Pacemaker Research Articles

Dual Chamber Pacemaker Implant in Coronary Sinus Leading to Several Complications

Permanent pacemaker implantation is a low-risk procedure. However, complications may occur at a rate of around 4–8%. We present a case where initial implantation resulted in complications that could have been avoided by meticulous assessment of lead position in different projections and early post-procedure X-ray that would have delineated other serious complications. We present a case where the right ventricular lead was placed in the coronary sinus, which resulted in the loss of pacing capture with further syncope after the pacemaker implant. This was apparent in the post-procedure electrocardiogram (ECG) with right bundle branch pacing and the lead was repositioned in the right ventricular apex the following day. Furthermore, the patient was discharged home without a chest X-ray (CXR), and she represented a week later with a haemo-pneumothorax and pericardial effusion. A chest drain was placed and was discharged after a slow recovery following several complications that could have been avoidable.

Magnetic resonance imaging in patients with cardiac implantable electronic devices: the RESONANCE Spanish registry.

Despite increasing evidence demonstrating the safety of magnetic resonance imaging (MRI) in patients with cardiac implantable electronic devices (CIEDs), this procedure is often neglected in this population. This Spanish registry aimed to determine the proportion of MRI referrals and performance among patients with pacemakers (PMs) or implantable cardioverter-defibrillators (ICDs). This prospective, multicenter, open-label registry involved 21 Spanish centers. Data were collected upon implant of PMs or ICDs from BIOTRONIK and one year after, and included the number of MRIs and computed tomography scans prescribed, performed and denied, and reasons for denial. Data from 1105 patients (mean age: 74.2 years) were analyzed and 982 completed the follow-up. Of them, 82.2% had a PM and 17.8% an ICD. A total of 351 imaging tests were prescribed in 220 patients (19.9%), including 52 MRIs in 39 patients (3.5%) and 299 computed tomography scans in 196 patients (17.8%). Among the MRIs, 44 (84.6%) were performed, five (9.6%) were not performed, and three (5.8%) were replaced by an alternative test. Most of the indicated computed tomography scans were performed (97.7%). The proportion of patients with an MRI scan referral was 4.6% during the pre-COVID-19 period and 2.6% during the COVID-19 period. No MRI-related arrhythmic ventricular event was reported. This registry revealed that only 3.5% of patients with CIEDs had an MRI referral over the study, with rates decreasing to 2.6% during the COVID-19 period. These rates contrast with the 85 MRIs conducted per 1000 inhabitants in Spain in 2020.

Sleep-Disordered Breathing and Cardiac Arrhythmias

A narrative review was performed, analyzing peer-reviewed articles from databases such as PubMed, EMBASE, Scopus, and Web of Science to examine the mechanistic links between sleep-disordered breathing (SDB), and cardiac arrhythmias, emphasizing intermittent hypoxia, autonomic imbalance, and intrathoracic pressure swings as key pathways. Studies, including the DREAM and CESAAR trials, consistently demonstrate that SDB patients face elevated risks: more than doubling the likelihood of overall arrhythmias (OR 2.24; 95% CI 1.48–3.39), quadrupling the risk of AF (OR 4.02; 95% CI 1.03–15.74), and tripling the risk of non-sustained ventricular tachycardia (NSVT) with higher apnea-hypopnea index (AHI) values. Additionally, SDB doubles the risk of bradyarrhythmia, such as sinus pause, second and third-degree atrioventricular block, and intraventricular conduction delay (OR 2.50; 95% CI 1.58–3.95). According to meta-analytical findings, continuous positive airway pressure (CPAP) therapy is a pivotal intervention, significantly reducing AF recurrence by 42% and lowering VA incidence by 58%. Moreover, CPAP therapy diminishes sinus bradycardia and occurrences of sinus pause and may reduce the necessity for pacemaker implantation. Recognizing SDB as a modifiable risk factor for cardiac arrhythmias highlights the importance of early diagnosis and effective management, primarily through CPAP therapy, to improve cardiovascular outcomes.

Prevalence and Prognostic Significance of Right Ventricular Dysfunction in Patients With Severe Low-Flow, Low-Gradient Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement.

Whether the presence of right ventricular (RV) dysfunction may influence the clinical outcome of patients with low-flow, low-gradient aortic stenosis (LFLG-AS) undergoing transcatheter aortic valve replacement (TAVR) has not yet been established. This study included consecutive patients with LFLG-AS undergoing TAVR at 2 high-volume Italian centers. RV dysfunction before TAVR procedure was defined as tricuspid annular plane systolic excursion assessed by transthoracic echocardiography lower than <17 mm. The primary outcome was all-cause death at 1 year. The propensity score weighting technique was implemented to account for potential selection bias between patients with and without RV dysfunction. A prespecified subgroup analysis was conducted to evaluate the consistency of the results in patients with classical and paradoxical LFLG-AS forms. This study included 392 patients; of them, 97 (24.7%) patients showed RV dysfunction before TAVR. At propensity score-weighted adjusted Cox regression analysis, RV dysfunction, according to dichotomous definition, was associated with an increased risk for the primary outcome (adjusted hazard ratio [HR], 3.11 [95% CI, 1.58-6.13]), cardiovascular death (adjusted HR, 3.26 [95% CI, 1.58-6.72]), and major adverse cardiovascular and cerebrovascular events (adjusted HR, 3.39 [95% CI, 1.76-6.53]). Conversely, no difference was detected for the risk of stroke and of permanent pacemaker implantation. No significant interaction of the classical and paradoxical LFLG-AS subgroups was detected for all the outcomes of interest. This study suggests that RV dysfunction echocardiographically assessed by tricuspid annular plane systolic excursion may improve the prognostic stratification of patients with LFLG-AS undergoing TAVR.

Pacemaker Implantation for Low-Grade Conduction Abnormalities After Balloon-Expandable Transcatheter Aortic Valve Implantation.

A frequent complication after TAVI are postinterventional conduction abnormalities requiring permanent pacemaker implantation. In this study, we analyzed the characteristics of borderline conduction abnormalities leading to pacemaker implantation and the resulting ventricular pacing amounts. All patients who underwent balloon-expandable TAVI between 2014 and 2019 in our tertiary center were analyzed in a retrospective manner. One hundred and sixty-five patients of 1083 TAVI-patients developed postinterventional conduction abnormalities leading to pacemaker implantation. Of these 19 (11.5%) did not represent a clear indication for cardiac pacing according to current European guidelines. Patient characteristics, underlying conduction abnormalities, and the temporal change of ventricular pacing percentages at 24 h and 6 weeks after pacemaker implantation were analyzed. The dominating borderline conduction abnormalities leading to pacemaker implantation were new-onset persisting bundle-branch-blocks and new first-degree AV-blocks with progression of AV-delay. While pacemaker implantation was safe and without severe complications in all cases, only 6 of 19 patients had high pacing amounts (95%-100%) after 24 h while 11 patients had low to no pacing amounts (0%-5%). After 6 weeks, 8 patients showed decreasing pacing amounts, no patient had an increasing amount of ventricular pacing and all patients had an intrinsic ventricular rhythm > 30/min. In our cohort of 1038 TAVI patients, 19 patients underwent PMI for borderline CAs (11.5% of all PMI). Of these, only 2 patients had high pacing amounts after 6 weeks. The risk of complete persisting heart block in these patients is very low. Furthermore, algorithms to reduce ventricular pacing are highly effective to avoid ventricular pacing whenever reasonable.

Lactate Dehydrogenase Levels after aortic valve replacement: What do they tell us?

Lactate dehydrogenase (LDH) is a standard postoperative marker for hemolysis in the presence of paravalvular leakage (PVL) after aortic valve replacement (AVR). LDH is elevated in certain valves by a fluttering phenomenon. Previous studies suggested a correlation between microparticles (MP) and LDH elevation after AVR. We analyze the postoperative relevance of LDH after AVR with transapical transcatheter aortic valves (TA-TAV) or rapid deployment valves (RDV). We retrospectively analyzed the data from patients who received an AVR with RDV and TA-TAV groups between 2015-2018. We compared PVL and LDH levels before and after surgery, transvalvular gradients, heart block that required pacemaker implantation, and 30-day mortality. 138 consecutive patients were selected: 79 patients in the RDV group (37 Sorin Perceval valve, 42 Edwards Intuity valves) and 59 in the TA-TAV group (Edwards Sapien valve). TA-TAV-group were older (median 10 years) and with higher incidence of PVL (Odds ratio 11, 95% CI from 2.5 - 73.2, p-value 0.04)). TA-TAV-Group showed lower levels of LDH despite higher rates of PVL while the Perceval valve trended towards higher LDH values. Additionally, the RDV group showed an increased arrhythmia profile (p=0.0041) although the results show lower incidence in pacemaker implantation (95 % CI 0.05 - 1.65, p=0.635). 30-day mortality was similar between groups. Our data do not support the association between hemolysis and PVL despite elevated LDH in suture-free valves. LDH could be a marker of extreme heart muscle output or fluttering phenomena and not a marker of hemolysis after sutureless AVR.

A Change of Pace: Modifying Pacemaker Settings in the Emergency Department as Emergency Medicine Physicians, A Case Report

Background: Pacemakers are implantable or external devices that send electrical impulses allowing the heart to contract. Some common indications for permanent pacemaker placement include symptomatic bradycardia due to high grade atrioventricular (AV) block, sick sinus syndrome, chronic bifascicular block, and post-cardiac transplantation. Like all devices pacemakers can malfunction or stop working entirely. We present a patient with an implantable pacemaker/cardioverter and defibrillator (ICD) displaying symptomatic failure to capture and settings were adjusted in the emergency department. Adjustment in the emergency department (ED) resolved the patient's symptoms and required no further interventions.Case Report: An 82-year-old female with atrial fibrillation, heart failure, and a Medtronic dual chamber pacer/ICD presented to the emergency department for complaints of weakness and lightheadedness. Emergency medical services (EMS) noted intermittent bradycardia, hypotension, and decreased responsiveness. Electrocardiogram (ECG) revealed failure to capture. The Medtronic application was used to interrogate and reprogram the device. The settings were DDD at a rate of 60 beats per minute (BPM) with ventricular output of 4.5 millivolts (mV) and atrial output of 4.5 mV which were changed ventricular lead outputs from 4.5 mV to 8.0 mV and rate from 60 to 80 for additional cardiac output. After this adjustment, the bradycardia resolved, and ECG showed a successful AV-paced rhythm. Transcutaneous pacing was never required.Why should an emergency physician be aware of this?Adjustment of pacer settings in the ED in order to stabilize the critically ill patient is within the scope of the emergency physician. We can reduce stress to the patient and prevent hospitalizations. Pacemakers can become a tool to optimize treatment plans for an aging population where pacemakers are becoming more common.

Minimally Invasive Video-Assisted Surgery for Concomitant Ascending Aorta and Aortic Valve Replacement via Right Infra-Axillary Thoracotomy.

This study aims to assess the safety, efficacy, and esthetic outcomes of an innovative 4 cm right infra-axillary incision approach for concomitant ascending aorta and aortic valve replacement (AAR and AVR), with a specific focus on achieving optimal surgical outcomes while ensuring minimal visible scarring. We retrospectively examined all elective cases of concomitant AAR and AVR surgery performed at our institution from July 2021 to June 2023. Exclusions encompassed emergency surgery, acute type A aortic dissection, active aortic valve endocarditis, redo cardiac surgery, the necessity for concurrent mitral valve replacement, or left ventricular assist device implantation. We collected and analyzed perioperative data for the patients. The study comprised 24 consecutive patients. Cardiopulmonary bypass time and aortic cross-clamp time averaged 215.0 (interquartile range [IQR], 38.0) and 158.0 (IQR, 37.0) min, respectively. No instances of reoperation due to postoperative bleeding or need for permanent pacemaker implantation were recorded. Initial 24-h postoperative drainage volume averaged 186.9 ± 76.9 mL. Average follow-up duration was 21.7 ± 6.2 months (range, 5 to 30 months). Throughout short-term follow-up, no occurrences of valve dysfunction, paravalvular leak, cardiovascular events necessitating readmission, or mortality were observed. The right infra-axillary incision approach effectively yields secure, successful, and cosmetically pleasing outcomes for concomitant AAR and AVR. Further research and comparisons are warranted to validate these findings.

Effect of Valve Type and Anesthesia Strategy for TAVR: 5-YearResultsoftheSOLVE-TAVITrial.

In the randomized SOLVE-TAVI (compariSon of secOnd-generation seLf-expandable vs. balloon-expandable Valves and gEneral vs. local anesthesia in Transcatheter Aortic Valve Implantation) trial comparing newer-generation self-expanding valves (SEV) and balloon-expandable valves (BEV), as well as conscious sedation (CS) and general anesthesia (GA), clinical outcomes were similar both for valve and anesthesia comparison at 30days and 1 year. Prosthesis durability may affect clinical outcomes during long-term follow-up. Moreover, the impact of the anesthesia strategy on long-term clinical outcomes is unknown so far. The authors sought to compare clinical outcomes during 5-year follow-up in the randomized SOLVE-TAVI trial. In the randomized, multicenter, 2× 2 factorial, open-label SOLVE-TAVI trial, 447 intermediate- to high-risk patients with severe, symptomatic aortic stenosis were randomly assigned to transfemoral transcatheter aortic valve replacement (TAVR) using either SEV (Evolut R, Medtronic) or BEV (SAPIEN 3, Edwards Lifesciences) and also to CS vs GA. Patients were followed-up for 5 years. During 5 years of follow-up, the combined predefined endpoint of all-cause mortality, stroke, moderate or severe paravalvular leakage, and permanent pacemaker implantation was similar in the SEV and BEV groups (67.7% vs 63.4%; HR: 0.89; 95%CI: 0.70-1.13; P=0.34). Stroke rates at 5 years were lower in the SEV group (2.2% vs 9.6%; HR: 4.84; 95%CI: 1.65-14.18; P=0.002). Regarding the anesthesia comparison, the primary endpoint of all-cause mortality, stroke, myocardial infarction, and acute kidney injury occurred in 51.4% in the CS group and 61.3% in the GA group (HR: 0.80; 95%CI: 0.62-1.04; P=0.09). All-cause mortality at 5 years was lower for CS (41.5% vs 54.3%; HR: 0.70; 95%CI: 0.53-0.94; P=0.02). Transfemoral TAVR using either SEV and BEV as well as CS and GA showed similar clinical outcomes at 5 years using a combined clinical endpoint.

Isoproterenol and phenylephrine infusions in a dog with sick sinus syndrome following external pacing failure: morbidity and mortality

Isoproterenol and phenylephrine infusions in a dog with sick sinus syndrome following external pacing failure: morbidity and mortality

Proposal for a pacemaker implant technique with minimum radiation exposure

Objective: To describe a standardized technique for implanting a pacemaker to reduce the time of surgery and radiation exposure and to demonstrate the results in a series of patients. Methods: Through descriptive and cross-sectional statistics, 109 patients undergoing dual-chamber (DDD) and single-chamber (VVI) pacemaker implantation were evaluated, using a standardized technical approach used in the cardiac surgery service of Santa Casa de Misericórdia of Ponta Grossa-PR, Brazil, from November 2016 to November 2019. Clinical aspects, implant indication, implant times, and radiation time were studied. The technique was described, and its most relevant aspects were discussed. Results: 68.81% of the pacemakers were DDD and the surgical time ranged from 11’22’’ to 34’43’’, with a median of 18’15’’. In these cases, the fluoroscopy time ranged from 34’’ to 5’10’’, with a mean of 1’42’’ and a 16.9 mGy median amount of radiation. The time to implant the VVI pacemaker ranged from 12’ to 42’, with a median of 17’12’’. The fluoroscopy time ranged from 26’’ to 6’25’’, with a mean of 1’41’’ and the median amount of radiation was 13.6 mGy. Conclusion: The technique proved to be agile, safe, with low fluoroscopy times and small amount of radiation. There were no postoperative complications. However, few studies were found for comparison.

Regional heterogeneity of cerebral blood flow immediately after the onset of ventricular pacing in anesthetized rats.

Selective distribution of cerebral blood flow (CBF) to vital brain regions likely occurs during rapid severe hypotension caused by tachyarrhythmia, but has not yet been demonstrated. In this study, we aimed to test the hypothesis that CBF is differentially preserved between brain regions depending on the degree of hypotension. In anesthetized rats, CBF was measured in the motor cortex (MC), medial prefrontal cortex, amygdala, thalamus, dorsal hypothalamus, hippocampus, ventral tegmental area, dorsolateral periaqueductal gray (dlPAG), and parabrachial nucleus (PB) by using laser-Doppler flowmetry. Ventricular pacing was performed for 30 s at 550-800 beats/min. The cerebrovascular CO2 response time and reactivity were evaluated during 5% CO2 exposure. During 1-4 s of ventricular pacing, mean arterial pressure (MAP) rapidly decreased, with minor changes in central venous and intracranial pressures. CBF was relatively well maintained in brain regions other than the MC (Ps ≤ 0.012) when moderate hypotension occurred (-34 mmHg ≤ ΔMAP ≤ -15 mmHg), whereas severe hypotension (-54 mmHg ≤ ΔMAP ≤ -35 mmHg) induced selective CBF distribution to regions other than the MC, thalamus, and dlPAG. The cerebrovascular CO2 response time/reactivity was rapid or high in the thalamus, dlPAG, and PB, which almost completely differed from the brain regions in which CBF was relatively maintained during pacing-induced severe hypotension. These results suggest that regional heterogeneity of CBF arises depending on the degree of tachyarrhythmia-induced hypotension. Clarifying the mechanisms and functions of CBF maintenance would be beneficial to syncope and cerebral ischemia management in patients with arrhythmia.

Transcatheter Valve Replacement in Severe Tricuspid Regurgitation.

Severe tricuspid regurgitation is associated with disabling symptoms and an increased risk of death. Data regarding outcomes after percutaneous transcatheter tricuspid-valve replacement are needed. In this international, multicenter trial, we randomly assigned 400 patients with severe symptomatic tricuspid regurgitation in a 2:1 ratio to undergo either transcatheter tricuspid-valve replacement and medical therapy (valve-replacement group) or medical therapy alone (control group). The hierarchical composite primary outcome was death from any cause, implantation of a right ventricular assist device or heart transplantation, postindex tricuspid-valve intervention, hospitalization for heart failure, an improvement of at least 10 points in the score on the Kansas City Cardiomyopathy Questionnaire overall summary (KCCQ-OS), an improvement of at least one New York Heart Association (NYHA) functional class, and an improvement of at least 30 m on the 6-minute walk distance. A win ratio was calculated for the primary outcome by comparing all possible patient pairs, starting with the first event in the hierarchy. A total of 267 patients were assigned to the valve-replacement group and 133 to the control group. At 1 year, the win ratio favoring valve replacement was 2.02 (95% confidence interval [CI], 1.56 to 2.62; P<0.001). In comparisons of patient pairs, those in the valve-replacement group had more wins than the control group with respect to death from any cause (14.8% vs. 12.5%), postindex tricuspid-valve intervention (3.2% vs. 0.6%), and improvement in the KCCQ-OS score (23.1% vs. 6.0%), NYHA class (10.2% vs. 0.8%), and 6-minute walk distance (1.1% vs. 0.9%). The valve-replacement group had fewer wins than the control group with respect to the annualized rate of hospitalization for heart failure (9.7% vs. 10.0%). Severe bleeding occurred in 15.4% of the valve-replacement group and in 5.3% of the control group (P = 0.003); new permanent pacemakers were implanted in 17.4% and 2.3%, respectively (P<0.001). For patients with severe tricuspid regurgitation, transcatheter tricuspid-valve replacement was superior to medical therapy alone for the primary composite outcome, driven primarily by improvements in symptoms and quality of life. (Funded by Edwards Lifesciences; TRISCEND II ClinicalTrials.gov number, NCT04482062.).

Mitigation of pacing-induced cardiomyopathy with superficial right ventricular mid-septal pacing: A long-term retrospective comparison with apical pacing.

It remains unclear if pacing induced cardiomyopathy (PICM) may be minimized by standard pacing of the right ventricle (RV) at sites other than the RV apex. The purpose of this study is to compare the relative frequency of PICM in a population of patients paced at either the superficial RV mid septum (RVMS) or RV apex (RVA), and other outcomes that may differ between these sites. A retrospective evaluation was performed on all patients undergoing pacemaker implantation between 2011 and 2022. Potential study patients were those with Medtronic 3830 superficial RVMS leads placed with septal specific guidance catheters, and any with RVA leads. Patients were included if they had ≥20% RV pacing, available baseline and follow-up measurements of left ventricular ejection fraction (LVEF) at least 6 months postimplantation, and a baseline LVEF ≥50%. PICM was defined as a decline in the LVEF of at least 10%, resulting in LVEF <50%. Patients were excluded for Biventricular devices, and for alternative causes of cardiomyopathy. The study criteria were met in 324 patients, with 220 RVMS and 104 RVA paced patients. PICM occurred in 4.5% of RVMS patients, and 22.1% of RVA patients (p < .001). Additional differences were demonstrated in paced QRS duration (144 ± 15.5 ms in RVMS, 166 ± 19.4 ms in RVA; p < .001); QRS axis (2.3 ± 64.9 in RVMS, -65.2 ± 49.5 in RVA; p < .001), and various qualitative QRS morphologic characteristics. Patients with normal LVEF experienced significantly less PICM with superficial RVMS pacing performed via septal specific guidance catheters than similar counterparts with RVA pacing. Narrower paced QRS duration and less left axis deviation was also demonstrated.

Late complete atrioventricular block after transcatheter perimembranous ventricular septal defect closure with the KONAR-MF™ VSD occluder: a case report and systematic review.

The soft nitinol KONAR-MF™ ventricular septal defect (VSD) Multifunctional Occluder (MFO) device is increasingly used for transcatheter perimembranous ventricular septal defect closure. We report for the first time a case of delayed complete atrioventricular block with pacemaker implantation 20 months post-procedure. Through a systematic review, the overall rate of persistent complete atrioventricular block was 0.6% with this device, but follow-up duration was limited.

Quadricuspid aortic valve with complete heart block: a double whammy

BackgroundDevelopmental abnormalities of aortic valve cusps are relatively common with the bicuspid valve being the most frequently encountered congenital heart disease. However, the quadricuspid aortic valve (QAV) is an exceedingly rare abnormality.Case presentationWe report a case involving a young, otherwise healthy male who presented with non-exertional syncope and was subsequently diagnosed with complete heart block (CHB). Further evaluation revealed the coexistence of a rare quadricuspid aortic valve and CHB. This combination, in the absence of surgery or infective endocarditis, has only been reported once before in the literature.The patient underwent successful permanent pacemaker implantation and continues to be monitored for aortic regurgitation.ConclusionsThe coexistence of a QAV with CHB, in the absence of infective endocarditis or aortic valve surgery, is extremely rare and necessitates careful evaluation and follow-up.

Characterization of tricuspid regurgitation in patients following left bundle branch pacing

Abstract Background Pacemakers placed in the right ventricle apex can lead to mechanical and electrical dyssynchrony. There is a growing interest in more physiologically stimulating techniques, and in this context, left bundle branch pacing (LBBP) emerges as an option. In this pacemaker, the lead is positioned perpendicular to the septum approximately 15-20 mm below the tricuspid valve annulus, and the helix is advanced towards the left side (Image 1). There is limited data on the incidence of new-onset tricuspid regurgitation (TR) or deterioration of pre-existing TR following the implantation of this type of pacemaker. Purpose To characterize the incidence of TR or deterioration of pre-existing TR after LBBP and to determine if there are predictors of a higher degree of TR. Methods All patients who received a pacemaker with LBBP between January and October 2023 were consecutively recruited. A transthoracic echocardiogram following the implantation of the pacemaker was performed to assess the size and function of right heart chambers, degree of TR and position of pacemaker lead. Continuous variables are expressed as mean ± SD or median [IQR] and categorical variables as absolute (%). Results There were 31 implants with a mean age of 73.4±8.7 years and 42% women. Nine patients (22.5%) had atrial fibrillation, and 7 patients (23%) had known coronary artery disease. The main indication for implant was a complete AV block (63.3%). Two patients had TR greater than moderate before the implantation of the pacemaker. Mean time elapsed between implantation and follow-up echocardiogram was 5.8 months. The distance between the lead-implanted site to the tricuspid annulus (Lead-TA distance) was 26.7±10.5 mm, mean lead depth in the interventricular septum (IVS) was 7.7±1.8mm and the IVS thickness at the lead-implanted site was 10.6±2.1 mm. Overall, TR worsed less than 1 degree after the lead implant (table 2) and was significantly related with the Lead-TA distance (TR worsed 0.3 degrees in Lead-TA distances shorter than 26.7mm and TR reduced 0.2 degrees in Lead-TA distances longer than 26.7mm, p=0.037). Conclusions In the short term following the implantation of an LBBP pacemaker the distance from the lead to the tricuspid annulus has an acute impact on tricuspid regurgitation, with TR worsening at short Lead-TA distances and TR improving at longer distances.

Can variants of genes associated with familial heart block predict conduction disease in the general population? A UK Biobank study.

Abstract Background Progressive familial heart block is a genetic disease that can present with worsening cardiac conduction disease (CCD) and risk of life-threatening bradycardia. The prevalence, penetrance, and expressivity of known rare pathogenic/likely pathogenic variants (P/LP) in the general population is unclear. In addition, the role of common genetic variation in this phenotypic expression is unknown. Understanding this is essential for patient management in clinic. Purpose 1). To investigate the prevalence of variants linked with early-onset CCD and phenotypic expression in a large biobank. 2). To investigate whether a PR interval polygenic risk score (PRS) improves risk prediction. Methods Early-onset conduction disease P/LP or variants of uncertain significance (VUS) were identified from ClinVar, genetic testing reports at a teaching hospital (6 variants), and the literature, mapping to 22 genes. From the full UK Biobank prospective cohort, 469,511 participants passed genetic quality control and were assigned to P/LP, VUS, or genotype negative (G-) groups, using whole exome sequencing analysed with bcftools. A PR-PRS was constructed using weights from a published meta-analysis excluding UKB data. The primary outcome was CCD (atrioventricular (AV) block, bundle branch block, pacemaker or ICD implantation) and secondary outcomes were high-grade AV block or pacemaker insertion, compared with lifetime risk Cox proportional hazards controlled for sex and age as a timescale. Results 55% of participants were female, 95% had European ancestry, and average age at censor was 71 years. There were 25 P/LP carriers, and 8,862 with a VUS, in 6 genes (MYH7, SCN5A, TNNI3K, TRPM4, TTN, and LMNA). Major demographic factors were the same between groups. CCD was significantly more prevalent in P/LP individuals (28% vs 5.8% in VUS vs 5.5% in G-; p&amp;lt;0.001) with a hazard ratio of HR 6.47 [95% CI=3.09-13.6] vs G-. This was driven by AV block and pacemaker implantation (HR 23.2 [95% CI=8.69-61.8] and 13.4 [95% CI=6.01-29.8], respectively). Results were similar in an unrelated subset and controlling for ischaemic heart disease and heart failure. The 7 P/LP individuals with conduction disease were mostly linked to a single LMNA variant (4 out of 6 carriers with penetrant disease). In the full cohort, the PR-PRS was predictive of CCD (HR=1.07 [95% CI=1.06-1.08]), AV block (HR=1.09 [95% CI=1.06-1.13]), and pacemaker implantation (HR=1.04 [95% CI=1.02-1.06]). When combined with P/LP status, both PR-PRS (HR=1.07 [95% CI=1.06-1.08]) and P/LP (HR=6.42 [95% CI=3.06-13.5]) were independent predictors of CCD. Conclusion(s) Rare variant carrier status predicts a 6.5-fold increased lifetime risk of CCD, a 23-fold increased risk of AV block and 13-fold risk for pacemaker requirement. However, phenotypic expression for some variants is highly variable. A PR-PRS captures risk independent of P/LP variants and warrants further investigation with updated PRS construction methods.

Assessment of ventricular mechanics by means of myocardial work in patients undergoing physiologic versus right ventricular apical stimulation:a prospective study

Abstract Introduction Left bundle branch area (LBBA) pacing has recently gained widespread acceptance in patients that need pacemaker (PM) stimulation. This type of physiologic pacing may improve ventricular mechanical contraction and reduce the risk of PM-induced left ventricular (LV) dysfunction. Myocardial work (MW), a new tool, based on the analysis of pressure-strain loops, combines the information from speckle tracking strain imaging and non-invasive estimate of LV pressure. It provides a better characterization of LV performance and detection of LV myocardial dysfunction. The aim of this study was to compare MW after PM implantation in LBBA pacing patients (group 1) vs right ventricular apical (RVA, group 2) pacing patients. A control group (group 3) was also enrolled for establishing MW normal values. Methods We studied 30 patients (56% females, age 80 y, IQR 75-84) who underwent PM implantation and had a high probability of a high % of stimulation and 21 controls (57% females, age 79 y, IQR 73-85, p=0.46 and p=0.73 respectively) Patients were prospectively included at two large university hospitals from March 23 until February 24. The mode of stimulation was chosen at their physician’s discretion. Exclusion criteria included LVEF &amp;lt;50% or significant structural or valvular disease. We compared MW parameters between group 1 and group 2 before PM implantation, and 24 hours and 3 months post PM implantation by Kruskal Wallis test. Additionally, we compared MW parameters between group 3 and PM patients after 24 hours using U Mann-Whitney test. Results The % of stimulation was 93%±12. There were no differences in baseline characteristics between group 1 (n=21, 71%) and group 2. At baseline, global work index (GWI), global constructive work (GCW), global wasted work (GWW) or global work efficiency (GWE) did not differ significantly between Group 1 and 2. At 24 hours, all the components of MW significantly improved in Group 1 and 2 and were maintained at 3 months, but the improvement was notably greater in Group 1 (see Table 1). Group 3 and PM patients were similar at baseline (HTN, 86% vs 80%, p=0.7197; DM, 29% vs 30%, p=0.91; coronary artery disease, 14% vs 10%, p=0.68; sinus rhythm, 76% vs 83%, p=0.68). Comparing group 3 and PM at 24 h, GWI, GCW, GWE was significantly higher in group 3 (p=0.0023, p=0.009, p=&amp;lt;0.0001) and GWW was significantly lower (p=&amp;lt;0.0001). Regarding the type of stimulation, MW parameters values in Group 1 were still lower than in Group 3 but clearly better than Group 2 values (see Figure 1). Discussion Our results showed that MW parameters improved to a greater extent in LBBA compared to RVA pacing immediately and after 3 months of PM implantation. Compared to our control group, LBBA pacing group achieved better performance than RVA pacing patients, yielding a more coordinated LV contraction. Nevertheless, more studies are needed to clarify if LBBA pacing causes less PM induced LV dysfunction compared to RVA pacing.

Cusp-overlap technique to reduce permanent pacemaker implantation rate after transcatheter aortic valve implantation

Abstract Background Persistent conduction disturbances requiring permanent pacemaker (PPM) implantation are one of the most common complications after Transcatheter Aortic Valve Implantation (TAVI). Cusp-Overlap Technique (COT) is a novel approach for self-expandable valve implantation to minimize the rate of procedural complications, mainly PPM implantation. Purpose To determine if the COT during TAVI with self-expandable valves leads to a reduction of PPM implantation rate in the real-world setting. Methods A retrospective analysis of consecutive patients undergoing TAVI between January 2020 and November 2023 in one high-volume tertiary care center in Portugal was conducted. Two groups were defined, the COT group and the control group based on the fluoroscopic approach. A baseline comparison between the 2 groups was made using independent-samples t-test and chi-square analysis to determine if there was a difference between the prevalence of known risk factors for PPM implantation after TAVI. Afterwards, chi-square analysis was used to determine if COT led to a reduction in the PPM implantation rate. Results Of the 539 completed procedures in this timeframe, 289 were excluded due to previous pacemaker implantation, use of a valve not amenable to COT or valve-in-valve implantation. COT was used in 57.6% of eligible cases. Baseline comparison did not show a significant difference in the prevalence of several known risk factors for PPM implantation, including complete right bundle branch block, atrio-ventricular block, calcium score, aortic ring dimensions and pre/post-dilation. PPM implantation after TAVI was required in 31.6% of cases. In the COT group the PPM implantation rate was 22.9% and in the control group 43.4%. Chi-square analysis showed a very statistically significant difference between the 2 analyzed groups (p-value = 0.001). Conclusion PPM implantation remains a frequent complication of TAVI. However, this study showed that the utilization of COT leads to a reduction of the PPM implantation rate.