Comparison of acute hemodynamic effect of prioritizing ventricular resynchronization vs left ventricular filling during optimization of cardiac resynchronization therapy.

BACKGROUND

Targeting maximal ventricular resynchronization, with the shortest QRS duration (QRSd), is commonly implemented after cardiac resynchronization therapy (CRT).

OBJECTIVE

The purpose of this study was to compare optimization of ventricular resynchronization with optimization of left ventricular (LV) filling during CRT by measuring their acute hemodynamic effects.

METHODS

Patients with standard CRT indications, recruited from 2 centers, underwent biventricular pacing (BVP) and left bundle branch pacing (LBBP). We performed a within-patient comparison of acute hemodynamic response of systolic blood pressure (SBP) at the atrioventricular delay (AVD) with the shortest QRSd against the AVD with the most efficient LV filling. In a validation substudy, we also performed electrical assessment using QRS area (QRSa) and hemodynamic assessment with the maximum rate of LV pressure rise (dP/dt).

RESULTS

Thirty patients (age 65 ± 10 years; 53% male) were recruited. The AVD producing maximal ventricular resynchronization was associated with a significantly shorter QRSd (difference 15 ± 12 ms for BVP and 18 ± 13 ms for LBBP, both P <.01) and a significantly smaller improvement in SBP (difference -3 ± 4 mm Hg for BVP and -2 ± 2 mm Hg for LBBP, both P <.01) compared with the AVD that optimized filling. Similar findings were observed in the substudy, with a significantly smaller improvement in dP/dt assessed with QRSd and QRSa (difference -9% ± 7% and -6% ± 4% during BVP, and -5% ± 6% and -3% ± 3% during LBBP, all P <.01).

CONCLUSION

Targeting the maximal ventricular resynchronization results in suboptimal acute hemodynamic performance with both BVP and LBBP as CRT. These findings support prioritizing LV filling when programming AVD for CRT.