Abstract
BACKGROUND: Cardiac resynchronisation therapy (CRT) is typically delivered via quadripolar leads that allow stimulation using either true bipolar pacing, where stimulation occurs between two electrodes (BP) on the quadripolar lead or extended bipole (EBP) LV pacing, with the quadripolar electrodes and RV coil acting as the cathode and anode respectively. True bipolar pacing is associated with reductions in mortality and it has been postulated that these differences are the result of enhanced electrical activation.
METHODS: Patients undergoing a CRT underwent an electrocardiographic imaging (ECGI) study where electrical activation data was recorded whilst different LV pacing vectors were temporarily programmed.
RESULTS: There were no differences in the total electrical activation times or dispersion of electrical activation between biventricular pacing with bipolar or corresponding EBP LV vector configurations (LVtat BP 74.70 ± 18.07 vs EBP 72.4 ± 22.64; P=0.45.) When dichotomised according to aetiology, no difference was observed in the activation time with either BP or EBP pacing (LVtat BP ICM 72.2 ± 17.4 vs BP DCM 79.9 ± 18.9; P=0.38.).
CONCLUSIONS: Bipolar pacing alters the mechanical activation sequence of the LV and is associated with reductions in all-cause mortality. It has been postulated these benefits derive from improvements in electromechanical activation of the LV. Our study would suggest that true bipolar pacing does not necessarily result in more favourable activation of the LV or improved electrical resynchronisation and other mechanisms should be explored.
METHODS: Patients undergoing a CRT underwent an electrocardiographic imaging (ECGI) study where electrical activation data was recorded whilst different LV pacing vectors were temporarily programmed.
RESULTS: There were no differences in the total electrical activation times or dispersion of electrical activation between biventricular pacing with bipolar or corresponding EBP LV vector configurations (LVtat BP 74.70 ± 18.07 vs EBP 72.4 ± 22.64; P=0.45.) When dichotomised according to aetiology, no difference was observed in the activation time with either BP or EBP pacing (LVtat BP ICM 72.2 ± 17.4 vs BP DCM 79.9 ± 18.9; P=0.38.).
CONCLUSIONS: Bipolar pacing alters the mechanical activation sequence of the LV and is associated with reductions in all-cause mortality. It has been postulated these benefits derive from improvements in electromechanical activation of the LV. Our study would suggest that true bipolar pacing does not necessarily result in more favourable activation of the LV or improved electrical resynchronisation and other mechanisms should be explored.
Original language | English |
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Journal | Journal of Cardiovascular Electrophysiology |
Early online date | 14 Aug 2018 |
DOIs | |
Publication status | E-pub ahead of print - 14 Aug 2018 |
Keywords
- Cardiac Resynchronisation Therapy Multi-polar Pacing Non-Responders Bipolar Pacing Extended Bipolar Pacing