These tracings illustrate the specificity of the AV delay programming in a pacemaker dependent patient (complete atrioventricular block). For this type of patient, regardless of the programmed AV delay, the appearance of the stimulated QRS remains unchanged since no fusion with a potential spontaneous QRS occurs. This allows you to concentrate only on the chosen optimization parameter: the longest filling time with no abbreviation of the A wave, the importance of mitral regurgitation, the dP / dt max, the cardiac output … Ideally, the optimal AV delay corresponds to the value that allows the best compromise between all these parameters. The analysis of the depolarization time is probably insufficient.

In this patient, the echocardiography showed a sharp amputation of the A wave by a premature mitral valve closure at the first illustrated paced AV delay (100 ms). With the second and longer AV delay (180 ms), the filling time was better with a dissociation of the A wave and the E wave and the absence of truncated A wave. The quality of the mitral filling pattern seemed reproducible. In contrast, high variations from cycle to cycle of the subaortic VTI signals were observed, making them not reproducible and therefore not interpretable.