Direct His bundle pacing preserves coronary perfusion compared with right ventricular apical pacing: a prospective, cross-over mid-term study

Aims The His bundle is regarded as the most physiological site for ventricular pacing, in that it avoids the adverse effects of right ventricular apical pacing (RVAP). However, very few studies have compared the effects of direct His bundle pacing (DHBP) and RVAP. The aim of our study was the intra-patient comparison of myocardial perfusion corresponding to these two different pacing techniques, as perfusion expresses local workload and is related to long-term outcome. Methods and results Twelve consecutive patients with standard pacemaker indication (9 male, 74 +/- 9 years) entered the study. Pacing leads were implanted in the right ventricular apex and directly in the His bundle, and were connected to different ports of the pacemaker. All patients first underwent 3 months of DHBP, followed by 3 months of RVAP. At the end of each 3-month period, myocardial perfusion was measured at rest using scintigraphy with Tc99m-SestaMIBI. The average values of perfusion were evaluated on a 20-segment basis. All patients also underwent clinical evaluation, echocardiography, and tissue Doppler imaging (TDI), to measure dyssynchrony, and a blood sample was taken for brain natriuretic peptide (BNP) assay. The perfusion score during DHBP pacing was significantly better than during RVAP (0.44 +/- 0.5 vs. 0.71 +/- 0.53, respectively; P = 0.011). None of the patients showed lower perfusion during DHBP than during RVAP. We found no significant difference in NYHA class, ventricular volumes, ejection fraction, or plasmatic BNP between DHBP and RVAP. However, mitral regurgitation (0.26 +/- 0.21 vs. 0.37 +/- 0.25; P < 0.001) and dyssynchrony (13.75 +/- 4.28 vs. 22.02 +/- 8.44; P = 0.008) were significantly less during DHBP than during RVAP. Conclusion Direct His bundle pacing is superior to RVAP in preserving the physiologic distribution of myocardial blood flow and reducing mitral regurgitation and left ventricular dyssynchrony.