RIGHT VENTRICULAR DIASTOLIC FUNCTION DURING EXERCISE - EFFECT OF ISCHEMIA

The effects of exercise on right ventricular function were evaluated in 14 patients who underwent supine rest and exercise right ventricular angiography, on the basis of coronary anatomy and exercise left ventricular regional wall motion analysis, these were classified into two groups: Group 1 (n = 7) had no or only mild coronary artery disease and Group 2 (n = 7) had significant coronary disease and exercise-induced left ventricular wall motion abnormalities suggesting ischemia. Chamber stiffness at rest was higher in Group 2 (48 × 10-3 ml-1/m2) than in Group 1 (18 × 10-3ml-1, p = 0.006). During exercise, right ventricular filing rate in the second half of diastole was significantly lower in Group 2 (126 versus 276 ml/m2 per s, p < 0.03). The time constant of right ventricular pressure decay decreased signiicantly in both groups with exercise; however, both groups displayed a parallel upward shift of the pressure-volume curve with exercise. Because ischemia could not be demonstrated in Group 1, it is an unlikely explanation for this shift. was not a significant factor with exercise. Because of an increase in left ventricular end-diastolic volume with exercise and a close correlation between right and left ventricular end-diastolic pressures (r = 0.96 for Group 1 and r = 0.76 for Group 2), pericardial constraint is the most likely cause for this upward shift of the pressure-volume carve. Therefore, an increase in right ventricular end-diastolic pressure may lot be a reliable indicator of ischemia during exercise because this pressure is coupled to changes in left ventricular volume and pericardial constraint. © 1990.