Termination of desynchronization rhythm and restoration of cardiac resynchronization by left‐sided ventricular premature complexes

Abstract

Cardiac resynchronization devices that sense left ventricular (LV) activity and can detect interruptions of resynchronization therapy are able to record all forms of desynchronization rhythms, which are triggered by misalignment of LV timing cycles. We report five cases of this desynchronization rhythm that were terminated by isolated left‐sided ventricular premature complexes (LVPC) undetected by the right ventricular (RV) channel and unaccompanied by changes in the duration of the RV pacing cycles. In three cases, the devices did not even sense the LVPCs responsible for desynchronization termination. The restoration of resynchronization in our cases is in contrast to the traditional termination mode that is invariably associated with changes in the duration of the RV cycles.

Left ventricular inhibition during cardiac resynchronization caused by sensed left‐sided ventricular premature complexes

“…Left‐sided VPCs exhibit two patterns. (1) The form with an absent (invisible) RV component is not rare and represents the majority of left‐sided VPCs . They exhibit no associated RV activity.…”

“…The RV cycle was 855 ms, and the coupling interval of the left‐sided VPC was 465 ms so that the sum of the RV cycle plus the LVURI was 865 and 10 ms longer than the 850 ms RV cycle. Sensed isolated left‐sided VPCs are not rare so that their coupling intervals are either inconsequential or they may affect device function in other ways . The term “isolated” implies that an RV component of an LVPC is unsensed or conduction from left to right ventricle is blocked.…”

“…The recording shows false signals generated by a defective LV lead recorded a few days after Sensed isolated left-sided VPCs are not rare so that their coupling intervals are either inconsequential or they may affect device function in other ways. 5 The term "isolated" implies that an RV component of an LVPC is unsensed or conduction from left to right ventricle is blocked. rare and easily identified by the lack of a clear-cut QRS deflection in the EGM.…”