Table 2. Limitations of conventional Doppler indices in the assessment of diastolic function.

Parameter	Limitations
Transmitral PW inflow pattern	- Preload dependent - Influenced by PW sample position - Difficult to analyze in AF and high heart rates - Influenced by age
Isovolumic relaxation time	- Technical difficulty in obtaining simultaneous tracings of transmitral inflow and LV outflow - Preload dependent - Low reproducibility
Pulmonary vein flow (Ard–Ad)	- Technically difficult to obtain in some patients - Cannot be used in atrial fibrillation - Dependent on heart rate
Mitral inflow propagation velocities	- Dependent on preload and LV cavity size - Low reproducibility

Ard, atrial reversal of pulmonary venous flow duration; Ad, late diastolic transmitral flow duration; PW, pulsed wave