Key result
Atrial paced stimulation links to a ~69 ms longer optimal AV delay than sensed stimulation.
Why the study?
DDD pacemakers vary considerably in AV delay programmability, and defining optimal AV delay ranges in a typical patient population is needed to establish programming standards.
What is the optimal range of programmable AV delays in patients with DDD pacemakers?
Observational (n=200)
What is the optimal range of programmable AV delays in patients with DDD pacemakers?
Mean Difference: 68.7
Absolute Event Rate: 169.1% vs 100.5%
p-value: p=<0.001
Optimal AV delays differ significantly between atrial sensed and paced stimulation, suggesting pacemakers should offer independently programmable AVDs ranging from 40 to 250 ms.
Separate AV delay settings for sensed versus paced modes may warrant consideration in DDD pacemakers; leaves open prospective outcome validation.
DDD pacemakers differ considerably in device specific extents of AV delay (AVD) programmability. To demonstrate the requirements of a mean DDD pacemaker patient population optimal AVDs in 200 DDD pacemaker patients (age 8 to 91 years) were estimated by left atrial electrography. The results should help to define an AVD programmability standard. Left atrial electrograms were recorded via a bipolar filtered esophageal lead. The method aims on adjusting the left atrial electrogram to 70 ms prior to the ventricular spike, both during VDD and DDD operation of the pacemaker. In atrial sensed stimulation the optimal AVD varied from 40 to 205 ms (100.5 +/- 24.5 ms) and in atrial paced stimulation from 85 to 245 ms (169.1 +/- 24.5 ms). The difference of the mean values is statistically significant (p < 0.001). The difference between both values in the individual patient, the individual AVD correction time, varied from 0 to 170 ms (68.7 +/- 26.6 ms). Thus, from our findings requirements on AV delay programmability standard can be derived: AVDs (1) should have a range from 40 to 250 ms, (2) should be independently programmable during atrial sensed and atrial paced operation, and (3) should provide as nominal settings 100 ms for atrial sensed and 170 ms for atrial paced stimulation.
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Knorre et al. (1998) conducted an observational in DDD pacemaker patients (n=200). Atrial paced stimulation vs. Atrial sensed stimulation was evaluated on Optimal AV delay (AVD) (MD 68.7, p=<0.001). Optimal AV delay was significantly longer during atrial paced stimulation compared to atrial sensed stimulation (169.1 vs 100.5 ms; p<0.001), indicating a need for independent programmability.
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