ABSTRACT
Objective: To evaluate the success rate of His-Purkinje system pacing (HPSP) in patients with various sites of atrioventricular block (AVB) and provide clinical evidence for the selection of HPSP in patients with AVB. Methods: This is a retrospective case analysis. 637 patients with AVB who underwent permanent cardiac pacemaker implantation and requiring high proportion of ventricular pacing from March 2016 to September 2021 in the Department of Cardiology, General Hospital of Northern Theater Command were enrolled. The site of AVB was determined by electrophysiological examination. His bundle pacing (HBP) was performed in the first 130 patients (20.4%) who were classified as the HBP group and HPSP included HBP and/or left bundle branch pacing (LBBP) was performed in later 507 patients (79.6%) and these patients were classified as the HPSP group. The basic clinical information such as age and sex of the two groups was compared, and the success rates of HBP or HPSP in patients with different sites of AVB and QRS intervals were analyzed. Results: The age of HBP group was (66.4±15.9) years with 75 males (57.7%). The age of HPSP group was (66.8±13.6) years with 288 (56.8%) males. Among 637 patients, 63.0% (401/637) had atrioventricular node block; 22.9% (146/637) had intra-His block; 14.1% (90/637) had distal or inferior His bundle block. Totally, the success rate of HPSP was higher than that of HBP [93.9% (476/507) vs. 86.9% (113/130), P<0.05]. In each group of patients with various AVB sites, the success rate of HPSP was higher than that of HBP respectively and both success rates of HBP and HPSP showed a declining trend with the distant AVB site. The success rate of HBP in patients with atrioventricular node block and intra-His block was higher than that in patients with distal or inferior His bundle block [95.2% (79/83) vs. 47.1% (8/17), P<0.001; 86.7% (26/30) vs. 47.1% (8/17), P=0.010]. The success rate of HPSP was higher than that of HBP in patients with distal or inferior His bundle block [87.7% (64/73) vs 47.1% (8/17), P=0.001]. In patients with QRS<120 ms, 94.9% (520/548) of AVB sites were in atrioventricular node or intra-His, and HBP had a similar high success rate with HPSP [95.6% (109/114) vs. 96.3% (418/434), P=0.943] in these patients. In patients with QRS ≥ 120 ms, 69.7% (62/89) of AVB sites were at distal or inferior His bundle, and the success rate of HBP was only 25.0% (4/16), while the success rate of HPSP was as high as 79.5% (58/73), P<0.001. Conclusions: In patients with QRS<120 ms and atrioventricular node block or intra-His block, success rates of HBP and HPSP are similarly high and HBP might be considered as the first choice. In patients with QRS ≥ 120 ms and AVB site at distal or inferior His bundle, the success rate of HPSP is higher than that of HBP, suggesting LBBP should be considered as the first-line treatment option.
Subject(s)
Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Atrioventricular Block/therapy , Bundle of His/physiology , Cardiac Pacing, Artificial , Electrocardiography , Retrospective Studies , Treatment OutcomeABSTRACT
Objective: To investigate the application and efficacy of left ventricular (LV) electrical delay (LVED) and the distance of right ventricular(RV) pacing polar to LV(DRLV) in optimizing LV pacing polar. Methods: Heart failure (HF) patients who implanted cardiac resynchronization therapy (CRT) device with a LV quadripolar lead from January 2014 to January 2018 at General Hospital of Northern Theater Command were enrolled in the study. Measurements of LVED and DRLV of each polar of the lead were performed in patients with HF who underwent CRT with LV quadripolar lead. The principle in turn for polar selecting used for clinical LV pacing was the pacing polar: (1)without phrenic nerve stimulation(PNS); (2)with appropriate capture threshold; (3)not located in apical; (4)with maximal LVED; (5)with maximal DRLV. The LV pacing polar was selected for CRT according to the procedure. The distribution of target veins implanted with LV quadripolar lead were calculated. The percentage of biventricular pacing at 6-month follow-up was recorded. The following indexes were compared before and 6-month after surgery, including QRS duration, LV end-systolic volume(LVESV), LV ejection fraction(LVEF), LV end-diastolic dimension(LVEDD), 6 minute walking distance(6MWD), New York Heart Association(NYHA) class. The efficacy and echocardiographic efficacy of CRT was evaluated. Results: There were twenty-nine HF patients enrolled. The mean age of enrolled patients was(61.7±7.6)years old, nineteen (66%)of them were male. There were seventeen(59%) patients diagnosed as dilated cardiomyopathy and twelve(41%) patients as ischemic cardiomyopathy. All patients were successfully implanted with LV quadripolar lead into target veins, and all four pacing sites were also in target veins. Target veins were located in lateral veins in 15 patients (52%), anterior veins in 2 patients (7%), posterior veins in 11 patients (38%), and lateral branches of great cardiac veins in 1 patient (3%). After 6-month of follow-up, the percentage of biventricular pacing was greater than 95%.There were nineteen(66%) patients optimized LV pacing polar by the largest LVED and four (14%) patients by the DRLV. Of the 29 patients, 5(17%) patients used D1 as the pacing polar, 5(17%) patients used M2 as the pacing polar, 7(24%) patients used M3 as the pacing polar, and 12(41%) patients used P4 as the pacing polar. The pacing polars (D1, M2) of traditional bipolar lead were used in 10(34%) patients, and the LV quadripolar lead specific pacing polars (M3, P4) were used in 19(66%) patients.Compared to a LV quadripolar lead, the LV pacing polar (M3, P4) selected in 19(66%) patients were not achievable with the traditional LV bipolar lead (D1, M2). Preoperative QRS duration, LVESV, LVEF, LVEDD, 6MWD and NYHA class were (171±24)ms, (231±79)ml, (28±5)%, (74±11)mm, (294±103)m, (3.2±1.0)class and the postoperative 6-month were (130±12)ms, (158±73)ml, (36±10)%, (66±12)mm, (371±86)m, (1.9±0.5)class. These indexes were significantly improved after 6 months operation(P<0.001). 97% and 83% patients were responders of CRT as assessed by 6-month efficacy and echocardiographic efficacy. Conclusion: The maximal LVED and DRLV can be used to select LV pacing polar with a high rate of CRT response rate.