Objectives To evaluate the impact of biventricular pacing combining AV node intrinsic conduction (the combination mode) on width of QRS complex in patients with cardiac resynchronisation therapy (CRT).
Methods All patients with congestive heart failure who met IA recommendation for CRT were enrolled from Jan-Dec 2009. Among 44 patients enrolled, 34 (77.3%) were male,25 (56.8%) were diagnosed as dilated cardiomyopathy (DCM) and 19 (43.2%) with ischaemic heart disease (IHD); the mean age was 62.11 ± 9.03. All patients underwent CRT insertion successfully. The CRT-P/D devices were programmed according to conventional optimisation method, which required the ventricles fully captured by CRT with echo optimisation, and then switched to the combination optimisation method which showed in the ECG as ventricular fusion beats with narrowest QRS width. QRS width, AVD/VVD and time consuming were compared between the two methods.
Results The mean QRS width was shorter under the combination mode compared to conventional mode immediate (117.00 ± 19.47ms vs.140.75 ± 18.75ms, P < 0.001) after programing. AVI immediate after programming was larger in the combination mode compared to conventional mode (22.15 ± 5.37 vs. 19.91 ± 5.53, P < 0.001).
Conclusions The biventricular pacing combining AV node prioritisation methodology shortened QRS duration in patients with CRT compared to conventional biventricular pacing. This method may benefit those CRT patients with sinus rhythm, short PR duration and not respond well to CRT including those whose QRS complex remained unchanged or even wider after CRT.