1991 Volume 55 Issue 3 Pages 204-212
Left ventricular (LV) systolic function was assessed in patients with hypertensive heart disease (HHD, n=30), hypertrophic cardiomyopathy (HCM, n=27), dilated cardiomyopathy (DCM, n=25), volume overload heart (VOH, n=31) and normal subjects (NS, n=32) in the two-dimensional framework of force-length (end-systolic stress-end-systolic volume index) and stress-shortening (mid-systolic stress-ejection fraction). Quadratic discriminant analysis revealed that the ellipses of confidence of HHD and normal subjects were in the same place with regard to both force-length and stress-shortening, while all other groups were well-discriminated. Three subgroups of patients, those with DCM with mild heart failure and those with VOH (with and without heart failure). were easily distinguishable on the basis of stress-shortening, but not on the basis of force-length measurements. It is concluded that LV systolic function and afterload are maintained within the normal range under pressure and volume overload until symptoms of heart failure appear via the mechanism of compensatory hypertrophy. Stress-shortening appears to be a more useful parameter than force-length for the analysis of LV systolic function in clinical practice.
