Mitral flow responses to two-week salt loading in elderly hypertensive patients

The effects of a two-week high sodium diet on mitral flow pattern were assessed in 29 patients with essential hypertension (81.9 +/- 6.9 years). Transmitral flow was recorded during different rates of salt intake; 7 g/day for 8 weeks and 20 g/day for 2 weeks. With sodium loading, 25 patients whose mean blood pressure (MBP) increased by 10 percent or more were termed salt-sensitive (SS) group, and 4 patients whose MBP did not change or increased by less than 10 percent were termed non-salt-sensitive (NSS) group with mitral flow velocity integral, cardiac output (CO) and total peripheral resistance (TPR) were calculated. Thirteen of the SS patients were defined as "SST" in which an increase in TPR was greater than that in CO with sodium repletion. In the remaining 12 SS patients termed "SSc", the increase in CO was greater than that in TPR with salt loading. CO increased significantly in the SSc patients, but did not change in the SST or NSS group with sodium loading. TPR increased significantly in the SST and NSS subjects, and decreased significantly in the SSc patients. Peak velocity of transmitral flow in the rapid filling phase (R) decreased significantly in the SST and NSS patients, and increased significantly in the SSc group. On the other hand peak velocity of transmitral flow in the atrial contraction phase (A) increased significantly in the SST and SSc groups, but remained unchanged in the NSS patients. There was a significant increase in A/R in the SSt group and a significant decrease in A/R in the SSc patients with sodium loading.