马文韬
中国医学科学院阜外医院 11病区
AIM:To assess the electrocardiogram patterns of paced QRS narrowing after successful left bundle branch area pacing (LBBAP) and echocardiographic measurements in patients with bradycardia and bundle branch block (BBB).METHODS:We prospectively enrolled 55 consecutive bradycardia patients with BBB and left ventricular ejection fraction ≥40% who had attempted LBBAP. Successful LBBAP was defined as paced QRS morphology of a right BBB (RBBB) pattern in lead V1 and a recording of abruptly shortened and then constant stimulus to peak left ventricular activation time with high and low output. Pacing characteristics and echocardiographic measurements were evaluated perioperatively and at 6-month follow-up.RESULTS:The success rate of LBBAP was 83.6% in patients with BBB, and median cumulative X-ray dose-area product was 100.5 µGym2 (60.0, 179.3). LBBAP was successful in 19 of 26 patients with left BBB (LBBB) (73.1%) and in 27 of 29 patients with RBBB (93.1%). The QRS duration (QRSd) was significantly shortened in patients with LBBB (QRSd 169.4 ± 22.6 to 119.6 ± 9.5 ms), and five forms of QRSd narrowing were observed in patients with RBBB with the mean QRSd shortened from 143.1 ± 16.6 ms to 119.5 ± 11.7 ms. The thresholds for narrowing of QRSd were higher in RBBB than LBBB (1.74 ± 0.36 V/0.4 ms vs 0.79 ± 0.17 V/0.4 ms, P < .001). During the 6-month follow-up, both left and right ventricular synchronies were improved, and narrow QRSd persisted in patients with BBB.CONCLUSION:In most bradycardia patients, RBBB could be completely or partially narrowed by LBBAP at different pacing models in addition to the correction of LBBB with LBBAP.
Pacing and clinical electrophysiology : PACE 2020
AIMS:This multicentre observational study aimed to prospectively assess the efficacy of left bundle branch area pacing (LBBAP) in heart failure patients with left bundle branch block (LBBB) and compare the 6-month outcomes between LBBAP and biventricular pacing (BVP).METHODS AND RESULTS:Consecutive patients with LBBB and left ventricular ejection fraction (LVEF) ≤ 35% were prospectively recruited if they had undergone LBBAP as a primary or rescue strategy from three separate centres from March to December 2018. Patients who received BVP in 2018 were retrospectively selected by using 2 to 1 propensity score matching to minimize bias. Implant characteristics and echocardiographic parameters were assessed during the 6-month follow-up. LBBAP procedure succeeded in 81.1% (30/37) of patients, with selective LBBAP in 10 patients, and 3 of 20 patients combined non-selective LBBAP and LV lead pacing for further QRS narrowing. LBBAP resulted in significant QRS narrowing (from 178.2 ± 18.8 to 121.8 ± 10.8 ms, P < 0.001, paced QRS duration ≤ 130 ms in 27 patients) and improved LVEF (from 28.8 ± 4.5% to 44.3 ± 8.7%, P < 0.001) during the 6-month follow-up. The comparison between 27 patients with LBBAP alone and 54 of 130 matching patients with BVP showed that LBBAP delivered a greater reduction in the QRSd (58.0 vs. 12.5 ms, P < 0.001), a greater increase in LVEF (15.6% vs. 7.0%, P < 0.001), and greater echocardiographic (88.9% vs. 66.7%, P = 0.035) and super response (44.4% vs. 16.7%, P = 0.007) to cardiac resynchronization therapy.CONCLUSIONS:LBBAP could deliver cardiac resynchronization therapy in most patients with heart failure and LBBB, and might be a promising alternative resynchronization approach to BVP.
ESC heart failure 2020
BACKGROUND:Left bundle branch area pacing (LBBAP), a new pacing approach, lacks adequate evaluation.OBJECTIVE:To assess the feasibility, safety, and acute effect of permanent LBBAP in patients with atrioventricular block (AVB).METHODS:A total of 33 AVB patients with indications for ventricular pacing were recruited. Electrocardiograms, pacing parameters, echocardiographic measurements, and complications associated with LBBAP were evaluated perioperatively and at 3-month follow-up. Successful LBBAP was defined as a paced QRS morphology of right bundle branch block pattern in lead V1 and QRS duration (QRSd) less than 130 ms.RESULTS:LBBAP was successfully performed in 90.9% (30/33) of patients (mean age: 55.1 ± 18.5 years; 66.7% male). The mean capture threshold was similar during the procedure (0.76 ± 0.26 V at 0.4 ms) and at the 3-month follow-up (0.64 ± 0.20 V at 0.4 ms). The paced QRSd was 112.8 ± 10.9 ms during the procedure and 116.8 ± 10.4 ms at the 3-month follow-up. Baseline left or right bundle branch block was corrected (intrinsic QRSd 153.3 ± 27.8 ms vs paced QRSd 122.2 ± 9.9 ms) with a success rate of 68.7% (11/16). One ventricular septal lead perforation occurred soon after the procedure with characteristics of pacing failure, and lead revision was successful. Cardiac function and left ventricular synchronization by 2-dimensional echocardiographic strain imaging at the 3-month follow-up slightly improved compared with that at baseline.CONCLUSIONS:Permanent LBBAP yielded a stable threshold, a narrow QRSd, and preserved left ventricular synchrony with few complications. Our preliminary results indicate that LBBAP holds promise as an attractive physiological pacing strategy for AVB.
Heart rhythm 2019
