1. Variables recommended for evaluation of diastolic function in patients with HCM are average E/e' ratio (>14), LA volume index (>34 mL/m²), pulmonary vein atrial reversal velocity (Ar-A duration ≥ 30 msec), and peak velocity of TR jet by CW Doppler (>2.8 m/sec). The parameters can be applied irrespective of the presence or absence of dynamic obstruction and MR, except for patients with more than moderate MR, in whom only Ar-A duration and peak velocity of TR jet are still valid.
2. If more than half of the variables (total available variables three or four) meet the cutoff values, then LAP is elevated and grade II diastolic dysfunction is present. If <50% of the variables (total available variables three or four) meet the cutoff values, then LAP is normal and grade I diastolic dysfunction is present. In case of 50% discordance with two or four available variables, findings are inconclusive to estimate LAP. Estimation of LAP is not recommended if there is only parameter with a satisfactory signal.
3. Grade III diastolic dysfunction is present in the presence of a restrictive filling pattern and abnormally reduced mitral annular e' velocity (septal <7 cm/sec, lateral <10 cm/ sec).