scholarly journals A Computer Simulation Research of Two Types of Cardiac Physiological Pacing

2021 ◽  
Vol 11 (1) ◽  
pp. 449
Author(s):  
Honglei Zhu ◽  
Lian Jin ◽  
Yanqi Huang ◽  
Xiaomei Wu
Keyword(s):  
Computer Simulation ◽  
Left Bundle Branch Block ◽  
Normal State ◽  
Simulation Method ◽  
Cardiac Modeling ◽  
Bundle Branch Block ◽  
Simulation Research ◽  
Qrs Duration ◽  
Electrical Activities ◽  
Atrial Excitation

This manuscript adopted the cardiac modeling and simulation method to study the problems of physiological pacing in clinical application. A multiscale rabbit ventricular electrophysiological model was constructed. We simulated His-bundle pacing (HBP) treatment for left bundle branch block (LBBB) and atrioventricular block (AVB), and left bundle branch pacing (LBBP) treatment for LBBB by setting various moments of the stimulus. The synthetic ECGs and detailed electrical activities were analyzed. Our electrophysiological model accurately simulated the normal state, HBP, and LBBP. The synthetic ECG showed that QRS duration was narrowed by 30% after HBP correction for LBBB. For LBBB correction with LBBP, the synthetic ECGs of LBBP starting before 30 ms (if the end of atrial excitation is set as 0 ms) presented right bundle branch block (RBBB), and those of LBBP starting at 30–38 ms were synchronous, while those of LBBP starting after 42 ms possessed LBBB morphologies. The best pacing results were obtained when LBBP started at 34 ms. This manuscript verified the feasibility of the constructed ventricular model, and studied the physiological pacing mechanism. The results showed that HBP realized correction for AVB and high LBBB. The performance of LBBP can be improved by applying the stimulus within a specific period of time (0–8 ms) after atrial excitation.

scholarly journals OPTIMIZATION OF RABBIT VENTRICULAR ELECTROPHYSIOLOGICAL MODEL AND SIMULATION OF SYNTHETIC ELECTROCARDIOGRAM

2021 ◽  
pp. 2150001
Author(s):  
HONGLEI ZHU ◽  
LIAN JIN ◽  
JIAYU ZHANG ◽  
XIAOMEI WU
Keyword(s):  
Normal State ◽  
Simulation Method ◽  
The Real ◽  
Model And Simulation ◽  
Network Simulations ◽  
Qrs Duration ◽  
Right Ventricular Apical Pacing ◽  
Cardiac Excitation ◽  
Electrocardiogram Ecg ◽  
Electrical Activities

This study aimed to use computer simulation method to study the mechanism of cardiac electrical activities. We optimized an electrophysiological rabbit ventricular model, including myocardial segmentation, heterogeneity and a realistic His-Purkinje network. Simulations of normal state, several types of ventricular premature contractions (VPC), conduction system pacing and right ventricular apical pacing were performed and the detailed cardiac electrical activities were studied from cell level to electrocardiogram (ECG) level. A detailed multiscale optimized ventricular model was obtained. The model effectively simulated various types of electrical activities. The synthetic ECG results were very similar to the real clinical ECG. The duration of QRS of typical VPC is 58[Formula: see text]ms, 71% longer than that of a normal-state synthetic QRS and the amplitude of the QRS is 35% larger, while the QRS duration and amplitude of the real clinical ECG of typical VPC are 69% longer and 36% larger than those of the real normal QRS. The duration of QRS of ventricular fusion beat is 31[Formula: see text]ms, 91% of that of a normal-state synthetic QRS and the amplitude of the QRS is 36% larger, while the QRS duration of the real clinical ECG of a ventricular fusion beat is 92% of the real normal QRS and the amplitude is 37% larger. Therefore, the results indicate that this model is effective and reliable in studying the detailed process of cardiac excitation and pacing.

scholarly journals Associations between left bundle branch block with different PR intervals, QRS durations, heart rates and the risk of heart failure: a register-based cohort study using ECG data from the primary care setting

Open Heart ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. e001425
Author(s):  
Marc Meller Søndergaard ◽  
Johannes Riis ◽  
Karoline Willum Bodker ◽  
Steen Møller Hansen ◽  
Jesper Nielsen ◽  
...  
Keyword(s):  
Heart Failure ◽  
Primary Care ◽  
Heart Rate ◽  
Left Bundle Branch Block ◽  
Bundle Branch Block ◽  
Increased Risk ◽  
Pr Interval ◽  
Qrs Duration ◽  
The Impact

AimLeft bundle branch block (LBBB) is associated with an increased risk of heart failure (HF). We assessed the impact of common ECG parameters on this association using large-scale data.Methods and resultsUsing ECGs recorded in a large primary care population from 2001 to 2011, we identified HF-naive patients with a first-time LBBB ECG. We obtained information on sex, age, emigration, medication, diseases and death from Danish registries. We investigated the association between the PR interval, QRS duration, and heart rate and the risk of HF over a 2-year follow-up period using Cox regression analysis.Of 2471 included patients with LBBB, 464 (18.8%) developed HF during follow-up. A significant interaction was found between QRS duration and heart rate (p<0.01), and the analyses were stratified on these parameters. Using a QRS duration <150 ms and a heart rate <70 beats per minute (bpm) as the reference, all groups were statistically significantly associated with the development of HF. Patients with a QRS duration ≥150 ms and heart rate ≥70 bpm had the highest risk of developing HF (HR 3.17 (95% CI 2.41 to 4.18, p<0.001). There was no association between the PR interval and HF after adjustment.ConclusionProlonged QRS duration and higher heart rate were associated with increased risk of HF among primary care patients with LBBB, while no association was observed with PR interval. Patients with LBBB with both a prolonged QRS duration (≥150 ms) and higher heart rate (≥70 bpm) have the highest risk of developing HF.

Abstract 13286: Non-Specific Intraventricular Conduction Delay and Risk of Sudden Death

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Audrey Uy-Evanado ◽  
Carmen Teodorescu ◽  
Kyndaron Reinier ◽  
Kumar Narayanan ◽  
Harpriya Chugh ◽  
...  
Keyword(s):  
Sudden Cardiac Death ◽  
General Population ◽  
Left Bundle Branch Block ◽  
Cardiac Death ◽  
Conduction Delay ◽  
Bundle Branch Block ◽  
Intraventricular Conduction ◽  
Qrs Morphology ◽  
Qrs Duration ◽  
Intraventricular Conduction Delay

Introduction: We and others have reported an independent association between prolonged QRS duration and risk of sudden cardiac death (SCD) in the general population. Left and right bundle branch block have been studied previously, but there is little information regarding non-specific intraventricular conduction delay and risk of SCD. Hypothesis: Completed conduction defects, including non-specific IVCD, are associated with increased SCD risk. Methods: Sudden cardiac death cases and controls from an ongoing large population based study in the Northwestern US (2002 to 2010) were included if age ≥ 35 years with a non-paced 12-lead ECG (recorded prior and unrelated to SCD in cases). QRS morphology was subcategorized as normal, intermediate [left anterior fascicular block (LAFB), left posterior fascicular block (LPFB), and incomplete right or left bundle branch block (IRBBB/ILBBB)] or completed conduction defects [left bundle branch block (LBBB), right bundle branch block (RBBB), or nonspecific intraventricular conduction delay (IVCD)]. Comparisons were conducted using chi-square tests for categorical variables and independent samples t-tests for continuous variables. Logistic regression was used to evaluate the association of QRS morphology with SCD. Results: We evaluated 761 SCD cases (64% male) and 539 controls (65% male). Cases were significantly older (69.7 vs 66.3 years, p<0.0001) with greater QRS duration (102 vs. 98 ms, p=0.001). For conduction categories, intermediate or completed conduction defects were significantly more common in cases whereas normal QRS morphology was more common among controls (p=0.01). And for specific morphology overall, QRS morphology patterns differed between cases and controls (p=0.03); abnormal QRS morphologies were more frequent in cases than controls except for LAFB. After adjustment for age and gender, however, only a finding of LBBB or non-specific IVCD remained a significant predictor of SCD [OR 1.34 (95% CI 1.03-1.75)]. Conclusions: LBBB and non-specific IVCD, but not RBBB, are significant predictors of SCD in the general population. These findings contribute to the utility of the 12-lead EKG for SCD risk stratification.

Evaluation of Conduction Disorders after Aortic Valve Replacement with Rapid Deployment Bioprostheses

2018 ◽  
Vol 13 (5) ◽  
pp. 356-360
Author(s):  
Augusto D'Onofrio ◽  
Lorenzo Bagozzi ◽  
Chiara Tessari ◽  
Annalisa Francescato ◽  
Giorgia Cibin ◽  
...  
Keyword(s):  
Left Bundle Branch Block ◽  
Pacemaker Implantation ◽  
Bundle Branch Block ◽  
End Point ◽  
Conduction Disorders ◽  
Single Center Study ◽  
Bundle Branch Blocks ◽  
Qrs Duration ◽  
Rapid Deployment ◽  
New Onset

Objective The aim of this retrospective, single-center study was to evaluate the occurrence of conduction disorders after rapid deployment aortic bioprosthesis implantation. Methods Electrocardiograms of patients undergoing INTUITY (Edwards Lifesciences, Irvine, CA USA) bioprosthesis implantation were collected at admission, during postoperative course, and at discharge. Primary end point was the occurrence of new-onset conduction disorders, defined as complete left bundle branch block, complete right bundle branch block, permanent pacemaker implantation, and worsening of pre-existing rhythm abnormalities. Secondary end points were the assessment of preoperative and postoperative QRS duration and the identification of transitory conduction disorders. Results Forty-four patients (July 2015–December 2016) were included in the analysis. Preoperatively, patients with normal conduction and with already existing disorders were 25 (56.8%) and 19 (43.2%), respectively. Primary end point occurred in 14 patients (31.8%). Two patients (4.5%) received pacemaker implantation. In patients with normal preoperative conduction, new abnormalities were found in eight cases (32%): all left bundle branch blocks with one pacemaker implantation. Worsening of pre-existing conduction disorders was found in six patients (31.6%) with one pacemaker implantation. QRS duration increased in 20 patients (45.4%), and average increase was 37 milliseconds. Overall, we observed a significant increase of QRS (96 ± 21 milliseconds vs. 111 ± 28 milliseconds, P < 0.001). Three patients experienced a new-onset temporary left bundle branch block. Conclusions New-onset conduction disorders or worsening of pre-existing rhythm abnormalities occur in one third of patients after rapid deployment aortic bioprosthesis implantation. Although the incidence of postoperative pacemaker implantation before discharge is low, strict follow-up is mandatory to identify a potential need for pacemaker implantation in a timely manner.

P2630Incidence and prognostic impact of new-onset left bundle branch block in patients with heart failure and reduced ejection fraction

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
S L Kristensen ◽  
R Roerth ◽  
P S Jhund ◽  
S Beggs ◽  
L Kober ◽  
...  
Keyword(s):  
Heart Failure ◽  
Ejection Fraction ◽  
Left Bundle Branch Block ◽  
Bundle Branch Block ◽  
Reduced Ejection Fraction ◽  
Patients With Heart Failure ◽  
All Cause Mortality ◽  
Qrs Duration ◽  
New Onset

Abstract Background Cardiac resynchronization therapy (CRT) improves survival in patients with heart failure, reduced ejection fraction (HFrEF) and left bundle branch block (LBBB). However, little is known about the incidence of LBBB in HFrEF and the risk factors for developing this. We addressed these questions in the PARADIGM-HF and ATMOSPHERE trials. Methods We identified 7703 patients with a non-paced rhythm on their baseline ECG, a QRS<130 ms, and at least one follow-up ECG (done at annual visits and end of study). Patients were stratified by baseline QRS duration (≤100 ms - reference; 101–115 ms and 116–129 ms) and followed until development of QRS duration ≥130 ms with a LBBB configuration or latest available ECG. The crude LBBB incidence rate per 100 person-years (py) was identified in the three QRS duration subgroups. Additionally, we examined risk of the primary composite outcome of cardiovascular death or HF hospitalization, and all-cause mortality, in patients with incident LBBB vs. no incident LBBB. Results Overall, 313 of 7703 patients (4%) developed LBBB during a mean follow-up of 2.7 years, yielding an incidence rate of 1.5 per 100 py. The rate ranged from 0.9 in those with QRS ≤100 ms to 4.0 per 100 py in patients with QRS 116–129 ms. Other predictors of incident LBBB included male sex, age, lower LVEF, HF duration and absence of AF. The risk of the primary composite endpoint was higher among those who developed incident LBBB vs no incident LBBB; event rates 13.5 vs 10.0 per 100 py, yielding an adjusted HR of 1.43 (1.05–1.96). For all-cause mortality the corresponding rates were 12.6 vs 7.3 per 100 py; HR 1.55 (1.16–2.07) (Table 1). Table 1. Risk of outcomes according to incident LBBB during follow-up No. events Crude rate per 100py Adjusted* HR (95% CI) HF hospitalization or CV death   No incident LBBB 2145 10.0 (9.6–10.4) 1.00 (ref.)   Incident LBBB 43 13.5 (10.0–18.2) 1.43 (1.05–1.96) All-cause mortality   No incident LBBB 1662 7.3 (6.9–7.6) 1.00 (ref.)   Incident LBBB 48 12.6 (9.5–16.7) 1.55 (1.16–2.07) Conclusion Among patients with HFrEF, the annual incidence of new-onset LBBB (and a potential indication for CRT), was around 1.5%, ranging from 1% in those with QRS duration below 100 ms to 4% in those with QRS 116–129 ms. Incident LBBB was associated with a much higher risk of adverse outcomes, highlighting the importance of repeat ECG monitoring in patients with HFrEF. Acknowledgement/Funding Novartis

P1242ECG predictors of outcome in non-left bundle branch block cardiac resynchronization therapy patients

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 ◽  
...  
Keyword(s):  
Cardiac Resynchronization Therapy ◽  
Patient Selection ◽  
Primary Endpoint ◽  
Left Bundle Branch Block ◽  
Left Ventricular ◽  
Cardiac Resynchronization ◽  
Resynchronization Therapy ◽  
Bundle Branch Block ◽  
Qrs Morphology ◽  
Qrs Duration

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

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