Pacing-induced Cardiomyopathy Research Articles

Right ventriculography to guide left bundle branch pacing in pacing-induced cardiomyopathy: a novel case report

Abstract Background There is emerging evidence for the potential utility of left bundle branch area pacing (LBBAP), as an alternative to conventional cardiac resynchronization therapy (CRT). The utility of right ventriculography by way of power injector to facilitate lead placement is not yet reported in literature. Case summary A 79-year-old female, with a background of poorly rate-controlled atrial fibrillation, presented with worsening dyspnoea. She had recently undergone single chamber pacemaker insertion prior to an atrio-ventricular nodal (AVN) ablation, owing to failure in achieving successful CRT coronary sinus lead placement. She had clinical evidence of volume overload and her electrocardiogram demonstrated right-ventricular pacing. Echocardiography demonstrated left ventricular (LV) impairment, with an ejection fraction (EF) of 35%, and severe functional mitral regurgitation (MR). Her diagnosis was overall consistent with pacing-induced cardiomyopathy. In this case, the use of right ventriculography, using power-injector delivered contrast, successfully facilitated placement of a left bundle branch area pacing lead, with confirmation of good threshold and sensing parameters. Following upgrade to conduction system pacing, the patient recovered well. On recent follow up, repeat echocardiography (24 months post initial presentation) demonstrated improved LV function (EF 45% from 35%) and only mild-moderate MR. Discussion In conclusion, we demonstrate the utility of right ventriculography to facilitate placement of a left bundle branch area pacing lead, successfully treating a patient who developed pacing-induced cardiomyopathy from chronic RV pacing following AVN ablation.

Left ventricular volumes and function in successful and failed His-BundLe Pacing. A comparative prospective study.

Initial data suggest that His Bundle Pacing (HBP) could preserve long-term cardiac structure and function better than Right Ventricular Pacing (RVP), but evidence is limited. We studied consecutive patients with baseline ejection fraction (EF) ≥ 50% who underwent HBP attempt, either successful (HBP group) or failed (RVP group). Two-dimensional (2D) and three-dimensional (3D) echocardiography were carried out at baseline and after 6 months of ventricular pacing burden > 20%. Among 68 patients, 40 underwent successful HBP, and 28 RVP. The HBP and RVP groups did not differ for age, sex and pacing indication. At baseline, the HBP and RVP groups did not differ for 2D EF (62% vs. 62%), 3D EF (60% vs. 63%), 2D (-19% vs. -19%) and 3D global longitudinal strain (GLS) (-15% vs. -16%). After 6 months, 2D EF (-3.86%) and 3D EF (-5.71%) significantly decreased in the RVP group and did not change in the HBP group (p for interaction .006 and <.001, respectively). 2D GLS (3.08%) and 3D GLS (2.22%) significantly increased in the RVP group, but did not change in the HBP group (p for interaction .013 and <.016, respectively). Pacing induced cardiomyopathy (PICM) (EF drop ≥ 10% and EF < 50%) occurred in 14% (RVP) versus 0% (HBP) of patients (p = .025). Successful HBP was superior to RVP in preserving LV systolic function despite a high ventricular pacing burden, and was less frequently associated with PICM.

Feasibility, safety and outcomes of conduction system pacing for bradycardia amongst the very elderly

The impact of age (≥ 85 vs < 85 years) on clinical outcomes and pacemaker performance of conduction system pacing (CSP) compared to right ventricular pacing (RVP) were examined. Consecutive patients from a prospective, observational, multicenter study with pacemakers implanted for bradycardia were studied. The primary endpoint was a composite of heart failure (HF)-hospitalizations, pacing-induced cardiomyopathy requiring cardiac resynchronization therapy or all-cause mortality. Secondary endpoints were acutely successful CSP, absence of pacing-complications, optimal pacemaker performance defined as pacing thresholds < 2.5 V, R-wave amplitude ≥ 5 V and absence of complications, threshold stability (no increases of > 1 V) and persistence of His-Purkinje capture on follow-up. Among 984 patients (age 74.1 ± 11.2 years, 41% CSP, 16% ≥ 85 years), CSP was independently associated with reduced hazard of the primary endpoint compared to RVP, regardless of age-group (< 85 years: adjusted hazard ratio [AHR] 0.63, 95% confidence interval [CI] 0.40–0.98; ≥ 85 years: AHR 0.40, 95% CI 0.17–0.94). Among patients with CSP, age did not significantly impact the secondary endpoints of acute CSP success (86% vs 88%), pacing complications (19% vs 11%), optimal pacemaker performance (64% vs 69%), threshold stability (96% vs 96%) and persistent His-Purkinje capture (86% vs 91%) on follow-up (all p > 0.05). CSP improves clinical outcomes in all age-groups, without compromising procedural safety or pacemaker performance in the very elderly.

Conduction system pacing upgrade versus biventricular pacing on pacemaker-induced cardiomyopathy: a retrospective observational study.

Objective: The feasibility of the conduction system pacing (CSP) upgrade as an alternative modality to the traditional biventricular pacing (BiVP) upgrade in patients with pacemaker-induced cardiomyopathy (PICM) remains uncertain. This study sought to compare two modalities of CSP (His bundle pacing (HBP) and left bundle branch pacing (LBBP)) with BiVP and no upgrades in patients with pacing-induced cardiomyopathy. Methods: This retrospective analysis comprised consecutive patients who underwent either BiVP or CSP upgrade for PICM at the cardiac department from 2017 to 2021. Patients with a follow-up period exceeding 12months were considered for the final analysis. Results: The final group of patients who underwent upgrades included 48 individuals: 11 with BiVP upgrades, 24 with HBP upgrades, and 13 with LBBP upgrades. Compared to the baseline data, there were significant improvements in cardiac performance at the last follow-up. After the upgrade, the QRS duration (127.81 ± 31.89 vs 177.08 ± 34.35ms, p < 0.001), NYHA class (2.28 ± 0.70 vs 3.04 ± 0.54, p < 0.05), left ventricular end-diastolic diameter (LVEDD) (54.08 ± 4.80 vs 57.50 ± 4.85mm, p < 0.05), and left ventricular ejection fraction (LVEF) (44.46% ± 6.39% vs 33.15% ± 5.25%, p < 0.001) were improved. There was a noticeable improvement in LVEF in the CSP group (32.15% ± 3.22% vs 44.95% ± 3.99% (p < 0.001)) and the BiVP group (33.90% ± 3.09% vs 40.83% ± 2.99% (p < 0.001)). The changes in QRS duration were more evident in CSP than in BiVP (56.65 ± 11.71 vs 34.67 ± 13.32, p < 0.001). Similarly, the changes in LVEF (12.8 ± 3.66 vs 6.93 ± 3.04, p < 0.001) and LVEDD (5.80 ± 1.71 vs 3.16 ± 1.35, p < 0.001) were greater in CSP than in BiVP. The changes in LVEDD (p = 0.549) and LVEF (p = 0.570) were similar in the LBBP and HBP groups. The threshold in LBBP was also lower than that in HBP (1.01 ± 0.43 vs 1.33 ± 0.32V, p = 0.019). Conclusion: The improvement of clinical outcomes in CSP was more significant than in BiVP. CSP may be an alternative therapy to CRT for patients with PICM. LBBP would be a better choice than HBP due to its lower thresholds.

Heart rate is an important predictor of pacing induced cardiomyopathy in a machine learning analysis

Abstract Background 10-20% of patients who have right ventricular pacing develop pacing induced cardiomyopathy (PICM). Home monitoring (HM) could identify patients developing PICM in real-time and facilitate echocardiographic confirmation, medication optimisation and if necessary cardiac resynchronisation therapy (CRT). Purpose To identify predictors of PICM using machine learning models. Methods Consecutive cases of patients who developed PICM (12) after dual chamber pacing were identified from our implant database and matched 4:1 with propensity matched controls who underwent pacing but did not develop PICM (48) (Table 1.) HM data from the 6 months prior to echocardiographic diagnosis of PICM was analysed. PICM was defined as (1) a deterioration in left ventricular (LV) ejection fraction (EF) of &amp;gt;10%, (2) to an EF of &amp;lt;45%, (3) with right ventricular (RV) pacing &amp;gt;20% and (4) the exclusion of alternative causes. Three types of ML models were generated (1) random forest, (2) extreme gradient boosted (XGBoost) (3) K-nearest neighbours algorithm (KNN), with 10-fold cross-validation. Results HM data were available for 12 PICM cases (75 ± 8 years, 72% male). PICM occurred at 2.0 ± 1.2 years. There was no difference between cases and controls in atrial pacing (8±15% vs 18±22% p=0.14), ventricular pacing (81±29% vs 85±24% p=0.62) or base rate (53±5bpm vs 53±5bpm p=0.80). Of the 34 RM features analysed, mean ventricular heart rate was identified as the most important predictor of PICM; area under curve with XG Boost 0.95, KNN 0.95, and random forest 0.86. Other RM features failed to add any more predictive power to the models. Mean ventricular rate was significantly higher in cases than controls (80±6 bpm vs 69±9 bpm p&amp;lt;0.001). Sensitivity analysis was performed to assess whether episodes of atrial fibrillation (AF) were responsible for the higher ventricular rates. After days of AF days were excluded, mean ventricular rate was still significantly higher in cases than controls (79± 6vs 69±9bpm p&amp;lt;0.001) (Figure 1). 10/12 patients had a subsequent CRT upgrade. No consistent pattern emerged in heart rate changes in the first 3 months after CRT upgrade. Conclusion In a group of patients with normal left ventricular function at implant, remotely monitored heart rate can predict early-onset PICM. Further work is required to understand when these heart rate differences emerge, and whether they improve with positive LV remodelling.Table 1.Figure 1.

Deep septal pacing for pacemaker-induced cardiomyopathy

Abstract Background Conventional right ventricular pacing can impair left ventricular function and cause heart failure, known as pacing induced cardiomyopathy (PICM). Upgrade to cardiac resynchronization therapy (CRT) is the most common treatment for PICM. Recently, left bundle branch area pacing (LBBAP) has emerged as a potential alternative both to conventional RV pacing and to CRT. In Deep septal pacing (DSP), a simplified alternative to LBBAP, the lead is inserted deep in the septum, does not reach the subendocardial area, but is still able to achieve narrower paced QRS than during conventional pacing. Purpose The aim of this study was to assess the effect of DSP in a cohort of patients with PICM. Methods We included consecutive patients diagnosed with PICM who were referred to our unit between January 2020 and January 2022 for a device upgrade. The aim was to upgrade patients to DSP. In the absence of terminal R wave in V1, the procedure was considered successful if a paced QRS duration ≤140 ms was obtained. Clinical and device follow-up were performed one and 6 months after the procedure, and echocardiography at 6 months. The study was approved by the Clinical Research Ethics Committee and all patients signed informed consent. Results Fifteen patients were recruited during the study period. One patient was excluded because a QRS ≤ 140 ms could not be achieved, and 2 other patients because a terminal R wave in paced QRS in V1 was obtained. The characteristics of the 12 included cases are detailed in Table 1. The mean LVEF was 33% (SD 4%) and the mean percentage of RV pacing was 99% (SD 1%). All patients had symptomatic heart failure. Non stylet-driven electrodes were used in 8 of the 12 patients. Acute threshold was &amp;lt; 1V - 0’4 ms in all, and remained stable during follow-up. No procedure-related complications or lead dislodgements were detected. The mean paced QRS duration with RV pacing was 172 ms (SD 14 ms) whereas after the upgrade it was 130 ms (SD 7 ms). As compared to RV pacing, DSP was associated with a significant reduction in paced QRS duration (mean difference 41 ms, p&amp;lt;0.001). As shown in Table 1, after DSP all patients except one (11/12, 92%) experienced an increase in LVEF of at least 10%; five patients (42%) achieved an LVEF&amp;gt;50%. The mean LVEF after the upgrade was 46% (SD 9%). The mean improvement in LVEF with DSP was 13% (SD 10%). Conclusions In patients with PICM, deep septal pacing achieves narrower QRS as compared to RV pacing and is associated with a significant improvement in LVEF. Deep septal pacing might be an effective and simpler alternative to biventricular or left bundle branch pacing in patients with PICM.Table 1

Serial GLS assessments over time in patients with preserved ejection fraction undergoing permanent cardiac pacemaker placement

Abstract Background Chronic right-ventricular (RV) pacing can exacerbate 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 our University Hospital, South Korea, included de novo patients with preserved EF undergoing transvenous permanent pacemaker (PPM) implantation for atrioventricular blockage from 2018 to 2022. Patients with EF &amp;gt; 50% and expected ventricular pacing &amp;gt; 40% were included. All patients were followed with serial echocardiography (preimplant, post implant, 12 months). All patients enrolled in this study were seen as outpatients every 3–6 months. Composite outcomes were cardiac death (pump failure), hospitalization because of heart failure, PICM, and biventricular pacing (BVP) upgrade. Results 71 patients (28 men, 73.1 ± 9.5 years) were included. After PPM implantation, EF and GLS were significantly decreased. During three years of follow-up, 2 patient died, 6 were hospitalized, 7 suffered PICM, and 3 underwent BVP upgrade. Cox regression analysis identified reduced post-implant global longitudinal strain (GLS) (HR, 1.524; 95% CI, 1.149–2.021; P = 0.003) as independent predictors of PICM. Post-implant GLS showed high predictive accuracy for PICM, with an area under the curve of 0.92 (95% CI 0.829–0.971; P &amp;lt; 0.001) Conclusion Post-implant GLS, rather than pre-implant GLS could help identify individuals at high risk of PICM. After PPM implantation, it is important to measure GLS, and patients with reduced GLS should be monitored more frequently and echocardiographic surveillance, with a view to an upgrade to BVP.Serial EF and GLS assessmentGLS ROC curve

Severe lead induced tricuspid regurgitation - clinical impact of repair or replacement of tricuspid valve

Abstract The prevalence of lead-induced tricuspid regurgitation (LITR) ranges between 7 to 45%. The most frequent mechanism of LITR is the impingement of the leaflets, but right ventricle remodelling, pacing-induced cardiomyopathy and tricuspid annular dilatation also can contribute to the severity of tricuspid regurgitation (TR). Different studies concluded that LITR was associated with an increased risk of all-cause mortality and heart failure hospitalizations. Beyond diuretics, patients (P) may be candidates for interventional treatment, including lead extraction, surgery, or percutaneous tricuspid trans-catheter ‘edge-to-edge’ repair (TEER) and heterotopic bicaval devices (HBD). Despite its importance, there is a scarcity of data concerning the management and clinical impact of severe LITR. The purpose of the current analysis is to improve the knowledge regarding the impact of interventional treatment on the outcomes in this population. Methods A retrospective, single-centre analysis was made including P with severe LITR referred to evaluation regarding eligibility for tricuspid percutaneous intervention in a tertiary hospital. All P were evaluated using both transthoracic echocardiography (TTE) and transoesophageal echocardiography (TEE). Data were collected regarding clinical characterization, management, intervention and follow-up. Results From January 2020 to September 2023, of the 97 P referred for tricuspid intervention eligibility, 36 (37%) had LITR, with 14 cases (39%) presenting lead impingement as the TR mechanism. The majority of P were female (58%), with a median age of 78 [IQR 72-83] years. Median Euroscore II was 6 % [IQR 3-9]), with 51% of the P having a previous heart surgery, and 97% presenting atrial fibrillation. Prior to cardiac electronic device (CIED) implantation, 14% already presented TR. When analysing post-CIED TR, 30% increased 1 grade of TR at 1-year follow-up, and 68% increased 2 grades of TR at 5 years. According to TTE, ventricular desynchrony was present in 30% of the P. After evaluation of TR, 30% underwent intervention (22% percutaneous - TEER or HBD - and 8% surgical). All P remained with the previous electrodes. Mortality was 21.1% in the intervention population and 78.9% on the remaining pts (p=0.027). The type of intervention had no statistically significant differences in outcome. Conclusions In our study, more than 1/3 of the cases referred due to severe TR presented lead impingement as the mechanism underlying TR. As previously reported, the intervened population had better outcomes than the remaining pts.

Left ventricular global longitudinal strain is a long-term predictor of pacemaker-associated cardiomyopathy

Abstract Background Implantation of a permanent pacemaker is an effective treatment for symptomatic bradycardia. However, chronic right ventricular pacing (RVP) may lead to compromised left ventricular (LV) function, atrial fibrillation, heart failure, and increased mortality via pacing induced electrical and mechanical dyssynchrony. A decrease in LV ejection fraction (LVEF) of ≥ 10% with a baseline LVEF &amp;gt; 50% prior to RVP and no alternative explanation for the decline in LVEF is termed pacing-induced cardiomyopathy (PICM). Predictive clinical and imaging-derived measures to identify patients at high risk for pacemaker induced cardiomyopathy (PMIC) are lacking, but essential. Objective The study is a prospective, single center, double-blinded trial evaluating the impact of right ventricular pacing on left ventricular function and clinical outcome. Methods In 105 patients (59 male / 46 female), who underwent a dual-chamber pacemaker implantation at the Charité Campus Virchow Klinikum, RVP burden, LVEF and left ventricular global longitudinal strain (LV-GLS) were obtained. Mean follow-up per patient was 29.6 ±13.9 months. We used a stepwise analytic approach including ROC analysis, univariate testing, binary regression as well as Cox-regression models and Kaplan-Meier analysis to compare low RVP burden (&amp;lt; 30%) and high RVP burden (≥ 30%) cohorts according to change in echocardiographic parameters and clinical outcome (all-cause mortality). Results Mean LVEF was 61 ± 6% and mean LV-GLS was 18 ± 4% at baseline. We identified 7 patients with a LVEF decline in the course of the study. In Pearson’s Chi-squared test, patients with a high RVP burden were more likely to develop LVEF and LV-GLS deterioration (6 patients versus 1 patient for LVEF, p&amp;lt;0.05; 28 versus 16 patients for LV-GLS, p&amp;lt;0.001). In multivariable binary logistic regression, LV-GLS (OR: 1.410, 95% CI: 1.201-1.610, p&amp;lt;0.001) deterioration was significantly associated with a LVEF decline and a high RVP burden ≥ 30% (OR: 1.358, 95% CI: 1.160-1.534, p&amp;lt;0.01). In a log-rank test, time to LVEF decline was significantly shorter in patients with a RVP burden ≥ 30% compared to a RVP burden &amp;lt; 30% (45.2±2.9 versus 55.7±1.0 months, p&amp;lt;0.05). In the Cox-regression analysis, LV-strain decline within 12 months (HR: 7.210, 95% CI: 4.239-9.516, p&amp;lt;0.05) was a significant predictor for a later LVEF decline. In a log-rank test, time to LVEF deterioration was significantly shorter in patients with LV-strain decline within 12 months compared to those without (34.7 ± 4.2 versus 53.7 ± 1.4 months, p&amp;lt;0.001). No significant difference in all-cause mortality between patients with a high RVP burden compared to those with low RVP burden (log-rank test, p=0.2). Conclusion A decline in LV-GLS is a sensitive long-term parameter of subsequent LVEF deterioration in patients with normal preimplant LVEF, who require RVP ≥ 30%. and is associated with a poor clinical outcome.

Which paced QRS duration can be achieved in selective and non-selective His bundle pacing?

Abstract Background The paced QRS duration (pQRS) is associated with the risk of developing a pacing-induced cardiomyopathy. His bundle pacing (HBP), either selective (sHBP) or non-selective (nsHBP) can achieve a rather narrow pQRSd in patients with a narrow intrinsic QRS (iQRS) or right bundle branch block (RBBB). We prospectively analyzed the pQRS in sHBP and nsHBP and correlated it with the iQRS. Patients and Methods All consecutive patients who received an implantation with sHBP or nsHBP were enrolled and received a 12-lead ECG before and after implantation (digital recording, 25 mm/s). Measurements of the pQRS after implantation were performed in unipolar VVI 100 bpm mode to exclude fusion beats. QRS duration was measured in 6fold magnification of the digital ECG (600%) 1) for the iQRS, 2) from the beginning to the end of the QRS in sHBP, 3) from the end of the pacing artifact to the end of the QRS in nsHBP, and 4) from the end of the pseudo-delta wave to the end of the QRS in nsHBP (see Fig.). Results In 388 patients (78±11 years, 38% female, 18% RBBB, 9% left bundle branch block) with an iQRS of 110±28 ms before implantation, sHBP was achieved in 206 patients (53%), nsHBP in 182 (47%). In sHBP, the pQRS was 88±18 ms, in nsHBP 123±18 ms including the pseudo-delta wave, 83±14 ms excluding the pseudo delta-wave. In sHBP, the pQRS was on average 15 ms shorter than the iQRS. In nsHBP, the pQRS was 9 ms longer than the iQRS when the pseudo-delta wave was included, and 31 ms shorter if it was excluded, the latter mostly due to correction of a RBBB by nsHBP. Conclusions In sHBP and nsHBP, very narrow pQRS durations of 80-90 ms can be achieved. The pQRS is frequently shorter than the iQRS, mostly by correction of a RBBB.QRS measurements in sHBP and nsHBP

Feasibility of left bundle branch area defibrillator implantation using three-dimensional delivery systems and traditional high voltage leads

Abstract Background Left bundle branch area (LBBA) pacing is an innovative cardiac pacing technique that provides physiological stimulation, which is useful in patients affected by atrioventricular block (preventing pacing-induced cardiomyopathy), and could be an alternative strategy to traditional cardiac resynchronization therapy. Recently, Huybrechts el al. have reported a proof-of-concept study concerning left bundle branch area defibrillator (LBBAD) implantation, evaluating the feasibility of positioning a standard high-voltage (HV) lead by manually pre-shaped delivery systems to achieve LBBAD. No follow-up data were available because the leads were moved to standard positions after testing. Purpose This study aimed to assess the safety and feasibility of definitively implanting a traditional HV lead, using novel three-dimensional delivery systems, to stimulate the LBBA and the lead performance in 1-month follow-up. Methods This is a single-center, non-randomized, prospective study. The study population consisted of consecutive patients referred for an ICD implantation between September and October 2023. LBBAD was attempted by exploiting three-dimensional delivery systems to reach the target transseptal location. After positioning an active fixation HV lead in the LBBA, acute pacing measurements were collected. Defibrillation testing was performed using either patient-tailored (DeFT Response) or fixed-tilt waveform. Echocardiographic evaluation using speckle tracking was performed after implantation. A short-term follow-up was planned in order to verify the stability of electrical parameters in one month. Results LBBAD was performed in 9 consecutive patients (mean age 69±11 years, 56% male). The mean time to implant the HV lead was 20 minutes. The HV lead was successfully implanted in 100% of patients, reaching LBBA in 6 (67%) patients at the first attempt and in 3 (33%) at the second attempt. LBBA pacing exhibited a mean QRS duration and V6 R-wave peak time of 128±9 ms and 64±12 ms. Acute LBBA pacing threshold, R-wave amplitudes, and pacing/shock impedances were 0.88±0.22 V at 0.5 ms, 8.4±2.8 mV, and 637±210 Ω/ 75±20 Ω. The defibrillation test (78% patient-tailored and 22% fixed-tilt waveform) was successful in 6 (75%) of patients at the first shock (~22J) and in 2 (25%) at the second shock (~33J)(test aborted in 1 patient due to respiratory issues during sedation). The mean peak strain dispersion of 31.7ms confirmed global synchrony during pacing. The electrical measurements remained stable, and no lead-related complications were observed at 1-month follow-up. Conclusion We performed for the first time ever LBBAD definitive implantation. This study proves the feasibility and safety of using three-dimensional delivery tools for LBBAD procedures and shows optimal results at the implant for up to one month. Nevertheless, a larger and long-term evaluation is needed to evaluate the performance of LBBAD implants.

Single-center experience with His bundle lead implantation: success rate, implantation method optimization, and lessons learned in 426 patients

Abstract Background Conduction system pacing (CSP) is increasingly used to avoid the development of pacing-induced cardiomyopathy in patients who require a high amount of ventricular pacing. His bundle pacing (HBP) is considered as ideal to achieve the narrowest paced QRS and optimal synchronization in patients with intrinsic narrow QRS or right bundle branch block but also as difficult at implantation. Purpose We analyzed our experience with HBP in terms of time and effort, pacing and sensing results, success rate, and lessons learned for optimization over a time period of 7 years. Methods All consecutive patients in whom HBP was attempted between 6/2016 and 11/2023 were included in this analysis. Implantations were performed using a pacing system analyzer (PSA) with high-resolution electrograms (EGMs). Data on implantation success [selective or non-selective HBP, left bundle branch area pacing (LBBAP)], sensing and pacing parameters, achievement of His bundle current of injury (coi), duration of implantation and fluoroscopy were collected prospectively. These results were compared for the 1st, 2nd, 3rd and 4th quartile of implantations and reasons for improvement or deterioration were analyzed. Results HBP was attempted in 426 patients (78±11 years, 38% female, 90% AV block, left ventricular ejection fraction 54±10 %, 81 single-, 286 dual-, 46 triple-chamber pacemakers, 2 dual- and 11 triple-chamber ICDs) and was successful in 404 patients (95%): 182 non-selective HBP, 206 selective HBP, and 16 LBBAP. R wave amplitude was 4.5±3.5 mV, pacing threshold 1.1 ± 0.6V/1.0 ms. In 16% of patients, a ventricular back-up lead was implanted. A His bundle coi was achieved in 61% of patients. The implantation duration was 92±43 min, fluoroscopy duration 10±8 min. Success rate increased from 89% in the 1st to 99% in the 4th quartile. Improved implantation success was associated with using a stiff 3D steerable sheath, implantation site at the distal His bundle, and an increased number of screw-in turns until a His bundle coi was visible. Conclusions Establishing an implantation routine with 1) a PSA and high-resolution EGMs, 2) use of a stiff 3D steerable sheath, 3) implantation at the distal His bundle with myocardial capture (non-selective HBP) as a back-up, and 4) an increased number of screw-in turns of the lead tip until a His bundle coi is achieved, HBP implantation can be facilitated and results optimized to a highly acceptable implantation effort and a success rate &amp;gt;95%.

Conduction system pacing preserves both electrical and mechanical interventricular synchrony, a UHF ECG validation study

Abstract Background Interventricular mechanical delay (IVMD) is an established echocardiographic risk factor for pacing-induced cardiomyopathy development. Ultra-high-frequency ECG (UHF-ECG) is a non-invasive tool visualizing the ventricular activation sequence. Purpose To compare UHF-ECG interventricular dyssynchrony with echocardiography and to establish interventricular dyssynchrony related to conductive system pacing (CSP) and right ventricular myocardial pacing (RVP). Methods 53 patients with advanced AV conduction disease, without organic heart disease, and preserved LV systolic function were prospectively included. Thirty-two had RVP, and twenty-one had CSP. CSP included both His bundle pacing (n=5) and left bundle branch area pacing (n=16). UHF-ECG and echocardiography were obtained at the baseline (during spontaneous rhythm) and after 1 year (during pacing). IVMD was manually calculated as a difference between the time from a distinct point of the QRS until the onset of the flow through LV and RV outflow tract using pulsed wave doppler imaging. Analysis was performed by two experienced and blinded cardiologists. Interventricular e-DYS was calculated automatically by a software as a time difference between activation in V8 (LV free wall) and V1 electrode (RV free wall). Results The average age of all included patients was 76 ± 6 years old and patients in both RVP and CSP group had similar clinical characteristics. The values of IVMD and interventricular e-DYS were similar in the whole study population both before the pacemaker implantation (-2 ± 21 ms for IVMD vs. 0 ± 20 ms for interventricular e-DYS; p=0.31) and after one year (14 ± 23 ms for IVMD vs. 14 ± 24 ms for UHF; p = 0.7). There were no significant differences in the baseline IVMD and interventricular e-DYS between those receiving CSP vs. RVP (IVMD -6 ± 22 ms for CSP vs 2 ± 20 ms for RVP, p=0.22) and interventricular e-DYS (e-DYS -5 ± 20 ms for CSP vs. 3 ± 20 ms for RVP, p=0.34). After one year of pacing, the patients with CSP preserved similar levels of both IVMD (mean change -2 ± 5 ms, p=0.74) and interventricular e-DYS V8-V1 (mean change 0 ± 4 ms, p = 0.95) – Figure 1. There was no difference between IVMD and interventricular e-DYS in CSP patients after one year (p=0.92). On the contrary, in the RVP group IVMD increased for 27 ± 5 ms (p &amp;lt;0.0001) and interventricular e-DYS for 24 ± 5 ms (p &amp;lt;0.0001) compared to the baseline - Figure 1. There was no difference between IVMD and interventricular e-DYS in RVP patients after one year (p=0.75). There was a moderate overall correlation between IVMD and e-DYS V8-V1 in all studied ventricular rhythms (R=0.73, p&amp;lt;0.0001) – Figure 2. Conclusions UHF-ECG expresses the interventricular dyssynchrony noninvasively by measuring the activation difference between V8-V1 chest leads. RV myocardial pacing increases interventricular dyssynchrony, while CSP preserves synchronous ventricular activation.CSP vs RVPcorrelation of dyssynchrony

Echocardiographic follow-up after AV node ablation combined with left bundle branch area pacing for patients with symptomatic atrial fibrillation

Abstract Background AV node ablation combined with permanent pacing is an established therapy for rate control in patients with symptomatic atrial fibrillation (AF) refractory or intolerant to pharmacological rate or rhythm control and not eligible for rhythm control by left atrial catheter ablation. The threshold for performing this so-called "pace-and-ablate" strategy has decreased since the introduction of conduction system pacing, and especially left bundle branch area pacing (LBBAP). Purpose To investigate the change of the left-ventricular (LV) ejection fraction (EF) and left-atrial volume index (LAVI) in patients with symptomatic AF, twelve months after LBBAP and AV-node ablation. Methods Consecutive patients with symptomatic AF intolerant or refractory to pharmacological rate and symptom control and deemed not eligible for left atrial catheter ablation were included. At baseline, the EHRA score was noted and the LVEF and LAVI were measured echocardiographically. Patients were subdivided in a normal baseline LV ejection fraction (LVEF &amp;gt;50%) or diminished baseline LVEF (LVEF &amp;lt;50%) group. After LBBAP, patients underwent AV node ablation in the same procedure or four weeks later. After twelve months, the LVEF and LAVI were reassessed in the entire cohort and the two subgroups. Results Twenty-two patients (68% female, mean age 79±4 years) scheduled for pace-and-ablate therapy were prospectively included. Three (14%) had paroxysmal, sixteen patients (72%) had persistent AF and three patients (14%) long-standing persistent AF. An EHRA class IIb or higher was found in eighteen patients (82%). At baseline, the mean LVEF was 51 ± 7%, the mean LVEDD 47 ± 6 mm and LAVI 54 ± 18 ml/m2. Twelve patients (55%) had a preserved LVEF, whereas ten patients (45%) had an LVEF &amp;lt;50%, fig. 1. After twelve months, the overall ejection fraction increased to 54 ± 5% (p=0.016), fig. 2A. This was mostly attributed to the increase in LVEF to 51 ± 5% in the subgroup with a reduced baseline LVEF (p=0.009 compared to baseline 44 ± 5%), fig. 2A. The LVEF was unaffected in the other group (57 ± 3% vs. 57 ± 4%, p=0.63), fig. 2A. The LAVI was not significantly reduced in the overall cohort or the subgroups (54 ± 18 ml/m2 to 51 ± 19 ml/m2, p=0.16), fig 2B. Conclusion AV node ablation combined with LBBAP results in a significant improvement in LVEF at twelve months follow-up. This is mainly driven by an improvement in LVEF in those patients with a diminished LVEF at baseline. The data suggests that the therapy can reverse a tachycardiomyopathy without inducing a pacing-induced cardiomyopathy. No significant reduction in LAVI was found.Baseline characteristicsChanges in LVEF (A) and LAVI (B)

Left bundle branch area versus conventional pacing after transcatheter valve implant for aortic stenosis: the LATVIA study.

Atrioventricular block (AVB) is a frequent complication in patients undergoing transcatheter aortic valve implantation (TAVI). Right apex ventricular pacing (RVP) represents the standard treatment but may induce cardiomyopathy over the long term. Left bundle branch area pacing (LBBAP) is a promising alternative, minimizing the risk of desynchrony. However, available evidence with LBBAP after TAVI is still low. To assess the feasibility and safety of LBBAP for AVB post-TAVI compared with RVP. Consecutive patients developing AVB early after TAVI were enrolled between 1 January 2022 and 31 December 2022 at three high-volume hospitals and received LBBAP or RVP. Data on procedure and at short-term follow-up (at least 3 months) were collected. A total of 38 patients (61% men, mean age 83 ± 6 years) were included; 20 patients (53%) received LBBAP. Procedural success was obtained in all patients according to chosen pacing strategy. Electrical pacing performance at implant and after a mean follow-up of 4.2 ± 2.8 months was clinically equivalent for both pacing modalities. In the LBBAP group, procedural time was longer (70 ± 17 versus 58 ± 15 min in the RVP group, P = 0.02) and paced QRS was shorter (120 ± 19 versus 155 ± 12 ms at implant, P < 0.001; 119 ± 18 versus 157 ± 9 ms at follow-up, P < 0.001). Complication rates did not differ between the two groups. In patients with AVB after TAVI, LBBAP is feasible and safe, resulting in a narrow QRS duration, either acutely and during the follow-up, compared with RVP. Further studies are needed to evaluate if LBBAP reduces pacing-induced cardiomyopathy in this clinical setting.

Optimizing Patient Selection for Physiological Pacing in Bradyarrhythmia: Factors Associated With High Ventricular Pacing Burden.

Right ventricular (RV) pacing is established as the most common ventricular pacing (VP) strategy for patients with symptomatic bradyarrhythmia. Some patients with high VP burden suffer deterioration of left ventricular (LV) function, termed pacing-induced cardiomyopathy (PICM). Patients who pace > 20% of the time from the RV apex are at increased risk of PICM, but independent predictors of increased RV pacing burden have not been elucidated in those who have a permanent pacemaker (PPM) inserted for bradyarrhythmia. We aimed to identify factors that are associated with increased VP burden > 20%, hence determining those at risk for resultant PICM. In this retrospective cohort study, we identified the most recent 300 consecutive cardiac implantable electronic device (CIED) implants in our center and collected past medical history, electrocardiogram (ECG), echo, medication and pacemaker check data. A total of 236 individuals met inclusion criteria. Of the patients, 35% had RV pacing burden < 20%, while 65% had VP burden ≥ 20%; 96.2% of patients with complete heart block (CHB) paced > 20% (P = 0.002). Utilization of DDD or VVI (75.2% and 89.2% of patients, respectively) without mode switch algorithms was associated with VP > 20% (P < 0.001). Male or previous coronary artery bypass grafting (CABG) patients also statistically paced > 20%. Other factors trending towards significance included prolonged PR interval, atrial fibrillation or more advanced age. High-grade atrioventricular (AV) block was associated with an RV pacing burden > 20% over 3 years but this was not consistent in patients with only transient episodes of high-grade AV block. We found a significant association between high VP% and male sex, previous CABG and the absence of mode switching algorithms.

Cardiomyopathy prediction in patients with permanent ventricular pacing using machine learning methods

Pacing-induced cardiomyopathy is a notable issue in patients needing permanent ventricular pacing. Identifying risk groups early and swiftly preventing the ailment can reduce patient harm. However, current prognostic methods require clarity. We employed machine learning to develop predictive models using medical data. Three algorithms — decision tree, group method of data handling, and logistic regression — formed models that forecast pacing-induced cardiomyopathy. These models displayed high accuracy in predicting development, signifying soundness. Factors like age, paced QRS width, pacing mode, and ventricular index during implantation significantly influenced predictions. Machine learning can enhance pacing-induced cardiomyopathy prediction in ventricular pacing patients, aiding medical practice and preventive strategies.

New Insights into Pacing Induced Cardiomyopathy.

Pacing induced cardiomyopathy (PICM) can occur as a complication due to pacing the right ventricle. Its precise definition varies across different studies, leading to uncertainty as to the best approach for managing this entity. More than 10% of patients who undergo chronic right ventricular pacing develop PICM. Risk factors associated with PICM include reduced left ventricular ejection fraction (LVEF), the proportion of right ventricular pacing, and paced QRS duration. The main approach to treating PICM has been upgrading to biventricular pacing cardiac resynchronization therapy when the LVEF decreases. However, emerging evidence suggest that conduction system pacing might provide an opportunity to manage PICM.

Modern physiological approach to inappropriate ICD shocks due to atrial fibrillation with very fast ventricular response. A case report

BackgroundFast-conducting atrial fibrillation misinterpreted as ventricular tachycardia is the leading cause for inappropriate shocks in patients with implantable cardiac defibrillators (ICD). These inappropriate shocks are associated with significant morbidity and mortality and cause great discomfort and stress.Case presentationWe report the case of a patient with ischemic cardiomyopathy, permanent atrial fibrillation, and a single-chamber DF-1 ICD implanted for the primary prevention of sudden cardiac death, who presented for multiple inappropriate internal shocks due to very fast-conducting atrial fibrillation, which was mislabeled as ventricular fibrillation by the ICD. Since the patient was under maximal atrioventricular nodal blocking medical therapy (beta-blockers and digitalis) and we didn`t find any reversible causes for the heart rate acceleration, we opted for rate control with atrioventricular node ablation. To counteract the risk of pacing-induced cardiomyopathy in this patient who would become totally pacemaker-dependent, we successfully performed left bundle branch area pacing. Because the patient`s ICD had a DF-1 connection and the battery had a long life remaining, we connected the physiological pacing lead to the IS-1 sense-pace port of the ICD. The 6-month follow-up showed an improvement in left ventricular function with no more inappropriate shocks.ConclusionsLeft bundle branch area pacing and atrioventricular node ablation in patients with an implantable single-chamber DF-1 defibrillator and fast-conducting permanent atrial fibrillation is a cost-efficient and very effective method to prevent and treat inappropriate shocks, avoiding the use of an additional dual-chamber or CRT-D device.

Detailed One-Year Follow-Up in Left Bundle Branch Area Pacing: Echocardiography, Natriuretic Peptide, Electrical Parameters and Complications.

Background: LBBAP is a promising method of cardiac pacing. Data on some follow-up details are still limited. We aimed to evaluate LBBAP over a one-year follow-up period. Methods: The studied population consisted of 110 patients who underwent LBBAP device implantation (93 for bradycardia indications, 17 for CRT). Echocardiography and NT-proBNP measurement were performed before the procedure and after one year. Electrical parameters, complications and some other conditions that required attention were noted during the observation period. Results: In total, 89 patients completed the one-year follow-up. NT-proBNP and echocardiographic parameters (LVEF, left ventricular end-diastolic dimension, left atrium dimension) improved after the one-year follow-up, especially in the patients with CRT indications, but also in the bradycardia patients. The independent predictors of a positive heart function response were higher baseline NT-proBNP and the presence of either RBBB or LBBB. The electrical parameters were satisfactory but a slight raise in the pacing threshold was observed at subsequent control visits. Major complications occurred in 4.5% of patients in the acute phase and in 4.4% during the follow-up (the most common was dislodgement of the non-LBBAP lead). One patient is presumed to have developed pacing-induced cardiomyopathy. The most frequent mild complications were intraprocedural RBBB (9.1%) and conversion to deep septal pacing during the follow-up period (5.5%). In addition, 4.4% of the patients required individual programming of the pacing output to maintain the optimal type of capture. Conclusions: The impact of LBBAP device implantation on cardiac function parameters is positive in a wide range of indications, especially in patients with RBBB or LBBB. The prevalence of complications is relatively high but major complications are rarely associated with LBBAP issues.