bluuebunny/crossref_metadata_2025 huggingface dataset:
Diagnostic reliability of AV synchrony self-diagnostics in leadless VDD pacemakers
Authors: Neugebauer F , Noti F , Van Gool S , Roten L , Baldinger SH , Seiler J , Madaffari A , Servatius H , Ryser A , Tanner H , Reichlin T , Haeberlin A
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Introduction

Leadless pacemakers (PMs) capable of atrio-ventricular (AV) synchronous pacing have been introduced recently. These devices provide mechanical atrial sensing by detection of the atrial contraction via an accelerometer. Atrial tracking may be disturbed by external influences such as body motions and higher heart rates in real life. To track the amount of AV synchronous pacing, the device statistic classifies all sensed and paced QRS complexes according to presumed AV synchrony. The reliability of this self-diagnostics to estimate the true degree of AV synchrony, however, is insufficiently studied.

Purpose

To investigate the informative value of the device statistics offered by leadless VDD PMs regarding true AV snychrony.

Methods

We prospectively included all patients who received a leadless VDD PM between 07/2020 and 05/2021 at our center in this observational study. During the regular outpatient follow-ups, device interrogation was performed, which included evaluation of the PM statistics. True AV synchrony (defined as a QRS complex preceded by a p-wave within 300ms) was analyzed repeatedly during follow-up using Holter ECGs.

Results

We analysed 34 Holter ECGs from 20 outpatients (816 hours of ECG in total). Patients had a median age of 80 years (interquartile range 76-86 years), 55% were females. For Holter ECG sequences that showed high degree or complete AV-Block (>80% ventricular pacing), the percentage of paced beats that were presumed to be AV synchronous by the device statistic (ratio "AM-VP"/total VP) correlated well with AV synchrony as assessed using Holter-ECGs (Kendall’s τ=0.312, p<0.001). AV synchrony in the Holter ECG was different in patients with <66.6% presumed AV synchrony than in patients with >66.6% presumed AV synchrony (p<0.001, figure). For Holter ECG sequences with mostly preserved intrinsic AV conduction (<20% ventricular pacing), the ratio "AM-VP"/total VP was not predictive for true AV synchrony (Kendall’s τ=0.07, p=n.s.). In this situation, however, "VS only" (Kendall’s τ=0.110, p=0.005) correlated with true AV synchrony (due to AV conduction mode switch) and "VP only" showed an inverse correlation with AV synchrony (Kendall’s τ=-0.215, p<0.001).

Conclusion

Leadless PMs provide device statistics that show a correlation with true AV synchrony. The clinical setting as well as the device programming (e.g. AV conduction mode switch) significantly influence the predictive value of the different parameters of the device’s statistics.
Electrocardiographic analysis of left bundle branch area pacing induced right ventricular activation delay
Authors: Ozpak E , Calle S , Demolder A , Kizilkilic S , Timmermans F , De Pooter J
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Left bundle branch area pacing (LBBAP) aims to capture the area of left bundle branch, resulting in fast activation of the left ventricle (LV) but delayed right ventricular (RV) activation. During intrinsic cardiac conduction, delayed RV activation results on the electrocardiogram (ECG) in a right bundle branch block (RBBB) pattern and is generally considered benign. As such, LBBAP-induced delayed RV activation is thought not to be harmful. However, to what extent left and right ventricular activation times during LBBAP resembles that of healthy individuals with acquired RBBB is currently not known.

Methods

Individuals with incomplete RBBB (iRBBB), complete RBBB (cRBBB) and LBBAP were included. Standard twelve lead electrocardiograms (ECG) were stored and analysed digitally using the MUSE ECG database. QRS duration was measured as global QRS duration. Left and right ventricular activation times were estimated by R-wave peak time in lead V6 (V6RWPT) and R’ peak time in lead V1 (V1RWPT), respectively. Delayed RV activation was further characterized by duration and area of R’ wave in lead V1.

Results

Paced QRS duration during LBBAP (n=86) measured 129±15ms whereas QRS duration of iRBBB (n=422) and cRBBB (n=223) individuals measured 103±8ms and 142±17ms respectively (p<0.001). V6RWPT during LBBAP (47±15ms) was significantly longer than V6RWPT in iRBBB (40±5ms) and cRBBB (39±7ms) (p<0.001). With LBBAP, V1RWPT (83±15ms) became delayed compared to iRBBB (74±9ms, p< 0.001), but remained shorter in comparison to cRBBB (98±17ms, p<0.001). Patients with LBBAP were further characterized by V1 R’ duration and R’ area which were shorter and smaller compared to cRBBB but similar to iRBBB individuals.

Conclusion

LBBAP-induced delayed RV activation resembles electrocardiographically more closely to the delayed RV activation as seen in individuals with incomplete rather than complete RBBB. Left ventricular activation times remain slightly prolonged during LBBAP as compared to RBBB individuals.
Usefulness of the physiological single chamber pacemaker VDD in elderly patients with normal sinus rhythm
Authors: Martinho A , Telo M , Antonio N , Almeida J , Elvas L , Goncalves L
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

In frail elderly patients or when atrioventricular block (AVB) is paroxysmal, and pacing anticipated to be infrequent, single chamber pacing (VVI or VDD) may be considered as it carries a lower complication rate compared with DDD devices. For sinus rhythm patients, the single lead VDD, by preserving atrial sensing, is a more physiological mode than VVI devices, with comparable time procedure and complication rates. However, there are few data assessing the performance of VDD pacemakers in elderly patients, with AVB and sinus rhythm.

Purpose

We want to evaluate the 3-years performance of VDD pacemakers (PM) in frailty elder patients with AVB.

Methods

We conducted a retrospective, observational study of 200 elderly (³75 years) patients with AVB and normal sinus rhythm who consecutively implanted VDD PM between 2016 and 2018. Baseline clinical characteristics were analyzed, and a 3-years follow-up was performed: atrial undersensing, atrial fibrillation (AF), heart failure (HF) hospitalization, cardiovascular (CV) and non-CV death.

Results

Mean age was 84±5 years and 55% were female. The study population presented several comorbidities: 74% had atrial hypertension, 49% dyslipidemia, 35% chronic kidney disease and 28% diabetes. After 3-years follow-up most of the patients (90%; n=162) were still programmed in their original mode with good atrial sensing. Due to permanent AF, 4%(n=8) patients had been switched to VVIR mode and 5.5% (n=11) due to P-wave undersensig. 0ne-third (n=65) died during follow-up, 89% (n=58) due to non-CV causes. Low amplitude P-wave (<0.5mV) at baseline had a numerical, non-statistically significant association with atrial undersensig and AF at 3-years (p=0.14 and p=0.77, respectively). Atrial undersensing during follow-up didn’t relate with all-cause death and HF hospitalization (p=0.58 and p=0.64, respectively), but was associated with atrial fibrillation (12.7% vs 31.6%, p=0.038).

Conclusion

A significantly larger number of VDD-paced elderly patients maintain their original mode program with good atrial sensing. Moreover, atrial undersensing did not influence mortality or HF hospitalization rate. These results reinforce the benefit of VDD use among frail and elderly patients.
Fractured epicardial lead in paediatric patients: can they be safely repaired?
Authors: Silvetti M S , Campisi M , Silvetti G , Tamburri I , Saputo FA , Battista V , Albanese S , Drago F
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction

Before bipolar epicardial leads became widely available and used by heart surgeons, unipolar epicardial leads were frequently implanted in small children requiring permanent pacing. Main complications are lead fractures causing pacing/sensing defect. Therefore, patients should undergo new epicardial or endocardial lead implantation with relevant procedural risks, especially in complex congenital heart disease (CHD). Proximal fractures, close to the generator, may be repaired using a dedicated Unipolar Lead Adapter and Extension, with reduced operative risks. Purpose of the study is the retrospective analysis of the outcome of the repair of unipolar epicardial leads in young patients (pts) in a single tertiary paediatric center.

Methods

Consecutive patients with proximal fracture underwent a trial of lead repair using the lead adapter/extension, during general anaesthesia, cefuroxime antibiotic profilaxis, from 2004 to 2020. Lead data (threshold, sensing, impedance) were compared before and after the repair procedure.

Results

18 patients with CHD (12pts, 10 of whom complex, 6 post-Fontan) or normal structural heart (6pts), who underwent pacemaker implantation at 2.5 (0.7-5.8)years of age for congenital/postoperative atrioventricular block (11pts) and sinus node dysfunction (7pts), showed lead (7 atrial, 11 ventricular) fractures after chronic pacing. At 13 (8-17)years of age, all leads were successfully repaired without any complications. Follow-up was 4 (2-6)years. Four pts (22%) showed again fractures of the repaired lead, after 1 month, 1and 3 years (2pts). Electrical lead parameters are shown in table 1: there were not significant differences between consecutive time of controls, also in the atrial and ventricular lead subgroups.

Table 1.-------------------Pre-repair;--intraprocedural;---1 month;----------1 year;-------------4 years.

Threshold (V/0.4 ms):--1.1 (0.7-1.4);--1.0 (0.8-1.6);-------1.2 (0.9-1.5);-----1.2 (0.9-2.1);-------1.5 (1.1-1.8).

Sensing (mV):--------- 7 (2.4-12);------5.4 (1.3-15);-------4 (1.5-11);----------5 (1.6-12);---------3 (2-10).

Impedance (ohm): 343 (289-407);---350 (246-415);--346 (250-432);--374 (250-589);--362 (220-470).

Conclusion

The repair of fractured unipolar epicardial leads in young patients is a safe and effective procedure, with few complications during follow-up. Effective repair can delay more aggressive procedures.
Transvenous lead advancement in paediatric pacing to overcome growth stretching
Authors: Silvetti M S , Tamburri I , Silvetti G , Campisi M , Saputo FA , Battista V , Drago F
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction

One of the main complications of transvenous leads implanted in paediatric patients is the stretching of the lead caused by the somatic growth. It may cause pacing and sensing defects and lead dislodgement or even fracture. Absorbable lead ligature and atrial loop may reduce this risk. However, the loop may induce traction or may unroll too early and therefore impair lead function. Lead extraction and replacement is another solution, although it has some procedural risks in young patients. Lead advancement through pushing it from the pocket may solve growth-induced traction and spare the electrode throughout childhood until post-puberty.

Purpose of the study is the retrospective analysis of the outcome of the transvenous lead advancement in children with a pacemaker (PM) in a single tertiary paediatric center.

Methods

Consecutive patients with a VVIR PM implanted for isolated congenital complete atrioventricular block (no structural heart disease) in alternative right ventricular (RV) pacing sites, with lead stretching underwent a trial of lead advancement during general anaesthesia, cefuroxime antibiotic profilaxis, from 2014 to 2021. After venous angiography showed venous patency, the PM pocket was opened, the lead was released from subcutaneous adherences and with a stylet was gently advanced to create a semi-loop in the atrium without dislodging the tip. Lead data (threshold, sensing, impedance) were compared before and after the procedure. Data are expressed as median (25th-75th centiles) Results: 7 patients underwent PM implantation at 6.9 (5.5-8.0) years of age, 20 (18-21) kg, 116 (106-120) cm, with the lead positioned at parahisian(3)/mid-septum (4 pts) sites. During a follow-up of 3 (1-5) years, advancement procedures were 2 (1-4) per patient. Between procedures, delta age was 15 (12-19) months, height 7 (6-11) cm and weight 4 (2-6) kg. All leads were successfully advanced without any procedural complications. Procedure time (skin to skin) was 91 (69-105) minutes, fluoroscopy was 0.4 (0.2-1.2) mGy, 13 (9-35) microGy/m2. Electrical lead parameters did not showed significant differences between consecutive control times. In one parahisian pacing, chronic threshold increased after 3 years (2 advancement procedures) from 0.7V to 2.6 V/0.4 ms.

Conclusion

the advancement of transvenous leads in children is a safe and effective procedure, without significant procedural complications and during follow-up, and with low fluoroscopy exposure. This procedure may maintain a good function of transvenous leads until growth has completed.
Pacemaker choice optimization based on expected pacing requirement
Authors: Breeman KTN , Dijkshoorn LA , Wilde AAM , Tjong FVY , Knops RE
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Bradyarrhythmias are adequately treated with pacemakers. Currently, different pacing modes (single- and dual-chamber, cardiac resynchronization therapy and physiologic pacing) and types (leadless, transvenous) are available. Expected pacing requirement is an important factor in determining optimal pacing mode and type.

Purpose

To evaluate atrial (AP) and ventricular pacing percentages (VP) over time, stratified by pacemaker indication.

Methods

All consecutive patients ≥18 years with a DDD(R) transvenous pacemaker and ≥1 year follow-up at a tertiary center between January 2008 and January 2020 were retrospectively included. Baseline characteristics and AP and VP at yearly follow-up visits were assessed.

Results

714 patients were included, of which 210 (29%) with incomplete AV block (AVB), 261 (37%) complete AVB, 243 (34%) sinus node disease (SND). Mean age at implant was 72±13, 68±16, 67±14 years (p=0.005). AP and VP over time is shown in Figure. For incomplete AVB, median AP increased from 3% (1-24%) to 21% (1-49%) and VP from 37% (7-93%) to 91% (16-100%); for complete AVB, median AP increased from 3% (1-17%) to 10% (2-30%) and VP remained stable (98% [13-100%] to 99% [62-100%]); for SND, median AP increased from 26% (5-63%) to 55% (8-90%) and VP remained stable (3% [1-13%] to 5% [1-31%]).

Conclusion

These results confirm the pathophysiology of different pacemaker indications, resulting in clear differences in pacing requirement over time and expected battery longevity. These results can be used to help guide optimal pacing mode and suitability for leadless or physiologic pacing.
Left ventricular septal pacing: how deep is enough?
Authors: Curila K , Jurak P , Waldauf P , Halamek J , Stros P , Smisek R , Plesinger F , Znojilova L , Leinveber P , Viscor I , Herman D , Osmancik P , Prinzen FW
Published: May 2022

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Charles University Research Program

Background

When pacing in the left septal area, it is not clear where the pacing lead needs to be implanted to obtain the most physiological ventricular activation during pure myocardial pacing.

Objective

To use UHF-ECG to compare ventricular activation between myocardial pacing of the left septum with and without the possibility to capture the left bundle branch by high output pacing.

Methods

This was a retrospective study of patients with bradycardia and deep septal myocardial pacing close to LBB (paraLBBP) or deep septal pacing more distant from LBB (DSTP), which both produced a pseudo-right bundle branch morphology in V1. During paraLBBP, left bundle branch capture was feasible during increasing pacing output up to 5V at 0.5 ms, but during DSTP, LBB capture was not possible during high output pacing. Only patients with both paraLBBP and DSTP were analyzed. Paced QRS morphology, presence of LBBpotential, QRSduration, R wave peak time (RWPT) in V5, lead depth in the septum and UHF-ECG parameters of dyssynchrony, i.e., e-DYS as the difference between the first and last ventricular activation and local depolarization durations in precordial leads (V1-V8d) were compared between them.

Results

From 119 consecutive bradycardia patients enrolled, we identified 23 with both paraLBBP and DSTP during an implant procedure. On X-ray, a lead tip was placed shallower during DSTP than paraLBBP (12 ± 3 vs. 15 ± 3 mm, p < 0.001). A pseudo right bundle branch block morphology was present in all cases, but LBB potential was more frequently present in paraLBBP (17 of 23) than in DSTP (4 of 36; p < 0.0001). QRSd was not significantly different (146 ± 14 vs. 142 ± 14 ms, p = 0.08), but DSTP had longer V5RWPT (86 ± 11 vs. 83 ± 9 ms; p = 0.03). paraLBBP resulted in larger interventricular dyssynchrony, e-DYS (-20 ± 15 vs. -12 ± 18 ms; p = 0.046), the same V1-6d, but its local depolarization durations in V7 and V8 (V7 and V8d) were shorter compared to DSTP (-5 and -7 ms; p < 0.05).

Conclusion

Interventricular dyssynchrony and LV lateral wall depolarization during myocardial pacing of the left septum are dependent on the relation of the leads´ tip to the LBB. Pacing positions closer to the LBB are responsible for bigger interventricular dyssynchrony and more physiological LV lateral wall depolarization.
Six year follow-up data on a leadless pacing system real life experience in comparison to data of the prospective trial
Authors: Winter S , Sinning J-M , Nguyen D-Q , Duquoc B , Scheffer A , Fischer S , Farahati K , Fehske W , Tuscher T
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Introduction

The Micra™ leadless intracardiac pacing system has been introduced and implemented into clinical routine in 2015, with its next generation MICRA AV ™ in 2020. Feasibility, implantation safety, and acute success have been proven in the setting of controlled studies. Even apart from controlled studies, this new technology was beneficial for the individual patient. We aimed to report our single center follow-up (FU) data with a follow-up of up to six years.

Methods

In 246 patients (134 men; age: 79±8 y), Micra™ implantation was performed.

Pacemaker interrogation was performed one to seven days after implantation and during FU (1; 3; 6, then every 6 month) up to 72 months. Data were assessed in a real-life setting and compared with existing data of a controlled prospective trial.

Results

The implantation was successful in all 246 attempts with only one pericardial effusion as major complication. During follow up there were two patients developing severe heart failure symptoms resulting in an implantation of a CRT-device and switching of the leadless pacemaker system.

The average acute thresholds, sensing and impedance after system release were: 0.62±0.45V@0.24ms; 10,55±3,61mV and 697±178Ohm. During follow up of up to 5 years neither, pacemaker failure, nor infections were reported. Measurements were reevaluated for long-term thresholds, sensing and impedance: 0.44 ± 0.07V @ 0.24 ms; 17,25 ±4,65 mV and 572 ± 80 Ohm. During five years, no significant changes from acute to long-term measurements were detectable. In comparison to the controlled trial, our measurements of this real-life cohort were very similar.

Conclusion

In a real-life setting, the implantation of the leadless Micra™ system demonstrates a high rate of implantation success without major complications. We were also able to show stable long-term system parameters in the clinical setting of up to six years of follow up with a very good battery longevity of about 12 years.
In-silico optimisation of ICD defibrillation efficacy by modifying lead/can configurations using a cohort of high-resolution whole-torso heart models
Authors: Qian S , Monaci S , Mendonca-Costa C , Campos F , Gemmell P , Zaidi S , Rajani R , Whitaker J , Rinaldi C , Bishop M
Published: May 2022

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Medical Research Council, UK

Background

ICD is an effective direct therapy against VT/VF by applying a strong electrical shock across the heart between the shocking coil and can. Conventionally, patients will have a shocking coil inside the right ventricle (RV) and a can at the upper left chest. However, due to infections or other conditions, the can may need to place towards the right chest. The placement of the RV coil may also vary in different cases, for example avoiding scar. However, it is unclear how defibrillation efficacy may be altered by these unavoidable modifications to conventional lead/can configurations and whether optimisation may be possible.

Purpose

To compare defibrillation efficacy of modifications of ICD configurations in a cohort of whole-torso models.

Methods

A cohort of 15 whole torso models was generated from high resolution CT data and contrast CT cardiac scans, including 5 dilated cardiomyopathy (DCM), 5 hypertrophic cardiomyopathy (HCM) and 5 structurally normal patients (Fig A). Transvenous ICDs were represented by a shocking coil inside the RV (near apex) and a (ground) can at the upper left chest as default settings. Configurations were then varied by moving the can to the right chest, moving the RV coil up the mid-septum or adding extra grounds (Superior Vena Cava (SVC) coil, coronary sinus (CS) coil (Fig A)). Defibrillation-strength shocks were applied to all models (Fig B). DFTs and mean electrical field were evaluated across the whole heart as well as specific LV, RV, RV insertion regions, along with overall impedance.

Results

Shifting the can from left to right significantly increased DFT for the whole heart (23 J vs 15 J, P=0.03) and LV (25 J vs 17 J, P=0.03) (Fig C) and reduced the mean electrical field. Moving the RV coil further up the septum did not significantly alter DFT (Fig D), but did reduce mean electrical field for all regions and reduce impedance significantly. Additional separate coils significantly reduced DFT for all regions (Fig D) by increasing mean electrical field, whilst adding both coils significantly reduced DFT the most (whole heart: 15 J vs 6 J, P=0.03) (Fig E). Impedance was increased significantly by adding SVC coil, but reduced significantly by adding CS coil. Adding both coils increased impedance slightly.

Conclusions

Although a right-sided can increases DFT by over 50%, additional leads (grounds) may mitigate this increase by increasing mean electrical field. Moving the RV coil closer to the mid-septum reduces DFT slightly, but also reduces mean electrical field and impedance significantly.
Ventricular arrhythmias and prognosis of patients after explantation of an infected ICD compared to patients with newly diagnosed heart failure using the wearable cardioverter-defibrillator
Authors: Mueller-Leisse J , Brunn J , Zormpas C , Hohmann S , Hillmann HAK , Eiringhaus J , Bauersachs J , Veltmann C , Duncker D
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Introduction

The wearable cardioverter-defibrillator (WCD) is a tool for temporary protection from sudden cardiac death (SCD). It is used in patients with newly diagnosed heart failure with reduced ejection fraction (HFrEF) as well as in patients with a preexisting ICD indication who need explantation of the device. There is no data on long-term prognosis after the WCD in this latter group of patients.

Methods

All patients receiving the WCD at a Medical School between 2012 and 2017 were analyzed. Patients with newly diagnosed HFrEF from the PROLONG-II study were compared to patients receiving the WCD after an ICD explantation. Follow-up (FU) data were analyzed after 3 months and at last available FU including WCD data, clinical status, medication, echocardiography and ECG.

Results

353 patients (69% male) with newly diagnosed HFrEF from the PROLONG-II study were compared to 29 patients (86% male) having received a WCD after explantation of an ICD (45% with secondary preventive indication). Mean baseline LVEF was 25±8% and 34±13% respectively (p<0.001). Follow-up was 2.8±1.5 and 3.2±1.8 years. WCD shocks occurred in 14 (4%) of the patients with newly diagnosed HFrEF and in 3 (10%) patients after ICD explantation (2 with a secondary preventive indication). During long-term FU, patients with an explanted ICD had a poorer prognosis compared to patients with newly diagnosed HFrEF (p=0.02), and appropriate WCD shocks were associated with even higher mortality in patients after ICD explantation (p=0.045).

Conclusion

Patients after ICD explantation have an increased risk of ventricular arrhythmias and WCD shocks, but also show an increased risk of all-cause mortality despite wearing the WCD compared to patients with newly diagnosed HFrEF.
Ventricular arrhythmias and implantable cardioverter-defibrillator therapy in women: a propensity score-matched analysis
Authors: Maglia G , Giammaria M , Zanotto G , D’onofrio A , Della Bella P , Marini M , Rovaris G , Iacopino S , Calvi V , Pisano’ EC , Caravati F , Balestri G , Giacopelli D , Gargaro A , Biffi M
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Introduction

The implantable cardioverter-defibrillator (ICD) is an established therapy for the prevention of sudden cardiac death in selected patients. Although current guidelines apply to both women and men, there is a growing awareness that the incidence of cardiac arrhythmias and device interventions is influenced by sex.

Purpose

To investigate sex-specific risk of sustained ventricular arrhythmias (SVAs) and device therapies, using remote monitoring data from ICDs and cardiac resynchronization therapy defibrillators (CRT-Ds).

Methods

Study endpoints were time to the first appropriate SVA, time to the first appropriate device therapy for SVA, and time to the first ICD shock. Appropriateness of device-detected SVAs was adjudicated by three expert electrophysiologists. Results were compared between women and a 1:1 propensity score (PS)-matched subgroup of men.

Results

In a cohort of 2,532 patients with an ICD or CRT-D (median age, 70 years), 488 patients (19.3%) were women. As compared to men, women more frequently had a CRT-D (51% vs. 40%, p<0.001), and nonischemic cardiomyopathy (65% vs. 45%, p<0.001). After a median follow-up of 2.1 years, SVAs occurred in 123 women (25.2%) and in 174 of the 488 PS-matched men (35.6%) with an adjusted hazard ratio (HR) of 0.65 (95% confidence interval [CI], 0.51-0.81; p<0.001). Women also showed a reduced risk of any device therapy (HR, 0.59; CI, 0.45-0.76; p<0.001) and shocks (HR, 0.66; CI, 0.47-0.94, p=0.021). Differences in sex-specific SVA risk profile were not confirmed in CRT-D patients (HR, 0.78; CI, 0.55-1.09; p=0.14) and in those with an ejection fraction <30% (HR, 0.80; CI, 0.52-1.23; p=0.31).

Conclusion

In our analysis of remote monitoring data, women exhibited a lower SVA risk profile than PS-matched men in the subgroup of patients with an ICD or/and ejection fraction ≥30%.
Synchronization of repolarization after cardiac resynchronization therapy: time course and relation to reverse remodeling
Authors: Prinzen F , Verzaal NJ , Van Deursen CJM , Pezzuto S , Wecke L , Vernooy K , Delhaas T , Auricchio A
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

The changes in ventricular repolarization after cardiac resynchronization therapy (CRT) are poorly understood.

Objective

Address this knowledge gap using a multimodality approach including electrocardiographic and echocardiographic measurements in patients and patient-specific computational modeling.

Methods

In a cohort of consecutive CRT patients, electrocardiographic and echocardiographic measurements were performed before and at various intervals after CRT, both during CRT-ON and temporary CRT-OFF. T-wave area was calculated from vectorcardiograms, reconstructed from the 12-lead ECG. Computer simulations were performed using a patient-specific eikonal model of cardiac activation with spatially varying action potential duration (APD) and repolarization rate, based on a patient’s ECG and MRI-based chest and cardiac anatomy.

Results

In 33 patients T-wave area during CRT-OFF doubled within 5 days of CRT (left figure) while other repolarization markers like QT-interval and peak-to-end T-wave interval hardly changed. Patients with T-wave area increase above the median increase showed a significantly larger increase in left ventricular ejection fraction than those with smaller T-wave area increase (+11±8% vs. +6±6%, respectively; p<0.05, n=76). Computer simulations (figure, right) show the sequence of depolarization and repolarization before CRT, obtained by the patient-specific model (BL LBBB) and following Acute CRT. Repolarization after chronic CRT-OFF was obtained by matching the measured CRT-OFF ECG with that provided by the model. The best match was obtained by changes in APD following chronic CRT that are opposite to the change in CRT-induced activation time. Such APD changes were associated with a reduction in right and left ventricular dispersion in repolarization during chronic CRT-ON compared with acute CRT-ON.

Conclusions

T-wave area during CRT-OFF is a sensitive marker for adaptations in ventricular repolarization after CRT that are related to CRT-induced reverse remodeling and may involve an inverse relation between activation time and APD, coinciding with lower right and left ventricular dispersion of repolarization and with larger increases in LV ejection fraction during chronic CRT.
Impact of the ESC 2021 guidelines on cardiac pacing and cardiac resynchronization therapy left bundle branch block definition on CRT patient selection and survival
Authors: Rijks J , Ghossein M , Luermans J , Maass A , Meine M , Prinzen F , Linz D , Vernooy K , Van Stipdonk A
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

The recently published ESC 2021 guidelines on cardiac pacing and cardiac resynchronization therapy (CRT) underwent significant changes compared to the ESC 2013 guidelines regarding the definition of left bundle branch block (LBBB) by adding notching or slurring in 2 adjacent leads as a prerequisite. The level of recommendation for CRT depends on diagnosing LBBB or non-LBBB. These changes may have a significant impact on patient selection for CRT, as fewer patients may be diagnosed with LBBB and may therefore get a lower level of recommendation for CRT.

Purpose

In this study we investigated the impact of these changes in LBBB definition on patient selection and heart transplantation/left ventricular assist device (LVAD) free survival.

Methods

A large multicenter CRT database, consisting of consecutive patients implanted with a CRT device between 2001 and 2015 in 3 university hospitals in the Netherlands, was used for this study. Patient selection, device implantation, lead positioning and follow-up were according to then prevailing guidelines and local protocols. For this study, patients were selected with baseline sinus rhythm, QRS duration >130ms, and without right ventricular pacing. Patients were stratified according to ESC 2013 and ESC 2021 guideline definitions on LBBB.

Results

The current analyses included 1.202 CRT patients. 66% of patients were male with an age of 66±11 years. Heart failure etiology was ischemic in 49% of patients with baseline left ventricular ejection fraction of 25% and baseline NYHA class II-III in 93% of patients. There is a considerable difference in LBBB diagnoses when stratifying patients according to ESC 2013 and ESC 2021 guideline definitions as especially the number of LBBB patients is reduced from 80.9% to 31.6% (Figure 1). Heart transplantation/LVAD free survival analyses when stratifying according to ESC 2013 LBBB definition showed significant separation of the curves (p<0.0001) (Figure 2). Furthermore, there was a significant difference between the wide (QRS>150ms) LBBB and wide non-LBBB subgroup concerning heart transplantation/LVAD free survival (p<0.0001). In contrast, there was no significant separation of the curves when stratifying according to ESC 2021 LBBB definition (Figure 2).

Conclusion

The changes made in LBBB definition in the ESC 2021 CRT guidelines lead to a difference in stratification of LBBB and non-LBBB. The ESC 2013 LBBB definition, however, seems to be better in predicting heart transplantation/LVAD free survival after CRT.
Longer left ventricular activation time is associated with lower mortality and risk of heart failure hospitalization in CRT recipients
Authors: Marinko S , Platonov PG , Carlson J , Borgquist R
Published: May 2022

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): ALF Governmental Funding within the Swedish health care system

Introduction

Cardiac resynchronization therapy (CRT) is an established treatment for heart failure in selected patients. Longer QRS duration has been showed to correlate to clinical outcome, but measures global activation time, rather than the left ventricular dyssynchrony that CRT aims to correct. This study therefore evaluated the incremental value of using Left Ventricular Activation Time (LVAT) for prediction of outcome after CRT.

Methods

Medical records of 445 patients receiving CRT implants at a large-volume tertiary care center were retrospectively evaluated. Digital electrocardiograms (ECG) before and after CRT implantation were collected and ECG parameters were analysed in relation to a primary composite endpoint of time to heart failure hospitalisation or death from any cause. LVAT was defined as time from QRS onset to maximum positive deflection in lead V6 (Figure 1).

Results

Patients were followed for up to 6 years (median 2.7), during which 147 patients (33%) reached the primary endpoint (93 deaths and 103 heart failure hospitalisations). LVAT was measured pre-implant (median 71ms [58-88]) and post-implant (median 74ms [57-96]). There was no CRT-mediated reduction in LVAT (delta -2.3ms +/-31ms, p=0.27). When divided into quartiles, preoperative LVAT had a significant association with clinical outcome (HR 0.76 [0.64-0.90] per increasing quartile, p=0.001), also shown in a median-split Kaplan Meier curve (Figure 2, log rank p=0.001). Multivariate hazard ratio (adjusted for relevant clinical variables) was 0.83; [0.69-0.99]; p=0.047). There was an interaction between LVAT and ECG morphology (p=0.033), and when ECG groups were analysed separately, there was only a significant result for those with native left bundle branch block morphology. Post-implant LVAT, or change in LVAT, did not correlate with the primary endpoint (p=0.25 and p=0.38 respectively.

Conclusion

In CRT recipients, longer pre-implant LVAT was associated with lower risk of heart failure hospitalisation and death during a follow-up of up to 6 years. This association was mainly seen in patients with native LBBB prior to implant. No association was seen with post-CRT LVAT and clinical outcome. If confirmed in prospective trials, evaluation of preoperative LVAT may help optimise patient selection for CRT.
Measurement of electrical dyssynchrony in CRT patients: 12-lead ECG versus 96-lead body surface map
Authors: Sedova K , Van Dam P , Sbrollini A , Burattini L , Blahova M , Necasova L , Sramko M , Kautzner J
Published: May 2022

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Grant agency AZV, Ministry of Health of the Czech Republic

Background

Quantification of electrical dyssynchrony would allow optimization of lead placement and timing in patients with CRT. The standard deviation of activation times (SDAT) derived from body surface maps (BSM) was proposed as a measure of electrical dyssynchrony in CRT patients. However, SDAT derived from standard 12-lead ECG would be clinically preferred.

Objective

To evaluate and compare the SDAT measured from BSM and 12-lead ECG for assessment of electrical resynchronization in patients with implanted CRT.

Methods

CRT patients with sinus rhythm and LBBB at baseline (n=19, 58% males; age 60±11 years; NYHA class II-III; QRS 160±29) were studied using 96-lead BSM. For each ECG lead, the activation time was automatically detected and SDAT was calculated using either 96 leads or standard 12 leads. Electrical dyssynchrony was assessed during native sinus rhythm and 6 different pacing modes (see figure).

Results

SDAT calculated from BSM and 12-lead ECG decreased during optimal BiV pacing as compared to sinus rhythm by 26% (p=0.006) and 30% (p=0.003), respectively. The two other BiV setups showed also a decrease in SDAT values. Importantly, a high degree of reliability was found between values of SDAT obtained from12-lead ECG and 96-lead BSM for different pacing modes, the intraclass correlation coefficient was 0.8 to 0.9 (95% CI 0.7 - 0.9, p<0.001).

Conclusion

SDAT assessment is considered an important metric of electrical dyssynchrony in CRT. Our results suggest that 12-lead ECG provides similar results as BSM and thus, allows simplification of the measurement. Further prospective studies are necessary to verify the clinical utility of SDAT from 12-lead ECG.
Improvement in electrical synchrony during bi-ventricular vs. left ventricular pacing with dynamic atrioventricular delays may be predicted by conduction times
Authors: Thibault B , Chow A , Mangual J , Badie N , Waddingham P , Mcspadden LUKE , Betts T , Calo L , Grieco D , Leyva F
Published: May 2022

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Abbott

Introduction

Automatic adjustment of atrioventricular delay (AVD) with SyncAV has been shown to improve electrical synchrony with either biventricular (BiV) or left ventricular (LV) only pacing. Selecting the optimal pacing mode may be guided by measuring conduction delays between the right atrium (RA), right ventricle (RV), and LV.

Purpose

Evaluate correlations between inter-chamber conduction delays and the QRS duration (QRSd) reduction achieved by BiV or LV-only pacing with SyncAV.

Methods

CRT implant patients (LBBB, QRSd ≥ 150 ms) were prospectively enrolled. Blinded QRSd was measured from 12-lead ECG during BiV and LV-only pacing, with SyncAV enabled and optimized to minimize QRSd. Conduction delays were measured by the device from unipolar electrograms during pacing and sensing (e.g. RAp-RVs). Correlations between each delay and which mode had the narrower QRSd was assessed by binomial regression.

Results

In total, 68 patients were evaluated (66.1 yr, 67.1% male, 32.5% ischemic, 26.3% EF, 165.1 ms intrinsic QRSd). BiV+SyncAV and LV+SyncAV reduced QRSd by 23.8% and 21.3% (P<0.001) vs. intrinsic conduction. Of all delays, RVs-LVs and LVp-RVs were significantly correlated with patient probability of BiV+SyncAV yielding a narrower QRSd than LV+SyncAV. BiV+SyncAV was favored in 70.6% (48/68) of all patients, but was favored in 92.3% (24/26) of patients with LVp-RVs < median (143 ms) (P=0.030 vs all).

Conclusion

When combined with SyncAV, BiV yielded a narrower QRSd than LV-only in the majority of patients, but was favored in a greater proportion who exhibit LVp-RVs delays below the median. Such conduction delay cut-offs can be used to facilitate pacing mode selection.
Upgrade pacemaker to CRT: predictors and the importance of LVEF
Authors: Silva BV , Silverio Antonio P , Couto Pereira S , Alves Da Silva P , Brito J , Garcia B , Oliveira C , Martins AM , Nunes Ferreira A , Magalhaes A , Cristina H , J Pinto F , Sousa J , Marques P
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Introduction

Nowadays 10-15% of CRT implantaon is upgrading from paents (pts) with pacemaker (PMK) who develop reduced LVEF and worsening symptoms from HF. There are few retrospecve studies showing some predictors of pts with single or dual chamber PMK that may need upgrade to CRT, but it is not completely established which pts may benefit the most.

Purpose

To identify predictors at follow-up of upgrading pacemaker to CRT in a population with pacemaker implantation.

Methods

Single center case-control study of pts that performed upgrading to CRT-pacemaker (CRT-P) in our hospital. We excluded pts that performed upgrade to CRT-D. We compare to a PMK populaon matched to age at implantaon and cause of PMK implantaon. Demographic, clinic and electrocardiographic (ECG) data were considered at baseline. Echocardiographic evaluation was performed before pacemaker/CRT upgrading implantaon and at follow-up. Predictors of upgrading were evaluated by the Cox regression. Prognosc impact of LVEF was evaluated as upgrading to CRT-P by Kaplan-Meier curves.

Results

We included 71 pts that performed CRT-P upgrade (mean age 77±10; 49,6% male, mean LVEF before PMK 54.9±9.2%) and 71 pts with pacemaker implantaon (mean age 78 ± 11; 50,4% male; mean LVEF 60.9±7.2%). The clinical characteriscs, ECG and echocardiographic were similar between pacemaker and CRT-P-upgrade, except atrial fibrillaon being more prevalent in PMK group (57.5% vs 42.5% p=0.039). Mortality was not different duringfollow-up between the two groups. In univariate analysis, QRS duraon (PMK: 115ms vs upgrade CRT-P: 132 ms, p=0.038), LVEF (PMK: 60.9% vs upgrade CRT-P: 54.9%, p=0.002) and LV end-diastolic diameter (LVEDD) (PMK: 48.9.4 ± 6.6mm vs upgrade CRT-P: 56.4 ± 6.6mm, p=0.001), LV end-sistolic diameter (LVESD) (PMK: 29.5 ± 6.5mm vs upgrade CRT-P: 37.9 ± 9 mm, p=0.006) were associate to upgrading to CRT. In our population, the unique independent predictor was lower LVEF(Long Rank 6.108, p=0.013) – Figure 1. The best LVEF cut- off to predict upgradingto CRT was 55% (AUC 0.954, sensitivity 64%, specificity 84%) – Figure 2.

Conclusion

In our populaon of CRT upgrading pts, a broad QRS duraon, lower LVEF and a higher LVEDD and LVESD were associated to upgrade to CTR-P. We try to establish a new value for LVEF that could lead to upgradingto CRT-P, and maybe the classical cut-off of 50% should be reviewed.
Systematic screening for right-to-left shunt prior to lead extraction
Authors: Breitenstein A , Hofer D , Starck CH , Steffel J
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Transvenous lead extraction has become a relevant treatment option in patients with device-associated infection, but also in the context of device- and lead dysfunction. Lead extraction can be complicated by a stroke, which may result from paradoxical embolization of lead debrids during lead extraction in the presence of a patent foramen ovale (PFO) with a right-to-left shunt.

Purpose

Analysis of the presence of a PFO in patients undergoing transvenous lead extraction in a Swiss tertiary centre. Furthermore, different strategies to reduce the risk for stroke due to the presence of a PFO will be summarized.

Methods and Results

In this retrospective analysis from January 2017 until December 2021, a total of 304 patients who underwent lead extraction were included. In nearly half of the population, lead dysfunction was the leading cause for extraction, while device-associated infection was present in 31 % of the patients. In 14 patients (4.6 %), a right-to-left shunt was detected either during (via transesophageal echocardiography) or prior to the procedure. Prior to the systematic pre-procedural PFO screening, 9 patients with a right-to-left shunt were identified of which 2 patients suffered from a peri-interventional stroke (22 %) while in the population without a PFO no stroke occurred. The remaining 5 patients with a right-to-left shunt were identified prior to the lead extraction procedure (after setting up an institutional PFO screening programm) and were treated accordingly. Since then, no further neurological episodes occurred (Figure 1). If a PFO was identified, an interventional PFO occlusion was performed either prior to the lead extraction (2 of 5 patients) or together with the lead extraction as a single procedure (1 patient). In the 2 other patients, where a device infection was present together with a PFO, the PFO shunt was occluded transiently using a sizing balloon during the lead extraction procedure to avoid to implant a PFO occluder device in an infectious environment.

Conclusions

Presence of a right-to-left shunt in patients who need to undergo transvenous lead extraction is a known risk factor for embolic strokes. Identification and treatment of this condition prior or during lead extraction is associated with a reduction in stroke events.
Transvenous lead extraction: the Tandem approach
Authors: Akhtar Z , Zuberi Z , Leung LWM , Kontogiannis C , Waleed K , Elbatran AI , Sohal M , Gallagher MM
Published: May 2022

Funding Acknowledgements

Type of funding sources: None.

Background

Transvenous lead extraction (TLE) has become an important strategy in the management of patients with cardiac implantable electronic devices (CIEDs). A rising population of patients with CIEDs coupled with an expanding indication for TLE, has fuelled demand. There are notable procedural risks however development of techniques and tools have contributed to an improvement in the safety and efficacy of TLE. The mechanical rotational dissecting sheath is safe and efficacious whilst the Needle’s Eye Snare (NES) is an additional ‘bail-out’ strategy contributing to procedural success.

Purpose

We sought to evaluate the outcomes of TLE performed from the superior access in conjunction with counter-traction provided by snaring of the targeted lead via the femoral access.

Method

The ‘Tandem’ procedure consisted of the rotational powered sheath performing dissection of the adhesions encapsulating the leads (at the superior access), in ‘Tandem’ with the Needle’s Eye Snare providing countertraction via the femoral vein. In brief: after deployment of the locking stylet in the lead lumen, the NES was used to grasp the lead in the right atrium and hold it tort while a rotational sheath was used to dissect through the veins. Once the sheath reached the right atrium, the lead was released from the snare and the sheath was used to continue dissection toward the lead tip. Data for all consecutive ‘Tandem’ procedures performed between 1/1/2021 – 1/1/2022 in our high-volume TLE institute were collected and evaluated for safety and efficacy.

Results

Forty patients aged 69.2±16.3 (70% male), underwent TLE of 75 leads (45 right ventricle, 25, right atrium, 5 left ventricle) with dwell time of 150.1±80.3 months for a non-infectious indication (65%). Of the 40 cases, 27 were hypertensives, 14 had ischaemic heart disease whilst 5 suffered diabetes with a left ventricle ejection fraction of 46.8±10.2%; 12 (30%) were pacing dependent. Procedures were performed by cardiologists in the cardiac catheterisation suite under general anaesthesia (95%) using a locking stylet (100%) with an Evolution RL (11-french 58.7%); a NES 13 millimetres curve (88%) was used to successfully snare 91% of the targeted leads. Complete procedural success was achieved in 92% of leads with 98.7% clinical success. Minor complications occurred in 2 cases (pneumothorax, pocket haematoma requiring intervention), in the absence of any major complications or peri-procedural mortality; there was no 30-day mortality.

Conclusion

The ‘Tandem’ procedure provides an additional strategy to improve the safety and efficacy of TLE, especially in leads of a long dwell time.