Major determinant of the occurrence of pacing-induced cardiomyopathy in complete atrioventricular block: a multicentre, retrospective analysis over a 15-year period in South Korea

Prediction of pacemaker-induced cardiomyopathy using a convolutional neural network based on clinical findings prior to pacemaker implantation

Risk factors for pacemaker-induced cardiomyopathy (PICM) have been previously reported, including a high burden of right ventricular pacing, lower left ventricular ejection fraction, a wide QRS duration, and left bundle branch block before pacemaker implantation (PMI). However, predicting the development of PICM remains challenging. This study aimed to use a convolutional neural network (CNN) model, based on clinical findings before PMI, to predict the development of PICM. Out of a total of 561 patients with dual-chamber PMI, 165 (mean age 71.6 years, 89 men [53.9%]) who underwent echocardiography both before and after dual-chamber PMI were enrolled. During a mean follow-up period of 1.7 years, 47 patients developed PICM. A CNN algorithm for prediction of the development of PICM was constructed based on a dataset prior to PMI that included 31 variables such as age, sex, body mass index, left ventricular ejection fraction, left ventricular end-diastolic diameter, left ventricular end-systolic diameter, left atrial diameter, severity of mitral regurgitation, severity of tricuspid regurgitation, ischemic heart disease, diabetes mellitus, hypertension, heart failure, New York Heart Association class, atrial fibrillation, the etiology of bradycardia (sick sinus syndrome or atrioventricular block) , right ventricular (RV) lead tip position (apex, septum, left bundle, His bundle, RV outflow tract), left bundle branch block, QRS duration, white blood cell count, haemoglobin, platelet count, serum total protein, albumin, aspartate transaminase, alanine transaminase, estimated glomerular filtration rate, sodium, potassium, C-reactive protein, and brain natriuretic peptide. The accuracy, sensitivity, specificity, and area under the curve of the CNN model were 75.8%, 55.6%, 83.3% and 0.78 respectively. The CNN model could accurately predict the development of PICM using clinical findings before PMI. This model could be useful for screening patients at risk of developing PICM, ensuring timely upgrades to physiological pacing to avoid missing the optimal intervention window.

Is left bundle branch pacing (LBBP) associated with better depolarization and repolarization kinetics than right ventricular mid septal pacing (RVSP)? - Comparison of frontal QRS -T angle in patients with LBBP, RVSP and normal ventricular conduction

AIMS

To assess the frontal QRS- T angle (f QRS- T angle) in patients with left bundle branch pacing (LBBP) as compared to right ventricular mid septal pacing (RVSP) implanted for symptomatic high degree atrioventricular (AV) block and to compare with control subjects with normal ventricular conduction (CSNVC) METHODS: A total of one-fifty subjects were chosen (50 patients with LBBP, 50 patients with RVSP and 50 CSNVC). The indication for pacemaker implantation was symptomatic high degree AV block. Baseline clinical and electrocardiogram (ECG) parameters like QRS duration (QRSD), QRS axis and f QRS-T angle and Ejection Fraction (EF) were assessed. f QRS-T angle was measured as the difference between the computerised mean frontal QRS and T wave axes in the limb leads. If the difference between the QRS axis and T-wave axis exceeds 180°, then the resultant QRS-T angle would be calculated as 360° minus the absolute angle to obtain a value between 0° and 180°. Baseline, immediate post procedural and 6 month follow up (f/u) ECGs and EF were chosen for the analysis.

RESULTS

Patients who underwent LBBP had significantly shorter paced QRSD than patients who had undergone RVSP (112 ± 12 ms vs 146 ± 13 ms; 95 % confidence interval (CI): 43, -31; p<0.001). There was no significant difference in the QRSD before and after LBBP. The QRSD before and after pacing in RVSP was 111 ± 27 ms and 146 ± 13 ms; 95 % CI: 43, -28; p < 0.001. The QRSD in control patients with NVC was 82.94 ± 9.59 ms. RVSP was associated with wider f QRS-T angle when compared with LBBP (103 ± 53° vs 82 ± 43°; 95 % CI: 39, -1.0; p = 0.037). The baseline and immediate post procedure f QRS-T angle in LBBP was 70 ± 48° and 82 ± 43°; 95 % CI: 31, 5.3; p = 0.2. At 6 months f/u, the f QRS-T angle was 61 ± 43°; 95 % CI: 8.5, 35; p=0.002. The baseline and immediate post procedure f QRS-T angle in RVSP was 67 ± 51° and 103 ± 53°; 95 % CI: 54, -17; p < 0.001. At 6 months f/u, the f QRS-T angle in RVSP group was 87 ± 58°; 95 % CI: 2.6, 29; p = 0.020. The f QRS T angle in control patients with NVC was 24 ± 16°. When subgroup analysis was done the difference in the f QRS-T angle was significant between RVSP and LBBP groups only in patients who had wide QRS escape. The mean LVEF at 6-month follow-up in LBBP vs RVSP was 61 ± 3.7 % vs 57.1 ± 7.8 %; 95 % CI:1.48, 6.32, p = 0.002. In the RVSP group, three patients developed pacing induced cardiomyopathy (PIC) whereas no patients in the LBBP group developed PIC at 6-month follow-up; p=0.021. One patient with PIC had deterioration of functional status with new onset HF symptoms. The patient symptoms improved with medical therapy and needed no hospitalisation. The patient declined further interventions including upgradation to CRT or LBB pacing. No deaths or ventricular arrhythmias were observed during the study period.

CONCLUSION

LBBP is associated with narrower f QRS-T angle as compared to RVSP both at post implant period and at 6 month f/u period. These findings might be due to the more physiological depolarization and repolarization kinetics associated with LBBP. RVSP was associated with 6 % incidence of PIC. Hence wide f QRS-T angle might be a predictor of PIC.

Pacing-induced cardiomyopathy in patients with preserved ejection fraction undergoing permanent cardiac pacemaker placement

BACKGROUND

Chronic right-ventricular (RV) pacing can worsen heart failure in patients with a low ejection fraction (EF), but little is known about pacing-induced cardiomyopathy (PICM) in patients with preserved EF. We aimed to investigate risk factors of PICM in these patients during long-term follow-up.

METHODS

The prospective registry at Chosun University Hospital, South Korea, included de novo patients with preserved EF undergoing transvenous permanent pacemaker (PPM) implantation for atrioventricular blockage from 2017 to 2021. Patients with EF ≥ 50% and expected ventricular pacing ≥ 40% were included. Composite outcomes were cardiac death (pump failure), hospitalization because of heart failure, PICM, and biventricular pacing (BVP) upgrade.

RESULTS

A total of 168 patients (69 men, 76.3 ± 10.4 years) were included. During three years of follow-up, one patient died, 14 were hospitalized, 16 suffered PICM, and two underwent BVP upgrade. PICM were associated with reduced global longitudinal strain (GLS), prolonged paced QRS duration (pQRSd) and diastolic variables (E/e', LAVI). Cox regression analysis identified pQRSd (hazard ratio [HR], 1.111; 95% confidence interval [CI], 1.011-1.222; P = 0.03) and reduced GLS (HR, 1.569; 95% CI, 1.163-2.118; P = 0.003) as independent predictors of PICM. GLS showed high predictive accuracy for PICM, with an area under the curve of 0.84 (95% CI 0.779-0.894; P < 0.001) [GLS -12.0, 62.5% sensitivity, and 86.1% specificity].

CONCLUSION

RV pacing increased the risk of PICM in patients with preserved EF. Reduced GLS and prolonged pQRSd could help identify individuals at high risk of PICM even with preserved EF.

Correlation of ventricular pacing burden and left ventricular function in patients with heart failure with reduced ejection fraction

BACKGROUND

Pacemaker-induced cardiomyopathy is a well described phenomenon in patients with preserved ejection fraction at the time of permanent pacemaker implant. One of the identified risk factors for pacemaker-induced cardiomyopathy is the degree of ventricular pacing burden. However, it is unclear how a high right ventricular pacing burden affects patients with depressed left ventricular function at the time of pacemaker implantation. We sought to assess the relationship between right ventricular pacing and change in left ventricular function over time.

METHODS

We conducted an analysis of all patients who had received either a single or dual lead cardiac implantable electronic devices, excluding biventricular devices, and had a prior transthoracic echocardiogram demonstrating an ejection fraction of less than 50%. The primary end-point was the correlation between the percentage of ventricular pacing and the change in LV ejection fraction.

RESULTS

Fifty eight patients with preceding heart failure had pacemakers implanted and had follow up echocardiograms. There was no correlation between the degree of ventricular pacing and the absolute change in LV function (r = .04, p = .979). None of the previously identified risk factors for pacemaker induced cardiomyopathy were predictive of a significant fall in ejection fraction.

CONCLUSION

The degree of RV pacing and other established risk factors for pacemaker-induced cardiomyopathy in patients with normal left ventricular function at the time of implantation do not appear to carry the same risk in patients with pre-existing heart failure who receive either single or dual lead pacemakers.

Assessment of Trend, Indication, Complications, and Outcomes of Pacemaker Implantation in Adult Patients at Tertiary Hospital of Ethiopia: Retrospective Follow Up Study

Background

A pacemaker is a device implanted in the chest to help people with symptomatic bradycardia and life-threatening irregular rhythm. However, it is also associated with many complications. Therefore, this study evaluated pacemaker-related complications and factors associated with them, as there is little data on pacemaker-related complications in sub-Saharan Africa and Ethiopia.

Methods

The study was conducted on 118 patients over 18 years old who had pacemakers implanted between 2017 and 2022 at Tikur Anbessa Comprehensive Specialized Hospital in Addis Ababa, Ethiopia who were reviewed by the authors from September 2022 to December 2022. Sociodemographic factors, clinical characteristics, and complications data were extracted using a structured questionnaire by retrospective review of patient records. The chi-square test or Fisher's exact test was performed to evaluate factors associated with complications.

Results

The median age of patients was 60.5 years (IQR = 15 years), with men accounting for 50.8% of patients. Hypertension was the most common comorbidity (64.2%). Symptomatic grade 3 AV block was the most common indication (78.8%) for pacemaker implantation. With a mean follow-up of 3.92 ± 1.94 years, 15.3% of patients had complications. Pneumothorax, pocket site infection, and lead dislodgement were the most common complications occurring in 2.54% of patients each. Patient age during surgery (p-value = 0.02), patient gender (p-value = 0.04), pacemaker implanting team (p-value = 0.01), and adherence to follow-up (p-value = 0.04) are related to pacemakers-related complications.

Conclusion

Pacemaker implantation is associated with many complications. Pneumothorax, pacemaker pocket infection, and lead dislodgement were the most common complications. Patient age at pacemaker implantation, patient gender, pacemaker implanting team, and follow-up compliance were factors associated with pacemaker-related complications. Skill development through specialized training and compliance counseling may improve outcomes for patients who have complications related to pacemaker implanting team and poor adherence to follow.

Revisiting predictors of worse atrioventricular valve and left ventricular systolic function following pacemaker therapy

BACKGROUND

Predictors of worsening atrioventricular valve regurgitation and left ventricular (LV) systolic function after implantation of a leadless pacemaker (LPM) remain unclear compared with those of a transvenous pacemaker (TPM).

METHODS

We retrospectively analyzed 205 patients who were newly implanted with a permanent pacemaker (119 LPMs and 86 TPMs) and underwent transthoracic echocardiography before and 8 ± 5 months after implantation. We evaluated the worsening of tricuspid and mitral regurgitation (TR and MR), defined as at least one-grade aggravation in severity, and changes in LV ejection fraction (LVEF).

RESULTS

Worsening TR occurred more frequently in the LPM group compared to the TPM group (33% vs. 20%, p = .04); however, there was no significant difference between the two groups regarding worsening MR (26% vs. 18%, p = .18) and LVEF change (-2 ± 10% vs. -3 ± 8%, p = .40). In multivariable analysis, independent predictors for worsening TR, MR, and LVEF after implantation were found to be (1) the change from sinus rhythm at baseline to atrioventricular asynchronous right ventricular (RV) pacing (odds ratio [OR]: 5.68, 95% confidence interval [CI]: 1.94-16.70, p < .01); (2) the change from non-pacing ventricular contraction at baseline to RV pacing (OR: 2.42, 95% CI: 1.12-5.24, p = .02); and (3) a higher RV pacing burden (β: -0.05, 95% CI: -0.08--0.02, p < .01), respectively.

CONCLUSION

Worsening TR, MR, and LVEF after pacemaker implantation were not associated with the type of pacing device but loss of atrioventricular synchrony or dependency on RV pacing.

Beneficial effects of upgrading to His-Purkinje system pacing in patients with pacing-induced cardiomyopathy: a systematic review and meta-analysis

Background

The purpose of this study was to evaluate the effectiveness of His-Purkinje system pacing (HPSP) in the management of patients with pace-induced cardiomyopathy (PICM).

Methods

PubMed, Embase, Web of Science, and the Cochrane Library were searched comprehensively to collect related studies published from the inception of databases to June 1, 2022. R 4.04 software, including the Metafor package, matrix package, and the Meta package, was utilized to conduct the singe-arm meta-analysis. The methodology index for non-randomized studies (MINORS) was used to assess the methodological quality of the included studies.

Results

A total of seven studies were included, involving 164 PICM patients. The meta-analysis showed that HPSP ameliorated the left ventricular ejection fraction (LVEF) by 13.41% (95% CI [11.21-15.61]), improved the New York Heart Association (NYHA) classification by 1.02 (95% CI [-1.41 to -0.63]), and shortened the QRS duration (QRSd) by 60.85 ms (95% CI [-63.94 to -57.75]), resulting in improved cardiac functions in PICM patients. Besides, HPSP reversed the ventricular remodeling, with a 32.46 ml (95% CI [-53.18 to -11.75]) decrease in left ventricular end systolic volume (LVESV) and a 5.93 mm (95% CI [-7.68 to -4.19]) decrease in left ventricular end-diastolic dimension (LVEDD). HPSP also showed stable electrical parameters of pacemakers, with a 0.07 V (95% CI [0.01-0.13]) increase in pacing threshold, a 0.02 mV (95% CI [-0.85 to 0.90]) increase in sensed R-wave amplitude, and a 31.12 Ω reduction in impedance (95% CI [-69.62 to 7.39]). Compared with LBBP, HBP improved LVEF by 13.28% (95% CI [-11.64 to 14.92]) vs 14.43% (95% CI [-13.01 to 15.85]), ameliorated NHYA classification by 1.18 (95% CI [-1.97 to -0.39]) vs 0.95 (95% CI [-1.33 to -0.58]), shortened QRSd by 63.16 ms (95% CI [-67.00 to -59.32]) vs 57.98 ms (95% CI [-62.52 to -53.25]), and decreased LVEDD by 4.12 mm (95% CI [-5.79 to -2.45]) vs 6.26 mm (95% CI [-62.52 to -53.25]). The electrical parameters of the pacemaker were stable in both groups.

Conclusions

This meta-analysis showed that HPSP could significantly improve cardiac function, promote reverse remodeling, and provide stable electrical parameters of pacemakers for PICM patients.

The estimated glomerular filtration rate predicts pacemaker-induced cardiomyopathy

Clinical predictors for pacemaker-induced cardiomyopathy (PICM) (e.g., a wide QRS duration and left bundle branch block at baseline) have been reported. However, factors involved in the development of PICM in patients with preserved left ventricular ejection fraction (LVEF) remain unknown. This study aimed to determine the risk factors for PICM in patients with preserved LVEF. The data of 113 patients (average age: 71.3 years; men: 54.9%) who had echocardiography before and after pacemaker implantation (PMI) among 465 patients undergoing dual-chamber PMI were retrospectively analyzed. Thirty-three patients were diagnosed with PICM (18.0/100 person-years; 95% CI 12.8-25.2). A univariate Cox regression analysis showed that an estimated glomerular filtration rate (eGFR) ≤ 30 mL/min/1.73 m2 (HR 3.47; 95% CI 1.48-8.16) and a past medical history of coronary artery disease (CAD) (HR 2.76; 95% CI 1.36-5.60) were significantly associated with the onset of PICM. After adjusting for clinical variables, an eGFR ≤ 30 mL/min/1.73 m2 (HR 2.62; 95% CI 1.09-6.29) and a medical history of CAD (HR 2.32; 95% CI 1.13-4.80) were independent risk factors for developing PICM. A medical history of CAD and low eGFR are independent risk factors for PICM in patients with preserved LVEF at baseline. These results could be helpful in predicting a decreased LVEF by ventricular pacing before PMI. Close follow-up by echocardiography is recommended to avoid a delay in upgrading to physiological pacing, such as cardiac resynchronization therapy or conduction system pacing.

Exploring the Temporal Patterns of Right Ventricular Pacing Burden

Elevated right ventricular pacing (RVP) burdens are associated with the development of pacing-induced cardiomyopathy. This association is alluded to in the recent European and American pacing guidelines where anticipated pacing burden forms part of the indications for conduction system pacing. Understanding the temporal pattern of RVP burden is important with respect to anticipating future burden and ensuring that the most appropriate pacing modality is selected for patients. To the best of our knowledge, this is the first study to assess how RVP burden changes over time in different pacing indications. A retrospective, single-center, observational study was performed. RVP burdens from pacing checks were extracted and plotted against 6-month time "bins." Graphical plots of RVP burdens for different pacing indications were produced. There was no significant change in the RVP burden across time, independent of the initial pacing indication. Individuals with sinus node disease (SND) and a P-R interval of >250 ms had increased RVP burden. Other than patients with SND and a P-R interval of <250 ms, individuals had pacing burdens higher than those proposed in both the European and American pacing guidelines for conduction system pacing.

Echocardiographic Evaluation of the Effect on Left Ventricular Function Between Left Bundle Branch Pacing and Right Ventricular Pacing

Purpose

The purpose of this study was to assess the left ventricular function effects of permanent left bundle branch pacing (LBBP) versus traditional right ventricular pacing (RVP).

Patients and Methods

Consecutive patients receiving pacemaker implantation were included and divided into left bundle branch block (LBBB) group and right ventricular pacing (RVP) group. Baseline characteristics were collected, and they received 1-year follow-up. Electrocardiogram (ECG) characteristics and pacing parameters were assessed before and after implantation. Cardiac function parameters such as left ventricular ejection fraction (LVEF) and tricuspid regurgitation (TR) were recorded and compared.

Results

Of 78 patients included, 45 patients received LBBP (mean age, 72.7 ± 12.2 years; male, 55.6%) and 33 patients underwent RVP (mean age 72.9 ± 11.8 years; male, 63.6%). The pacing parameters were satisfactory during the implantation and remained stable during mid-term follow-up. During the follow-up period, LBBP patients had a greater decrease in LVEDD and LVESD. The TR in the LBBP group was significantly improved as compared to the RVP group (P=0.016).

Conclusion

Permanent LBBP achieves favorable cardiac hemodynamic effects with good stability and safety. LBBP may reduce severe TR at 1-year follow-up, and LBBP may be an option for patients with severe TR.

2023 HRS/EHRA/APHRS/LAHRS expert consensus statement on practical management of the remote device clinic

Remote monitoring is beneficial for the management of patients with cardiovascular implantable electronic devices by impacting morbidity and mortality. With increasing numbers of patients using remote monitoring, keeping up with higher volume of remote monitoring transmissions creates challenges for device clinic staff. This international multidisciplinary document is intended to guide cardiac electrophysiologists, allied professionals, and hospital administrators in managing remote monitoring clinics. This includes guidance for remote monitoring clinic staffing, appropriate clinic workflows, patient education, and alert management. This expert consensus statement also addresses other topics such as communication of transmission results, use of third-party resources, manufacturer responsibilities, and programming concerns. The goal is to provide evidence-based recommendations impacting all aspects of remote monitoring services. Gaps in current knowledge and guidance for future research directions are also identified.

Pacing induced cardiomyopathy: recognition and management

Right ventricle (RV) apex continues to remain as the standard pacing site in the ventricle due to ease of implantation, procedural safety and lack of convincing evidence of better clinical outcomes from non-apical pacing sites. Electrical dyssynchrony resulting in abnormal ventricular activation and mechanical dyssynchrony resulting in abnormal ventricular contraction during RV pacing can result in adverse LV remodelling predisposing some patients for recurrent heart failure (HF) hospitalisation, atrial arrhythmias and increased mortality. While there are significant variations in the definition of pacing induced cardiomyopathy (PIC), combining both echocardiographic and clinical features, the most acceptable definition for PIC would be left ventricular ejection fraction (LVEF) of <50%, absolute decline of LVEF by ≥10% and/or new-onset HF symptoms or atrial fibrillation (AF) after pacemaker implantation. Based on the definitions used, the prevalence of PIC varies between 6% and 25% with overall pooled prevalence of 12%. While most patients undergoing RV pacing do not develop PIC, male sex, chronic kidney disease, previous myocardial infarction, pre-existing AF, baseline LVEF, native QRS duration, RV pacing burden, and paced QRS duration are the factors associated with increased risk for PIC. While conduction system pacing (CSP) using His bundle pacing and left bundle branch pacing appear to reduce the risk for PIC compared with RV pacing, both biventricular pacing and CSP may be used to effectively reverse PIC.

Pacing-Induced Cardiomyopathy

Right ventricular (RV) pacing-induced cardiomyopathy (PICM) is typically defined as left ventricular systolic dysfunction resulting from electrical and mechanical dyssynchrony caused by RV pacing. RV PICM is common, occurring in 10-20% of individuals exposed to frequent RV pacing. Multiple risk factors for PICM have been identified, including male sex, wider native and paced QRS durations, and higher RV pacing percentage, but the ability to predict which individuals will develop PICM remains modest. Biventricular and conduction system pacing, which better preserve electrical and mechanical synchrony, typically prevent the development of PICM and reverse left ventricular systolic dysfunction after PICM has occurred.

Pacing-Induced Cardiomyopathy in Leadless and Traditional Pacemakers: A Single-Center Retrospective Analysis

BACKGROUND

 Pacing-induced cardiomyopathy (PICM) is a clinical syndrome that is characterized by a drop in the left ventricular ejection fraction (LVEF) due to chronic high-burden right ventricular (RV) pacing. It has been postulated that leadless pacemakers (LPs) cause decreased risk of PICM compared to transvenous pacemakers (TVPs), but the exact risk reduction is unknown.

METHODS

We performed a single-center retrospective analysis of adults who received an LP or TVP between January 1, 2014, and April 1, 2022, and had echocardiograms before and after the pacemaker implant. This study's outcomes were the RV pacing percentage, change in EF, the need for cardiac resynchronization therapy (CRT) upgrade, and follow-up duration. A Wilcoxon rank-sum test calculated the change in EF. RV time, defined as the duration from pacemaker placement to the follow-up echocardiogram in months multiplied by the RV pacing percentage, served as a surrogate for how long the RV was paced.

RESULTS

A total of 614 patients were screened, and 198 patients were included in the study, where 72 received LP and 126 received TVP. The median follow-up was 480 days. The average of the reported RV percentage pacing was 63.43% for LP and 71.30% for TVP (p=0.14). The incidence of PICM and CRT upgrade was 44% and 9.7% in the LP group and 37% and 9.5% in the TVP group (p=0.3 and p>0.9), respectively. After accounting for age, sex, LP versus TVP, atrioventricular nodal ablation, RV pacing percentage, and follow-up duration, univariate analysis showed that RV time was significantly different between the two types of pacemakers (13.54 ± 14.21 months (LP) versus 9.26 ± 13.95 months (TVP), p=0.009). The difference in RV time between patients who underwent CRT upgrade and those who did not was statistically insignificant (12.11 ± 14.47 months (no CRT) versus 9.19 ± 12.00 months (CRT), p=0.5).

CONCLUSIONS

This analysis demonstrated that the incidence of PICM was high in both groups (44% (LP) versus 37% (TVP)), despite significantly more RV time in patients with LP. There was no difference in CRT upgrade between LP and TVP.

2023 HRS/EHRA/APHRS/LAHRS Expert Consensus Statement on Practical Management of the Remote Device Clinic

Remote monitoring is beneficial for the management of patients with cardiovascular implantable electronic devices by impacting morbidity and mortality. With increasing numbers of patients using remote monitoring, keeping up with higher volume of remote monitoring transmissions creates challenges for device clinic staff. This international multidisciplinary document is intended to guide cardiac electrophysiologists, allied professionals, and hospital administrators in managing remote monitoring clinics. This includes guidance for remote monitoring clinic staffing, appropriate clinic workflows, patient education, and alert management. This expert consensus statement also addresses other topics such as communication of transmission results, use of third-party resources, manufacturer responsibilities, and programming concerns. The goal is to provide evidence-based recommendations impacting all aspects of remote monitoring services. Gaps in current knowledge and guidance for future research directions are also identified.

Left Ventricular Mass Index Predicts Pacemaker-Induced Cardiomyopathy in Patients with Dual Chamber Permanent Pacemakers Implanted Due to Complete Atrioventricular Block

Background

Pacing-induced cardiomyopathy (PICM) occurs as a result of high-burden right ventricular (RV) pacing, which usually develops in patients with complete atrioventricular (AV) block. There is a paucity of data on the association between PICM and pre-implantation left ventricular mass index (LVMI). Thus, the purpose of this study was to analyze the influence of LVMI on PICM in patients who had dual chamber permanent pacemakers (PPMs) implanted secondary to complete AV block.

Methods

Overall, 577 patients with dual chamber permanent pacemakers (PPMs) were classified into three tertiles according to their pre- implantation LVMI. The average follow-up period was 57 ± 38 months. The baseline characteristics, laboratory and echocardiographic variables were compared between the tertiles. PICM was defined as a ≥ 10% drop in left ventricular ejection fraction (LVEF) from pre-implantation with a resultant LVEF < 50%. PICM occurred in 42 (7.2%) patients. The independent predictors of PICM development, as well as the impact of LVMI on PICM, were investigated.

Results

After controlling for confounding baseline variables, the tertile with the greatest LVMI had a 1.8 times higher risk for the development of long-term PICM compared with the tertile with the lowest LVMI, which was accepted as the reference group. A receiver operating characteristic curve analysis revealed that the best LVMI cut- off value for predicting long-term PICM was 109.8 g/m2 with 71% sensitivity and 62% specificity (area under curve: 0.68; 95% confidence interval: 0.60-0.76; p < 0.001).

Conclusions

This investigation revealed that pre-implantation LVMI had a prognostic role in predicting PICM in patients with an implanted dual chamber PPM due to complete AV block.

The therapeutic benefit of upgrade to cardiac resynchronization therapy in patients with pacing-induced cardiomyopathy

Background

Pacing-induced cardiomyopathy (PICM) is an important cause of heart failure in patients with a right ventricular pacing burden. Recent evidence suggests that an upgrade to cardiac resynchronization therapy (CRT) may confer benefit in PICM.

Objective

To assess the extent and identify predictors of improvement following upgrade to CRT in patients with PICM.

Methods

We retrospectively analyzed 43 patients undergoing CRT upgrade for PICM over the 10-year period of 2011 to 2021 at our center. All patients with PICM who underwent device upgrade from a dual- or single-chamber ventricular pacemaker to CRT were included. PICM was defined as a decrease of ≥10% in left ventricular ejection fraction (LVEF), resulting in an LVEF <50% among patients with ≥20% Right ventricular pacing burden without an alternative cause for cardiomyopathy.

Results

LVEF significantly improved from 28.7% preupgrade to 44.3% post-CRT upgrade (P < .01). Of 37 patients with severe LV dysfunction, 34 (91.9%) improved to an LVEF >35% and 13 (35.1%) improved to an LVEF >50%. The LV end-diastolic diameter decreased from 5.9 cm preupgrade to 5.4 cm postupgrade (P < .01). Using linear regression, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use was associated with significant LVEF improvement (+7.21%, P = .05). We observed a low rate of complications, and 1 in 4 CRT upgrades required venoplasty (n = 10 of 43, 23.3%).

Conclusion

We provide further evidence for the benefit of CRT upgrade in the management of patients with PICM.

The soluble suppression of tumorigenicity 2 as a biomarker of early cardiac remodeling in bradycardia patients receiving permanent pacemaker therapy

Aim: This study aims to evaluate: the difference of soluble suppression of tumorigenicity 2 (sST2) level, a biomarker for cardiac remodeling and echocardiography parameters value prior to and 1 month after implantation; and the association between pacemaker parameters and pacemaker mode along with delta sST2 levels. Materials & methods: This prospective cohort study enrolled all symptomatic bradycardia patients aged >18 years with preserved ejection fraction who underwent permanent pacemaker (PPM) implantation. Results: A total of 49 patients were included in this study. The sST2 level (ng/ml) were significantly different between prior and 1 month following PPM implantation (23.4 ± 28.4 vs 39.9 ± 63.7; p = 0.001). Conclusion: The early cardiac remodeling has occurred within 1 month after PPM implantation as indicated by increasing delta sST2 level.

Adverse effects of right ventricular pacing on cardiac function: prevalence, prevention and treatment with physiologic pacing

Right ventricular (RV) pacing is the main treatment modality for patients with advanced atrioventricular (AV) block. Chronic RV pacing can cause cardiac systolic dysfunction and heart failure (HF). In this review, we discuss studies that have shown deleterious effects of chronic RV pacing on systolic cardiac function causing pacing-induced cardiomyopathy (PiCM), heart failure (HF), HF hospitalization, atrial fibrillation (AF) and cardiac mortality. RV apical pacing is the most widely used and studied. Adverse effects of RV pacing appear to be directly related to pacing burden and are worse in patients with pre-existing left ventricular (LV) dysfunction. Chronic RV pacing is also associated with heart failure with preserved ejection fraction (HFpEF). Mechanisms, risk factors, clinical and echocardiographic features, and strategies to minimize RV pacing-induced cardiac dysfunction are discussed in light of the latest data. Studies on biventricular (Bi-V) pacing upgrade in patients who develop RV PiCM, use of alternate RV pacing sites, de novo Bi-V pacing, and physiologic pacing using HIS bundle pacing (HBP) and left bundle area (LBBA) pacing in patients with an anticipated high RV pacing burden are discussed.

Pacing-induced cardiomyopathy: A systematic review and meta-analysis of definition, prevalence, risk factors, and management

Pacing-induced cardiomyopathy is a potential complication of right ventricular pacing. Definition varies between studies and the optimal management approach is uncertain. We aimed to characterize definition, prevalence, risk factors, and treatment strategies of pacing-induced cardiomyopathy (PiCM). We performed a systematic review and meta-analysis of studies that evaluated PiCM after pacemaker implantation identified through a literature search of PubMed and EMBASE up to March 2022. We collected data on the study definition of PiCM and calculated pooled prevalence across studies. Meta-analysis with random effects modeling was used to assess the association between potential risk factors and PiCM, reported as odds ratio with 95% confidence interval. Twenty-six studies (6 prospective studies) with a total of 57,993 patients (mean/median age range was 51-78 years; female 45%) were included in the final analysis. Fifteen unique definitions of PiCM were reported. The pooled prevalence of PiCM was 12% (95% confidence interval 11%-14%). In meta-analysis, risk factors included male sex, history of myocardial infarction, chronic kidney disease, atrial fibrillation, baseline left ventricular ejection fraction, native QRS duration, right ventricular pacing percentage, and paced QRS duration. Treatment strategies identified included biventricular cardiac resynchronization therapy (6 studies) and His-bundle pacing (3 studies). Definition of PiCM varied significantly between studies. More than 1 in 10 patients with chronic right ventricular pacing developed PiCM. Key risk factors included baseline left ventricular ejection fraction, native QRS duration, RV pacing percentage, and paced QRS duration. The optimal management strategy has yet to be defined. Further research is needed to define and treat this understated complication.

Assessment of Cardiac Function and Ventricular Mechanical Synchronization in Left Bundle Branch Area Pacing by Speckle Tracking and Three-Dimensional Echocardiography

Real-time 3-dimensional echocardiography combined with speckle tracking was used in this study. A total of 90 patients with normal left ventricular ejection fraction were divided into 3 groups according to the pacing site: left bundle branch area pacing (LBBAP), right ventricular septal pacing (RVSP) or right ventricular apical pacing (RVAP). Procedure duration (90 ± 18 vs 61 ± 6.6 vs 58 ± 5.6 minutes, p = 0.015), Fluoroscopy duration (15.5 ± 5.4 vs 4.8 ± 2.2 vs 4 ± 1.9 minutes, p = 0.004), and ventricular capture threshold at implantation (0.8 ± 0.3 vs 0.6 ± 0.2 vs 0.6 ± 0.1 V, p = 0.002) were significantly increased in patients that received LBBAP compared with RVSP or RVAP. At 4 weeks of follow-up, brain natriuretic peptide levels were significantly lower (22 [12 to 59] vs 135 [86 to 231] vs 235 [147 to 428] pg/ml, p = 0.04), paced QRS duration was significantly shorter (115 ± 26 vs 134 ± 28 vs 157 ± 29 ms, p = 0.012), and global longitudinal strain (-19.4 ± 2.4 vs -19.3 ± 3.4 vs -17.3 ± 3.5%, p = 0.026) and systolic dyssynchrony index (2.5 ± 0.3 vs 5.9 ± 0.9 vs 7.7 ± 1.2, p = 0.001), longitudinal absolute maximum difference of time to peak strain (17 [6 to 68] vs 117 [71 to 173] vs 126 [79 to 178] ms, p <0.0001), and circumferential absolute maximum difference of time to peak strain (76 [32 to 129] vs 148 [117 to 208] vs 161 [118 to 266] ms, p = 0.005) were significantly lower in patients that received LBBAP compared with RVSP or RVAP. In conclusion, LBBAP can provide a more physiological ventricular activation pattern than RVSP or RVAP and results in good left ventricular electrical and mechanical synchronization.

Initial Experience with Left Bundle Branch Area Pacing in Patients with Atrioventricular Block and Impaired LV Function

Chronic right ventricular (RV) pacing can exacerbate heart failure in patients with a low left ventricular ejection fraction (LVEF). Left bundle branch area pacing (LBBAP) has emerged as a novel physiological pacing technique; however, information remains limited on its use among patients with a low EF. This study investigated the safety and short-term clinical outcomes of LBBAP among patients with impaired left ventricular (LV) function. This retrospective analysis of pacemakers at Chosun University Hospital, South Korea, included all patients with impaired LV function (EF<50%) who underwent pacemaker implantation for atrioventricular blockage from 2019-2022. Clinical characteristics, 12-lead electrocardiography findings, echocardiography findings, and laboratory parameters were evaluated. Composite outcomes were defined as all-cause mortality, cardiac death, and hospitalization due to heart failure during the 6-month follow-up. Altogether 57 patients (25 men; mean age, 77.4±10.8 y; LVEF, 41.5±3.8%) were divided into LBBAP (n=16), biventricular pacing (BVP; n=16), and conventional RV pacing (RVP; n=25) groups. In the LBBAP group, the mean paced QRS duration (pQRSd) was narrower (119.5±14.7 vs. 140.2±14.3 vs. 163.2±13.9; p<0.001) and cardiac troponin I level was elevated post-pacing (1.14±1.29 vs. 0.20±0.29 vs. 0.24±0.51, p=0.001). Lead parameters were stable. One patient was hospitalized, and four died (one patient each from heart failure admission, myocardial infarction, unexplained death, and pneumonia in RVP vs. one from intracerebral hemorrhage in BVP) during the follow-up period. In conclusion, LBBAP is feasible in patients with impaired LV function without acute or significant complications and provides a remarkably narrower pQRSd with a stable pacing threshold.

Impact of diastolic dysfunction in patients with preserved ejection fraction undergoing permanent cardiac pacemaker placement

Background

Chronic right-ventricular (RV) pacing can exacerbate heart failure in patients with a low ejection fraction (EF). There is little information on the effects of diastolic dysfunction (DD) in patients with preserved EF undergoing permanent pacemaker (PPM) placement. We aimed to investigate the clinical outcomes in these patients.

Methods

This multicenter, retrospective analysis of PPM use in Chonnam, South Korea, included all patients with preserved EF undergoing transvenous PPM implantation for atrioventricular blockage from 2017 to 2019. Patients were divided into two groups according to DD, which were assessed by including mitral flow velocities (E′ velocity, E/E′ ratio), peak velocity of the tricuspid regurgitant, and left atrial maximum volume index. Composite outcomes were defined as (1) cardiovascular death, and (2) hospitalization by heart failure during the follow-up period.

Results

One hundred sixty-seven patients (66 men; overall mean age, 75.3 ± 11.9 years) were divided into two groups: 125 normal versus 42 DD. Compared with normal subjects, the DD group included older patients (mean age, 79.1 ± 9.9 vs. 74.0 ± 12.3; p = 0.016), and had longer paced QTc interval (pQTc, 168.5 ± 20.1 vs. 159.1 ± 16.3 ms; p < 0.001). Fifteen patients were hospitalized and two died. In a Cox proportional regression analysis, DD (hazard ratio [HR], 7.343; 95% confidence interval [CI], 2.035–26.494; p = 0.002) and pQRSd (HR, 1.046; 95% CI, 1.004–1.091; p = 0.033) were independent predictors of composite outcomes.

Conclusion

In patients with DD, RV pacing raised the risk of pacing-induced heart failure despite preserved left-ventricular function. Thus, patients with DD should be monitored intensively.

A systematic review and Bayesian network meta-analysis comparing left bundle branch pacing, his bundle branch pacing, and right ventricular pacing for atrioventricular block

Background

Although right ventricular pacing (RVP) is recommended by most of the guidelines for atrioventricular block, it can cause electrical and mechanical desynchrony, impair left ventricular function, and increase the risk of atrial fibrillation. Recently, the His-Purkinje system pacing, including His bundle pacing (HBP) and left bundle branch pacing (LBBP), has emerged as a physiological pacing modality. However, few studies have compared their efficacy and safety in atrioventricular block (AVB).

Methods and results

The PubMed, Web of Science, Cochrane Library, and ScienceDirect databases were searched for observational studies and randomized trials of patients with atrioventricular block requiring permanent pacing, from database inception until 10 January 2022. The primary outcomes were complications and heart failure hospitalization. The secondary outcomes included changes in left ventricular ejection fraction (LVEF) and left ventricular end-diastolic diameter (LVEDD), pacing parameters, procedure duration, and success rate. After extracting the data at baseline and the longest follow-up duration available, a pairwise meta-analysis and a Bayesian random-effects network meta-analysis were performed. Odds ratios (ORs) with 95% confidence intervals (CIs) or 95% credible intervals (CrIs) were calculated for dichotomous outcomes, whereas mean differences (MDs) with 95% CIs or 95% CrIs were calculated for continuous outcomes. Seven studies and 1,069 patients were included. Overall, 43.4% underwent LBBP, 33.5% HBP, and 23.1% RVP. Compared with RVP, LBBP and HBP were associated with a shorter paced QRS duration and a more preserved LVEF. HBP significantly increased the pacing threshold and reduced the R-wave amplitude. There was no difference in the risk of complications or the implant success rate. The pacing threshold remained stable during follow-up for the three pacing modalities. The pacing impedance was significantly reduced in HBP, while a numerical but non-significant pacing impedance decrease was observed in both LBBP and RVP. LBBP was associated with an increased R-wave amplitude during follow-up.

Conclusion

In this systematic review and network meta-analysis, HBP and LBBP were superior to RVP in paced QRS duration and preservation of LVEF for patients with atrioventricular block. LBBP was associated with a lower pacing threshold and a greater R-wave amplitude than HBP. However, the stability of the pacing output of LBBP may be a concern. Further investigation of the long-term efficacy in left ventricular function and the risk of heart failure hospitalization is needed.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=315046], identifier [CRD42022315046].

Predictors of right ventricular pacing-induced left ventricular dysfunction in pacemaker recipients with preserved ejection fraction

BACKGROUND

Pacing is an effective treatment in the management of patients with bradyarrhythmias. Chronic right ventricular pacing may cause electrical and mechanical dyssynchrony leading to a deterioration of left ventricular ejection fraction (LVEF). This deterioration of LVEF has been described as pacing-induced cardiomyopathy (PICM). The incidence of PICM has been described by many studies, ranging between 10% and 26%. Predictors for PICM are not yet established-studies were limited by variations in the definition of PICM and the follow-up period. The authors studied the incidence and predictors of PICM in patients with preserved LVEF who underwent pacemaker implantation.

PATIENTS AND METHODS

This retrospective study included 320 patients that underwent single- or dual-chamber pacemaker implantation, with a mean follow up period of 4.7 ± 2.0 years. Implantable cardioverter defibrillator and cardiac resynchronization therapy patients were excluded from this study. Individuals that had a baseline LVEF ≥ 50% before implantation in transthoracic echocardiography were included in the study.

RESULTS

Of the 320 patients included in the study, 45% were male, with a mean age 55.5 years. The incidence of PICM was 7.5%. Wider native QRS duration, particularly > 140 ms (P < 0.001), wider paced QRS (pQRS) duration > 150 ms (P < 0.001), low normal ejection fraction < 56% pre-implantation (P = 0.023) and increased LV end diastolic diameter (LVEDD) > 53 mm and LV end systolic diameter (LVESD) > 38 mm (P < 0.001) predicted the development of PICM. There was no association between burden of right ventricular pacing (P = 0.782) or pacing site (P = 0.876) and the development of pacemaker-induced cardiomyopathy.

CONCLUSION

Right ventricular pacing-induced left ventricular dysfunction is not uncommon, with an incidence of 7.5%. Wider native and paced QRS durations, low normal ejection fraction (< 56%) pre-implantation and increased LVEDD and LVESD post implantation are the most important predictors for the development of PICM.

Ventricular Dyssynchrony and Pacing-induced Cardiomyopathy in Patients with Pacemakers, the Utility of Ultra-high-frequency ECG and Other Dyssynchrony Assessment Tools

The majority of patients tolerate right ventricular pacing well; however, some patients manifest signs of heart failure after pacemaker implantation and develop pacing-induced cardiomyopathy. This is a consequence of non-physiological ventricular activation bypassing the conduction system. Ventricular dyssynchrony was identified as one of the main factors responsible for pacing-induced cardiomyopathy development. Currently, methods that would allow rapid and reliable ventricular dyssynchrony assessment, ideally during the implant procedure, are lacking. Paced QRS duration is an imperfect marker of dyssynchrony, and methods based on body surface mapping, electrocardiographic imaging or echocardiography are laborious and time-consuming, and can be difficult to use during the implantation procedure. However, the ventricular activation sequence can be readily displayed from the chest leads using an ultra-high-frequency ECG. It can be performed during the implantation procedure to visualise ventricular depolarisation and resultant ventricular dyssynchrony during pacing. This information can assist the electrophysiologist in selecting a pacing location that avoids dyssynchronous ventricular activation.

Delta Increment in Pacing QRS Duration Predicts Cardiovascular Mortality in Patients with Pre-Existing Bundle Branch Block Receiving Permanent Pacemakers

BACKGROUND

The clinical implication of pre-existing intraventricular conduction disturbance (IVCD) in permanent pacemaker (PPM) recipients is unknown.

OBJECTIVES

To explore the clinical outcomes in patients with pre-existing IVCD after implantation of PPMs.

METHODS

A total of 1424 patients who received PPMs were categorized into three groups by pre-procedural electrocardiography: patients without IVCD (n = 1045), patients with right bundle branch block (RBBB) (n = 309), and patients with left bundle branch block (LBBB) (n = 70). The primary outcome was cardiovascular (CV) mortality. Receiver operating characteristic curve analysis was performed to determine the optimal cut-off values of variable in predicting CV mortality.

RESULTS

During follow-up, there was no significant difference in CV mortality between patients with and without IVCD. In multivariate analysis, independent predictors of CV mortality were age [hazard ratio (HR): 1.03; 95% confidence interval (95% CI): 1.00-1.05; p = 0.026], history of heart failure [HR: 1.98; 95% CI: 1.19-3.29; p = 0.009], chronic kidney disease [HR: 1.75; 95% CI: 1.11-2.74; p = 0.015] and increment in pacing QRS duration [HR: 1.01; 95% CI: 1.00-1.04; p = 0.038]. Delta increments in pacing QRS duration ≥ 43 msec [HR: 2.91; 95% CI: 1.23-6.83; p = 0.014] in patients with pre-existing RBBB, and ≥ 33 msec [HR: 11.44; 95% CI: 2.03-64.30; p = 0.006] in patients with pre-existing LBBB were independent determinants of CV mortality.

CONCLUSIONS

There was no difference in CV mortality between patients with or without IVCD. However, wider pacing QRS duration increased the risk of CV mortality in PPM recipients, and delta increment in pacing QRS duration increased the risk of CV mortality in patients with pre-existing IVCD.

Risk factors of pacing-induced cardiomyopathy-Insights from lead position

There was no significant difference in the incidence of pacing-induced cardiomyopathy between right ventricular apex pacing group and OpenCurlyQuote;true CloseCurlyQuote; mid-right ventricular septum pacing group. The preoperative left ventricular end-systolic diameter and paced QRS duration were independent predictors of PICM.

Initial Experience with Left Bundle Branch Area Pacing with Conventional Stylet-Driven Extendable Screw-In Leads and New Pre-Shaped Delivery Sheaths

Until recently, left bundle branch area pacing (LBBAp) has mostly been performed using lumen-less fixed screw leads. There are limited data on LBBAp with conventional style-driven extendable screw-in (SDES) leads, particularly data performed by operators with no previous experience with LBBAp procedures. In total, 42 consecutive patients undergoing LBBAp using SDES leads and newly designed delivery sheaths (LBBAp group) were compared with those treated with conventional right ventricular pacing (RVp) for atrioventricular block (RVp group, n = 84) using propensity score matching (1:2 ratio). The LBBAp was successful in 83% (35/42) of patients, with satisfactory pacing thresholds (0.8 ± 0.2 V at 0.4 ms). In the LBBAp group, the mean paced-QRS duration obtained during RV apical pacing (173 ± 18 ms) was significantly reduced by LBBAp (116 ± 14 ms, p < 0.001). Compared with the RVp group, the LBBAp group showed more physiological pacing, suggested by a much narrower paced-QRS duration (116 ± 14 vs. 151 ± 21 ms, p < 0.001). The pacing threshold was comparable in both groups. The LBBAp group revealed stable pacing thresholds for 6.8 ± 4.8 months post-implant and no serious complications including lead dislodgement or septal perforation. The novel approach of LBBAp using SDES leads and the new dedicated pre-shaped delivery sheaths was effectively and safely performed, even by inexperienced operators with LBBAp procedures.

Incidence and predictors of pacemaker-induced cardiomyopathy with right ventricular pacing: a systematic review

INTRODUCTION

This systematic review aims to evaluate the incidence and predictors of PICM in patients undergoing right ventricular pacing.

AREAS COVERED

A literature review was conducted using Mesh terms (Right ventricular pacing, Pacemaker-related cardiomyopathy, Pacemaker-induced cardiomyopathy) in PubMed, EMBASE, Web of science CINAHL, and the Cochrane Library until October 2021. All data reporting the incidence of PICM after implantation of right-sided pacemakers or implantable cardioverter-defibrillator (ICD) were retrieved from the eligible studies.

EXPERT OPINION

Out of 3,625 articles, 20 studies met the inclusion criteria that included 5,381 patients with PICM. The mean age of the patients ranged between 55.8 ± 13.5 and 77.4 ± 10.8 years. The mean incidence of PICM was 25.7%. Mean EF at baseline ranged from 48 ± 1% and 62.1 ± 11.2%, while mean EF at follow up ranged between 33.7± 7.4% and 53.2 ± 8.2%. Three studies reported a decline of >20% EF at follow-up. RV pacing was associated with a considerable risk of PICM, with biological factors such as male gender, old age, increased QRS duration, and chronic RV pacing burden playing an important role in the development of disease.

Understanding Pacemaker-Induced Cardiomyopathy Incidence and Predictors in Patients with Right Ventricular Pacing: A Systematic Review

This study aimed to figure out the incidence and predictors of pacemaker-induced cardiomyopathy (PICM) in patients with right ventricular (RV) pacing. We systematically searched in PubMed on March 18, 2020, for English language abstract and full-article journals, using the following criteria: pacemaker induced cardiomyopathy AND right ventricular AND pacemaker AND patients AND human NOT implantable cardioverter defibrillator NOT ICD NOT animal. Four studies were included in this review after filtering 35 studies through year of publication and abstract selection. The average PICM incidence from 1,365 patients included from the four studies was 10.7 to 13.7%. One study stated that preimplantation left ventricular ejection fraction (LVEF) was the predictor for the development of PICM. Three studies mentioned that RV pacing burden was the predictor for the development of PICM. However, the percentage differ in three studies: ≥20, >40, and 60%. In addition, one of the studies also included interventricular dyssynchrony as another predictor. The incidence of PICM in patients with RV pacing ranged from 10.7 to 13.7%. Preimplantation LVEF, interventricular dyssynchrony, and burden of RV pacing are reported as the predictors for the development of PICM in patients with RV pacing.

Clinical outcomes in patients with atrioventricular block undergoing pacemaker: 3-year follow-up

PURPOSE

Left ventricular function can be affected by chronic ventricular pacing. Different right ventricular (RV) pacing sites have shown heterogeneous clinical outcomes. We investigated these factors in patients receiving permanent pacemaker (PPM) implants.

METHODS

This multicenter, retrospective analysis of PPM use in South Korea, included all patients undergoing de novo transvenous PPM implantation for atrioventricular block from 2017 to 2019. Clinical characteristics, 12-lead electrocardiograms, echocardiography, and laboratory parameters were evaluated. Composite outcomes are defined by two coprimary endpoints: (1) hospitalizations and (2) cardiac death by heart failure during follow-up period.

RESULTS

There were 167 patients (66 males; overall mean age 75.3 ± 11.9 years), divided into two groups according to the pacing site: 83 apical RV (RVA) vs. 84 septal RV (RVS). There were no significant baseline differences. Paced QRS duration (pQRSd) increased with RVA (168.5 ± 20.1 vs. 159.1 ± 16.3 ms; p < 0.001). Over a median 31-month follow-up, there were 15 hospitalizations and 2 deaths. More patients with RVA were hospitalized or died (16% vs. 5%, respectively; p = 0.049). In Cox proportional regression analysis, pQRSd (hazard ratio [HR] 1.046; 95% confidence interval [CI] 1.004-1.091; p = 0.033), and diastolic dysfunction (HR 7.343; 95% CI 2.035-26.494; p = 0.002) were independent predictors of composite clinical outcomes.

CONCLUSIONS

RVS placement shortened the pQRSd and improved clinical outcomes. However, the determinants of these were pQRSd and diastolic dysfunction. Therefore, clinicians should try to shorten the pQRSd when implanting a PPM, and patients with diastolic dysfunction should be monitored intensively.

The short term influence of right ventricular pacing burden on echocardiographic and spiroergometric parameters in patients with preserved left ventricular ejection fraction

Background

The incidence of worsened clinical outcome due to high right ventricular (RV) pacing burden in patients with preserved left ventricular function remains controversial.

Objective

To investigate the impact of RV pacing on several echocardiographic and spiroergometric parameters.

Methods

In 60 pacemaker patients with preserved left ventricular ejection fraction (LVEF) serial echocardiographies and spiroergometries were performed over a time course of 12 months. Additionally, in 48 patients retrospective echocardiographic analyses of the LV- and RV function were carried out up to 24 months after pacemaker implantation.

Results

The patients were divided into two groups: The high RV pacing burden group (hRVP: ≥ 40%) and the low RV pacing group (lRVP < 40%) according to the definitions in previous randomized MOST and DAVID trials. After a period of 12-month pacemaker therapy no changes to left ventricular end diastolic diameter (LVEDD), left ventricular end systolic diameter (LVESD), LVEF, E/A-ratio; E/E′-ratio and tricuspid annular plane systolic excursion (TAPSE) could be revealed, independently of the RV pacing burden. Additionally, after 24-month long term follow-up there were no differences in LVEF and TAPSE in both groups. Accordingly, no relevant changes of peak exercise capacity, ventilatory anaerobic threshold or maximal oxygen consumption could be demonstrated independently of the RV pacing.

Conclusions

In pacemaker patients with preserved LVEF the burden of RV pacing has no adverse influence on several echocardiographic and spiroergometric surrogate parameters of pacemaker-induced cardiomyopathy after a follow-up of 12 to 24 month. Despite this, screening for pacemaker induced cardiomyopathy should be performed especially in the presence of new heart failure symptoms.

Risk factors for developing pacing induced LV dysfunction: Experience from a tertiary centre in the UK

INTRODUCTION

The risk factors for developing pacing induced Left Ventricular dysfunction (LVD) in patients with high burden of right ventricular pacing (RVP) is poorly understood. Therefore, in the present study, we aimed to assess the determinants of pacing induced LVD.

METHODS

Our data were retrospectively collected from 146 patients with RVP > 40% who underwent generator change (GC) or cardiac resynchronisation therapy (CRT) upgrade between 2016-2019 who had left ventricular ejection fraction (EF) ≥50% at initial implant.

RESULTS

75 patients had CRT upgrade due to pacing induced LVD (EF<50%) and 71 patients with preserved LV function (EF ≥50%) had a GC. Primary indication for pacing in both groups was complete heart block. Male predominance (p = 0.008), prior myocardial infarction (MI) (p = 0.001), atrial fibrillation (AF) (p = 0.009), chronic kidney disease (CKD) (p = 0.005), and borderline low systolic function (BLSF) (EF 50-55%) (p = 0.04) were more prevalent in the CRT upgrade group. Presence of AF (OR = 3.05, 95% CI 1.42-6.58; p = 0.004), BLSF (OR = 3.8, 95% CI 1.22-11.8; p = 0.02) and male gender (OR = 2.41, 95% CI 1.14-5.08; p = 0.02) were independent predictors for RVP induced LVD. Age (OR = 1.08, 95% CI 1.02-1.14; p = 0.005) and BLSF (OR = 5.33, 95% CI 1.26-22.5; p = 0.023) were independent predictors of earlier development of LVD after implant.

CONCLUSIONS

Our results suggested that AF, BLSF and male gender are predictors for development of pacing induced LVD in patients with high RVP burden. LVD can occur at any time after pacemaker implant with BLSF and increasing age associated with earlier development of LVD. This article is protected by copyright. All rights reserved.

Pacing-Induced Cardiomyopathy

Right ventricular (RV) pacing-induced cardiomyopathy (PICM) is typically defined as left ventricular systolic dysfunction resulting from electrical and mechanical dyssynchrony caused by RV pacing. RV PICM is common, occurring in 10-20% of individuals exposed to frequent RV pacing. Multiple risk factors for PICM have been identified, including male sex, wider native and paced QRS durations, and higher RV pacing percentage, but the ability to predict which individuals will develop PICM remains modest. Biventricular and conduction system pacing, which better preserve electrical and mechanical synchrony, typically prevent the development of PICM and reverse left ventricular systolic dysfunction after PICM has occurred.

His-Purkinje conduction system pacing: A systematic review and network meta-analysis in bradycardia and conduction disorders

BACKGROUND

His-Purkinje conduction system pacing (HPCSP) has emerged as an effective alternative to overcome the limitations of right ventricular pacing (RVP) via physiological left ventricular activation, but there remains a paucity of comparative information for His bundle pacing (HBP) and left bundle branch pacing (LBBP).

METHODS

A Bayesian random-effects network analysis was conducted to compare the relative effects of HBP, LBBP, and RVP in patients with bradycardia and conduction disorders. PubMed, Embase, Cochrane Library, and Web of Science were systematically searched from database inception until September 21, 2021.

RESULTS

Twenty-eight studies involving 4160 patients were included in this meta-analysis. LBBP significantly improved success rate, pacing threshold, pacing impedance, and R-wave amplitude compared with HBP. LBBP also demonstrated a nonsignificant trend towards superior outcomes of lead complications, heart failure hospitalization, atrial fibrillation, and all-cause death. However, HBP was associated with significantly shorter paced QRS duration relative to LBBP. Despite higher success rates, shorter procedure/fluoroscopy duration, and fewer lead complications, patients receiving RVP were more likely to experience reduced left ventricular ejection fraction, longer paced QRS duration, and higher rates of heart failure hospitalization than those receiving HPCSP. No statistical differences were observed in the remaining outcome measures.

CONCLUSIONS

This network meta-analysis demonstrates the efficacy and safety of HPCSP for the treatment of bradycardia and conduction disorders, with differences in pacing parameters, electrophysiology characteristics, and clinical outcomes between HBP and LBBP. Larger-scale, long-term comparative studies are warranted for further verification.

Do the predictors of right ventricular pacing-induced cardiomyopathy add up?

Objective

Knowledge of factors causing pacing-induced cardiomyopathy (PICM) is incomplete. We sought to estimate the incidence and predisposing factors for PICM and evaluate if the risk they portend adds up.

Methods

Single centre retrospective study where consecutive patients with preserved LVEF undergoing pacemaker (PM) implantation between 2012 and 2018 were analysed.

Results

A total of 749 patients (68.4 % male; mean age 59.2 ± 14.08 years) were included in the analysis. PICM developed in 74 (9.9%) patients over a median follow up of 2.2 years (IQR 1.1–3.2). Pre-implant LVEF, paced QRS duration and RV pacing burden were independent predictors of PICM. Using 90 % specificity cut-off values for LVEF and paced QRS, and the value separating lowest tertile of RV pacing from the higher tertiles, three risk factors were identified: (i) baseline LVEF < 55 %, (ii) paced QRS duration > 160 msec, and (iii) RV pacing burden > 33 %. Patients with two or more risk factors were at the highest risk (OR 11.62, 95 % CI 4.62–29.21, p-value < 0.001) for developing PICM while those with one risk factor had an intermediate risk (OR 3.89, 95 % CI 1.62–9.34, p-value 0.002) when compared to those without any risk factors.

Conclusion

Low-normal baseline LVEF, wider paced QRS and higher RV pacing burden independently predicted the development of PICM. The presence of ≥2 factors increased the odds of PICM, twelve-fold. A narrower paced QRS, the only modifiable risk factor may help mitigate development of PICM.

Comparison of efficacy and safety of His-Purkinje system pacing versus cardiac resynchronisation therapy in patients with pacing-induced cardiomyopathy: protocol for a randomised controlled trial

INTRODUCTION

Recent studies have shown that the His-Purkinje system pacing (HPSP) can achieve electrocardiomechanical synchronisation, and thus improve cardiac function. For patients with pacing-induced cardiomyopathy (PICM) who should be treated with pacemaker upgrade, the HPSP is a viable alternative to cardiac resynchronisation therapy (CRT). However, no randomised controlled trial has been performed to evaluate the efficacy and safety of HPSP in patients with PICM. The present study compared the efficacy and safety of HPSP with that of traditional CRT in the treatment of patients with PICM.

METHODS AND ANALYSIS

This study is a single-centre, randomised controlled non-inferiority trial. This trial was carried out at the cardiac centre of Beijing Anzhen Hospital. A total of 46 patients with PICM who needed pacemaker upgrade treatment between January 2022 and December 2023 will be enrolled in this study. Patients will be randomised into an investigational group (HPSP) and a control group (CRT) at a 1:1 ratio. The primary outcome is the duration of QRS complex (QRS width), and the secondary outcomes are NT-proBNP (N terminal pro B type natriuretic peptide), C reactive protein, the number of antibiotics used, left ventricular ejection fraction, end systolic volume, end diastolic volume, the hospitalisation duration, the incidence of postoperative infection, pacemaker parameters (threshold, sensing and impedance), the 6-minute walking test, and quality of life (36-Item Short Form Survey scale), all-cause mortality, cardiovascular death, heart failure-related rehospitalisation rate, other rehospitalisation rates, major complication rates and procedure costs.

ETHICS AND DISSEMINATION

This study has been approved by the Beijing Anzhen Hospital Medical Ethics Committee (No. 2020043X).

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry (ChiCTR2000034265).

Left ventricular systolic function between left bundle branch pacing and right ventricular septum pacing in patients with pacemaker dependence by three-dimensional speckle tracking imaging

OBJECTIVES

To compare the left ventricular systolic function between the 1eft bundle branch pacing (LBBP) and right ventricular septum pacing (RVSP) in patients with pacemaker dependence by three-dimensional speckle tracking imaging (3D-STI).

METHODS

A total of 65 patients with atrioventricular block (AVB) (Mobitz type II second-degree AVB, high-degree AVB, or third-degree AVB), who underwent permanent cardiac pacing implantation including 32 patients receiving LBBP (LBBP group) and 33 patients receiving RVSP (RVSP group) from June 2018 to June 2019,were enrolled in this study. These patients met the following inclusion criterion: pre-operative left ventricular ejection fraction (LVEF)>50% and ventricular pacing rate>40% at 6-month programming follow-up; and the patients underwent echocardiography at pre-operation and 6 months after operation. The 3D-STI was used to obtain global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS), and global area strain (GAS).

RESULTS

All the patients in the LBBP group and the RVSP group had normal LVEF, there was no significant difference between the 2 group (P>0.05). The LVEF was slightly decreased at 6-month follow-up in the RVSP group, but there was no significant change compared with pre-operation (P>0.05). There were no significant difference in LVEF, GLS, GCS, GRS and GAS at pre-operation and 6-month after operation between the LBBP group and the RVSP group (all P>0.05). Compared with pre-operation, the GLS and GCS were significantly decreased in the LBBP group; while the GLS, GCS, GRS and GAS in the RVSP group were also significantly decreased at 6-month follow-up (all P<0.05).

CONCLUSIONS

For patients with pacemaker dependence and normal LVEF at pre-operation, the cardiac function in the LBBP group is not significantly better than that in the RVSP group in short term follow-up. But in terms of physiologic pacing and long-term cardiac function protection, the 1eft bundle branch pacing is an optimal pacing mode.

Prevalence and predictors of pacing-induced cardiomyopathy in young adult patients (<60 years) with pacemakers

INTRODUCTION

Clinical trials and observational studies of pacing-induced cardiomyopathy (PICM) have largely included elderly patients with mean age >70 years. The prevalence and predictors of PICM in younger patients (age < 60 years) after pacemaker implantation are not known.

METHODS

Adults (18-59 years) who received single-chamber ventricular or dual-chamber pacemakers at Vanderbilt University Medical Center from 1986 to 2015 were included. Patients without documented ventricular pacing burden and patients with baseline left ventricular ejection fraction (LVEF) <35% were excluded. PICM was defined as LVEF decrease of ≥ 10% and LVEF < 50% during follow-up with right ventricular pacing ≥20%, and without alternative explanations for cardiomyopathy.

RESULTS

A total of 325 patients were included in the study. During a median follow-up duration of 11.5 (Interquartile range 7-17) years, 38 patients (11.7%) developed PICM (1.3 per 100 patient-year). Older age (HR 2.5 for age ≥50 years, p = .013), reduced baseline LVEF (HR 2.4, p = .022), and preimplant AVB (HR 2.7, p = .007) were associated with an increased risk of PICM in the multivariate analysis. Furthermore, baseline AF conferred an increased risk of PICM only in patients without preimplant AVB but not patients with pre-implant AVB.

CONCLUSIONS

The incidence of PICM in young patients was low, but PICM could occur more than a decade after pacemaker implantation. Older age, baseline reduced LVEF, and preimplant AVB were associated with an increased risk of PICM in the young patient cohort.

Is the right ventricular function affected by permanent pacemaker?

AIMS

The effect of right ventricular (RV) pacing on left ventricular (LV) function has been extensively evaluated, but the effect on RV function per se has not been evaluated systematically. We aimed to assess the effect of dual chamber pacemaker on RV function.

METHODS AND RESULTS

All consecutive patients undergoing dual chamber pacemaker from January 2018 to March 2019 for AV block with a structurally normal heart were included. They underwent pre-procedure detailed echocardiography (including three-dimensional [3D] RV ejection fraction [RVEF]), a screening echocardiogram 2 days after pacemaker implantation and again a detailed echocardiogram at 6-month follow-up. We compared the baseline echocardiographic RV parameters with those 6 months after the pacemaker implantation. A total of 60 patients underwent successful pacemaker implantation. At 6 months, most of the patients were pacemaker dependent with pacing percentage of 98.9% ± 2.4%; there was a significant increase in TR and a mean drop in RVEF by 2.8 ± 5%, with 23 (38.3%) having at least a 5% decrease in RVEF. The drop in RVEF positively correlated with TR vena contracta at 6 months but did not correlate with pulmonary artery systolic pressure at 6 months.

CONCLUSION

Our study shows the presence of demonstrable RV dysfunction as early as 6 months in a majority of patients who have undergone pacemaker implantation.

Progressive QRS Duration and Ventricular Dysfunction in Pediatric Patients with Chronic Ventricular Pacing

Pacemakers are a mainstay of therapy for patients with congenital and acquired heart block, but ventricular pacing is related to ventricular dysfunction. We sought to evaluate patient and device characteristics associated with ventricular dysfunction in pediatric patients with chronic ventricular pacing. This was a retrospective cohort of pediatric patients with heart block and chronic ventricular pacing. Patient, ECG, and device characteristics were analyzed to determine factors associated with ventricular dysfunction. Longitudinal ECG and echocardiogram parameters were obtained to track changes in QRS and systemic ventricular systolic function over time. In total, 82 patients were included (median age at implant 0.81 years). Over a follow-up time of 6.1 years, 18% developed ventricular dysfunction. Patients with dysfunction had greater current QRS duration (p = 0.002) compared to those with preserved function with a similar time from device implantation. There was no difference between lead location or age at device implantation. QRS duration increased with time from implant and the resultant ΔQRS was associated with ventricular dysfunction (p = 0.01). QRS duration >162 ms was associated with a 5.8 (2-9)-fold increased risk for dysfunction. Transvenous leads were associated with longer QRS duration with no difference compared to epicardial leads in development of ventricular dysfunction. This study demonstrated that the absolute paced QRS duration and Δpaced QRS were association with long-term ventricular dysfunction independent of how long a given patient was paced. Patients in high-risk categories may benefit from close echocardiographic monitoring. Whether permissive junctional rhythm or His bundle/biventricular pacing decreases the rate of dysfunction needs further study.

Central Sleep Apnea and Pacing-Induced Cardiomyopathy

The role of central sleep apnea (CSA) in pacing-induced cardiomyopathy (PICM) remains speculative. In a prospective trial entitled UPGRADE, the presence of CSA was assessed by single-night polysomnography (PSG) in 54 PICM patients within 1 month after left ventricular lead implantation (with biventricular stimulation still not activated). CSA was diagnosed in half of patients (n = 27). Patients with moderate or severe CSA were randomized to cardiac resynchronization therapy (CRT) versus right ventricular pacing (RVP) in a double-blinded cross-over design and re-scheduled for a follow-up PSG within 3 to 5 months. After crossing-over of stimulation mode another PSG was conducted 3 to 5 months later. CRT led to a significant increase in left ventricular ejection fraction and significant reduction in left ventricular end systolic volumes and N-terminal pro brain natriuretic peptide plasma levels, whereas no significant effects were observed with ongoing RVP. CSA was significantly improved after 3.9 (3.2 to 4.4) months of CRT: apnea-hypopnea index decreased from 39.1 (32.1 to 54.0) events per hour at baseline to 22.2/h (10.9 to 36.7) by CRT (p <0.001). Central apnea index decreased from 27.1/h (17.7 to 36.1) at baseline to 6.8/h (1.1 to 14.4) after CRT activation (p <0.001). Ongoing RVP yielded only a minor improvement in apnea-hypopnea index and central apnea index. Pre-existent CSA did not affect structural response rate and had no impact on mid-term follow-up (median 2.8 years). In conclusion, CSA is highly prevalent in patients with PICM. CRT upgrading significantly improves CSA leading to a similar outcome in PICM patients without pre-existent CSA.

Pre-implant global longitudinal strain as an early sign of pacing-induced cardiomyopathy in patients with complete atrioventricular block

Introduction

Long‐term right ventricular pacing is the only treatment for patients with a complete atrioventricular block (CAVB); however, it frequently triggers ventricular dys‐synchrony with left ventricular (LV) dysfunction. Previous studies showed that an early decline of LV global longitudinal strain (GLS) predicts pacing‐induced LV dysfunction. We aimed to investigate the potential ability of the initial LV strain to predict pacing‐induced cardiomyopathy (PICM) through long‐term follow‐ups.

Methods

We retrospectively enrolled 80 patients with CAVB with normal LV function who were implanted with dual‐chamber pacemakers between 2008 and 2018. Echocardiographic data and parameters (including longitudinal, radial, and circumferential strain based on speckle‐tracking) were analyzed for the pre‐implant (≤6 months) and post‐implant periods. PICM was defined as a ≥10% reduction in the left ventricular ejection fraction (LVEF) resulting in an LVEF of <50% during the post‐implant period. Predictors of PICM were identified using Cox proportional hazard models.

Results

Patients who developed PICM were more likely to exhibit lower baseline LV GLS, as well as wider native and pacing QRS durations, than those who did not develop PICM (P = .016, P = .011, and P = .026, respectively). In the multivariate analysis, pre‐implant LV GLS (hazard ratio: 1.27; 95% confidence interval 1.009–1.492; P = .004) was independently associated with the development of PICM.

Conclusion

A lower baseline LV GLS predicts an increased risk of PICM. Patients with CAVB exhibiting low GLS are at increased risk of PICM. More frequent follow‐up visits are warranted in these patients, who may also require de novo His‐bundle pacing or an upgrade to biventricular pacing.

Comparison of cardiac function between left bundle branch pacing and right ventricular outflow tract septal pacing in the short-term: A registered controlled clinical trial

BACKGROUND

The novel method of left bundle branch pacing (LBBP) has been reported to produce a narrower QRS duration and lower pacing threshold than right ventricular outflow tract septal pacing (RVOP). However, whether LBBP is superior to traditional RVOP in improving cardiac function still lacks sufficient evidence.

OBJECTIVE

The purpose of this study was to compare the changes in cardiac function (especially in brain natriuretic peptide (BNP)levels, left atrial function, and left ventricular diastolic function) within 7 days between LBBP and RVOP.

METHODS AND RESULTS

A single-centre prospective controlled registered clinical study was conducted with 84 patients with bradycardia indications. Forty-two patients underwent RVOP, and 42 patients underwent LBBP. The pacemaker parameters were adjusted so that the ventricular ratio was over 90% and rate was 60-70 bpm. The changes in BNP levels and echocardiogram and speckle-tracking echocardiagraphy findings were compared between the two groups before and within 7 days after implantation: (1) BNP: there was no significant difference in BNP level between the two groups before and 1 day after implantation, while the LBBP group had significantly lower levels than the RVOP group on day 7 [(65.15 ± 56.96)pg/ml vs.(129.82 ± 101.92)pg/ml, P < 0.001]. (2) Cardiac echocardiography: the e' value of the LBBP group was higher than that of the RVOP group 7 days after implantation[(6.39 ± 2.65) cm/s vs. (5.45 ± 1.35)cm/s, P = 0.049]. The E/e' and peak E-wave velocity in the LBBP group decreased significantly after 7 days [16.57 ± 6.55 vs. 12.75 ± 5.16 P = 0.043, (88.6 ± 24.37)cm/s vs. (75.68 ± 28.10)cm/s P = 0.030]; in contrast, there were no significant changes in the RVOP group [14.13 ± 3.85 vs.14.10 ± 4.85 P = 0.50, (77.33 ± 21.14)cm/s vs. (74.45 ± 23.03)cm/s P = 0.56). (3)Speckle-tracking echocardiagraphy: there was no significant difference in left atrial strain or the strain rate between the LBBP and RVOP groups，but the absolute values of left atrial strain and strain rate in the LBBP group increased, while those in the RVOP group decreased.

CONCLUSION

This study demonstrates that compared to RVOP, LBBP can increase left ventricular early diastolic function, improve BNP levels, and has a tendency to increase left atrial myocardial elasticity and left atrial strain capacity in the short term in pacemaker-dependent patients.