Objectives:
This investigation was designed 1) to assess whether the early diastolic velocity of the mitral annulus (ea) obtained with doppler tissue imaging (dti) behaves as a preload-independent index of left ventricular (lv) relaxation; and 2) to evaluate the relation of the mitral e/ea ratio to lv filling pressures.
Background:
Recent observations suggest that ea is an index of lv relaxation that is less influenced by lv filling pressures.
Methods:
One hundred twenty-five study subjects were classified into three groups according to mitral e/a ratio, lv ejection fraction (lvef) and clinical symptoms: 34 asymptomatic subjects with a normal lvef and an e/a ratio > or =1; 40 with a normal lvef, an e/a ratio <1 and no heart failure symptoms (impaired relaxation [ir]); and 51 with heart failure symptoms and an e/a ratio >1 (pseudonormal [pn]). ea was derived from the lateral border of the annulus. a subset of 60 patients had invasive measurement of pulmonary capillary wedge pressure (pcwp) simultaneous with doppler echocardiographic dti.
Results:
Ea was reduced in the ir and pn groups compared with the group of normal subjects: 5.8 +/- 1.5 and 5.2 +/- 1.4 vs. 12 +/- 2.8 cm/s, respectively (p < 0.001). mean pcwp (20 +/- 8 mm hg) related weakly to mitral e (r = 0.68) but not to ea. the e/ea ratio related well to pcwp (r = 0.87; pcwp = 1.24 [e/ea] + 1.9), with a difference between doppler and catheter measurements of 0.1 +/- 3.8 mm hg.
Conclusions:
Ea behaves as a preload-independent index of lv relaxation. mitral e velocity, corrected for the influence of relaxation (i.e., the e/ea ratio), relates well to mean pcwp and may be used to estimate lv filling pressures.