Factors of mortality in patients with cardiac implantable electronic device: 5-year experience

OBJECTIVE

The use of cardiac implantable electronic devices has increased in recent years. It has also brought some issues. Among these, the complications of cardiac implantable electronic devices infection and pocket hematoma are difficult to manage. It can be fatal with the contribution of patient-related risk factors. In this study, we aimed to find mortality rates in patients who developed cardiac implantable electronic devices infection and pocket hematoma over 5 years. We also investigated the risk factors affecting mortality in patients with cardiac implantable electronic devices.

METHODS

A total of 288 cardiac implantable electronic devices patients were evaluated. Demographic details, history, and clinical data of all patients were recorded. Cardiac implantable electronic devices infection was defined according to the modified Duke criteria. The national registry was used to ascertain the mortality status of the patients. The patients were divided into two groups (exitus and survival groups). In addition, the pocket hematoma was defined as significant bleeding at the pocket site after cardiac implantable electronic devices placement.

RESULTS

The cardiac implantable electronic devices infection was similar in both groups (p=0.919), and the pocket hematoma was higher in the exitus group (p=0.019). The exitus group had higher usage of P2Y12 inhibitors (p≤0.001) and novel oral anticoagulants (p=0.031). The Cox regression analysis, including mortality-related factors, revealed that renal failure is the most significant risk factor for mortality. Renal failure was linked to a 2.78-fold higher risk of death.

CONCLUSION

No correlation was observed between cardiac implantable electronic devices infection and mortality, whereas pocket hematoma was associated with mortality. Furthermore, renal failure was the cause of the highest mortality rate in patients with cardiac implantable electronic devices.

Transvenous lead advancement in pediatric pacing to overcome growth-induced lead straightening and stretching

BACKGROUND

The stretching of the lead caused by somatic growth may lead to complications (dislodgement, fracture, failure) of transvenous leads implanted in pediatric patients. Atrial loop and absorbable ligatures may prevent it. Periodical lead advancement with lead pushing from the pocket may be an option to growth-induced stretching. Our aim was to analyze retrospectively the outcome of periodical transvenous lead advancement in children with pacemaker (PM).

METHODS

A procedure of lead advancement was performed in patients with a single-chamber PM implanted for isolated congenital complete atrioventricular block or sinus node dysfunction with growth-induced lead straightening/stretching. The PM pocket was opened, the lead was released from subcutaneous adherences and was gently advanced to shape again a loop/semi-loop in the atrium without dislodging the tip. Lead data (threshold, sensing, impedance) were compared before and after the procedure. Data are described as median (25th-75th centiles).

RESULTS

14 patients with 13 VVIR and 1 AAIR PM implanted at 6.8 (5.9-8.0) years of age, 23 (19-26) kg, 118 (108-124) cm, underwent 30 advancement procedures, 1.5 (1.0-2.3) per patient, during follow-up [45 (35-63) months]. Delta between procedures was: 18 (14-25) months, 11 (7-13) cm, 6 (4-9) kg; 90% of leads were successfully advanced without complications. Three unsuccessful procedures occurred with longer times [30 (14-37) months]. Electrical lead parameters did not show significant differences pre-/post-procedures.

CONCLUSION

the advancement of transvenous leads in children seems safe and effective. This procedure may be another possible choice to preserve transvenous lead position and function until growth has completed.

New Guidelines of Pediatric Cardiac Implantable Electronic Devices: What Is Changing in Clinical Practice?

Guidelines are important tools to guide the diagnosis and treatment of patients to improve the decision-making process of health professionals. They are periodically updated according to new evidence. Four new Guidelines in 2021, 2022 and 2023 referred to pediatric pacing and defibrillation. There are some relevant changes in permanent pacing. In patients with atrioventricular block, the heart rate limit in which pacemaker implantation is recommended was decreased to reduce too-early device implantation. However, it was underlined that the heart rate criterion is not absolute, as signs or symptoms of hemodynamically not tolerated bradycardia may even occur at higher rates. In sinus node dysfunction, symptomatic bradycardia is the most relevant recommendation for pacing. Physiological pacing is increasingly used and recommended when the amount of ventricular pacing is presumed to be high. New recommendations suggest that loop recorders may guide the management of inherited arrhythmia syndromes and may be useful for severe but not frequent palpitations. Regarding defibrillator implantation, the main changes are in primary prevention recommendations. In hypertrophic cardiomyopathy, pediatric risk calculators have been included in the Guidelines. In dilated cardiomyopathy, due to the rarity of sudden cardiac death in pediatric age, low ejection fraction criteria were demoted to class II. In long QT syndrome, new criteria included severely prolonged QTc with different limits according to genotype, and some specific mutations. In arrhythmogenic cardiomyopathy, hemodynamically tolerated ventricular tachycardia and arrhythmic syncope were downgraded to class II recommendation. In conclusion, these new Guidelines aim to assess all aspects of cardiac implantable electronic devices and improve treatment strategies.

Percutaneous extraction of a Micra AV transcatheter pacing system due to a rare sudden battery failure after 19 months from implantation: A first experience worldwide

INTRODUCTION

Micra AV Transcatheter Pacing System (TPS) represents an innovative second-generation leadless pacemaker which represents an effective alternative to conventional devices in selected cases. Intrinsic malfunctions of these devices are rare, requiring sometimes their retrieval. When performed in experienced centers, this procedure is safe.

CASE PRESENTATION

We describe a case of sudden battery malfunction of a Micra AV TPS, which required the extraction and the placement of a new pacing system in the right ventricle.

DISCUSSION

This case, which has never been reported, highlights the need to a careful fluoroscopic evaluation and the usefulness of remote monitoring.

Antithrombotic Therapy for Patients Undergoing Cardiac Electrophysiological and Interventional Procedures: JACC State-of-the-Art Review

Electrophysiological and interventional procedures have been increasingly used to reduce morbidity and mortality in patients experiencing cardiovascular diseases. Although antithrombotic therapies are critical to reduce the risk of stroke or other thromboembolic events, they can nonetheless increase the bleeding hazard. This is even more true in an aging population undergoing cardiac procedures in which the combination of oral anticoagulants and antiplatelet therapies would further increase the hemorrhagic risk. Hence, the timing, dose, and combination of antithrombotic therapies should be carefully chosen in each case. However, the maze of society guidelines and consensus documents published so far have progressively led to a hazier scenario in this setting. Aim of this review is to provide-in a single document-a quick, evidenced-based practical summary of the antithrombotic approaches used in different cardiac electrophysiology and interventional procedures to guide the busy clinician and the cardiac proceduralist in their everyday practice.

Outcomes of left bundle branch area pacing compared to His bundle pacing as a primary pacing strategy: Systematic review and meta-analysis

BACKGROUND

Novel pacing technologies, such as His bundle pacing (HBP) and left bundle branch area pacing (LBBaP), have emerged to maintain physiological ventricular activation. We investigated the outcomes of LBBP with HBP for patients requiring a de novo permanent pacing.

METHODS AND RESULTS

Systematic review of randomized clinical trials and observational studies comparing LBBaP with HBP until March 01, 2023 was performed. Random and fixed effects meta-analyses of the effect of pacing technology on outcomes were performed. Study outcomes included pacing metrics, QRS duration, lead revision, procedure parameters, all-cause mortality and heart failure hospitalization (HFH). Overall, 10 studies with 1596 patients were included. Implant success rate was higher in LBBaP compared with HBP (RR 1.24, 95% CI: 1.08 to 1.42, p = .002). LBBaP was associated with lower capture threshold at implantation (mean difference (MD) -0.62 V, 95% CI: -0.74 to -0.51 V, p < .0001) and at follow-up (MD -0.74 V, 95% CI: -0.96 to -0.53, p < .0001), shorter procedure duration (MD -14.66 min, 95% CI: -23.54 to -5.78, p = .001) and shorter fluoroscopy time (MD -4.2 min, 95% CI: -8.4 to -0.0, p = .05). Compared with HBP, LBBaP was associated with a decreased risk of all-cause mortality (RR: 0.50, 95% CI: 0.33 to 0.77, p = .002) and HFH (RR: 0.57, 95% CI: 0.33 to 1.00, p = .05). No statistical differences were found in lead revisions and QRS duration before and after pacing.

CONCLUSION

This meta-analysis found that LBBaP was superior to HBP regarding pacing metrics and implant success rate as an initial pacing strategy, although absence of head-to-head randomized comparison warrants caution in interpretation of the results.

Feasibility and safety of left bundle branch area pacing in patients with septal hypertrophy

INTRODUCTION

Left bundle branch area pacing (LBBAP) aims to provide physiological ventricular activation during pacing. Left ventricular septal hypertrophy (LVSH) might be challenging for LBBAP due to the thickness of the interventricular septum and potential presence of septal scar. This study assesses the feasibility, safety, and outcome of LBBAP in patients with LVSH using primarily stylet-driven leads (SDL).

METHODS

Adult patients with LVSH who underwent LBBAP between March 2019 and November 2022 were enrolled. Baseline patient characteristics, procedural data and postprocedural results were collected. The feasibility of LBBAP in LVSH patients was compared to a cohort of LBBAP patients with normal septal wall thickness (NST).

RESULTS

Seventeen LVSH and 133 NST patients underwent LBBAP with successful implantation achieved in 15 LVSH patients (88%). Mean implant depth was 17.2 ± 1.9 mm, with 53% proven left bundle branch (LBB) capture. Paced QRS duration (146 ± 14 ms) and V6 R-wave peak time (V6 RWPT; 79 ± 20 ms) were comparable between patients with and without septal hypertrophy, although patients with NST had higher rates of proven LBB capture (71% vs. 53%). In LVSH pacing thresholds (0.6 ± 0.3 V at 0.4 ms) and R-wave amplitude (13.9 ± 5.6 mV) were favorable and remained stable at follow-up. At 12 months, 87% of patients had stable or improved left ventricular ejection fraction.

CONCLUSION

The results of the study indicate that LBBAP in patients with LVSH is safe and feasible and no lead-related complications were observed despite a mean implant depth exceeding 15 mm. LBBAP using SDL results in favorable pacing and electrocardiographic characteristics in LVSH patients, comparable to patients with NST.

Direct wire pacing during measurement of fractional flow reserve: A randomized proof-of-concept noninferiority crossover trial

Background

Adenosine administration for fractional flow reserve (FFR) measurement may induce heart pauses.

Aims

To assess the accuracy and tolerability of direct wire pacing (DWP) during measurement of FFR.

Methods

Adults with at least one intermediate coronary artery stenosis (40%-80%) were consecutively enrolled between June 2021 and February 2022 in this randomized, noninferiority, crossover trial (NCT04970082) carried out in France. DWP was applied (DWP) or not (standard method) through the pressure guidewire used for FFR measurement during adenosine-induced maximal hyperaemia. Subjects were randomly assigned to the allocation sequence (DWP first or standard first). A 2-minute washout period was observed between the two FFR measurements performed for each stenosis. The primary endpoint was the reproducibility of FFR measurements between methods.

Results

A total of 150 focal lesions, presented by 94 subjects, were randomized (ratio: 1:1). The FFR values obtained with each method were nearly identical (R = 0.98, p = 0.005). The mean FFR difference of 0.00054 (95% confidence interval: 0.004 to 0.003) showed the noninferiority of FFR measurement with DWP vs. that with the standard method. Higher levels of chest discomfort were reported with DWP than with the standard method (0.61 ± 0.84 vs. 1.05 ± 0.89, p < 0.001), and a correlation was observed between the electrical sensations reported with DWP and chest discomfort (p < 0.001). Pauses (n = 20/148 lesions) were observed with the standard method, but did not correlate with chest discomfort (p = 0.21). No pauses were observed with DWP.

Conclusions

DWP during FFR measurement resulted in accurate and reproducible FFR values, and eliminated the pauses induced by adenosine.

Left ventricular endocardial activation maps during right ventricular pacing in pediatric patients

BACKGROUND

Cardiac pacing from right ventricular (RV) sites may cause electromechanical ventricular dyssynchrony. Invasive and noninvasive mapping studies showed left ventricular (LV) activation sequence in adults. Aim of this study was to seek out the LV endocardial activation (LVEA) in pediatric patients who underwent RV pacing.

METHODS

Single-center, prospective study conducted on pediatric patients who underwent left sided catheter ablation of accessory pathways with the Carto Univu mapping system. After successful ablation procedures, LVEA was recorded by the ablation catheter during sinus rhythm (SR) and during para-hisian (PHP), midseptum (MSP), and apical (RVAP) pacing.

RESULTS

Seventeen patients, 13 males, aged 12 (10-15) years, registered LV activation maps and times (LVAT). SR showed significantly shorter LVAT than during pacing. LVAT of PHP was shorter than MSP, while there were not significant differences among PHP and MSP versus RVAP. In SR initial LV endocardial activation occurred in two midseptum sites, inferior-posterior and superior-anterior. During PHP, initial activation occurred at parahisian basal septum, rapidly followed by midseptum as in SR. During MSP and RVAP initial activation occurred at midseptum and apex, respectively. From all initial sites, the excitation spreads toward the base of the lateral LV free wall. A mild linear correlation was found between QRS duration and LVAT for MSP and for PHP.

CONCLUSIONS

In pediatric patients LVEA maps during RV pacing showed that the shortest LVAT was obtained with PHP. The LV activation pattern seemed similar in sinus rhythm, PHP and MSP, from midseptum to LV lateral base.

The physiological response during optogenetic-based cardiac pacing in awake freely moving mice

There are several methods to control a heart rate, such as electrical stimulation and drug administration. However, these methods may be invasive or affect other organs. Recently, an optogenetic-based cardiac pacing method has enabled us to stimulate the cardiac muscle in non-contact. In many previous studies, the pacing was applied ex vivo or in anesthetized animals. Therefore, the physiologic response of animals during optogenetic pacing remains unclear. Here, we established a method of optogenetic-based cardiac pacing in awake, freely moving mice and simultaneously measured electrocardiogram, blood pressure, and respiration. As a result, light-induced myocardial contraction produces blood flow and indirectly affects the respiration rhythm. Additionally, light illumination enabled heart rate recovery in bradycardic mice. These findings may be employed for further research that relates a heartbeat state to animal behavior. Together, this method may drive the development of less invasive pacemakers without pacing leads.

The specific value of upgrading to left bundle branch area pacing in patients with pacing-induced cardiomyopathy or non-pacing-induced cardiomyopathy related upgrade status: A retrospective study

AIMS

Left bundle branch area pacing (LBBaP) upgrade can improve cardiac function and clinical outcomes in patients with pacing-induced cardiomyopathy (PICM), but the specific value of LBBaP upgrade, especially compared with the cardiac function level before right ventricular pacing (RVP) in patients with PICM and non-pacing-induced cardiomyopathy-related upgrade status (Non-PICMUS) is still unknown.

METHODS

This study retrospectively enrolled 70 patients with LBBaP upgrade (38 patients with PICM and 32 patients with Non-PICMUS). All upgrade patients experienced three stages: before RVP (Pre-RVP), before LBBaP upgrade (Pre-LBBaP), and after LBBaP upgrade (Post-LBBaP). QRS duration (QRSd), lead parameters, echocardiographic indicators, and clinical outcomes evaluation were recorded at multiple time points.

RESULTS

At the follow-up of 12 months, for PICM patients, left ventricular ejection fraction (LVEF) significantly increased from 36.6% ± 7.2% to 51.3% ± 8.7% Post-LBBaP (p < .001), and left ventricular end-diastolic diameter (LVEDD) significantly decreased from 61.5 ± 6.4 mm to 55.2 ± 6.5 mm Post-LBBaP (p < .001), but they both failed to restore the level Pre-RVP (both p < .001). For PICM patients, New York Heart Association (NYHA) classification, the number of moderate-to-severe heart failure (NYHA III-IV), and diuretics using rate after the LBBaP upgrade also could not restore to the level Pre-RVP (all p < .001). At the follow-up of 12 months, Non-PICMUS patients after the LBBaP upgrade had no significant improvement in LVEF, LVEDD, and NYHA classification (all p > .05).

CONCLUSION

LBBaP upgrade effectively improved the cardiac function and clinical outcomes in PICM patients, but its effectiveness seemed to be limited as the deteriorated cardiac function cannot be completely reversed. For Non-PICMUS patients, the cardiac function and clinical outcomes Post-LBBaP had no significant improvement.

Left ventricular electrical potential measured by the NOGA XP electromechanical mapping method as a predictor of response to cardiac resynchronization therapy

Objectives

The aim of the study was to determine whether left ventricular electrical potential measured by electromechanical mapping with the NOGA XP system has predictive value for response to CRT.

Background

Approximately 30% of patients who undergo cardiac resynchronization therapy do not see the expected effects.

Methods

The group of 38 patients qualified for CRT implantation were included in the study, of which 33 patients were analyzed. A 15% reduction in ESV after 6 months of pacing was used as a criterion for a positive response to CRT. The mean value and sum of unipolar and bipolar potentials obtained by mapping with the NOGA XP system and their predictive value in relation to the effect of CRT were analyzed using a bulls-eye projection at three levels: 1) the global value of the left ventricular (LV) potentials, 2) the potentials of the individual LV walls and 3) the mean value of the potentials of the individual segments (basal and middle) of the individual LV walls.

Results

24 patients met the criterion of a positive response to CRT vs. 9 non-responders. At the global analysis stage, the independent predictors of favorable response to CRT were the sum of the unipolar potential and bipolar mean potential. In the analysis of individual left ventricular walls, the mean bipolar potential of the anterior and posterior wall and in the unipolar system, mean septal potential was found to be an independent predictor of favorable response to CRT. In the detailed segmental analysis, the independent predictors were the bipolar potential of the mid-posterior wall segment and the basal anterior wall segment.

Conclusions

Measurement of bipolar and unipolar electrical potentials with the NOGA XP system is a valuable method for predicting a favorable response to CRT.

Application of Novel Technologies in Cardiac Electrotherapy to Prevent Complications

(1) Background: Cardiac electrotherapy is developing quickly, which implies that it will face a higher number of complications, with cardiac device-related infective endocarditis (CDRIE) being the most frequent, but not the only one. (2) Methods: This is a retrospective case study followed by a literature review, which presents a patient with a rare but dangerous complication of electrotherapy, which could have been prevented if modern technology had been used. (3) Results: A 34-year-old female was admitted with suspicion of CDRIE based on an unclear echocardiographic presentation. However, with no signs of infection, that diagnosis was not confirmed, though an endocardial implantable cardioverter-defibrillator (ICD) lead was found folded into the pulmonary trunk. The final treatment included transvenous lead extraction (TLE) and subcutaneous ICD (S-ICD) implantation. (4) Conclusions: With the increasing number of implantations of cardiac electronic devices and their consequences, a high index of suspicion among clinicians is required. The entity of the clinical picture must be thoroughly considered, and various diagnostic tools should be applied. Lead dislocation into the pulmonary trunk is an extremely rare complication. Our findings align with the available literature data, where asymptomatic cases are usually effectively treated with TLE. Modern technologies, such as S-ICD, can effectively prevent lead-related problems and are indicated in young patients necessitating long-term ICD therapy.

AMI in (bi)ventricular pacing - do not discard the ECG

BACKGROUND

There is a growing number of patients with ventricular paced rhythm, who present to the emergency department with chest pain. The diagnosis of ST-segment elevation myocardial infarction (STEMI) and subsequent percutaneous coronary intervention (PCI) is often postponed, as the 12 leads-electrocardiogram (ECG) is discarded as not interpretable. There is a growing body of literature that suggests that Smith-modified Sgarbossa criteria can be applied for the diagnosis of STEMI in patients with paced rhythms. These criteria were originally developed for the interpretation of ECGs in patients with a left bundle branch block (LBBB) and chest pain, but have been expanded to paced ECGs.

METHODOLOGY

We present three case reports with chest pain and right ventricular or biventricular pacing.

FINDINGS

In all three cases, the Smith-modified Sgarbossa was positive and the diagnosis of STEMI could have been made early on.

IMPLICATIONS

It remains important to look for ST-segment deviations and to compare the symptomatic ECG with previous asymptomatic ECGs. As the number of patients with potential acute myocardial infarction (AMI) and paced rhythms is likely to rise in the future, these criteria should be known to emergency physicians and cardiologists.

Clinical use conditions of lead deployment and simulated lead fracture rate in left bundle branch area pacing

INTRODUCTION

Left bundle branch area pacing (LBBAP) is achieved by advancing the lead tip deep in the septum. Most LBBAP implants are performed using the Medtronic SelectSecure™ MRI SecureScan™ Model 3830 featuring a unique 4 Fr fixed helix lumenless design. Details of lead use conditions and long-term reliability have not been reported. This study was designed to quantify the mechanical use conditions for the 3830 lead during and after LBBAP implant, and to evaluate reliability using bench testing and simulation.

METHODS

Fifty bradycardia patients with implantation of the 3830 lead for LBBAP were enrolled. Use conditions of lead deployment at implantation were collected and computed tomography (CT) scans were performed at 3-month follow-up. Curvature amplitude along the pacing lead was determined with CT images. Fatigue bending was performed using accelerated testing in a more severe environment than routine clinical use conditions. Conductor fracture rate in a simulated patient population was estimated based on clinical use conditions and fatigue test results.

RESULTS

The number of attempts to place the 3830 lead for LBBAP was 2.1 ± 1.3 (range: 1-7) with 13 ± 6 lead rotations at the final attempt. Extreme implant conditions were simulated in bench testing with 5 applications of 20 turns followed by up to 400 million bending cycles. Reliability modeling predicted a 10-year fracture rate of 0.02%.

CONCLUSIONS

LBBAP implants require more lead rotations than standard pacing implants and result in unique lead bending. Application of simulated LBBAP use conditions to the 3830 lead in an accelerated in-vitro model does not produce excess conductor fractures. IMAGE-LBBP Study ID of ClinicalTrial.GOV: NCT04119323.

Novel non-invasive ECG imaging method based on the 12-lead ECG for reconstruction of ventricular activation: A proof-of-concept study

Aim

Current non-invasive electrocardiographic imaging (ECGi) methods are often based on complex body surface potential mapping, limiting the clinical applicability. The aim of this pilot study was to evaluate the ability of a novel non-invasive ECGi method, based on the standard 12-lead ECG, to localize initial site of ventricular activation in right ventricular (RV) paced patients. Validation of the method was performed by comparing the ECGi reconstructed earliest site of activation against the true RV pacing site determined from cardiac computed tomography (CT).

Methods

This was a retrospective study using data from 34 patients, previously implanted with a dual chamber pacemaker due to advanced atrioventricular block. True RV lead position was determined from analysis of a post-implant cardiac CT scan. The ECGi method was based on an inverse-ECG algorithm applying electrophysiological rules. The algorithm integrated information from an RV paced 12-lead ECG together with a CT-derived patient-specific heart-thorax geometric model to reconstruct a 3D electrical ventricular activation map.

Results

The mean geodesic localization error (LE) between the ECGi reconstructed initial site of activation and the RV lead insertion site determined from CT was 13.9 ± 5.6 mm. The mean RV endocardial surface area was 146.0 ± 30.0 cm² and the mean circular LE area was 7.0 ± 5.2 cm² resulting in a relative LE of 5.0 ± 4.0%.

Conclusion

We demonstrated a novel non-invasive ECGi method, based on the 12-lead ECG, that accurately localized the RV pacing site in relation to the ventricular anatomy.

Augmented Ouabain-Induced Vascular Response Reduces Cardiac Efficiency in Mice with Migraine-Associated Mutation in the Na+, K+-ATPase α2-Isoform

Heterozygous mice (α₂^+/G301R mice) for the migraine-associated mutation (G301R) in the Na⁺,K⁺-ATPase α₂-isoform have decreased expression of cardiovascular α₂-isoform. The α₂^+/G301R mice exhibit a pro-contractile vascular phenotype associated with decreased left ventricular ejection fraction. However, the integrated functional cardiovascular consequences of this phenotype remain to be addressed in vivo. We hypothesized that the vascular response to α₂-isoform-specific inhibition of the Na⁺,K⁺-ATPase by ouabain is augmented in α₂^+/G301R mice leading to reduced cardiac efficiency. Thus, we aimed to assess the functional contribution of the α₂-isoform to in vivo cardiovascular function of wild-type (WT) and α₂^+/G301R mice. Blood pressure, stroke volume, heart rate, total peripheral resistance, arterial dP/dt, and systolic time intervals were assessed in anesthetized WT and α₂^+/G301R mice. To address rate-dependent cardiac changes, cardiovascular variables were compared before and after intraperitoneal injection of ouabain (1.5 mg/kg) or vehicle during atrial pacing. The α₂^+/G301R mice showed an enhanced ouabain-induced increase in total peripheral resistance associated with reduced efficiency of systolic development compared to WT. When the hearts were paced, ouabain reduced stroke volume in α₂^+/G301R mice. In conclusion, the ouabain-induced vascular response was augmented in α₂^+/G301R mice with consequent suppression of cardiac function.

Right Ventricular Septal Versus Apical Pacing: Long-Term Incidence of Heart Failure and Survival

The clinical benefits of right ventricular septal (RVS) pacing compared to those of right ventricular apical (RVA) pacing are still in debate. We aimed to compare the incidence of heart failure (HF) and all-cause mortality in patients submitted to RVS and RVA pacing during a longer follow-up. This a single-center, retrospective study analysis of consecutive patients submitted to pacemaker implantation. The primary outcome was defined as the occurrence of HF during follow-up. The secondary outcome was all-cause death. A total of 251 patients were included, 47 (18.7%) with RVS pacing. RVS pacing was associated to younger age, male gender, lower body mass index, ischemic heart disease, and atrial fibrillation. During a follow-up period of 5.2 years, the primary outcome occurred in 89 (37.1%) patients. RVS pacing was independently associated with a 3-fold lower risk of HF, after adjustment. The secondary outcome occurred in 83 (34.2%) patients, and pacemaker lead position was not a predictor. Fluoroscopy time and rate of complications (rarely life-threatening) were similar in both groups. Our study points to a potential clinical benefit of RVS positioning, with a 3.3-fold lower risk of HF, without accompanying increase in procedure complexity nor complication rate.

Left Bundle Branch Pacing Postatrioventricular Junction Ablation for Atrial Fibrillation: Propensity Score Matching With His Bundle Pacing

BACKGROUND

Left bundle branch pacing (LBBP) has emerged as a promising pacing modality to preserve physiological left ventricular activation; however, prospective data evaluating its long-term safety and efficacy in pacemaker-dependent patients following atrioventricular junction (AVJ) ablation are lacking. This study aimed to examine the feasibility, safety, and efficacy of LBBP in patients with atrial fibrillation and heart failure (HF) after AVJ ablation and compare LBBP with His bundle pacing (HBP) through a propensity score (PS) matching analysis.

METHODS

We prospectively enrolled patients with atrial fibrillation and HF referred for AVJ ablation and LBBP between July 2017 and December 2019. The control group was patients selected from HBP implants performed from 2012 to 2019 using PS matching with a 1:1 ratio.

RESULTS

A total of 99 patients were enrolled in the study. The LBBP implant success rate was 100%. Left ventricular ejection fraction improved from baseline 30.3±4.9 to 1-year 47.3±14.5 in HF patients with reduced ejection fraction and from baseline 56.3±12.1 to 1-year 62.3±9.1 in HF patients with preserved ejection fraction (both P<0.001), and left ventricular ejection fraction in both groups remained stable for up to 3 years of follow-up. A threshold increase >2 V at 0.5 ms occurred in only one patient. Of 176 (81.9%) of 215 patients who received permanent HBP post-AVJ ablation, 86 were matched to the LBBP group by 1:1 PS (propensity score matched His bundle pacing, N=86; propensity score matched left bundle branch pacing, N=86). No significant differences in echocardiographic or clinical outcomes were observed between the 2 groups (P>0.05), whereas lower thresholds, greater sensed R-wave amplitudes, and fewer complications were observed in the propensity score matched left bundle branch pacing group (P<0.05).

CONCLUSIONS

LBBP is feasible, safe, and effective in patients with atrial fibrillation and HF post-AVJ ablation and has similar clinical benefits, a higher implant success rate, better pacing parameters, and fewer complications compared with HBP.

Favourable outcome of a severe bradyarrhythmia in a neonate: a case report

We report the case of a term neonate with severe fetal bradycardia with an unusually benign clinical course with follow-up till infancy.

OUTCOMES OF LEADLESS PACEMAKER IMPLANTATION IN PATIENTS WITH MECHANICAL HEART VALVES

INTRODUCTION

Device infections constitute a major complication of transvenous pacemakers. Mechanical heart valves (MHV) increase the risk of infective endocarditis (IE) and pacemaker infection, requiring lifelong vitamin K-antagonists (VKA), which may affect patient management. Leadless pacemakers (LP) are associated with low infection rates, posing an attractive option in MHV patients requiring permanent pacing.This study describes outcomes following LP implantation in patients with MHV.

METHODS

This is a multicenter, observational, retrospective study including consecutive patients implanted with an LP at 5 centers between June 2015 and January 2020.Procedural outcomes, antithrombotic management, complications, performance during follow-up and episodes of bacteremia and IE were compared between patients with and without an MHV (MHV and non-MHV groups).

RESULTS

Four hundred fifty-nine patients were included (74 in the MHV group, 16.1%, and 385 in the non-MHV group, 83.9%).Procedural outcomes and acute electrical performance were comparable between groups.Vascular complications and cardiac perforation occurred in 2.7 vs. 2.3% (p=1) and 0% vs. 0.8% (p=1) in the MHV group and non-MHV group.One case of IE occurred in the MHV group and 2 in the non-MHV group.In MHV patients, uninterrupted VKA was used in 83.8 %, whereas 16.2 % were heparin-bridged.Vascular complication or tamponade occurred in 1(8.3 %) MHV heparin-bridged patient vs. 1 (1.6 %) MHV uninterrupted VKA patient (p=0.3).

CONCLUSION

LP implantation outcomes in MHV patients are comparable to the general LP population.Device-related infections are rare following LP implantation, including in patients with MHV.In the MHV group, periprocedural anticoagulation management was not associated with significantly different rates of tamponade or vascular complication. This article is protected by copyright. All rights reserved.

Magnetoelectric Bio-Implants Powered and Programmed by a Single Transmitter for Coordinated Multisite Stimulation

This paper presents a hardware platform including stimulating implants wirelessly powered and controlled by a shared transmitter for coordinated leadless multisite stimulation. The adopted novel single-transmitter, multiple-implant structure can flexibly deploy stimuli, improve system efficiency, easily scale stimulating channel quantity and relieve efforts in device synchronization. In the proposed system, a wireless link leveraging magnetoelectric effects is co-designed with a robust and efficient system-on-chip to enable reliable operation and individual programming of every implant. Each implant integrates a 0.8-mm² chip, a 6-mm² magnetoelectric film, and an energy storage capacitor within a 6.2-mm³ size. Magnetoelectric power transfer is capable of safely transmitting milliwatt power to devices placed several centimeters away from the transmitter coil, maintaining good efficiency with size constraints and tolerating 60-degree, 1.5-cm misalignment in angular and lateral movement. The SoC robustly operates with 2-V source amplitude variations that spans a 40-mm transmitter-implant distance change, realizes individual addressability through physical unclonable function IDs, and achieves 90% efficiency for 1.5-to-3.5-V stimulation with fully programmable stimulation parameters.

Eligibility of patients with temporary paced rhythm for a subcutaneous implantable cardioverter-defibrillator

BACKGROUND

A concomitant use of a pacemaker and a subcutaneous implantable cardioverter-de-fibrillator (S-ICD) may be required in some patients.

AIMS

Our study aimed to evaluate the influence of permanent cardiac pacing on the morphology of the QRS complex in the context of S-ICD screening.

METHODS

One hundred patients with cardiac electronic implantable devices (CIEDs) were included in whom S-ICD screening could be performed both during intrinsic and paced rhythm.

RESULTS

The positive result of screening during spontaneous rhythm for at least one vector (in both supine and standing positions) was obtained in 80% and for 2 vectors in 59% of patients. Positive screening during paced rhythm for at least one vector was recorded in 36% of patients (78% right ventricular and 22% biventricular pacing) and for 2 vectors in 15% of patients (93% right ventricular and 7% biventricular pacing). At least one vector acceptable during both types of rhythm and in both positions was recorded in 23% of patients and at least 2 vectors in 8% of patients.

CONCLUSIONS

The use of S-ICD in patients with paced ventricular rhythm is associated with a serious risk of inappropriate sensing due to different QRS morphology during intrinsic and paced rhythm, and it is particularly high in patients in whom periods of spontaneous rhythm interchange with periods of ventricular pacing. That risk has been hardly acknowledged in available reports, but according to our data, it is significant, and therefore it should be considered during S-ICD screening.

Permanent pacemaker implantation in a challenging anatomy: Persistent left superior vena cava

The persistence of the left superior vena cava is one of the most common abnormalities that could affect the thoracic venous return, despite its rare occurrence. It can usually be found as the only or in combination with other congenital cardiac abnormalities. Even though it is usually asymptomatic and it rarely has important consequences on the hemodynamics, it could sometimes represent a serious threat. In this regard, PLSVC often represents an incidental finding during an invasive procedure or imaging. We present an interesting case of a 66-year-old patient, with permanent atrial fibrillation and chronic kidney disease who presented to our clinic for a syncope due to complete atrioventricular block. The implant procedure was marked by the incidental intraprocedural finding of unusual venous anatomy. This anomaly included the absence of the superior vena cava, with the communication of the right brachiocephalic trunk and right subclavian vein with a persistent left superior vena cava which drainage directly into the coronary sinus. The right-side approach, as well as the limitation of using contrast-based venography, due to the kidney disease, made the procedure more difficult, but the final position of an active fixation ventricular lead was successfully achieved with optimal and stable pacing parameters through the formation of a particular curve of the lead stylet. Persistence of the left superior vena cava is a venous anomaly, which is frequently suspicioned at transthoracic echocardiography examination when the examiner found a dilated coronary sinus but diagnosed on the implant table of a cardiac device. These anomalies can pose problems and exponentially increase the procedural time even in experienced hands.

Case Report: Interventricular Septal Hematoma Complicating Left Bundle Branch Pacing Lead Implantation

Background: Left bundle branch pacing (LBBP) is a novel physiological pacing and previous studies have confirmed the feasibility and safety of it. The incidence of complications in LBBP is relatively low as reported. Here we present a case of interventricular septal hematoma complicating LBBP lead implantation.

Case summary: LBBP was achieved for treatment of high-grade atrioventricular block in a 67-year-old female. Chest pain began 1 h after implantation when the electrocardiogram showed ST-T changes. Then bedside echocardiography confirmed the formation of interventricular septal hematoma. Urgent coronary angiography showed the contrast agent retention and overflow in the interventricular septum. The symptom was relieved half an hour later. Echocardiogram performed 2 h later revealed the size of the hematoma was the same as before. The electrocardiography, coronary angiography and CTA confirmed the resolution of the hematoma at 1-month follow-up. Pacing parameters and cardiac function remained stable during 6-month follow-up.

Conclusion: This is the first reported case describing the clinic features and management of interventricular septum hematoma complicating LBBP. The importance of routine echocardiograms after implantation for identifying the hematoma should be highlighted.

Conduction abnormalities and role of cardiac pacing in cardiac amyloidosis: A systematic review

Cardiac amyloidosis (CA) is an increasingly recognized cause of heart failure, characterized by extracellular deposition of insoluble protein fibrils leading to progressive myocardial dysfunction. The most common types of cardiac amyloidosis are immunoglobin light-chain (AL) and transthyretin (ATTR). Conduction abnormalities are commonly encountered among patients with cardiac amyloidosis and are an important cause of morbidity and mortality. Abnormalities range from infra-Hisian intraventricular conduction delay and bundle branch block to complete atrioventricular block. Pacemaker placement in CA patients follows established guidelines, similar to those for patients without CA, with generally good efficacy. The role and appropriate timing of pacemakers for primary prevention of brady-arrhythmias in CA remains uncertain. While biventricular (BiV) pacing has been shown to improve clinical outcomes in patients with systolic heart failure without CA, there are few data examining the utility of BiV pacing in patients with CA. With the advent of effective treatments for AL and ATTR, appropriate application of pacing is important to support patients with CA and conduction disease through therapeutic trials. This systematic review summarizes the current literature examining the utility of pacing in CA.

Computed tomography validated right ventricular mid-septal lead implantation using right ventricular angiography

BACKGROUND

Right ventricular (RV) mid-septal pacing has been proposed as an alternative to RV apical pacing. Fluoroscopic and electrocardiogram criteria are unreliable for predicting the RV mid-septal lead position. This study aimed to define the optimal RV mid-septal pacing site using RV angiography.

METHODS

We randomized patients undergoing pacemaker implantation (PPM) to the RV angiography-guided group (Group A) or conventional fluoroscopy-guided group (Group F). In Group A, we performed an angiogram in right anterior oblique (RAO 30°), left anterior oblique (LAO 40°), and left lateral (LL) views. We made a 5-segment grid in RAO 30° and LL views and a 3-segment grid in LAO 40° on the angiographic silhouette to define the lead position. Computed tomography (CT) was used to validate the lead tip position in both groups.

RESULTS

We enrolled 53 patients (Group A: 26, Group F: 27) with a mean age of 55.9 ± 12.2 years. CT images validated the lead position in the mid-septum (Group A, 23 [88.5%]; Group F, 11 [40.7%], P = .0003) and anteroseptal (Group A, 3 [11.5%]; Group F, 5 [18.5%], P = .24). In Group F, the lead was in the anterior wall in 9 patients (33.3%) and the right ventricular outflow tract in 2 (7.4%) patients and none in these two positions in Group A. The lead tip in segment one on the angiographic 5-segment grid in RAO 30° and LL views indicated a mid-septal lead position on CT.

CONCLUSIONS

RV angiography is safe and may be used to confirm the mid-septal lead position during PPM.

The Infectious Tale of Aerococcal Aortic Endocarditis: Cardiac Pacing in Acute Aortic Insufficiency With Complete Heart Block as a Bridge to Aortic Valve Replacement

Here, we describe a rare case of Aerococcus endocarditis causing aortic insufficiency and paravalvular abscess presenting as complete heart block and shock. A 76-year-old man with diabetes mellitus presented to the emergency department with fever and dyspnea. His temperature was 102.4°F, heart rate 59 beats per minute, blood pressure 105/44 mmHg, and oxygen saturation was 98% on 6L oxygen. Examination revealed bounding carotid pulses, a 2/6 early blowing diastolic murmur at the left lower sternal border, and diminished lung sounds at the bases. Laboratory data showed leukocytosis of 19.65 k/µL, blood urea nitrogen 72 mg/dL, creatinine 2.92 mg/dL, lactic acid 3.1 mmol/L, pro-B-type natriuretic peptide 15,342 pg/mL, high-sensitivity troponin 136 ng/L, aspartate aminotransferase 129 U/L, and alanine aminotransferase of 115 U/L. An electrocardiogram showed complete heart block, and a transvenous pacemaker was placed. A transesophageal echocardiogram revealed an aortic root abscess and severe aortic insufficiency secondary to Aerococcus urinae. Ventricular pacing was used to decrease aortic insufficiency and optimize computed tomography with gating to view the coronary arteries due to wall motion abnormalities seen on the transthoracic echocardiogram. His aortic valve was replaced, and a pacemaker was planned. Aortic valve Aerococcus endocarditis is rare and can lead to complete heart block and aortic insufficiency. Cardiac pacing improves hemodynamics by increasing heart rate and decreasing left ventricular end-diastolic pressure.

Ventricular pacemaker lead in the left hemithorax: Mechanisms and evidence-based management of a late-onset hazardous complication

Late-onset migration of pacing leads in the left hemithorax is a rare but potentially life-threatening complication. Radiological examinations are required to detect any involvement of either left ventricle or lung parenchyma, prompting immediate surgical extraction in this setting. Identification of high-risk patients is mandatory to prevent this complex iatrogenic complication.

Feasibility and Outcomes of Upgrading to Left Bundle Branch Pacing in Patients With Pacing-Induced Cardiomyopathy and Infranodal Atrioventricular Block

His bundle pacing (HBP) can reverse left ventricular (LV) remodeling in patients with right ventricular (RV) pacing-induced cardimyopathy (PICM) but may be unable to correct infranodal atrioventricular block (AVB). Left bundle branch pacing (LBBP) results in rapid LV activation and may be able to reliably pace beyond the site of AVB. Our study was conducted to assess the feasibility, safety, and outcomes of permanent LBBP in infranodal AVB and PICM patients. Patients with infranodal AVB and PICM who underwent LBBP for cardiac resynchronization therapy (CRT) were included. Clinical evaluation and echocardiographic and electrocardiographic assessments were recorded at baseline and follow-up. Permanent LBBP upgrade was successful in 19 of 20 patients with a median follow-up duration of 12 months. QRS duration (QRSd) increased from 139.3 ± 28.0 ms at baseline to 176.2 ± 21.4 ms (P < 0.001) with right ventricular pacing (RVP) and was shortened to 120.9 ± 15.2 ms after LBBP (P < 0.001). The mean LBBP threshold was 0.7 ± 0.3 V at 0.4 ms at implant and remained stable during follow-up. The left ventricular ejection fraction (LVEF) increased from 36.3% ± 6.5% to 51.9% ± 13.0% (P < 0.001) with left ventricular end-systolic volume (LVESV) reduced from 180.1 ± 43.5 to 136.8 ± 36.7 ml (P < 0.001) during last follow-up. LBBP paced beyond the site of block, which results in a low pacing threshold with a high success rate in infranodal AVB patients. LBBP improved LV function with stable parameters over the 12 months, making it a reasonable alternative to cardiac resynchronization pacing via a coronary sinus lead in infranodal AVB and PICM patients.

A pilot study to determine if left ventricular activation time is a useful parameter for left bundle branch capture: Validated by ventricular mechanical synchrony with SPECT imaging

BACKGROUND

Left bundle branch (LBB) pacing has emerged as a novel pacing modality. Left ventricular activation time (LVAT) was reported to be associated with the activation via LBB, but the value of LVAT for determining LBB pacing was unknown. We conducted a pilot study to determine if LVAT could define LBB capture by validating left ventricular (LV) mechanical synchrony.

METHODS

We analyzed LVAT in 68 bradycardia-indicated patients who received LBB pacing. LVAT was measured from the stimulus to R-wave peak in lead V5 and V6. LV mechanical synchrony assessed by SPECT MPI was compared according to the value of LVAT and the presence of LBB potential.

RESULTS

The mean LVAT was 75.4 ± 12.7 ms. LBB potential was recorded in 47 patients (69.1%). Patients with LVAT < 76 ms had better LV mechanical synchrony than those with LVAT ≥ 76 ms. Patients with LVAT < 76 ms or LBB potential had better mechanical synchrony than those with LVAT ≥ 76 ms and no potential. LVAT < 76 ms could predict the normal synchrony with a sensitivity of 88.9% and a specificity of 87.5%.

CONCLUSION

A short LVAT indicated favorable mechanical synchrony in SPECT imaging. LVAT < 76 ms might be a practical parameter for defining LBB capture.

Is the right ventricular function affected by permanent pacemaker?

AIMS

The effect of right ventricular (RV) pacing on left ventricular (LV) function has been extensively evaluated, but the effect on RV function per se has not been evaluated systematically. We aimed to assess the effect of dual chamber pacemaker on RV function.

METHODS AND RESULTS

All consecutive patients undergoing dual chamber pacemaker from January 2018 to March 2019 for AV block with a structurally normal heart were included. They underwent pre-procedure detailed echocardiography (including three-dimensional [3D] RV ejection fraction [RVEF]), a screening echocardiogram 2 days after pacemaker implantation and again a detailed echocardiogram at 6-month follow-up. We compared the baseline echocardiographic RV parameters with those 6 months after the pacemaker implantation. A total of 60 patients underwent successful pacemaker implantation. At 6 months, most of the patients were pacemaker dependent with pacing percentage of 98.9% ± 2.4%; there was a significant increase in TR and a mean drop in RVEF by 2.8 ± 5%, with 23 (38.3%) having at least a 5% decrease in RVEF. The drop in RVEF positively correlated with TR vena contracta at 6 months but did not correlate with pulmonary artery systolic pressure at 6 months.

CONCLUSION

Our study shows the presence of demonstrable RV dysfunction as early as 6 months in a majority of patients who have undergone pacemaker implantation.

Single-Chamber Cardiac Pacemaker Implantation in a Donkey with Complete AV Block: A Long-Term Follow-Up

A five-month-old African jenny was presented with a history of exercise intolerance and syncopal episodes. Severe bradycardic arrhythmia due to a high-grade second-degree atrioventricular (AV) block with progression to complete AV block was diagnosed. The jenny underwent a transvenous single-chamber pacemaker implantation. The implantation procedure was performed in a lateral recumbency and the ventricular lead was inserted through the jugular vein. Positioning of the lead was guided by echocardiography. The pacemaker was programmed to VVI mode with a minimal ventricular rate of 40 pulses per minute, a pulse amplitude of 2.4 V, a pulse width of 0.5 ms and sensing amplitude of 2.5 mV. Short-term complications associated with the procedure included lead dislodgement and pacemaker pocket infection. The long-term outcome was satisfactory; the jenny showed improvement in heart function and quality of life after pacemaker implantation. The pulse generator replacement was performed twice (at nine-year intervals) and the intervention was always associated with a local inflammatory reaction around the pacing device. Cardiac examination 18 years after pacemaker implantation revealed no morphological changes in the heart; the electrode lead was still in the correct position and successful pacing and sensing of the ventricle were obtained. Regular follow-up checks are important to evaluate pacemaker function.

Long-Term Safety and Feasibility of Left Bundle Branch Pacing in a Large Single-Center Study

BACKGROUND

Left bundle branch pacing (LBBP) is a novel pacing method and has been observed to have low and stable pacing thresholds in prior small short-term studies. The objective of this study was to evaluate the feasibility and safety of LBBP in a large consecutive diverse group of patients with long-term follow-up.

METHODS

This study prospectively enrolled 632 consecutive pacemaker patients with attempted LBBP from April 2017 to July 2019. Pacing parameters, complications, ECG, and echocardiographic measurements were assessed at implant and during follow-up of 1, 6, 12, and 24 months.

RESULTS

LBBP was successful in 618/632 (97.8%) patients according to strict criteria for LBB capture. Mean follow-up time was 18.6±6.7 months. Two hundred thirty-one patients had follow-up over 2 years. LBB capture threshold at implant was 0.65±0.27 mV at 0.5 ms and 0.69±0.24 mV at 0.5 ms at 2-year follow-up. A significant decrease in QRS duration was observed in patients with left bundle branch block (167.22±18.99 versus 124.02±24.15 ms, P<0.001). Postimplantation left ventricular ejection fraction improved in patients with QRS≥120 ms (48.82±17.78% versus 58.12±13.04%, P<0.001). The number of patients with moderate and severe tricuspid regurgitation decreased at 1 year. Permanent right bundle branch injury occurred in 55 (8.9%) patients. LBB capture threshold increased to >3 V or loss of bundle capture in 6 patients (1%), 2 patients of them had a loss of conduction system capture. Two patients required lead revision due to dislodgement.

CONCLUSIONS

This large observational study suggests that LBBP is feasible with high success rates and low complication rates during long-term follow-up. Therefore, LBBP appears to be a reliable method for physiological pacing for patients with either a bradycardia or heart failure pacing indication.

Evaluation and Management of Asymptomatic Bradyarrhythmias

Asymptomatic bradyarrhythmias involving sinus node dysfunction and atrioventicular blocks are frequently noted in clinical practice. Its prevalence is expected to rise as devices that are developed for monitoring cardiac rhythm for longer duration become more widely available. Episodes of bradyarrhythmia that are asymptomatic are considered to have a benign course compared with those that cause symptoms and do not necessitate further treatment. However, in certain cases, they can be a harbinger of future symptoms or cardiac manifestations of systemic diseases. The evaluation and risk stratification of individuals presenting with asymptomatic bradyarrhythmias is important not only for preventing implantation of unnecessary permanent pacing devices but also for reducing significant morbidity by implementing proper treatment as required. In this article, we will review the current evidence on the pathophysiology, diagnosis, evaluation and management of patients with asymptomatic bradyarrhythmias.

Evaluation of different lead types and implantation techniques in pediatric populations with permanent pacemakers: Single-center with 10 years' experience

BACKGROUND

Permanent pacemaker (PM) implantation is performed for various indications and by different techniques in children; however, many problems with lead performance are encountered during follow-up. This study aims to evaluate the possible effects of different lead types and implantation techniques on pacing at early and midterm in children with a permanent PM.

PATIENTS AND METHODS

Pediatric patients who underwent permanent PM system implantation at our tertiary cardiac surgery center between January 1, 2010 and January 1, 2020 were evaluated retrospectively. Patients were categorized in the epicardial pacing lead (EP), transvenous pacing lead (TP), and transvenous bipolar lumenless (Select Secure [SS]) lead groups according to the lead implantation technique and lead type with the same manufacturer. Groups were evaluated statistically for demographic features, pacing type and indication for implantation, lead electrical performance, lead failure, complications, and outcome.

RESULTS

Over 10 years, 323 lead implantations were performed on 167 patients (96 males, median age 68 months [5 days-18 years]). Of 323 leads, 213 (66%) were EP, 64 (20%) were TP, and 46 (14%) were SS. Of the total, 136 of the leads were implanted in atria, and 187 were implanted in ventricles. Primary pacing indications were postoperative complete atrioventricular (AV) block (n = 95), congenital AV block (n = 71), sinus node dysfunction (n = 13), and acquired complete AV block (n = 1). Additional cardiac diseases were present in 115 patients (69%). No statistically significant difference was observed in gender, syndrome, or pacing indication (P > .05). Atrial and ventricular capture, threshold, sensing, and lead impedance measurements were not significantly different at the initial and follow-up periods (P > .05). The median follow-up duration was 3.3 years (6 months-10 years). Twenty lead failures were determined in 15 patients (EP: 14 lead failures in 10 patients; TP: two lead failures in two patients; and SS: four lead failures in three patients) during follow-up, and no statistically significant difference was found between groups (P = .466). The 5-year lead survival was 98% for TP, 95% for EP, and 90% for SS; the 10-year lead survival was 90% for TP, 70% for EP, and 70% for SS. There was no mortality related to chronic pacing or due to the procedure of implantation.

CONCLUSIONS

Despite improvements in technology, lead failure is still one of the most critical problems during these patients' follow-up. Early to midterm lead survival rates of all three lead types were satisfactory.

Performance of pacemaker leads in alternative lead positions after tricuspid valve replacement

BACKGROUND

Bradycardic arrhythmias requiring pacemaker (PM) implantation are still common in patients in need of tricuspid valve replacement (TVR). Leaving an existing PM lead in an extravalvular position may represent a helpful alternative in special situations like the implantation of a mechanical TV. This study aimed to examine the short- to mid-term outcome of paravalvular leads concerning lead survival and prosthesis dysfunction in patients after TVR.

METHODS

A retrospective case-control study of patients with TVR and ventricular pacing was conducted. Patients from the database of the Leipzig Heart Center were included. Data of the paravalvular lead group (PVG) and coronary sinus lead group (CSG) were compared to a control group with conventional transvalvular leads (TVG).

RESULTS

Eighty patients with TVR and cardiac PM (TVG [n = 13], PVG [n = 40], and CSG [n = 27]) were included. The mean follow-up was 2.8 years. The rate of lead revisions (TVG 15.4%, PVG 2.5%, and CSG 7.5%) was lower in PVG but without significance (P = .286). The CSG demonstrated significantly higher pacing thresholds (1.4 V/0.8 ms) than TVG (0.5 V/0.4 ms), P = .004. However, the deterioration of threshold amplitudes during follow-up was similar in CSG (7.4%) and PVG (7.5%) compared with controls (7.7%). Function of TV prosthesis regarding development of stenosis or regurgitation showed a similarity between the groups (regurgitation PVG P = .692, CSG P = 1; stenosis PVG P = .586, CSG P = 0.69).

CONCLUSION

Paravalvular positioning of PM leads seems to represent a reasonable alternative to the conventional transvalvular lead positioning concerning the lead and Tricuspid Valve prosthesis's function and durability in selected patients.

Etiology of syncope in patients with preexisting atrioventricular conduction disorders

BACKGROUND

The discussion about the feasibility of empiric pacemaker implantation in patients with preexisting atrioventricular (AV) conduction disorders continues. The aim of the study was to determine the etiology of syncope and the need for pacemaker insertion in patients with AV conduction impairment using implantable loop recorder (ILR).

METHODS

ILR was implanted after negative diagnostic workup in 37 patients with syncope (24 men, 13 women, age 72 ± 10 years) and preexisting impairment of AV conduction. First-degree AV block (AVB I) was present in 26 patients, and bundle branch block (BBB) in 17 patients.

RESULTS

ILR-based diagnosis was made in 28 patients (75%)-sinus arrest in 13 patients, complete AVB in 10 patients, and vasodepressor syncope in five patients. In patients with preexisting BBB, sinus arrest occurred during ILR monitoring significantly more frequently than in patients without BBB (53% vs 20%, P = .03). Complete AVB was significantly less common in patients with preexisting BBB than in patients without BBB (12% vs 40%, P = .04). On multivariate regression analysis, the only independent predictor of AVB occurrence during ILR monitoring was preexisting AVB I (P = .03). The only independent predictor of sinus arrest during ILR monitoring was preexisting BBB (P = .03).

CONCLUSIONS

In patients with preexisting AV conduction disorders, prevailing syncopal mechanism during ILR monitoring was asystole. However, sinus arrest occurred more often than complete AVB and was predicted by preexisting BBB. Preexisting AVB was a predictor of complete AVB during ILR monitoring.

Nonpharmacological Treatment of Atrial Fibrillation: What Is the Role of Device Therapy?

Atrial fibrillation is the most common arrhythmia in the adult population, and its incidence and prevalence are still rising. Cardiac devices are widely used in clinical practice in the management of various rhythm disturbances and heart failure treatment. Many patients who receive a pacemaker, implantable cardioverter-defibrillator, or cardiac resynchronization therapy also experience atrial fibrillation in the course of their life. Therefore, this review aims to describe the role of these devices in the treatment and prevention of atrial fibrillation in the device recipients. In addition, all these implantable devices also serve as permanent ECG (electrocardiogram) monitors, thus providing important information about the presence and characteristics of atrial fibrillation that may or may not be detected by the patient but can modify our therapeutical approach with regard to the stroke prevention.

Network meta-analysis of His bundle, biventricular, or right ventricular pacing as a primary strategy for advanced atrioventricular conduction disease with normal or mildly reduced ejection fraction

INTRODUCTION

Although right ventricular pacing (RVP) may impair ventricular function, it is commonly used for advanced atrioventricular block (AVB) and normal or mildly reduced ejection fraction (EF). We aimed to compare His bundle pacing (HBP), biventricular pacing (BiVP), and RVP for advanced AVB in patients with normal or mildly reduced EF.

METHODS AND RESULTS

MEDLINE, Embase, Cochrane CENTRAL, ClinicalTrials.gov, Scopus, and Web of Science were searched. Outcomes were all-cause death, heart failure hospitalizations (HFH), EF, left ventricular volumes, 6-minute walk test, and QRS duration. HBP or BiVP was compared with RVP. Subsequently, network meta-analysis compared the three pacing options. Our protocol was registered in PROSPERO (CRD42018094132). Six studies compared BiVP and RVP (704 vs 614 patients) and four compared HBP and RVP (463 vs 568 patients). Follow-up was 6 months to 5 years. There was significantly lower mortality and HFH with HBP or BiVP as compared with RVP (odds ratio [OR], 0.66, [0.51-0.85], P = .002; OR, 0.61 [0.45-0.82], P < .001, respectively]. HBP or BiVP also showed significant increase in EF and decrease in QRS duration (mean difference [MD], 5.27 [3.86-6.69], P < .001; MD -42.2 [-51.2 to -33.3], P < .001, respectively). In network meta-analysis, HBP and BiVP were associated with significantly improved survival compared to RVP, with surface under the cumulative ranking curve (SUCRA) probability of 79.4%, 69.4%, and 1.2% for HBP, BiVP, and RVP, respectively. For HFH, SUCRA probability was 91.5%, 57.2%, and 1.3%, respectively.

CONCLUSION

HBP or BiVP were the superior strategies to reduce all-cause death and HFH for advanced AVB with normal or mildly reduced EF, with no significant difference between BiVP and HBP.

Reflex Atrioventricular Block

Reflex atrioventricular block is well-recorded although it is considered rare. Recent data suggests that it is less rare than has been supposed. It has been shown to occur in both vasovagal and carotid sinus reflexes. It has to be distinguished from paroxysmal atrioventricular block due to ventricular conduction tissue disease. Low chronic adenosine levels combined with adenosine release may mimic reflex atrioventricular block. Explanations of the mechanism of these phenomena have been lacking until the recent past. The relevance of reflex atrioventricular block to clinical decision-making is as a possible indication for pacing the heart with consideration given to the vasodepressor component of the reflex.

Optogenetics: Background, Methodological Advances and Potential Applications for Cardiovascular Research and Medicine

Optogenetics is an elegant approach of precisely controlling and monitoring the biological functions of a cell, group of cells, tissues, or organs with high temporal and spatial resolution by using optical system and genetic engineering technologies. The field evolved with the need to precisely control neurons and decipher neural circuity and has made great accomplishments in neuroscience. It also evolved in cardiovascular research almost a decade ago and has made considerable progress in both in vitro and in vivo animal studies. Thus, this review is written with an objective to provide information on the evolution, background, methodical advances, and potential scope of the field for cardiovascular research and medicine. We begin with a review of literatures on optogenetic proteins related to their origin, structure, types, mechanism of action, methods to improve their performance, and the delivery vehicles and methods to express such proteins on target cells and tissues for cardiovascular research. Next, we reviewed historical and recent literatures to demonstrate the scope of optogenetics for cardiovascular research and regenerative medicine and examined that cardiac optogenetics is vital in mimicking heart diseases, understanding the mechanisms of disease progression and also in introducing novel therapies to treat cardiac abnormalities, such as arrhythmias. We also reviewed optogenetics as promising tools in providing high-throughput data for cardiotoxicity screening in drug development and also in deciphering dynamic roles of signaling moieties in cell signaling. Finally, we put forth considerations on the need of scaling up of the optogenetic system, clinically relevant in vivo and in silico models, light attenuation issues, and concerns over the level, immune reactions, toxicity, and ectopic expression with opsin expression. Detailed investigations on such considerations would accelerate the translation of cardiac optogenetics from present in vitro and in vivo animal studies to clinical therapies.

Subclinical and Device-Detected Atrial Fibrillation: Pondering the Knowledge Gap: A Scientific Statement From the American Heart Association

The widespread use of cardiac implantable electronic devices and wearable monitors has led to the detection of subclinical atrial fibrillation in a substantial proportion of patients. There is evidence that these asymptomatic arrhythmias are associated with increased risk of stroke. Thus, detection of subclinical atrial fibrillation may offer an opportunity to reduce stroke risk by initiating anticoagulation. However, it is unknown whether long-term anticoagulation is warranted and in what populations. This scientific statement explores the existing data on the prevalence, clinical significance, and management of subclinical atrial fibrillation and identifies current gaps in knowledge and areas of controversy and consensus.