1. In patients with first degree AV block, the variables used to evaluate diastolic function and filling pressures likely remain valid as long as there is no fusion of mitral E and A velocities.
2. The accuracy of mitral annular velocities and E/e' ratio is less in the presence of left bundle branch block, RV pacing, and in patients who have received cardiac resynchronization therapy.
3. If only mitral A velocity is present, only TR peak velocity (>2.8 m/sec) can be used as an indicator of LV filling pressures.