Myocardial supply-demand ratio in aortic regurgitation

To analyze the relationship between the myocardial supply and demand for oxygen in patients with aortic regurgitation, the ratio of the diastolic pressure-time index (DPTI) over the systolic pressure-time index (SPTI) was derived from recordings of pressure during cardiac catheterization in 24 patients with aortic regurgitation, and this ratio was compared with that in 14 normal subjects and in ten patients with congestive cardiomyopathy (an ejection fraction less than 0.30). Patients with aortic regurgitation had a DPTI/SPTI of 0.75 +/- 0.06 (mean +/- SE), which was lower than in the normal subjects (1.24 +/- 0.06) and patients with cardiomyopathy (1.06 +/- 0.03) (P less than 0.001). Among the patients with aortic regurgitation, the 13 with a DPTI/SPTI below 0.70 had more severe aortic regurgitation than the 11 with a DPTI/SPTI above 0.70. Aortic regurgitation results in a reduced myocardial supply-demand ratio, as measured by the DPTI/SPTI, which is related to the severity of the valvular regurgitation and is not present in patients with left ventricular dysfunction secondary to congestive cardiomyopathy.