Table 2.
Hemodynamic effects of simultaneous variation of left ventricular pacing site and interventricular pacing delay with biventricular pacing during acute left ventricular volume overload
| Best Settings |
|||||
|---|---|---|---|---|---|
| Functional Index | LVPS | VVD†, ms | Change From Worst Settings | Change From Default Settings‡ | LVPS-VVD Interaction |
| CO, l/min | No effect | −20 | 8±2% | 3±1% | P = 0.293 |
| Interventricular synchrony (APP)* | Apex | −80 | −0.45±0.03 | −0.31±0.02 | P < 0.001 |
| LV dP/dtmax, mmHg/s | OM | −40 | 9±3% | 1±1% | P = 0.012 |
| RV dP/dtmax, mmHg/s | Apex | −20 | 12±3% | 7±4% | P < 0.001 |
Values are mean ± SE. LVPS, left ventricular pacing site; VVD, interventricular pacing delay; No effect, lack of significant parameter effect; OM, obtuse margin.
*
Positive APP indicates RV preceding LV pressure.
†
Positive VVD indicates RV-first pacing.
‡
Default settings (the most common clinically implemented biventricular pacing protocol): LVPS = circumflex; VVD = 0 ms.