Correlation of different pressure-volume loop parameters during biventricular pacing in heart failure patients

Abstract

Introduction: Cardiac resynchronization therapy (CRT) with biventricular pacing improves acute cardiac hemodynamics. We investigated the correlation of different hemodynamic parameters commonly used to assess acute response. Methods: Forty-four patients (pts) receiving CRT implant with a quadripolar left ventricular (LV) lead and multisite LV pacing-enabled device underwent LV hemodynamic assessment using a PV loop system. PV loops were recorded during biventricular pacing with each of two single LV sites, 4-7 multisite LV pacing settings, and RV pacing (BASELINE). Correlations between dP/dtMax, stroke work (SW), and stroke volume (SV) during different pacing interventions were quantified for each patient with Spearman's rank coefficient (ρ). Results: Evaluable recordings were obtained in 42 pts. SW and SV were positively correlated (ρ > 0.3 in 33 pts, ρ 0.3 in 18 pts, -0.3 0.3 in 11 pts, -0.3 < ρ < 0.3 in 19 pts, and ρ < -0.3 in 12 pts. In one example patient (see Fig.), strong positive correlation existed between SW and SV (ρ = 1.0, p-value < 0.001), while both SW and SV correlated negatively with dP/dtMax (SW: ρ = -0.73, p-value = 0.03, SV: ρ = -0.73, p-value = 0.03). ![Figure][1] Conclusion: Correlation of different hemodynamic parameters varies between pts. Understanding the relationship between hemodynamic parameters could help individualize the selection of a parameter for CRT optimization. [1]: pending:yes