Apical Pacing Research Articles

Mitigation of pacing-induced cardiomyopathy with superficial right ventricular mid-septal pacing: A long-term retrospective comparison with apical pacing.

It remains unclear if pacing induced cardiomyopathy (PICM) may be minimized by standard pacing of the right ventricle (RV) at sites other than the RV apex. The purpose of this study is to compare the relative frequency of PICM in a population of patients paced at either the superficial RV mid septum (RVMS) or RV apex (RVA), and other outcomes that may differ between these sites. A retrospective evaluation was performed on all patients undergoing pacemaker implantation between 2011 and 2022. Potential study patients were those with Medtronic 3830 superficial RVMS leads placed with septal specific guidance catheters, and any with RVA leads. Patients were included if they had ≥20% RV pacing, available baseline and follow-up measurements of left ventricular ejection fraction (LVEF) at least 6 months postimplantation, and a baseline LVEF ≥50%. PICM was defined as a decline in the LVEF of at least 10%, resulting in LVEF <50%. Patients were excluded for Biventricular devices, and for alternative causes of cardiomyopathy. The study criteria were met in 324 patients, with 220 RVMS and 104 RVA paced patients. PICM occurred in 4.5% of RVMS patients, and 22.1% of RVA patients (p < .001). Additional differences were demonstrated in paced QRS duration (144 ± 15.5 ms in RVMS, 166 ± 19.4 ms in RVA; p < .001); QRS axis (2.3 ± 64.9 in RVMS, -65.2 ± 49.5 in RVA; p < .001), and various qualitative QRS morphologic characteristics. Patients with normal LVEF experienced significantly less PICM with superficial RVMS pacing performed via septal specific guidance catheters than similar counterparts with RVA pacing. Narrower paced QRS duration and less left axis deviation was also demonstrated.

Study of right atrial and right ventricular function in dual chamber pacemaker patients

Abstract Background Unlike left ventricular function, right ventricular (RV) function in pacemaker patients is less well studied with less studies comparing septal versus apical pacing effects on the RV function and almost none on the right atrial (RA) function. Purpose To assess the effect of RV pacing on the echocardiographic and clinical parameters of the RV and RA function and their correlation with the site of right ventricular lead implantation. Methods The study assessed 59 patients in need of permanent dual chamber pacemaker implantation using clinical and echocardiographic data of the RV and RA size and function using tricuspid annular plane systolic excursion (TAPSE), S wave velocity of the tricuspid annulus and fractional area change (FAC), free wall strain (FWSL), global longitudinal strain (GLS) of the RV, RA strain including reservoir, conduit and contraction phases and 3D ejection fraction of the RV using Epiq 7 Ultrasound machine (Philips Healthcare) by the same echocardiographer before implantation and 6 months after. All programming parameters were recorded postoperative and 6 months later. Results 31 patients had the RV lead in the RV apex whereas 28 had it in the septum and all patients had their RA lead in the right atrial appendage, with no significant difference between both groups regarding baseline demographic, clinical nor echocardiographic data. At 6 months, there was a significant decline of the 3D RVEF from a mean of (58.57% ± 6.35%) to (56.41% ± 6.17%), TAPSE from (2.61 cm ± 0.51) to (2.35 cm ± 0.52) and S wave from (13.73 cm/sec ± 2.84) to (12.64 cm/sec ± 2.61) but none showed a significant difference between septal and apical pacing, on the other hand, the RV strain showed a significant decline 6 months after implantation in both the FWSL from (-31.75% ± 5.39) to (-27.82% ± 5.73) and the GLS from (-25.89% ± 5.17) to (-21.65% ± 4.51) with more decline in the septal group compared to the apical (-20.33% ± 4.70 versus -22.84% ± 4.04 regarding the GLS and -26.11% ± 6.41 versus -29.37% ± 4.62 in the FWSL, respectively). There was no difference in the FAC, tricuspid regurgitation severity, gradient nor the estimated pulmonary artery pressure at 6 months. The RA size showed a significant decline at 6 months but no difference in any of the strain parameters. No clinical RV failure symptoms nor signs were observed. Programming revealed a mean percentage of ventricular pacing of (97.92% ± 2.67%) with a minimum of 91% and atrial pacing of (10.41% ± 12.52%), and the thresholds, impedance and atrial high-rate episodes were comparable postoperatively and 6 months after, with no difference between the septal and apical groups. Conclusion At 6 months follow-up after pacemaker implantation, right ventricular function starts to show decline in both the septal and apical groups with only the right ventricular strain more affected in the septal group compared to the apical.3D right ventricular ejection fraction3D right ventricular strain

Assessment of ventricular mechanics by means of myocardial work in patients undergoing physiologic versus right ventricular apical stimulation:a prospective study

Abstract Introduction Left bundle branch area (LBBA) pacing has recently gained widespread acceptance in patients that need pacemaker (PM) stimulation. This type of physiologic pacing may improve ventricular mechanical contraction and reduce the risk of PM-induced left ventricular (LV) dysfunction. Myocardial work (MW), a new tool, based on the analysis of pressure-strain loops, combines the information from speckle tracking strain imaging and non-invasive estimate of LV pressure. It provides a better characterization of LV performance and detection of LV myocardial dysfunction. The aim of this study was to compare MW after PM implantation in LBBA pacing patients (group 1) vs right ventricular apical (RVA, group 2) pacing patients. A control group (group 3) was also enrolled for establishing MW normal values. Methods We studied 30 patients (56% females, age 80 y, IQR 75-84) who underwent PM implantation and had a high probability of a high % of stimulation and 21 controls (57% females, age 79 y, IQR 73-85, p=0.46 and p=0.73 respectively) Patients were prospectively included at two large university hospitals from March 23 until February 24. The mode of stimulation was chosen at their physician’s discretion. Exclusion criteria included LVEF &amp;lt;50% or significant structural or valvular disease. We compared MW parameters between group 1 and group 2 before PM implantation, and 24 hours and 3 months post PM implantation by Kruskal Wallis test. Additionally, we compared MW parameters between group 3 and PM patients after 24 hours using U Mann-Whitney test. Results The % of stimulation was 93%±12. There were no differences in baseline characteristics between group 1 (n=21, 71%) and group 2. At baseline, global work index (GWI), global constructive work (GCW), global wasted work (GWW) or global work efficiency (GWE) did not differ significantly between Group 1 and 2. At 24 hours, all the components of MW significantly improved in Group 1 and 2 and were maintained at 3 months, but the improvement was notably greater in Group 1 (see Table 1). Group 3 and PM patients were similar at baseline (HTN, 86% vs 80%, p=0.7197; DM, 29% vs 30%, p=0.91; coronary artery disease, 14% vs 10%, p=0.68; sinus rhythm, 76% vs 83%, p=0.68). Comparing group 3 and PM at 24 h, GWI, GCW, GWE was significantly higher in group 3 (p=0.0023, p=0.009, p=&amp;lt;0.0001) and GWW was significantly lower (p=&amp;lt;0.0001). Regarding the type of stimulation, MW parameters values in Group 1 were still lower than in Group 3 but clearly better than Group 2 values (see Figure 1). Discussion Our results showed that MW parameters improved to a greater extent in LBBA compared to RVA pacing immediately and after 3 months of PM implantation. Compared to our control group, LBBA pacing group achieved better performance than RVA pacing patients, yielding a more coordinated LV contraction. Nevertheless, more studies are needed to clarify if LBBA pacing causes less PM induced LV dysfunction compared to RVA pacing.

Observational study of left bundle branch area pacing: implantation of the solia S lead using the selectra 3D sheath at an inclined angle

BackgroundLeft Bundle Branch Area Pacing (LBBaP) is a cardiac pacing technique designed to mimic the natural conduction system of the heart. Traditional right ventricular apical pacing has been associated with increased risks of heart failure and atrial fibrillation. This study investigates the stability and safety of LBBaP using the Selectra 3D sheath (Biotronik) with an inclined angle for implanting the Solia S lead (Biotronik, SE & Co, KG).MethodsA single-center retrospective study was conducted on 25 patients who underwent LBBaP implantation using the Selectra 3D sheath at our hospital. The procedure involved inserting the Solia S lead into the interventricular septum at an inclined angle. Surgical and postoperative data were collected, including the success rate, depth and angle of electrode insertion, complications, and follow-up data.ResultsThe success rate of LBBaP implantation was 92%. The length of electrode insertion into the interventricular septum ranged from 12 to 23.0 mm, with an average of 18.1 ± 3.08 mm. The angle formed between the electrode and the septum ranged from 0° to 57.3°, with an average of 35.14°±14.31°. During the 3-month follow-up period, pacing parameters remained stable, and no complications were reported.ConclusionsLBBaP implantation using the Selectra 3D sheath with an inclined angle for the Solia S implantation demonstrates stability and safety. The procedure boasts a high success rate and offers an effective option for LBBaP implantation.

The effect of right ventricle septal pacing versus apical pacing in dual-chamber pacemakers on patients’ anxiety and depression: a one-year follow-up study

BackgroundAnxiety and depression are potentially harmful outcomes of permanent cardiac pacemakers. Dual-chamber P.P.M. is frequently used to treat life threatening bradycardia. The study aims to estimate the effect of the right ventricular PM lead position on recipients’ anxiety and depression before, 6 months, and 1 year after implantation.ResultsA statistically significant correlation was discovered between the studied groups regarding HADS depression score after 6 months (p 0.013) and 1 year (p 0.013). A statistically non-significant difference was found among the studied groups at any point of time regarding baseline (p 0.063), after 6 months (p 0.054), or after 1 year (p 0.099). Significance was found between HADS anxiety score (p 0.015) or depression score after 1 year and the incidence of complications (p 0.001).ConclusionsA strong relationship was found between the level of depression and the R.V. site of implantation, as patients with the apical group had higher levels of depression post-implantation. The septal position has less stress and depression on the patient’s well-being than the apical one.

Distal Ventricular Pacing for Drug-Refractory Mid-Cavity Obstructive Hypertrophic Cardiomyopathy: A Randomized, Placebo-Controlled Trial of Personalized Pacing.

Patients with refractory, symptomatic left ventricular (LV) mid-cavity obstructive (LVMCO) hypertrophic cardiomyopathy have few therapeutic options. Right ventricular pacing is associated with modest hemodynamic and symptomatic improvement, and LV pacing pilot data suggest therapeutic potential. We hypothesized that site-specific pacing would reduce LVMCO gradients and improve symptoms. Patients with symptomatic-drug-refractory LVMCO were recruited for a randomized, blinded trial of personalized prescription of pacing (PPoP). Multiple LV and apical right ventricular pacing sites were assessed during an invasive hemodynamic study of multisite pacing. Patient-specific pacing-site and atrioventricular delays, defining PPoP, were selected on the basis of LVMCO gradient reduction and acceptable pacing parameters. Patients were randomized to 6 months of active PPoP or backup pacing in a crossover design. The primary outcome examined invasive gradient change with best-site pacing. Secondary outcomes assessed quality of life and exercise following randomization to PPoP. A total of 17 patients were recruited; 16 of whom met primary end points. Baseline New York Heart Association was 3±0.6, despite optimal medical therapy. Hemodynamic effects were assessed during pacing at the right ventricular apex and at a mean of 8 LV sites. The gradients in all 16 patients fell with pacing, with maximum gradient reduction achieved via LV pacing in 14 (88%) patients and right ventricular apex in 2. The mean baseline gradient of 80±29 mm Hg fell to 31±21 mm Hg with best-site pacing, a 60% reduction (P<0.0001). One cardiac vein perforation occurred in 1 case, and 15 subjects entered crossover; 2 withdrawals occurred during crossover. Of the 13 completing crossover, 9 (69%) chose active pacing in PPoP configuration as preferred setting. PPoP was associated with improved 6-minute walking test performance (328.5±99.9 versus 285.8±105.5 m; P=0.018); other outcome measures also indicated benefit with PPoP. In a randomized placebo-controlled trial, PPoP reduces obstruction and improves exercise performance in severely symptomatic patients with LVMCO. URL: https://clinicaltrials.gov/study; Unique Identifier: NCT03450252.

Differential right apical and left basal pacing: a new maneuver that rules out the presence of a left accessory pathway with retrograde conduction

Abstract Background Differential apex-base pacing or entrainment is a very useful maneuver in patients with concealed septal accessory pathways. This study evaluates for the first time the diagnostic value of differential right apical pacing (aRV) and basal left ventricular pacing (bLV) in patients with left accessory pathways before and after ablation. Purpose To determine the value of differential aRV and bLV pacing as a simple maneuver to assess the successful ablation of left accessory pathways. Methods Successive patients with preexcitation or concealed left accessory pathways were prospectively included. Baseline pre-ablation (PRE) 1:1 retrograde conduction was evaluated by the S-A interval during pacing at the aRV (PREaRV) and at the bLV (PREbLV) measured to the earliest atrial electrogram detected by a decapolar catheter placed in the coronary sinus. The S-A interval resulting from direct atrial capture during high outputpacing at the bLV at (PREdir) was also measured. The same S-A intervals, pacing at the same locations and measured to the same dipole in the coronary sinus were reassessed after ablation (POSaRV, POSbLV, POSdir) in order to compare the total values and their differences. Results 47 patients were included (age 31 yo [range 4 – 76 yo], 70% male sex, transeptal approach used in 62%). Ablation of the accessory pathway was successful in all patients. 5 patients could not be analyzed due to absence of 1:1 retrograde conduction before ablation, 27/43 (63%) patients had 1:1 retrograde nodal conduction after ablation. A significant prolongation of the S-A intervals were observed after ablation during pacing at the aRV (POSaRV – PREaRV = 43±38 ms, IC95% 27-59 ms, p&amp;lt;0,001) and from the bLV (POSbVI – PREbVI = 126±53 ms, IC95% 105-147 ms, p&amp;lt;0,001). As expected, the S-A interval during direct atrial capture from the bLV did not prolong (POSdir – PREdir = 2±10 ms, IC95% -2 – 6 ms, p=0,41). The difference PREaRV – PREbLV before ablation (difPRE) was 80±26 ms (IC95% 72-88 ms) and never overlapped with the difference POSaRV – POSbLV after ablation (-6 ±33 ms, IC95% -19 – 8 ms) (difPOS) except in one case of left posteroseptal accessory pathway. The δ value (difPRE – difPOS) was 83±40 ms (IC95% 67-100 ms, p&amp;lt;0,001). A difPOS value &amp;lt;20 ms discriminated all successful ablations of non posteroseptal accesory pathways. Conclusion The S-A values obtained during differential RV apical and LV basal pacing before and after ablation are valid to discriminate the efficacy of the procedure. The POSaVD – POSbVI value is always &amp;lt;20 ms after successful ablation and excludes retrograde conduction over any left non-posteroseptal accesory pathway. This same value is ≤0 ms in 72% of cases of successful ablation.Figure.

LV systolic function assessment in conventional cardiac pacing: a simple and forgotten parameter - MAPSE

Abstract Background Mitral annular plane systolic excursion (MAPSE) was a widely used M-mode echocardiographic marker of left ventricular longitudinal systolic function. On the other hand, right ventricle (RV) apical pacing is associated with left ventricle (LV) dysfunction development due to dysynchronous activation, while non-apical pacing may provide a more physiological LV activation. The aim of this study is to ascertain the clinical usefulness of MAPSE in the assessment of LV contractile function in patients with permanent RV pacing. Methods Consecutive patients with indication for permanent cardiac pacing (with ventricular pacing percentages over 20% - Vp&amp;gt;20%) were retrospectively enrolled from 2019 to 2023. All patients were assessed by echocardiography with MAPSE, left ventricule ejection fraction (LVEF) and diastolic filling patterns being measured at the time of implant and at subsequent follow-ups. Results 359 patients (age range 41-80yo; mean age=60,5yo) were included, 244 men and 115 women, 173 implanted with single-chamber devices and 186 dual-chamber. 259 patients were paced from the RVA (right ventricle apex) and 62 had septal lead positioning. The mean follow-up period was 18±2 months. The results showed that a MAPSE cut off value of ≤10 mm was associated with a LVEF&amp;lt;42±2%, while MAPSE values &amp;gt;10mm were associated with LVEF&amp;gt;45±3% (p&amp;lt;0.01). RV septal pacing was associated with a higher average MAPSE value (14,28 mm) than RVA pacing (13,47). Conclusions MAPSE seems to corelate well with LVEF in RV conventional pacing. Younger patients with preserved LVEF and less than grade II diastolic dysfunction were not associated with a significant decrese in MAPSE value. However, older patients with HFmrEF and RVA pacing seem to have a more substantial reduction in MAPSE value, suggesting that non-apical or conduction system pacing might be beneficial in this subgroup. MAPSE seems to be a quick and reliable echocardiographic marker of LV systolic function in patients with permanent cardiac pacing. It may be used as an early predictive marker for heart failure in conventional RV paced patients.

Clinical characteristics of patients with better ejection fraction recovery after upgrading to cardiac resynchronization therapy

Abstract Background Chronic right ventricular (RV) pacing can cause cardiac systolic dysfunction and heart failure (HF), increased risk of HF hospitalization and adverse outcomes. In these patients upgrading to cardiac resynchronization therapy (CRT) may improve left ventricular function. Purpose We aimed to identify the profile of patients (their clinical, electrical and echocardiographic characteristics) who are more likely to make a significant change in left ventricular ejection fraction (LVEF) one year after revision of the RV pacing system to CRT. Methods This was a retrospective, observational, single-center study. We included patients with a permanent antibradycardia pacemaker who had no systolic dysfunction and HF symptoms at the time of pacemaker implantation and who experienced a drop in LVEF below 35% during follow-up, with development of HF symptoms and with at least 20% of ventricular pacing. In all patient's revision to CRT was performed at our center between January 2014 and December 2019. We excluded patients who were indicated for a system upgrade regardless of the percentage of ventricular pacing and those in whom the drop in LVEF is due to a new coronary event. We used patients’ medical records to collect data on baseline characteristics. LVEF was measured pre-revision and 12 months after upgrade. To examine the difference in LVEF change between specified subgroups of patients we used a t-test. Results During the defined period, 82 upgrade procedures from conventional pacemaker to CRT were done in our center. We excluded 12 patients with left bundle branch block (LBBB) QRS morphology, 4 with non-LBBB QRS morphology but with QRS duration over 150ms and 4 patients who died within a year after revision to CRT. Therefore, we analyzed 62 patients (20.9% female, mean age 66.9 ± 11.2 years, mean LVEF 25.9 ± 6.8). After 12 months, 58.1% of patients had an increase in EF above 5%, and the mean change in LVEF (ΔLVEF) was 7.8 ± 11.8. Compared to those with non-ischemic cardiomyopathy (NICMP), patients with ischemic etiology had statistically significantly less improvement in LVEF (ΔLVEF 1.8 ± 6.8 vs 13.1 ± 12.7, p &amp;lt; 0.01), as well as patients with an RV apical pacing compared to those with a septal lead position (ΔLVEF 5.1 ± 9.1 vs 14.1 ± 14.7, p = 0.021). Patients with narrower paced QRS complex (&amp;lt;150ms) before upgrade had a significantly greater improvement in LVEF compared to those with a wider paced QRS complex (≥150ms) (ΔLVEF 10.9 ± 12.2 vs 4.8 ± 10.7, p = 0.04), and those with post-revision paced QRS width above 150ms had significantly lower change in LVEF compared to those with a narrower paced QRS (ΔLVEF 4.6 ± 9.8 vs 11.1 ± 12.8, p = 0.028). Conclusion Patients with NICMP and with width of the paced QRS complex before and after revision to CRT below 150ms had significantly greater improvement in LVEF 12 months after the upgrade. The position of RV lead significantly affects the success of the upgrade procedure.

Comparison between left bundle branch area pacing and right ventricular pacing: ventricular electromechanical synchrony and risk of atrial high-rate episodes.

The electromechanical dyssynchrony associated with right ventricular pacing (RVP) has been found to have adverse impact on clinical outcomes. Several studies have shown that left bundle branch area pacing (LBBAP) has superior pacing parameters compared with RVP. We aimed to assess the difference in ventricular electromechanical synchrony and investigate the risk of atrial high-rate episodes (AHREs) in patients with LBBAP and RVP. We consecutively identified 40 patients with atrioventricular block and no prior atrial fibrillation. They were divided according to the ventricular pacing sites: the LBBAP group and the RVP group (including the right ventricular apical pacing (RVA) group and the right side ventricular septal pacing (RVS) group). Evaluation of ventricular electromechanical synchrony was implemented using electrocardiogram and two-dimensional speckle tracking echocardiography (2D-STE). AHRE was defined as event with an atrial frequency of ≥176 bpm lasting for ≥6 min recorded by pacemakers during follow-up. The paced QRS duration of the LBBAP group was significantly shorter than that of the other two groups: LBBAP 113.56 ± 9.66 ms vs. RVA 164.73 ± 14.49 ms, p < 0.001; LBBAP 113.56 ± 9.66 ms vs. RVS 148.23 ± 17.3 ms, p < 0.001. The LBBAP group showed shorter maximum difference (TDmax), and standard deviation (SD) of the time to peak systolic strain among the 18 left ventricular segments, and time of septal-to-posterior wall motion delay (SPWMD) compared with the RVA group (TDmax, 87.56 ± 56.01 ms vs. 189.85 ± 91.88 ms, p = 0.001; SD, 25.40 ± 14.61 ms vs. 67.13 ± 27.40 ms, p < 0.001; SPWMD, 28.75 ± 21.89 ms vs. 99.09 ± 46.56 ms, p < 0.001) and the RVS group (TDmax, 87.56 ± 56.01 ms vs. 156.46 ± 55.54 ms, p = 0.003; SD, 25.40 ± 14.61 ms vs. 49.02 ± 17.85 ms, p = 0.001; SPWMD, 28.75 ± 21.89 ms vs. 91.54 ± 26.67 ms, p < 0.001). The interventricular mechanical delay (IVMD) was shorter in the LBBAP group compared with the RVA group (-5.38 ± 9.31 ms vs. 44.82 ± 16.42 ms, p < 0.001) and the RVS group (-5.38 ± 9.31 ms vs. 25.31 ± 21.36 ms, p < 0.001). Comparing the RVA group and the RVS group, the paced QRS duration and IVMD were significantly shorter in the RVS group (QRS duration, 164.73 ± 14.49 ms vs. 148.23 ± 17.3 ms, p = 0.02; IVMD, 44.82 ± 16.42 ms vs. 25.31 ± 21.36 ms, p = 0.022). During follow-up, 2/16 (12.5%) LBBAP patients, 4/11 (36.4%) RVA patients, and 8/13 (61.5%) RVS patients had recorded novel AHREs. LBBAP was proven to be independently associated with decreased risk of AHREs than RVP (log-rank p = 0.043). LBBAP generates narrower paced QRS and better intro-left ventricular and biventricular contraction synchronization compared with traditional RVP. LBBAP was associated with a decreased risk of AHREs compared with RVP.

Permanent Cardiac Pacing of the Right Ventricular Outflow Tract Guided by Real-time Assessment of Electromechanical Synchrony.

Permanent right ventricular apical pacing deteriorates cardiac systolic function in some patients. We investigated an alternative site for permanent pacemaker (PPM) lead positioning with the goal of achieving more physiological pacing. A total of 132 patients with bradyarrhythmias underwent PPM implantation at the right ventricular outflow tract (RVOT) with conventional active-fixation leads. A real-time cross-correlation analysis (CCA) was performed using the Synchromax® software (EXO Health, Seattle, WA, USA) to determine the optimal site for ventricular lead implantation based on the cardiac synchrony index. The follow-up period ranged from 6-36 months, and the following parameters were assessed: pacing capture threshold, lead stability, and the need for lead repositioning. Adequate parameters were achieved in 129 patients (98%), and there were no procedure-related complications. At follow-up, no leads were dislodged, pacing thresholds remained stable, and no lead required repositioning. Using real-time CCA as an intraoperative parameter during PPM implantation at the septal RVOT helps to achieve cardiac synchrony in the vast majority of cases. This technique is a simple, effective, and safe way to simplify and standardize PPM implantation at the RVOT.

Lead performance of stylet-driven leads in left bundle branch area pacing: Results from a large single-center cohort and insights from in vitro bench testing

BackgroundLeft bundle branch area pacing (LBBAP) requires deep septal lead deployment for left-sided conduction stimulation. Advancing leads toward deep septal positions might add mechanical stress on these leads. Concerns about lead performance and reliability remain an unanswered question. ObjectiveThe purpose of this study was to analyze lead performance and integrity of stylet-driven pacing leads (SDLs) for LBBAP. MethodsThis study assessed lead fracture rates of SDL in a large single-center cohort of adult LBBAP patients. Fluoroscopic analysis of lead bending angulations at the septal insertion point and in vitro bench testing of lead preconditioning were performed to simulate clinical use conditions. Lead performance was compared between LBBAP and conventional right ventricular apical pacing (RVp) sites. ResultsThe study included 325 LBBAP patients (66% male; age 71±15 years). During median follow-up of 18 months, 2 patients (0.6%) experienced conductor fracture between tip housing and ring electrode, whereas no such fractures occurred with RVp patients (n = 149; P = .22). X-ray analysis revealed that high lead bending angulations occurred in 1.3% of the patients. Accelerated bench testing of excessive preconditioned leads showcased a higher probability of early conductor fracture compared to standard preconditioned leads. ConclusionThe incidence of early conductor failure in LBBAP seems higher than with conventional RVp sites. The most vulnerable lead part seems to be the interelectrode space between the tip housing and ring electrode. Excessive angulation and preconditioning might contribute to early fatigue fracture.

Outcomes of left bundle branch area pacing compared to His bundle pacing and right ventricular apical pacing in Japanese patients with bradycardia.

His bundle pacing (HBP) and left bundle branch area pacing (LBBAP) emerge as better alternatives to right ventricular apical pacing (RVAP) in patients with bradycardia requiring permanent cardiac pacing. We aimed to compare the clinical outcomes of LBBAP, HBP, and RVAP in Japanese patients with bradycardia. A total of 424 patients who underwent successful pacemaker implantation (HBP, n = 53; LBBAP, n = 75; and RVAP, n = 296) were retrospectively enrolled in this study. The primary study endpoint was the cumulative incidence of heart failure hospitalization (HFH) during the follow-up. The success rate for implantation was higher in the LBBAP group than in the HBP group (94.9% and 81.5%, respectively). Capture threshold increase >1V during the follow-up occurred in the HBP and RVAP groups (9.4% and 5.1%, respectively), while it did not in the LBBAP group. The cumulative incidence of HFH was significantly lower in the LBBAP group than the RVAP (adjusted hazard ratio, 0.12 [95% confidence interval: 0.02-0.86]; p = .034); it did not differ between the HBP and RVAP groups (adjusted hazard ratio, 0.48 [95% confidence interval: 0.17-1.34]; p = .16). Advanced age, mean percent right ventricular pacing (per 10% increase), left ventricular ejection fraction <50%, and RVAP were associated with HFH. Compared to RVAP and HBP, LBBAP appeared more feasible and effective in patients with bradycardia requiring permanent cardiac pacing.

Safety and Efficacy of His Bundle Area (Para-Hisian) Pacing Using a Mathematical Cross-Correlation Cardiac Synchrony Index

Background: The deleterious effects of right ventricular (RV) apical pacing promoted the need for more physiological pacing techniques, such as conduction system, His bundle area, and mid-septal ventricular pacing. We aimed to compare permanent mid-septal and His bundle area pacing (HBAP) vs RV apical pacing to determine which is more physiological and to assess lead stability and pacing thresholds. Methods: We retrospectively analyzed 137 consecutive patients undergoing permanent pacing (63% men, mean age 61 ± 24 years). Seventy-one (52%) had a baseline QRS of &lt; 120 ms, with no evidence of intraventricular conduction abnormalities, 37 (27%) had right bundle branch block, and 29 (21%) had left bundle branch block. The ventricular lead was implanted at the RV apex in 54 patients, at the His bundle area in 66, and at the mid interventricular septum in 17. Twelve-lead electrocardiogram was recorded, and electrical synchrony was assessed using the Synchromax® crosscorrelation cardiac synchrony index (CSI). Results: QRS duration was prolonged in all pacing sites. There was no correlation between QRS duration and the CSI (r = 0.028, p = 0.79). The CSI was significantly improved only in patients undergoing HBAP, despite a slight widening of the QRS complex. There was no difference in pacing thresholds and sensed R wave voltage. Lead dislodgment occurred in only 1 lead implanted at the His bundle area. Conclusions: HBAP successfully captures the conduction system, normalizing the CSI despite producing a wider QRS, meaning that coordination is more important than duration for achieving optimal cardiac synchrony

Secret signal delayed mapping in patients with premature ventricular contractions.

Mapping and radiofrequency ablation (RFA) of premature ventricular contractions (PVC) that show diurnal changes during the day, and which are rare during 3-D mapping has become very difficult. The most delayed signal mapping in the right ventricular outflow tract (RVOT) with RV apical pacing might be useful in these situations and we called this method Secret Signal Delayed Mapping (SSDM). To compare the classical RFA and SSDM in patients with PVC. A total of 60 patients with > 10% PVCs detected in 24-hour rhythm Holter recordings and admitted to the laboratory for RFA, 30 of whom underwent classical ablation according to the local activation time (LAT) and 30 of whom were included in the SSDM group, were included in our study. In patients who did not have enough PVCs during 3-D mapping, a catheter was placed in the right ventricle, and delayed signals after the ventricular electrogram (EGM) were collected by fixed pacing and such patients were included in the SSDM group. In all patients, PVC originated from the RVOT. The mean follow-up time of the patients was 10.2 ±1.6 months. Recurrence was detected in 11 (36.6%) patients in the LAT group and 4 (13.3%) patients in the SSDM group. Signal earlyness in LAT mapping was significantly higher in the LAT group (p < 0.001). In the SSDM group, an average of 128 ±24 delayed signals were collected, the mean delayed signal time was 77.6 ±17.7 ms. In the SSDM group, the average distance between the earliest signal on the LAT and the most delayed signal on the SSDM was 4.8 ±1.2 mm. In the treatment of PVCs with RFA, the SSDM method can be used in addition to classical ablation.

Effects of Right Ventricular Non-Apical Pacing and Right Ventricular Apical Pacing on Left Ventricular Function: A Systematic Review and Meta-Analysis

Effects of Right Ventricular Non-Apical Pacing and Right Ventricular Apical Pacing on Left Ventricular Function: A Systematic Review and Meta-Analysis

Loss of capture of conduction system pacemaker caused by fibrosis surrounding the lead: a case report

BackgroundConduction system pacing (CSP) is a novel technique that involves pacing the His-Purkinje system instead of the traditional right ventricular (RV) apex. This technique aims to avoid the adverse effects of RV apical pacing, which can lead to ventricular dyssynchrony and heart failure over time. CSP is gaining popularity but its long-term efficacy and challenges remain uncertain. This report discusses a case where CSP was initially successful but faced complications due to an increasing pacing threshold.Case presentationA 65-year-old female with total atrioventricular block was referred for brady-pacing. Due to the potential for chronic RV pacing, CSP was chosen. The CSP implantation involved subcutaneous device placement, with a CSP lead in the left bundle branch area (LBBA) and an RV backup lead. A year after successful implantation, the LBBA pacing threshold progressively increased. Subsequent efforts to correct it led to anodal capture and battery depletion. Cardiac magnetic resonance imaging (CMR) revealed mid-septal fibrosis at the area of LBBA lead placement and suggested cardiac sarcoidosis as a possible cause.ConclusionCSP is a promising technique for treating bradyarrhythmias, but this case underscores the need for vigilance in monitoring pacing thresholds. Increasing thresholds can render CSP ineffective, necessitating alternative pacing methods. The CMR findings of mid-septal fibrosis and the potential diagnosis of cardiac sarcoidosis emphasize the importance of pre-implantation assessment, as CSP may be compromised by underlying structural abnormalities. This report highlights the complexities of pacing strategy selection and the significance of comprehensive evaluation before adopting CSP.

Absent ventriculo-atrial conduction during right ventricular apical pacing but nodal response during para-Hisian pacing – What is the mechanism?

A 13-year-old-girl presented with one episode of pre-syncope while standing in a train. Her ECG was suggestive of preexcitation. Echocardiography revealed structurally normal heart without any ventricular hypertrophy. During electrophysiology study, her ventriculo-atrial (VA) conduction was absent even on isoprenaline. However, a para-Hisian pacing maneuver (PHP) revealed consistent VA conduction with a nodal response. This finding indicated that the VA dissociation at baseline was at infra-Hisian (VH) level and conduction at HA level was intact. In addition, this finding is coherent with a speculation of a fasciculo-ventricular pathway (FVP) resulting in such an ECG pattern in her. Pacing from various atrial sites (right atrium, coronary sinus) exhibited nearly fixed preexcitation and short non-varying HV interval confirmatory of FVP. Testing for a PRKAG mutation was advised for her.

Utility of a guiding catheter for conduction system pacing: An early multicenter experience

BackgroundConduction system pacing (CSP), either as His bundle pacing (HBP) or as left bundle branch area pacing (LBBAP), may be superior to right ventricular apical or septal pacing. ObjectiveTo present acute results for a new guiding catheter (Biotronik Selectra 3D) designed for CSP implantations of a retractable screw-in lead (Biotronik Solia S). MethodsThe primary endpoint of the prospective, international non-randomized BIO|MASTER.Selectra 3D study was freedom from catheter-related serious adverse device effects (SADEs) within one week of lead implantation. ResultsOf 157 enrolled patients, CSP was achieved in 147 patients (93.6%). No SADEs occurred within 7 days. LBBAP was achieved in 82 patients (45 as crossover from an HBP attempt) and HBP in 65 patients (44.2%). In centers considering both HBP and LBBAP, the CSP implantation success approached 99%. Successful CSP implantations lasted on average ≈50 min (fluoroscopy ≈6 min). Most procedures (87.9%) needed only one catheter, even after switch from HBP to LBBAP. The catheter’s handling was rated largely positive. In patients without bundle branch block (BBB), mean QRS duration increased from 106 ms (intrinsic) to 122 ms (CSP; P=0.001). In patients with BBB, mean QRS duration decreased from 151 ms (intrinsic) to 137 ms (CSP; P=0.004). ConclusionThe Selectra 3D catheter is a valuable tool for HBP and LBBAP implantations of the stylet-supported pacemaker leads. When implanters considered both HBP and LBBAP, the success rate was ≈99%. Flexibility to change between different approaches may be advisable in heterogeneous and challenging areas, such as CSP implantations.

Electrical characteristics and clinical outcomes during left bundle branch area pacing in patients with narrow QRS and comparison in mechanical synchrony with his bundle pacing, biventricular pacing and right ventricular apical pacing

Electrical characteristics and clinical outcomes during left bundle branch area pacing in patients with narrow QRS and comparison in mechanical synchrony with his bundle pacing, biventricular pacing and right ventricular apical pacing