Effect of different programmed AV delay on left ventricular diastolic function in DDD-paced patients

The aim of the study was to asses the effect of DDD pacing with different p rogrammed AVD (100,150,170,200 ms.) on left ventricular filling. Material and methods: The study group consisted of 19 pts, mean age, x= 63+/-4 y with DDD pacemak ers implanted due to complete av block. All pts were PM-dependent at rest. The pts were divided into 2 groups: Group I (11 pts, 5F/6M, x=62+/-3y) with LV hypertrophy (LVPWTh >1.2 cm, LVMI>125g/m2), Group II (8pts,3F/5M,x=63+/ -3y) with structurally normal hearts, lin order to evaluate LV systolic and diastolic function echo-doppler examination was performed in all pts durin g DDD pacing at rest with different programmed AVD. Stroke volume (SV) and following transmitral flow parameters were measured : early diastolic peak velocity (E),end diastolic peak velocity (A), E/A ratio, isovolumetric rela xation time (IVRT) and deceleration time (DT). Results In group I we observed a significant decrease of IVRT (126.0 vs. 96.5 ms), DT (290 vs. 220 ms), A (69.7 vs. 60.6 cm/s) and increase of E (44.9 vs. 53. 0 cm/s), E/A (0.64 vs. 0.87), SV (94.9 vs. 126 ml) during pacing with the s hort (100 ms) AVD as compared with the long (200 ms) AVD. In group II chang es in AVD caused no consistent variations in the filling pattern. Conclusion Programming optimal AV delay in DDD paced patients with LV hypertrophy can improve abnormal LV diastolic function.