Parameter | Definition | Cut-off | Ref. | Example |
---|---|---|---|---|
Interventricular electromechanical delay (IMD) | Interventricular electromechanical delay between pulmonary and aortic outflow. Measured as the time between the onset of the QRS to onset of aortic flow vs. QRS to onset of pulmonary flow | ≥ 40 ms | 6 | 1 |
Septal-to-posterior wall motion delay (SPWMD) | M-mode: the interval between the maximum contraction of the septum and the maximum contraction of the left ventricular posterior wall | ≥ 130 ms | 14, 15 | 2 |
Ts-12 | Maximum difference in Ts between any 2 of 12 LV segments | ≥ 104 ms | 16 | 3 |
Ts-12-SD | Standard deviation of the time to peak myocardial velocity (Ts) of the 12 LV segments | ≥ 34.4 ms | 16 | 4 |
Septal-to-lateral delay in peak systolic velocity (TDId) | Delay between the basal septal and basal lateral Ts, assessed with color-coded TDI | ≥ 60 ms | 17 | 5 |
LVEMD | aortic pre-ejection delay measured as the time between the onset of the QRS to beginning aortic flow | > 140 ms | 6 | 6 |
Delayed longitudinal contraction (DLC) | Number of LV segments with DLC assessed by tissue tracking in the apical 4-chamber, 2-chamber and long-axis view | ≥ 2 | 18 | 7 |