Cardiovascular Implantable Electronic Devices -> Bradycardia Devices: -> Device Technology D-PO02 - Poster Session II (ID 47) Poster

D-PO02-102 - Acutely Improved LV Diastolic Function With His Bundle Pacing Compared To Right Ventricular Apical Pacing In Patients With Av Block, Exertional Intolerance And Preserved LV Systolic Function (ID 204)


Background: In absence of LV systolic dysfunction RV pacing (RVP) can be associated with exertional intolerance. The mechanism is not well understood. His bundle pacing (HBP) can re-establish physiologic ventricular activation in patients with complete AV block (AVB).
Objective: To compare the acute hemodynamic effects of HBP compared to RVP in patients with preserved LV systolic function.
Methods: 5 patients with AVB and conventional dual chamber (RV apical) pacemaker suffered from exertional intolerance in spite of preserved LV systolic function (age 80±3, 4 female, BMI 27± 6. All patients underwent implantation of a HBP lead which resulted in non-selective capture. Echocardiograms were done after initiation of HBP. AV intervals were optimized using the mitral inflow iterative method and parameters were measured during RVP and HBP at equal AV intervals.
Results: QRS duration was 179±13ms and 113±6 ms with RVP and HBP, respectively (p<0.001). HBP immediately improved exertional tolerance in 4/5 patients (NYHA class from 2.6±0.5 to 1.8±0.4, p<0.05). LV EF was 59±6% with RVP and 64±8% with HBP (p=0.5). Compared to R, HBP was associated with increased diastolic filling time (440±67 ms vs. 484±47 ms, p<0.05), increase in septal E’ (5.6± 1.5 vs. 6.0±1.7, p<0.05) and decreased Tei index (0.57±0.27 vs. 0.44±0.19, p=0.08).
Conclusion: In patients with AVB, exertional intolerance and preserved LV systolic function HBP may improve diastolic function when compared to RVP. Further, prospective studies are needed to confirm this observation.