bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ventricular tachycardia as presenting arrhythmia as a determinant of appropriate implantable cardioverter-defibrillator therapy in secondary prevention
Authors: Noordman A B P , Rienstra M , Blaauw Y , Mulder B A , Maass A H 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Sudden cardiac death (SCD) is a leading cause of death. The implantable cardioverter-defibrillator (ICD) is an established therapy to prevent SCD in patients with prior ventricular tachycardia (VT) or ventricular fibrillation (VF). Determination of patient characteristics related to ICD therapies may provide targets for more intensive monitoring or management of ventricular arrhythmias. Therefore, we aimed to find determinants of appropriate ICD therapy.

Methods
In this retrospective, single-centre study, 223 consecutive secondary prevention ICD recipients were included. Data was obtained on medical history, laboratory measurements, electrocardiography and echocardiography. The primary outcome was appropriate ICD therapy, which included shock and antitachycardia pacing (ATP) given for VF or VT. Backward stepwise Cox regression analysis was performed to find determinants of appropriate therapy.

Results
The median age of the study population was 65.3 years (interquartile range (IQR) 55.4 – 72.0 years). 188 (84.3%) patients were male. 153 (68.6%) patients had ischemic heart disease. During a median follow-up duration of 6.00 years (interquartile range (IQR) 4.85 – 7.70 years), appropriate ICD therapy occurred in 89 (39.9%) patients, appropriate ICD shock in 65 (29.1%) patients, death in 55 (24.7%), inappropriate shock in 11 (4.9%) and device-related complications in 18 (8.1%). VT as index arrhythmia, QRS fragmentation and diminished right ventricular function were determinants of appropriate device therapy. Interestingly, whereas the majority of patients (141 (63.2%)) had an ICD implanted for initial presentation with VF, the first occurrence of appropriate therapy during follow-up was for monomorphic VT in the majority of patients (84 (94.4%)).

Conclusion
In patients with a secondary prevention ICD indication, VT as presenting arrhythmia is a determinant of appropriate ICD therapy during follow-up. Most ICD therapies during follow-up were applied for monomorphic VT.
Do co-morbidities, frailty and functional status identify patients who may not benefit from ICD therapy?
Authors: Wilson D G , James S X , Power D F , Sharma-Oates A , Lord J M , Roberts P R , Morgan J M 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Boston Scientific ISR lite.

Background
In carefully selected patients, Implantable Cardioverter Defibrillators reduce all-cause mortality by reducing the burden of sudden cardiac death. Most patients who have an ICD implant do not receive life-prolonging therapy from it. Little research has been undertaken to determine which patients benefit the least from ICD therapy. As patients age and accumulate comorbidities, the risk of death increases and the benefit of ICDs diminishes.

Purpose
We sought to evaluate the impact of comorbidity, frailty, functional status on death prior to ICD therapy as this group has the least to gain from ICD therapy.

Methods
A prospective, multicentre, observational study involving 15 English hospitals was undertaken. Patients were eligible for inclusion for the study if they were scheduled to have a de novo, replacement or an upgrade to a high-energy device (transvenous or subcutaneous ICD or CRT-D). Baseline characteristics were collected including age, gender, device type, LV function, medication, baseline bloods if available and were asked to complete a frailty assessment, Fried score; a functional status questionnaire (EQ5D5L), Charlson Co-morbidity Score and EQ5D5L data were calculated.

Results
In total, 662 patients were enrolled, mean age 65.6 (IQR 65-75) years, 77.3% male, 55.9% de novo implants, 33.4% replacements and 10.5% upgrade. Overall, 32% were for a secondary prevention indication, 49.% had a single or dual chamber transvenous ICD, 45.3% had a CRT-D and 5% had an S-ICD) implanted. A total of 63 patients (9.5%) died across this period, of these, 54 died without receiving appropriate therapy. Frailty was present in 83/662 (12.5%) and severe co-morbidity was present in 69/662 (10.4%). The overall survival probability estimated to be 90.2% at 2.5 years, and was 68% in frail patients. Figure 1.
Multivariate predictors of death with no appropriate therapy were identified and a risk score comprising frailty, severe co-morbidity, age &gt;70 years, eGFR &lt;60 ml/min/1.73 m2 EQ5D5L &lt;0.6 was developed. Table 1. The model performance was: sensitivity= 80.7%; specificity = 81.6%; precision 27.3%; accuracy 81.6% and AUC 0.81.

Conclusion
Frailty and severe co-morbidity are powerful, independent predictors of death with no appropriate in ICD/CRT-D recipients.
Clinical predictors of very low defibrillation threshold in the extravascular ICD
Authors: Murgatroyd F , Crozier I , Leclercq C , Clementy N , Amin A , Roukoz H , Nikolski V , Lande J , Degroot P , Boersma L 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: Private company. Main funding source(s): Medtronic, Inc.

Background
The extravascular ICD (EV ICD) is a 40J device utilising a lead placed behind the sternum and a subcutaneous can in the axilla to achieve defibrillation efficacy, size, and predicted longevity comparable to transvenous devices, as well as providing pause prevention and antitachycardia pacing. In the worldwide EV ICD Pivotal Study, 98.7% of 302 patients completed the defibrillation (DF) testing protocol with a safety margin of ≥10J. In 71.5% of patients, defibrillation was successful at lower energies (20J or 15J). Factors associated with lower energy defibrillation in EV ICD patients have yet to be determined.

Purpose
In this analysis we examine what factors are associated with very low DF thresholds (safety margin ≥20J).

Methods
Multivariate analysis was performed to look for clinical and implant predictors in patients with success at very low energies (15J or 20J, n = 216) versus those in whom either success was achieved at higher energies (2x 30J before or after polarity changes/revisions, n = 82), or DF testing failed (n=4) or was incomplete (n = 4).

Results
24 variables were examined: 18 pre-implant clinical factors (including gender, body measurements, aetiology, LV ejection fraction, medications) and 6 peri-implant electrical measurements. Univariate analysis identified 5 clinical factors and 4 implant measurements as predictors of defibrillation success at very low energy; multivariate analysis with a gate of p &lt;0.1 found 6 factors to be independent predictors (see table).

Conclusions
Certain pre-implant clinical factors and implant details are independent predictors of successful defibrillation at very low energies. If confirmed, these findings suggest that in many cases DF testing at EV ICD implant may not be necessary.
Effects of CRT on atrial and ventricular arrhythmias in patients with HF
Authors: Taleski J , Pocesta B , Janusevski F , Risteski D , Poposka L 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
Cardiac resynchronization therapy (CRT) is an accepted treatment for patients with heart failure (HF). Cardiac arrhythmias present a significant and complex issue in this patient group. Evidence exploring the influence of CRT on cardiac arrhythmias rate variations is limited.

Purpose
Our research investigates the effectiveness of CRT in the treatment of existing and newly diagnosed atrial and ventricular arrhythmias, and impact of epicardial lead position on these arrhythmias rate variations, as well as on the CRT response.

Methods
This single-center, prospective, observational study included 75 consecutive patients admitted for CRT implantation over a 12-month period. All included patients had episodes of atrial and/or ventricular arrhythmias, diagnosed by 12-lead ECG or 24-hour Holter monitoring. Pre-procedural demographic characteristics were collected for all patients, including ECG records, NYHA functional class, echocardiographic assessment of left ventricular ejection function and questionnaire for quality-of-life. During device follow up atrial and ventricular arrhythmias appearance was monitored. Additional assessment of echocardiographic parameters, NYHA - functional class, quality of life and rate of major cardiovascular complications and rehospitalizations was performed.

Results
The mean age of the patients was 62.4 ± 10.3 years, with 74.6% male and 25.3% females. 72% had a non-ischemic HF etiology. Pre-procedural paroxysmal AF was present in 34.7%, persistent AF in 36%, PVCs in 32%, NSVT 16%, and VT in 18,7% patients. 55% of the included patients were responders to CRT. Our results showed decrease in rate of all ventricular arrhythmias, with significant reduction in the percentage of VT (p=0.003), regardless of CRT response. Significant reduction of PVCs and NSVT rate (p=0.012 & p=0.024) was found in the responder group of patients. Regarding AF, our results showed a decrease in the number of AF events in both patient groups, however this was most visible in the responder patients with paroxysmal AF (p=0.057). In CRT responders, left ventricular pacing lead was most commonly located in a lateral branch vein of the CS with middle and mid/lateral position. In terms of quality of life and general condition of the patients, we noticed a significant improvement in the NYHA - functional class (p &lt;0.001), as well as in both parts of the quality-of-life assessment questionnaire (p=0.0135, p&lt;0.001).

Conclusion
CRT is an effective treatment for atrial and ventricular arrhythmias in HF patients, especially in responders to this therapy. LV epicardial lead position proved to be very important influence in the process of LV reverse remodeling, which is in direct correlation of the CRT responders and its effectiveness in reducing the rate of cardiac arrhythmias.
Hemodynamic optimization of cardiac resynchronization therapy by heart sound sensor in pulse generator
Authors: Prinzen F , Westphal P , Luo H , Shahmohammadi M , Delhaas T , Cornelussen R N 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: Public grant(s) – EU funding. Main funding source(s): EU-HORIZON 2020-International Training Network H2020-MSCA-ITN-2017.

Background
Continuous ambulatory AV-optimization for Cardiac Resynchronization Therapy (CRT) is mainly performed by electrical means.

Objective
Develop an estimation model of cardiac function that uses feedback from a piezoelectric transducer embedded in an internal pulse generator to guide CRT optimization.

Methods
During implantation procedures measurements were performed of left ventricular pressure (LVP) and heart sound waveforms, the latter using the piezoelectric alarm transducer of the device in 22 CRT patients at atrioventricular (AV)-delays of 60-330 ms. Post-hoc, machine learning (ML) was employed to produce models that use heart-sound based features to estimate cardiac function in terms of maximum LVP (LVPmax) and the maximum positive derivative of LVP (LVdP/dtmax). Polynomial curve fitting was used to compare estimated and measured AV-delays with highest LVPmax and LVdP/dtmax.

Results
The figure displays the concept of the study and an example of the measured and estimated optimization curve. With a dataset of ~30,000 beats, ML provided three most suitable features. Using LVPmax, ML-based estimated optimal AV-delays were not significantly different from measured ones (-5.6 ± 17.1ms for LVPmax and +5.1 ± 46.7ms for LVdP/dtmax). The difference in function between the estimated and measured optimal AV-delays was small and not statically significant (1 ± 3mmHg for LVPmax and 9 ± 57mmHg/s for LVdP/dtmax).

Conclusion
Heart sound sensors in devices in combination with ML provide a reliable assessment of absolute LVPmax and LVdP/dtmax and may be used for continuous optimization of AV-delays in CRT patients.
Interaction between atrial-ventricular and ventricular-ventricular delay in CRT
Authors: Bank A , Burns K , Brown C , Johnson K 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: Foundation. Main funding source(s): United Hospital Medical Education and Research Committee, United Hospital Foundation.

Background
Appropriate programming of atrial-ventricular delay (AVD) and ventricular-ventricular delay (VVD) is critical for delivery of optimal cardiac resynchronization therapy (CRT). However, there is debate over how to determine optimal programming for a given patient. This is complicated by the use of 2 distinct methods of defining the activation timing at a given AVD and VVD used by different device manufacturers.

Purpose
To describe how electrical dyssynchrony is affected by changes in AVD, VVD and the method used to program AVD and VVD.

Methods
We measured electrical synchrony at multiple combinations of AVD/VVD in 41 patients with underlying left bundle branch block (LBBB) using a novel methodology called electrical dyssynchrony mapping (EDM). Electrical dyssynchrony was quantified by cardiac resynchronization index (CRI), calculated as % change in area under the curve between combinations of 9 anterior and 9 posterior surface electrograms.

Results
EDM (Figure 1) shows CRI at multiple combinations of atrial-to-RV-paced, (A-RVp, y-axis) and atrial-to-LV-paced (A-LVp, x-axis) intervals. VVD changes to produce LV preactivation are shown at short and long AVDs using the methods of 2 different CRT device manufacturers: Method 1: fixing A-RVp and shortening A-LVp; and Method 2: fixing A-LVp and lengthening A-RVp. During simultaneous BiV pacing, CRI at short AVD (61.7±20.9) was significantly (p&lt;0.001) greater than at long AVD (46.9±14.0). On average, CRI was significantly greater at short AVD than at long AVD during LV preactivation of 20 or 40 ms (Figure 2). At short AVD, Method 2 resulted in slightly but significantly better CRI at VVD 20 and 40 ms. At long AVD, Method 1 resulted in large and significantly better CRI at VVD 20 and 40 ms.

Conclusions
The interaction between AVD and VVD is complex, and the electrical resynchronization achieved when programming depends on both the AVD at which VVD is programmed, and the programming algorithm used by the device manufacturer. At longer AVDs, Method 1 yields significantly better resynchronization than Method 2 when programming VVD. Studies assessing effects of AVD and VVD programming that involve patients with CRT devices from different manufacturers need to modify programming parameters appropriately in order to accurately interpret results.

Methods
For programming VVD and EDM
Both LBBP and LVSP significantly improve ventricular dyssynchrony and effectivity of LV performance compared to RV apical pacing in heart failure patients with LBBB and an indication to CRT
Authors: Curila K , Stros P , Poviser L , Sussenbek O , Waldauf P , Vondra V , Smisek R , Leinveber P , Jurak P 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Supported by the Ministry of Health of the Czech Republic, grant number NU21-02-00584 and by the project National Institute for Research of Metabolic and Cardiovascular Diseases (Programme EXCELES, ID Project No. LX22NPO5104) - Funded by the European Union – Next Generation EU.

Background
Left bundle branch pacing and left septal myocardial pacing (LVSP) are novel methods of CRT in patients with heart failure. However, their exact impact on ventricular synchrony visualized by noninvasive assessment and the LV performance effectivity is unknown.

Aims
To compare ventricular synchrony and a change in blood pressure values between nonselective left bundle branch pacing (nsLBBP), LVSP, and RV apical pacing (RVAP) in heart failure patients.

Methods
In patients with CRT indication and LBBB, a lead was placed in the left septal area, where the transition between nsLBBP and LVSP was observed during decremental output pacing. Another lead was placed in the RV apex. UHF-ECG was used to assess ventricular synchrony during RVAP, nsLBBP, and LVSP. Dyssynchrony parameter e-DYS was calculated as an absolute value of the time difference between the first and last activation. Systolic blood pressure measurements were obtained invasively from the radial artery during VVI pacing at rates ten beats/minute higher than spontaneous rhythm. The protocol included multiple transitions between RVAP, nsLBBP, and LVSP.

Results
The study protocol was finalized in six patients; mean age 67 years, LVEF 33%, 3 had ischemic cardiomyopathy, and QRSd during spontaneous LBBB was 172±8 ms. QRSd was prolonged to 182±10ms during RVAP and shortened to 145±12 ms and 149±13 ms during nsLBBP and LVSP, respectively. The dyssynchrony parameter e-DYS shortened from 46±18 ms during RVAP to 1±16 ms during nsLBBP and 12±13 ms during LVSP, p &lt; 0.05 for RVAP vs. nsLBBP and LVSP, and p = 0.4 for nsLBBP vs. LVSP. Both nsLBBP and LVSP led to a significant increase in the systolic blood pressure compared to RVAP (9±1 mmHg and 10±1 mmHg for nsLBBp and LVSP vs. RVAP, p &lt; 0.001, respectively. nsLBBP produced slightly higher systolic blood pressure than LVSP (mean difference 2±1 mmHg, p = 0.005.

Conclusion
In patients with LBBB and CRT indication, both nsLBBp and LVSP significantly reduce ventricular dyssynchrony and lead to better effectivity of the LV performance compared to RV apical pacing.
Left bundle branch area pacing produces more physiological ventricular activation than biventricular pacing in patients with heart failure and LBBB
Authors: Sussenbek O , Rademakers L , Waldauf P , Jurak P , Stros P , Poviser L , Vesela J , Plesinger F , Halamek J , Smisek R , Leinveber P , Curila K 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: Public grant(s) – EU funding. Main funding source(s): National Institute for Research of Metabolic and Cardiovascular Diseases, Programme EXCELES, Ministry of Health of the Czech Republic, grant number NU21-02-00584.

Introduction
Biventricular pacing (BiV) is an established treatment for patients with heart failure and dyssynchronous ventricular activation. Left bundle branch area pacing (LBBAP) appears to be a promising alternative to BiV-CRT. To date, there is insufficient data regarding their effect on the reduction of ventricular dyssynchrony.

Purpose
To compare ventricular synchrony during spontaneous rhythm, BiV and LBBAP in patients with heart failure, reduced left ventricular ejection fraction (LVEF), and LBBB using ultra-high-frequency ECG (UHF-ECG).

Methods
This was a retrospective analysis of consecutive patients with indication to CRT from two centers. It included patients with heart failure, QRS of LBBB morphology, and LVEF ≤ 40%, treated by BiV and/or LBBAP-CRT. UHF-ECG data were obtained during spontaneous and paced rhythms. These parameters were calculated: eDYS (time difference between the first and last activation), Vdmean (average of V1-V8 local depolarization durations) and QRSd (measured from pacing artifact).

Results
Analyzes were performed on 80 spontaneous rhythms, 39 biventricular captures and 64 LBBAP, obtained from 80 patients. Their mean age was 74±10 years, 61% were men, mean LV ejection fraction was 31±9 %, and 32% had ischemic cardiomyopathy. Both BiV and LBBAP-CRT significantly reduced QRSd compared to the spontaneous rhythm (from 172 ms, 95% CI [168;176] to 146 ms [141;152] during BiV and 143 ms [139;149] during LBBAP). Also, the eDYS and Vdmean were significantly reduced by both BiV and LBBAP-CRT, i.e., the eDYS from 82 ms [76;86] during LBBB to 33 ms [28;37], p&lt;0.001 during biventricular pacing and to 24 ms [20;28], p&lt;0.001, during LBBAP and Vdmean from 71 ms [68;73] to 59 ms [56;61], p&lt;0.001 during BiV and to 53 ms [51;55], p&lt;0.001 during LBBAP. Although the QRSd did not differ between LBBAP and biventricular pacing (143ms [139;148] vs 146ms [141;152], p=NS), LBBAP compared to BiV led to significantly shorter eDYS (24ms [20;28] vs 33ms [28;38]; p&lt;0.008 and Vdmean (53ms [51;55] vs 59ms [56;61], respectively; p&lt;0.003}.

Conclusions
In patients with heart failure, LBBB and reduced LVEF, both BiV and LBBAP CRT significantly reduce ventricular dyssynchrony compared to the spontaneous rhythm. Our results indicate that LBBAP is associated with more physiological ventricular activation than BiV-CRT.
Ventricular dyssynchrony assessed by ultra-high-frequency electrocardiography predicts the response to biventricular cardiac resynchronization therapy
Authors: Leinveber P , Lipoldova J , Nagy A , Matejkova M , Meluzin J , Novak M , Jurak P , Halamek J , Plesinger F , Smisek R , Waldauf P , Vesela J , Mizner J , Curila K 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Supported by the European Regional Development Fund - Project ENOCH No.CZ.02.1.01/0.0/0.0/16_019/0000868, by the project National Institute for Research of Metabolic and Cardiovascular Diseases (Programme EXCELES, ID Project No. LX22NPO5104) - Funded by the European Union – Next Generation EU, by the Ministry of Health of the Czech republic, grant number NU21-02-00584, and by the CAS project RVO:68081731.

Background
Ultra-High-Frequency ECG (UHF-ECG) visualizes ventricular dyssynchrony during spontaneous and paced rhythms. It is unknown whether the UHF-ECG can be used to predict the response to Biventricular cardiac resynchronization therapy (CRT) in patients with heart failure and wide QRS complex.

Purpose
To show a predictive value of UHF-ECG dyssynchrony parameters in patients with an indication of Biventricular CRT.

Methods
This prospective study included consecutive patients with heart failure NYHA II-III, LVEF ≤ 35%, and QRS duration &gt; 120 ms of nonRBBB morphology. All patients received biventricular CRT. Clinical data, UHF-ECG ventricular dyssynchrony assessment were done before, and echocardiography also six months after the CRT. A positive response was defined by a change in LVESV ≥ 10%. Ventricular dyssynchrony parameter e-DYS was defined as a difference between the first and last UHF-ECG ventricular activation.

Results
The study population included 92 patients of mean age 66±9 years, 76% men, LVEF 24±9%, and 45% with ischemic cardiomyopathy. The average change of the LVEF after six months of CRT was 5% and was greater in non-ischemic than ischemic CMP (7% vs. 3%, p &lt; 0.001). 29% of the patients were nonresponders to CRT by the LVESV change. The optimal value of e-DYS to predict response after CRT was 47 ms (sensitivity 78%, specificity 79%). In univariate analysis, the e-DYS &gt; 47 ms, QRSd ≥ 150ms, female sex, presence of non-ischemic heart disease, and Strauss LBBB were significant predictors of response; however, after multivariate analysis, only e-DYS &gt; 47 ms remained significant predictor of response after CRT (p = 0.008).

Conclusion
In nonRBBB patients with heart failure and CRT indication, UHF-ECG electrical ventricular dyssynchrony during the spontaneous rhythm is the predictor of echocardiographic response to CRT.