Introduction: In patients with medically refractory heart failure due to severe left ventricular (LV) systolic dysfunction and interventricular conduction delay biventricular pacemaker stimulation can result in an increase of exercise function and left ventricular ejection fraction. A hemodynamic optimization of the atrioventricular (AVD) and interventricular delay (VVD) is crucial to maximize the response to this treatment and lower the number of non-responders. Various methods for optimization include echocardiographic studies, invasive measurements and electrogram-based algorithms. Most methods are time-consuming, thus CRT devices are frequently programmed to empiric recommendation instead of being optimized. The QuickOpt algorithm (St.Jude Medical, USA) provides a quick automatic hemodynamic optimization in CRT devices. Aim of this study was the comparison of the resulting AVDs and VVDs from the optimization via QuickOpt and empiric programming.
Methods: We reviewed the follow-ups of a total of 250 CRT patients with St.Jude Medical CRT devices (Promote, Unify, Promote Quadra) retrospectively. The AVDs and VVDs were documented, patients were assigned to the QuickOpt group if the algorithm was utilized for routine follow-ups.
Results: In 38 % of all patients of the QuickOpt algorithm was employed for the hemodynamic optimization on a routine basis. Mean AVD in the QuickOpt group was 171 ms paced and 122 ms sensed, mean VVD was 50 ms (range 0 to -75 ms). Empiric AVDs and VVDs were significantly lower than the QuickOpt measurements (p<0.01). Mean AVD in the empiric group was 156 ms paced and 113 ms sensed, mean VVD was 15 ms (range 0 to -75 ms). In all devices both ventricles were paced simultaneously or LV before RV.
Conclusions: The performance of a hemodynamic optimization is crucial for heart failure patients with biventricular pacing. Algorithms for the timing cycle adjustment may provide significantly longer results for optimized AVDs and VVDs. Further investigations are necessary to improve the process of hemodynamic optimization and duration of that process.