Abstract P64: Right Ventricular Outflow Septal Pacing as Cardiac Resynchronization Therapy in Patients with Right Bundle-Branch Block: Results in 62 Patients

Author(s):  
Phillip E Schrumpf ◽  
Michael Giudici ◽  
Deborah Paul ◽  
Roselyn Krupa ◽  
Cynthia Meirbachtol

Background: Cardiac resynchronization therapy has been shown to improve left ventricular performance in patients with left ventricular dysfunction and a left-sided interventricular conduction delay. This is performed by placing a pacing lead on the lateral left ventricular wall to stimulate the area normally stimulated by the left bundle branch. In patients with right bundle branch block (RBBB), pacing the right bundle branch could also result in resynchronization. Previous studies have shown that right ventricular outflow septal (RVOS) pacing does, in fact, utilize the native conduction system. Methods: 62 consecutive patients, 46 male/16 female, aged 75 +/− 10.5 yr, with RBBB and indications for pacing, underwent RVOS lead placement using commercially available pacing systems. The patients subsequently underwent bedside A-V optimization to achieve the narrowest QRS duration and most “normal” QRS complex. Echocardiography was performed to evaluate changes in wall motion comparing baseline with optimal pacing. Results: Baseline mean QRS duration 146 +/− 20.9 ms Optimized mean QRS duration 111 +/− 20.5 ms Average decrease in QRS duration -35 +/− 21.5 ms p < 0.001 Echocardiography demonstrated improvement in septal contraction abnormalities. Conclusions: 1) RVOS pacing in RBBB patients can significantly narrow the QRS complex on ECG. 2) Septal contraction abnormalities due to RBBB can be improved with RVOS pacing and optimal A-V timing. 3) Further studies are warranted to evaluate this therapy in a heart failure population.

2021 ◽  
Vol 5 (8) ◽  
Author(s):  
Dmytro Volkov ◽  
Dmytro Lopin ◽  
Stanislav Rybchynskyi ◽  
Dmytro Skoryi

Abstract Background  Cardiac resynchronization therapy (CRT) is an option for treatment for chronic heart failure (HF) associated with left bundle branch block (LBBB). Patients with HF and right bundle branch block (RBBB) have potentially worse outcomes in comparison to LBBB. Traditional CRT in RBBB can increase mortality and HF deterioration rates over native disease progression. His bundle pacing may improve the results of CRT in those patients. Furthermore, atrioventricular node ablation (AVNA) for rate control in atrial fibrillation (AF) can be challenging in patients with previously implanted leads in His region. Case summary  We report the case of 74-year-old gentleman with a 5-year history of HF, permanent AF with a rapid ventricular response, and RBBB. He was admitted to the hospital with complaints of severe weakness and shortness of breath. Left ventricular ejection fraction (LVEF) was decreased (41%), right ventricle (RV) was dilated (41 mm), and QRS was prolonged (200 ms) with RBBB morphology. The patient underwent His-optimized CRT with further left-sided AVNA. As a result, LVEF increased to 51%, RV dimensions decreased to 35 mm with an improvement of the clinical status during a 6-month follow-up. Discussion  Patients with AF, RBBB, and HF represent the least evaluated clinical subgroup of individuals with less beneficial clinical outcomes according to CRT studies. Achieving the most effective resynchronization could require pacing fusion from sites beyond traditional with the intention to recruit intrinsic conduction pathways. This approach can be favourable for reducing RV dilatation, improving LVEF, and maximizing electrical resynchronization.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
A M W Van Stipdonk ◽  
M Dural ◽  
F Salden ◽  
I A H Ter Horst ◽  
H J G M Crijns ◽  
...  

Abstract Background The effectiveness of cardiac resynchronization therapy (CRT) in patients without left bundle branch block (non-LBBB) QRS morphology is limited, compared to those with LBBB. Still, a substantial part of these patients can benefit from therapy and additional selection criteria are needed to identify these patients. Purpose To evaluate the association of additional baseline 12-lead ECG features; with clinical and echocardiographic outcomes in CRT-treated non-LBBB patients. Methods Pre-implantation 12-lead ECGs from 790 consecutive non-LBBB CRT patients from 3 implanting centres in the Netherlands were evaluated for the presence of predefined ECG parameters. QRS morphology (right bundle branch block and intraventricular conduction delay), QRS duration (≥/<150ms), QRS area (≥/<109μVs), left ventricular activation time ((≥/<125ms), and the presence of fragmented QRS (fQRS). The association with the primary endpoint, the combination of left ventricular assist device implantation, cardiac transplantation and all-cause mortality, was evaluated. Results There was a significantly lower occurrence of the primary endpoint in non-LBBB patients with QRS area ≥109 μVs (p<0.001) and in those without fQRS present (p=0.004) (figure 1). Figure 1 Conclusion A large QRS area and the absence of fQRS are positively associated to event free survival in non-LBBB patients treated with CRT. Whereas currently used patient selection cut-off QRS duration is not associated to outcome in these patients. These data may provide additional value for the non-LBBB patient selection for CRT and warrant prospective evaluation of these ECG features. Acknowledgement/Funding None


2013 ◽  
Vol 154 (18) ◽  
pp. 688-693 ◽  
Author(s):  
István Préda

If New York Heart Association Class II–IV heart failure is present, and ejection fraction ≤35%, electrocardiographic QRS width ≥ 120 ms in the presence of left bundle branch block, cardiac resynchronization therapy is indicated. Reevaluation of the data of cardiac resynchronization trials and electrophysiologic findings in left bundle branch block provided evidence that “true” left bundle branch block requires a QRS width of ≥130 ms (in woman) and ≥140 ms (in man). In “true” left bundle branch block, after the 40th ms of the QRS notched/slurred R waves are characteristic in minimum two of I, aVL, V1, V2, V5 and V6 leads, in addition to a ≥40 ms increase of the QRS complex, as compared to the original QRS complex. In contrast, slowly and continuously widened “left bundle branch block like” QRS patterns are mostly occur in left ventricular hypertrophy or in a metabolic/infiltrative disease. Orv. Hetil., 2013, 154, 688–693.


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