Table 1.
Baseline demographics.
Fig 1.
Following completion of drive train, two examples of triggered ventricular ectopy (premature ventricular contraction [PVC], arrow) in participants with hypertrophic cardiomyopathy.
Fig 2.
The QT-RR relationship in control and HCM patients.
Data is shown separately for those patients with intact AV node conduction (atrial pacing only) and those receiving atrioventricular sequential pacing due to absent/inadequate AV node conduction. The QT-RR relationship was similar amongst patients with or without intact AV node conduction in both groups (HCM vs control). Slope for each group: Control = 0.181 [95% CI 0.166, 0.195]; HCM = 0.193 [95% CI 0.177, 0.210]. There were 127 observations from 10 patients in the control group and 74 observations from 8 patients in the HCM group.
Fig 3.
No significant difference was seen between groups in QT interval on the first post-pause recovery beat following delivery of the drive trains.
Slope for each group: Control = 0.0626 [95% CI 0.0109, 0.115]; HCM = 0.0887 [95% CI 0.0403, 0.136]. There were 127 observations from 10 patients in the control group and 74 observations from 8 patients in the HCM group. Note that in some instances the post-drive train recovery interval was >1000 msec; these instances occurred prior to protocol standardization specifying temporary re-programming of device lower rate limit to 1000 msec.
Table 2.
Summary of contractility assessment during delivery of slowest and fastest drive trains.