Aims The optimal site for biventricular endocardial (BIV ENDO ) pacing remains undefined. Acute haemodynamic response (AHR) is reproducible marker of left ventricular (LV) contractility, best expressed as the change in the maximum rate of LV pressure (LV-dp/dt max ), from a baseline state. We examined the relationship between factors known to impact LV contractility, whilst delivering BIV ENDO pacing at a variety of LV endocardial (LV ENDO ) locations. Methods and results We compiled a registry of acute LV ENDO pacing studies from five international centres: Johns Hopkins-USA, Bordeaux-France, Eindhoven-The Netherlands, Oxford-United Kingdom, and Guys and St Thomas’ NHS Foundation Trust, London-UK. In all, 104 patients incorporating 687 endocardial and 93 epicardial pacing locations were studied. Mean age was 66 ± 11 years, mean left ventricular ejection fraction 24.6 ± 7.7% and mean QRS duration of 163 ± 30 ms. In all, 50% were ischaemic [ischaemic cardiomyopathy (ICM)]. Scarred segments were associated with worse haemodynamics (dp/dt max ; 890 mmHg/s vs. 982 mmHg/s, P < 0.01). Delivering BiV ENDO pacing in areas of electrical latency was associated with greater improvements in AHR (P < 0.01). Stimulating late activating tissue (LVLED >50%) achieved greater increases in AHR than non-late activating tissue (LVLED < 50%) (8.6 ± 9.6% vs. 16.1 ± 16.2%, P = 0.002). However, the LV ENDO pacing location with the latest Q-LV, was associated with the optimal AHR in just 62% of cases. Conclusions Identifying viable LV ENDO tissue which displays late electrical activation is crucial to identifying the optimal BiV ENDO pacing site. Stimulating late activating tissue (LVLED >50%) yields greater improvements in AHR however, the optimal location is frequently not the site of latest activation.
- Biventricular pacing/cardiac resynchronization therapy
- Leadless pacing
- Left ventricular endocardial pacing
- Personalized medicine
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine
- Physiology (medical)