Comparison of methods for delivering cardiac resynchronization therapy: an acute electrical and haemodynamic within-patient comparison of left bundle branch area, His bundle, and biventricular pacing

Abstract

Aims Left bundle branch area pacing (LBBAP) is a promising method for delivering cardiac resynchronization therapy (CRT), but its relative physiological effectiveness compared with His bundle pacing (HBP) is unknown. We conducted a within-patient comparison of HBP, LBBAP, and biventricular pacing (BVP). Methods and results Patients referred for CRT were recruited. We assessed electrical response using non-invasive mapping, and acute haemodynamic response using a high-precision haemodynamic protocol. Nineteen patients were recruited: 14 male, mean LVEF of 30%. Twelve had time for BVP measurements. All three modalities reduced total ventricular activation time (TVAT), (ΔTVATHBP -43 ± 14 ms and ΔTVATLBBAP −35 ± 20 ms vs. ΔTVATBVP −19 ± 30 ms, P = 0.03 and P = 0.1, respectively). HBP produced a significantly greater reduction in TVAT compared with LBBAP in all 19 patients (−46 ± 15 ms, −36 ± 17 ms, P = 0.03). His bundle pacing and LBBAP reduced left ventricular activation time (LVAT) more than BVP (ΔLVATHBP −43 ± 16 ms, P < 0.01 vs. BVP, ΔLVATLBBAP −45 ± 17 ms, P < 0.01 vs. BVP, ΔLVATBVP −13 ± 36 ms), with no difference between HBP and LBBAP (P = 0.65). Acute systolic blood pressure was increased by all three modalities. In the 12 with BVP, greater improvement was seen with HBP and LBBAP (6.4 ± 3.8 mmHg BVP, 8.1 ± 3.8 mmHg HBP, P = 0.02 vs. BVP and 8.4 ± 8.2 mmHg for LBBAP, P = 0.3 vs. BVP), with no difference between HBP and LBBAP (P = 0.8). Conclusion HBP delivered better ventricular resynchronization than LBBAP because right ventricular activation was slower during LBBAP. But LBBAP was not inferior to HBP with respect to LV electrical resynchronization and acute haemodynamic response.

Comparison of novel ventricular pacing strategies using an electro-mechanical simulation platform

“…This is in line with a recent study, which found that LBBAP was not inferior to HSP with respect to LV function, but both HBP and LBBAP outperformed BiVP in terms of haemodynamic improvement. 31 However, sLBBP without fusion led to a non-physiological late activation of the RV, which has also been reported in other studies. 31 , 32 This late RV activation effectively replicated an right bundle branch block-like pattern leading to an increased load on the RVfw.…”

“… 31 However, sLBBP without fusion led to a non-physiological late activation of the RV, which has also been reported in other studies. 31 , 32 This late RV activation effectively replicated an right bundle branch block-like pattern leading to an increased load on the RVfw. Furthermore, sLBBP is an unstable condition and will likely progress to nsLBBP, 33 also making it clinically unfeasible.…”

Effect of scar and His–Purkinje and myocardium conduction on response to conduction system pacing

“…We performed an in silico electrophysiology clinical trial to study the Although selective HBP was reported to shorten and sometimes normalize the QRS duration, 6,22 many patients are left with partial dyssynchrony. HBP effectiveness relies on the assumption that most blocks happen proximally along the His bundle.…”

“…We assessed LV synchrony by computing 95% of LV activation time (LVAT‐95), computed as the shortest interval to activate 95% of the LV, and the LV dyssynchronous index (LVDI), defined as the standard deviation of LV activation times. Both LVAT‐95 and LVDI have been used in the literature to quantify response to pacing from ECGi data 22 . Similarly, BIV dyssynchrony was quantified by computing 90% of biventricular activation time (BIVAT‐90) and the biventricular dyssynchronous index (BIVDI).…”

“…Both LVAT-95 and LVDI have been used in the literature to quantify response to pacing from ECGi data. 22 Similarly, BIV dyssynchrony was quantified by computing 90% of biventricular activation time (BIVAT-90) and the biventricular dyssynchronous index (BIVDI). For all metrics, the outflow tracts and the area around the mitral and the tricuspid valve annuli were excluded from the activation time calculations.…”