Type of dyssynchrony | Underlying electrical disease | Functional consequence |
---|---|---|
Atrioventricular | Prolonged PR/AV block | Diastolic impairment |
Inter-ventricular | Wide QRS | Systolic impairment |
Intra-ventricular LV | Wide QRS (LBBB) | Systolic and diastolic impairment Mitral regurgitation |
Echography parameter | Method | Cut-off values |
---|---|---|
Septal to posterior wall motion delay[ |
M-mode | ≥ 130 ms |
Septal flash[ |
M-mode | Nonquantifiable |
Apical rocking[ |
2D apical 4 chambers | Nonquantifiable |
Basal septal to lateral Ts delay[ |
Tissue Doppler imaging | ≥ 60 ms |
Maximum delay in Ts in 4 basal LV segments[ |
Tissue Doppler imaging | > 65 ms |
SD of Ts of 6 basal LV segments[ |
Tissue Doppler imaging | ≥ 34.4 ms |
Antero-septal to posterior time to peak strain difference (radial strain[ |
2D speckle tracking | ≥ 130 ms |
SD of time to minimum systolic volume of 16 LV segments (systolic dyssynchrony index)[ |
3D echocardiography | > 5.6% |