Automated functional imaging in atrioventricular delay time optimisation in patients with dual chamber pacemakers

Background: Optimisation of atrioventricular (AV) delay time has positive effects on left ventricular (LV) functions in patients with a DDD pacemaker. However, the method used for optimisation is still debated. Aim: To evaluate the effect of different AV delay times on various LV systolic performances by using automated functional imaging (AFI) in patients with a DDD pacemaker and preserved LV systolic function. Methods: The study population consisted of 40 patients with a DDD pacemaker implanted for third degree AV block and preserved LV systolic function (19 men; mean age 64.3 +/- 10.9 years). During each pacing period, blood samples were taken for the measurement of B-type natriuretic peptide (BNP) levels, and telemetric and echocardiographic evaluations were performed to all patients. Also peak systolic global longitudinal strain (PSGLS) was calculated using the AFI method. Results: No significant differences except for LV outflow tract-velocity time integral (LVOT-VTI) were observed in pulse wave Doppler parameters with different AV delay times. PSGLS were better at 150 and 200 ms AV delay times compared to 100 ms (p < 0.001 for 100-150 ms and 100-200 ms). Similarly, LVOT-VTI values were significantly higher at 150 and 200 ms AV delay times compared to 100 ms (for 100-150 ms, p = 0.017 and for 100-200 ms, p = 0.013). Also there was a significant reduction in BNP levels at 150 ms and 200 ms compared to 100 ms AV delay time (for 100-150 ms, p = 0.001, and for 100-200 ms, p < 0.001). Conclusions: In patients with an implanted DDD pacemaker and preserved LV systolic function, increasing AV delay time has beneficial effects on LV systolic performance in the acute phase, as shown by the AFI method in our study.