary as well as systemic vascular resistances using standard hemodynamic procedures. Measurements were made in nine healt hy horses at rest and during treadmill exercise at 8 and 13 m/s. Resul ts of those measurements are presented.