The utility of Doppler mitral flow pattems for the indirect assessment of left ventricular diastolic function is valid and widely used. One of the most common variables affecting mitral flow is heart rate. The aim of this study was to compare between mitral flow and mitral annulus velocity by Doppler tissue imaging (DTI) according to increment of heart rate.

17 healthy volunteers (M: F=10: 7, mean age 27±2 years) comprised this study. They were free of any acute or chronic illness. The heart rate was elevated by increments of 10 beats (baseline, 80, 90, 100, 110, 120) by transesophageal atrial pacing. We measured mitral flow parameters (E and A velocity, E/A ratio, IVRT, DT of E) and mitral annulus velocity by DTI (e and a velocity, e/a ratio, RIVRT). We gave the score of visual estimation at baseline and each heart rate. The definition of the score was as follows, 1: well visualization of each envelope 2: summation of velocity wave forms 3: no differentiation, completely fused.

1) The E of mitral flow was significantly increased from 100 to 120 BPM and A velocity was significantly increased from 80 to 100 BPM (p<0.05). E/A ratio was significantly decreased from 90 to 100 BPM than baseline (p<0.05). 2) The e and e/a ratio of mitral annulus velocity were significantly increased from above 110, 100 BPM than baseline, respectively (p<0.05). But a velocity was little changed. 3) The score was all significantly higher in mitral annulus velocity pattern by DTI than mitral flow at each heart rate.

The mitral annulus velocity by DTI is less affected by heart rate and visualized better than mitral fiow in increased heart rate. Therefore the assessment of mitral annulus velocity may be helpful for evaluating diastolic function during heart rates of physiologic range.