Selective His Bundle Capture Research Articles

Physiologic Differentiation Between Selective His Bundle, Nonselective His Bundle and Septal Pacing.

His bundle (HB) pacing is an increasingly popular method of physiologic ventricular pacing. The electrocardiographic hallmark of physiologic pacing is the preservation or restoration of physiologic activation times in the left ventricle-a principle of paramount diagnostic importance. The current review focuses on the differentiation between 3 possible capture types when the pacing lead is placed in the HB region: selective HB capture when only HB is activated, nonselective HB capture when there is simultaneous activation of the adjacent right ventricular septal (RVS) myocardium, and selective RVS capture when HB is not activated at all but only septal myocardium.

The relationship between anatomy and electrical parameters in His bundle pacing

Abstract Background The relationship between anatomy and electrical parameters of His bundle (HB) pacing has not been extensively studied. Purpose To characterize the anatomical location of the HB lead tip and its relationship with acute electrical parameters. Methods Consecutive patients who underwent HB lead implantation, guided by standard fluoroscopy and electrophysiology, were prospectively enrolled. The relationship between HB lead tip and tricuspid valve plane (TVP) was assessed with post-procedure transthoracic echocardiography. Results Twenty-five patients were studied. In 11 patients (44%), the HB lead tip did not cross the TVP (A group): in 7 cases it was screwed in the right atrium at a mean distance of −6.1 mm from the TVP and, in 4 cases, at the level of the tricuspid annulus. In the remaining 14 patients (56%), the lead tip crossed the TVP (V group): it was screwed in the right ventricle at a mean distance of 9.3 mm from the TVP. A and V groups had comparable HB capture thresholds (1.6±1 V vs 1.7±0.7 V, 1 ms pulse-width; p=0.66); selective HB capture was significantly more represented in the A group (91% vs 21%; p=0.001). Significantly higher R-wave amplitudes were seen in the V group (6.7±3 vs 2.5±1.7 mV; p=0.0004), and they positively correlated with the distance from the TVP (p=0.0038). Atrial oversensing was never observed. Conclusion In a consecutive cohort of HBP recipients, the rate of patients who had an effective HB capture in the atrium was substantial and was characterized by different electrophysiological properties than in the ventricle. Funding Acknowledgement Type of funding sources: None.

The relationship between anatomy and electrical parameters in His bundle pacing: A transthoracic echocardiography evaluation

PurposeThe implantation site of the His bundle (HB) lead may influence pacing parameters. Our aim was to characterize the anatomical location of the HB lead tip and its relationship with acute electrical parameters. MethodsConsecutive patients who underwent HB lead implantation, guided by standard fluoroscopy and electrophysiology, were prospectively enrolled. The relationship between HB lead tip and tricuspid valve plane (TVP) was assessed with post-procedure transthoracic echocardiography. ResultsTwenty-five patients were studied. In 11 patients (44%), the HB lead tip did not cross the TVP (A group): in 7 cases it was screwed in the right atrium at a mean distance of −6.1 mm from the TVP and, in 4 cases, at the level of the tricuspid annulus. In the remaining 14 patients (56%), the lead tip crossed the TVP (V group): it was screwed in the right ventricle at a mean distance of 9.3 mm from the TVP. A and V groups had comparable HB capture thresholds (1.6 ± 1 V vs 1.7 ± 0.7 V, 1 ms pulse-width; p = 0.66); selective HB capture was significantly more represented in the A group (91% vs 21%; p = 0.001). Significantly higher R-wave amplitudes were seen in the V group (6.7 ± 3 vs 2.5 ± 1.7 mV; p = 0.0004), and they positively correlated with the distance from the TVP (p = 0.0038). Atrial oversensing was never observed. ConclusionIn a consecutive cohort of HB pacing recipients, the rate of patients who had an effective HB capture in the atrium was substantial and was characterized by different electrophysiological properties than in the ventricle.

Can chronic his bundle pacing be safely started in centers with lack of experience of this technique? Mid-term data from a multicentric registry

Right ventricular pacing (RVP) induces ventricular asynchrony in patients with normal QRS and increases the risk of heart failure and atrial fibrillation on long-term. His bundle pacing (HBP) is a physiological alternative to RVP. Interest in HBP has been hampered in part by technical challenges and limited implantation tool set. Recent studies showed that it was feasible and safe in expert centers with a vast experience of HBP. These results may not apply to less experienced centers. To evaluate feasibility and safety of permanent His bundle pacing in hospitals with limited technical training to this technique and to evaluate stability of His bundle capture (HBC) thresholds. We included all patients who underwent pacemaker implantation with attempt of HBP in 3 hospitals between September 2017 and January 2019. All the 5 operators were novice for HBP. HBC thresholds were recorded at 3 months and 9 months follow-up. HPB was successful in 62 of 69 patients (89.9%); selective HBC was obtained in 48 patients while nonselective HBC occurred in 14 patients. Indication for pacemaker implantation was atrioventricular conduction disease in 39 patients, sinus node dysfunction in 6 patients and AV nodal ablation for non-controlled atrial arrhythmias in 24 patients. The mean procedure duration was 75 ± 8 min, and mean fluoroscopy duration was 10 ± 2 min The mean HBC threshold was 1.39 ± 0.26 V and did not increase at 3 months follow-up (1.08 ± 0.25 V, n = 48 patients) and 9 months follow-up (1.37 ± 0.31 V, n = 14 patients). Only 7 patients had HBC threshold > 2.5 V/0.5ms. There was no pericardial effusion, no pneumothorax and no device infection. Ventricular lead revision was required at 3 months in one patient for sudden threshold increase, without obvious dislodgement ( Fig. 1 ). His bundle pacing performed by novice operators to this technique appeared feasible and safe. The mean HBC threshold did not increase at 3 months and 9 months follow-up.

218 His Bundle Pacing for Cardiac Resynchronisation Following Coronary Sinus Left Ventricular Lead Failure

Cardiac Resynchronisation Therapy (CRT) has been well established to provide both symptomatic and prognostic benefit in patients with heart failure with reduced ejection fraction (HFREF) and ventricular dyssynchrony, however coronary sinus (CS) lead placement is unsuccessful in between 2 and 5% of patients due to unsuitable cardiac vein anatomy or phrenic nerve stimulation. His-bundle pacing (HBP) is a strategy which may be capable of providing the benefits of CRT in patients where CS lead placement is unsuccessful. We reviewed outcomes in patients from a single centre where HBP was employed as a salvage therapy following failed CS lead placement. 5 cases were identified where CS lead placement was unsuccessful. All patients had Class I indications for CRT as recommended by the 2013 ESC guidelines. In 3 patients cardiac branch vein anatomy was unsuitable and in 2 patients unacceptable phrenic nerve stimulation was present at threshold voltages. All 5 patients underwent successful HBP without procedural complications. Median threshold for selective His-bundle capture was 0.8 V (IQR 0.5–2.5V). Median QRS duration was significantly reduced from 160msec (IQR 137.5 – 183msec) to 120msec (IQR 105–142msec) with HBP (mean of differences -37.2msec, p=0.0004). Median LVEF significantly improved from 25% (IQR 24–32) to 37.5% (IQR 35–45%, mean of differences 12.25, p=0.004). All 5 patients reported subjective improvement in heart failure symptoms. This case series illustrates the utility of HBP as an alternative method of CRT in patients who have failed CS lead implantation, reinforcing HBP as an essential tool in the armamentarium of the modern electrophysiologist.

P6018Can chronic his bundle pacing be safely started in centers with lack of experience of this technique? Data from a multicentric registry

Abstract Introduction Right ventricular pacing (RVP) induces ventricular asynchrony in patients with normal QRS and increases the risk of heart failure and atrial fibrillation on long term. His bundle pacing (HBP) is a physiological alternative to RVP. Interest in HBP has been hampered in part by technical challenges and limited implantation tool set. Recent studies assessed feasibility and safety in expert centers with a vast experience of HBP. These results may not apply to less experienced centers. Purpose To evaluate feasibility and safety of permanent his bundle pacing in hospitals with limited technical training to this technique and to evaluate stability of his bundle capture thresholds at 3 months follow up. Methods We included all patients who underwent pacemaker implantation with attempt of HBP in three hospitals between September 2017 and December 2018. All the 5 operators were novice for HBP at the beginning of the study. Selective his bundle capture (HBC) was defined as concordance of QRS and T waves complexes with the native ECG (patients with underlying bundle branch block may normalize), presence of a delay between spike and QRS complex, absence of widening of the QRS at a low pacing output, and recordable his bundle electrogram. At 3 months follow-up, his bundle capture thresholds, R-wave amplitudes and pacing impedances were recorded. Results HPB was successful in 51 of 58 patients (87.9%); selective HBC was obtained in 40 patients while nonselective HBC occurred in 11 patients. Indication for pacemaker implantation was atrioventricular conduction disease in 31 patients (53%), sinus node dysfunction in 5 patients (9%) and AV nodal ablation for non-controlled atrial arrhythmias in 22 patients (38%). AV nodal ablation was performed during the same procedure in 14 patients. The mean procedure duration was 75±8 min, and mean fluoroscopy duration was 10±2 min. The mean HBP threshold was 1.47±0.27 V and did not increase after a 3 months follow-up (1.12±0.18 V). Only 7 patients (14%) had HBP threshold >2V/0.5ms. The mean impedance was 477±37 Ω and slightly decreased at 3 months (364±24Ω). The mean R-wave amplitude was 4.1±1 mV at implantation and 3.2±0.6 mV at 3 months. Bundle branch block correction was achieved in 5 of 7 patients with underlying left bundle branch block. There was no pericardial effusion, no pneumothorax and no device infection. Ventricular lead revision was required at 3 months in one patient for sudden threshold increase, without obvious dislodgement. LBBB correction after HBP Conclusion His bundle pacing performed by novice operators to this technique appeared feasible and safe. The mean HBP threshold did not increase at 3 months follow-up.

His bundle has a shorter chronaxie than does the adjacent ventricular myocardium: Implications for pacemaker programming

Strength-duration curves for permanent His bundle (HB) pacing are potentially important for pacemaker programming. We aimed to calculate strength-duration curves and chronaxies of the HB and of the adjacent right ventricular (RV) working myocardium and to analyze zones of selective HB capture and battery current drain when pacing at different pulse durations (PDs). Consecutive patients with permanent HB pacing were studied. The RV and HB capture thresholds were assessed at several PDs. Battery current drain and zones of selective HB capture at PDs of 0.1, 0.2, 0.4, and 1.0 ms were determined. In the whole group (N = 127), the HB chronaxie was shorter than the RV chronaxie. This difference was driven by patients with selective HB pacing (HB chronaxie 0.47 ms vs RV chronaxie 0.79 ms). The strength-duration curve for the HB had a lower rheobase and its steep portion started at shorter PDs, thus creating wider distance-zone of programmable selective HB pacing-between the HB and RV strength-duration curves at shorter PDs. The battery current drain was lower with pacing at PDs of 0.1-0.4 ms vs 1.0 ms. Chronaxie-adjusted PDs offered the lowest current drain. For the first time, the strength-duration curves for permanent selective and nonselective HB pacing were determined. Selective HB capture and battery longevity can be promoted by shorter PDs (0.2 ms). Longer PDs (1.0 ms) offer greater safety margin for RV capture and may be preferable if simultaneous RV capture during HB pacing is desired.

Early experience of His bundle pacing as an alternative of chronic right ventricular pacing: Initial and short-term results

Right ventricular pacing (RVP) induces ventricular desynchronization in patients with normal QRS and increases the risk of heart failure and atrial fibrillation on long term. His bundle pacing (HBP) is a physiological alternative to RVP. To evaluate feasibility and safety of permanent HBP and to evaluate stability of His capture thresholds at 3 months follow-up. We included all patients who underwent pacemaker implantation with attempt of His bundle pacing in Rouen University Hospital and GH Le Havre between September 2017 and September 2018. Selective His capture was defined as concordance of QRS and T waves complexes with the native ECG (patients with underlying bundle branch block may normalize), presence of a delay between spike and QRS complex, absence of widening of the QRS at a low pacing output, and recordable His bundle electrogram. At 3 months follow-up, His bundle capture thresholds, R-wave amplitudes and pacing impedances were recorded. His bundle capture (HBC) was successful in 35 of 40 patients (87.5%); selective HBC was obtained in 28 patients while nonselective HBC occurred in 7 patients. Indication for pacemaker implantation was atrioventricular conduction disease in 18 patients (45%), sinus node dysfunction in 4 patients (10%) and AV nodal ablation for non-controlled atrial arrhythmias in 18 patients (45%). AV nodal ablation was performed during the same procedure in 12 patients. Mean procedure duration was 74 ± 10 min, and mean fluoroscopy duration was 10.3 ± 7 min. Mean His bundle capture threshold was 1.37 ± 0.3 V and did not increase after a 3 months follow-up (1.02 ± 0.3 V). Only 2 patients had His capture threshold > 2 V/0.5ms. There was no pericardial effusion, no pneumothorax, no device infection and no ventricular lead revision required at 3 months ( Fig. 1 ). His bundle pacing was feasible and safe after a one-year experience. His bundle capture thresholds slightly decreased at 3 months follow-up.

Selective His-Bundle Pacing May Preserve Intrinsic Repolarization as Well as Depolarization

A 79-year-old man with chronic atrial fibrillation underwent single-chamber His-bundle pacemaker implantation. The post-implant electrocardiogram (ECG) demonstrated selective His-bundle capture, with a narrow paced QRS and repolarization pattern similar to that of the baseline ECG. Furthermore, repolarization changes prototypic of ventricular pacing did not occur with selective His-bundle capture. While His-bundle pacing, with or without selective His-bundle capture, can preserve physiologic patterns of depolarization, only His-bundle selective pacing can preserve intrinsic ST- and T-wave patterns. Thus, the maintenance of physiologic repolarization may have various advantages, including accurate interpretation of ECG changes that are not generally interpretable in the setting of ventricular pacing.