Table 2.
Some of the new ultrasound technologies-derived measures for evaluation of LV mechanical dyssynchrony and discoordination.
| Index | Cut-Off Value |
Imaging Method |
Echocardiographic View |
Parameter to Evaluate |
|---|---|---|---|---|
| ASPWD | 130 ms | 2D STE | PSAX (papillary muscles) | LV radial dyssynchrony |
| SDI | 25% | 2D STE | Apical 4-, 2-, and 3-C | LV longitudinal dyssynchrony |
| Tε-SD (MDI) | 60 ms | 2D STE | Apical 4-, 2-, and 3-C | LV longitudinal dyssynchrony |
| Septal flash | 130 ms | 2D STE | Apical 4-C | LV discoordination/ anomalous wall movements |
| Apical rocking | 9.8% | 2D STE | Apical 4-C or 3-C | LV discoordination/ anomalous wall movements |
| RDI | >40% | 2D STE | PSAX (papillary muscles) | LV radial discoordination |
| SRS | 4.7% | 2D STE | Apical 4-C | LV discoordination/ anomalous wall movements |
ASPWD: anteroseptal-posterior wall delay; LV: left ventricular; LVPEP: left ventricular pre-ejection period; MDI: mechanical dispersion index; PLAX: parasternal long-axis; PSAX: parasternal short-axis; PW: pulsed wave; RDI: radial discoordination index; SDI: strain delay index; SPWMD: septal to posterior wall motion delay; SRS: septal rebound stretch; STE: speckle tracking echocardiography; TDI: tissue Doppler imaging; T-SD: time to peak longitudinal strain standard deviation; 2D: two-dimensional; 2-C: 2-chamber; 3-C: 3-chamber; 4-C: 4-chamber; 5-C: 5-chamber.