Types Of Pacemakers Research Articles

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.

Patient satisfaction followed by remote monitoring

Abstract Introduction Remote monitoring (RM) of cardiac implantable electronic devices has increased significantly in the last years. The safety and efficacy of RM have been demonstrated, however, there are few data on patient satisfaction. The objective of this study was to evaluate the satisfaction of patients with an implanted pacemaker (PM) followed through remote monitoring. Methods Patients implanted with a conventional or leadless PM who had been using RM system for at least 3 months were included. Patients had to be able to understand and answer questionnaires, having no significant cognitive impairment. An specific, and previous validate, patient satisfaction RM questionnaire with 30-item, self-completed, measured on a 5-point Likert scale (0=No, nothing, 4=Yes, a lot) was administered. The questionnaire is structured in 5 dimensions: Information on cardiac condition, device convenience, transmission process, satisfaction with medical monitoring, and benefits. The results are presented as mean. The difference between mean was analyzed using the T-Student test. Results A total of 98 patients were included (77.8±8.2 years old, 67% male), 82 % had conventional PM and 18 % leadless PM. According RM connectivity 70% had daily automatic transmission, 12% automatic transmission and 18% manual transmission. On average, participants answered 83% of the items. The overall satisfaction of the patient was high (3.66). The mean score for each dimension is summarized in Table 1. The Device convenience had the highest mean (3.75), and the Transmission process had the lowest mean (3.56). There was no difference between patients with a conventional pacemaker versus leadless pacemakers (Fig 1, p=0,30). Results Patients with PM followed through RM have a high level of satisfaction when evaluated using an specific questionnaire. The level of satisfaction is independent of the type of PM or the connectivity of the system.Table 1Mean dimension score by device type

Survival predictors after pacemaker implantation in a very elderly population

Abstract Background Electrophysiological studies and ablation procedures are the most prevalent activities in electrophysiology. However, device implantation represents a great deal of the daily activity. In several European regions, aging populations are becoming a big concern, not only increasing the number of pacemakers implantations but also raising the age threshold for implantation. Purpose Assessment of survival rates after device implantations on patients over ninety years of age. Are there any markers that could help us infer survival rates? How prevalent are complications? What key performance indicators should be paying attention to? Methods Observational retrospective study of a cohort of 903 patients referred to the arrhythmia unit of our institution for pacemaker implantation, during the period from 2016 to 2019. Cox regression analysis performed over that cohort. Hazard-ratio (HR) and confidence intervals (CI 95%)calculated. Survival curves represented with Kaplan-Meier method and statistical significance estimated with log-rank test. Results Out of the 903 patients, 82 (9.1%) are nonagenarians. Follow-up was 3.97 ± 4.98 years. The mean age at the time of pacemaker implantation was 78.94 ± 10.11 years. Some complications were observed in 9.9% of patients under 90 years of age, compared to 4.9% in those over that age. At the time of the follow-up, 82.5% of the patients were alive. In the univariate analysis, the following predictors of mortality were identified: age; atrial fibrillation (AF); renal function; anemia; comorbidity, estimated by Charlson score; underlying heart disease; type of pacemaker implanted; and, whether the patient was institutionalized. In the multivariate analysis, the following were independent predictors of mortality: age (HR 1.129; 95% CI 1.1-1.159; p<0.001), comorbidity reflected as a Charlson score ≥ 5 (HR 4.116; 95% CI 2.349 -7.212; p<0.001); heart disease (HR 2.496; 95% CI 1.725-3.612; p<0.001); institutionalization of the patient (HR 2.794; 95% CI 1.632-4.783; p<0.001); and the single-chamber pacemaker (HR 2.201; 95% CI 1.455-3.329; p<0.001). In the group of nonagenarian patients, the univariate analysis showed the following variables as predictors of lower survival: age; serum creatinine; comorbidity, estimated by the Charlson score; and, underlying heart disease. In the multivariate analysis, the following were identified as independent predictors of mortality: comorbidity, reflected as a Charlson score ≥ 5 (HR 7.299; 95% CI 2.468-21.589; p<0.001); age (HR: 1.193; 95% CI 1.063- 1.339; p 0.003) and institutionalization of the patient (HR 3.033; 95% CI 1.237- 7.439; p 0.015). Conclusions Comorbility estimated by Charlson score is the most powerful survival predictor after pacemaker implantation, both in the general population and in those over 90 years of age. Being institutionalized is an independent survival predictor in both groups. Nonagenarian patients do not show a higher complication rate.Baseline characteristics >90 y.o.Survival curves K-M

Economic Considerations of Cardiovascular Implantable Electronic Devices for The Treatment of Heart Failure.

Heart failure (HF) is a major public health problem worldwide, affecting more than 64 million people [1]. The complex and severe nature of HF presents challenges in providing cost-effective care as patients often require multiple hospitalizations and treatments. This review of relevant studies with focus on the last 10years summarizes the health and economic implications of various HF treatment options in Europe and beyond. Although the main cost drivers in HF treatment are clinical (re)admission and decompensation of HF, an assessment of the economic impacts of various other device therapy options for HF care are included in this review. This includes: cardiovascular implantable electronic devices (CIEDs) such as cardiac-resynchronisation-therapy devices that include pacemaking (CRT-P), cardiac-resynchronisation-therapy devices that include defibrillation (CRT-D), implantable cardioverter/defibrillators (ICDs) and various types of pacemakers. The impact of (semi)automated (tele)monitoring as a relevant factor for increasing both the quality and economic impact of care is also taken into consideration. Quality of life adjusted life years (QALYs) are used in the overall context as a composite metric reflecting quantity and quality of life as a standardized measurement of incremental cost-effectiveness ratios (ICER) of different device-based HF interventions. In terms of the total cost of different devices, CRT-Ds were found in several studies to be more expensive than all other devices in regards to runtime and maintenance costs including (re)implantation. In the case of CRT combined with an implantable cardioverter-defibrillator (CRT-D) versus ICD alone, CRT-D was found to be the most cost-effective treatment in research work over the past 10years. Further comparison between CRT-D vs. CRT-P does not show an economic advantage of CRT-D as a minority of patients require shock therapy. Furthermore, a positive health economic effect and higher survival rate is seen in CRT-P full ventricular stimulation vs. right heart only stimulation. Telemedical care has been found to provide a positive health economic impact for selected patient groups-even reducing patient mortality. For heart failure both in ICD and CRT-D subgroups the given telemonitoring benefit seems to be greater in higher-risk populations with a worse HF prognosis. In patients with HF, all CIED therapies are in the range of commonly accepted cost-effectiveness. QALY and ICER calculations provide a more nuanced understanding of the economic impact these therapies create in the healthcare landscape. For severe cases of HF, CRT-D with telemedical care seems to be the better option from a health economic standpoint, as therapy is more expensive, but costs per QALY range below the commonly accepted threshold.

Corrosion in Pacemakers: Mechanisms, Implications and Advances in Prevention

Corrosion of pacemaker and its leads presents a significant concern in cardiac device management, potentially leading to device malfunction and patient harm. This paper reviews the current understanding of corrosion mechanisms in pacemaker leads, including the effects of physiological conditions, material properties, and environmental factors. Various prevention techniques for corrosion and types of corrosion resistant pacemakers are discussed, along with emerging technologies and types of pacemakers. The metals/alloys suitable for pacemakers are also noted. By addressing these issues, researchers and clinicians can improve the reliability and longevity of pacemaker leads, enhancing patient safety and device performance. Key Words: pacemaker leads, corrosion, prevention techniques, mitigation strategies

Conduction system disease management in patients candidate and/or treated for the aortic valve disease: an Italian Survey promoted by Italian Association of Arrhythmology and Cardiac Pacing (AIAC)

Background Conduction system disorders represent a frequent complication in patients undergoing surgical (surgical aortic valve replacement, SAVR) or percutaneous (transcatheter aortic valve implantation, TAVI) aortic valve replacement. The purpose of this survey was to evaluate experienced operators approach in this clinical condition. Methods This survey was independently conducted by the Italian Association of Arrhythmology and Cardiac Pacing (AIAC) and it consisted of 24 questions regarding the respondents’ profile, the characteristics of participating centres, and conduction disease management in different scenarios. Results Fifty-five physicians from 55 Italian arrhythmia centres took part in the survey. Prophylactic pacemaker implantation is rare. In case of persistent complete atrioventricular block (AVB), 49% and 73% respondents wait less than one week before implanting a definitive pacemaker after SAVR and TAVI, respectively. In case of second degree AVB, the respondents wait some days more for definitive implantation. Respondents consider bundle branch blocks, in particular pre-existing left bundle branch block (LBBB), the worst prognostic factors for pacemaker implantation after TAVI. The implanted valve type is considered a relevant element to evaluate. In patients with new-onset LBBB and severe/moderate left ventricular systolic dysfunction, respondents would implant a biventricular pacemaker in 100/55% of cases, respectively. Conclusions Waiting time before a definitive pacemaker implantation after aortic valve replacement has reduced compared to the past, and it is anticipated in TAVI vs. SAVR. Bundle branch blocks are considered the worse prognostic factor for pacemaker implantation after TAVI. The type of pacemaker implanted in new-onset LBBB patients without severe left ventricular systolic dysfunction is heterogeneous.

Retrievable leadless pacemakers (Aveir VR) may be beneficial in adult patients with congenital heart disease

IntroductionCongenital heart disease may present in up to 1.6 % of newborns. Given high burden of pacing need in adult patients with repaired congenital heart disease and availability of different pacing options, more information on outcomes of newer pacemaker types are needed. Retrievable leadless pacemaker implants in adult congenital patients have not been described. MethodsRetrospective review of three Aveir (Abbott) retrievable leadless pacemaker implants were reviewed at the UC Davis Medical Center. All patients underwent implant via femoral access. ResultsAll patients had one deployment only, after mapping prior. No complications occurred. Implant thresholds were 0.5 V (V) @0.2msilliseconds (ms) for patients 1 and 2 and 1 V @0.4 ms for patient 3. With impedances between 500 and 1290 Ω. Sensing was 5.5–8 mV (mV). Follow-up occurred up to one year (for two patients) with similar values overall. The predicted longevities of each device were between 22.6 and >25 years. ConclusionSafety and short-mid-term parameters of retrievable leadless pacemaker implantation is reported in three patients with adult congenital heart disease.

Clinical outcome for heart failure hospitalizations in patients with leadless pacemaker

Abstract Background Leadless pacemaker has a low risk of complications such as infection, pneumothorax, and skin erosion, and it is good adaptation for elderly patients. While ventricular pacing induces ventricular desynchronization, and that is causes of heart failure. The aim of the present study, therefore, was to investigate the association between heart failure hospitalization and leadless pacemaker implantation. Methods Between September 2017 and January 2022, 929 consecutive patients were implanted pacemakers. The patients were divided according to types of pacemakers: leadless pacemaker (LPM group, n=368), and conventional pacemaker (PM group, n=561). The clinical outcome was heart failure hospitalization. Hospitalization was considered when patients presented with sign and symptoms consistent with heart failure and required intravenous therapy, and the indication of heart failure hospitalization was at the discretion of the physician. Follow-up visit was planned at 1, 3, 12, 24, and 36 months after pacemaker implantation. Clinical follow-up data were obtained from medical records and/or by telephone contact with the patients, families, or referring physicians. Results The median follow-up duration was 1.7 years (interquartile range 0.8-2.6 years). Hospitalization rate for heart failure in the LPM group was 9.3% at 1 year, 15.6% at 2 years, and 21.6% at 3 years, respectively. Adjusted heart failure hospitalization risk in the LPM group was significantly higher than the risk in the PM group (hazard ratio [HR] 1.70, 95% confidence interval [CI] 1.09-2.64, P=0.01). Patients with symptomatic bradycardia caused by sinus node dysfunction (SND) in the LPM group (n=150) were more admitted to the hospital for heart failure, compared with in the PM group (n=219) (HR 2.02, 95%CI 1.04-3.90, P=0.03), while no significant difference was observed between the two groups in the patients with bradycardia caused by atrial fibrillation (LPM group, n=71; PM group, n=18) or atrioventricular block (LPM group, n=147; PM group, n=324). Conclusions Hospitalization risk for heart failure was higher in patients with leadless pacemakers, compared with conventional pacemakers. The greater risk was mainly driven by older patients and patients with SND.

Impact of leadless pacemaker therapy on tricuspid regurgitation

Abstract Background The association between conventional transvenous pacemaker leads and tricuspid regurgitation (TR) has been well described. Leadless pacemakers (LP) have risen as an alternative to conventional transvenous pacemakers in order to avoid lead associated complications. Prior studies have included a mix of leadless pacemaker types including: Nanostim, Micra, etc. This is the first study exploring only one model of LP. Purpose The purpose of the study was to investigate the impact of leadless pacemaker therapy on tricuspid regurgitation. Methods Adult patients who underwent Micra leadless pacemaker implantation at a single center from 2016 to 2022 were identified retrospectively. Patients who had an echocardiogram prior to the procedure and within 24 months after the procedure were included. Echocardiograms were reviewed to assess for change in presence or in severity of tricuspid regurgitation. Results There were 310 patients in total who received LP at our hospital. Of these, 104 met inclusion criteria. 189 patients were excluded because they did not have an echocardiogram before or after the procedure. 17 more were excluded because their post procedure echo was done more than 2 years later. The average age of our patient population was 78. Of the 104 total patients, 97 had some TR before LP implantation (Trace 41%, Trace-Mild 4%, Mild 31%, Mild-Moderate 7%, Moderate 13%, Moderate-Severe 1%, Severe 2%). After implantation, 34 patients had worsening TR (33%), 23 patients had improved TR (22%), and 47 patients had no change in TR severity (45%) p=0.053. Conclusion Overall, the results did not show a statistically significant improvement or worsening in TR severity after LP implantation. Further studies should be done to validate these findings, to evaluate the effect of a larger sample size, and to examine whether controlling for additional confounders maintains or contradicts this finding.

Lanthanum modulated reaction pacemakers on a single catalytic nanoparticle

Promoters are important in catalysis, but the atomistic details of their function and particularly their role in reaction instabilities such as kinetic phase transitions and oscillations are often unknown. Employing hydrogen oxidation as probe reaction, a Rh nanotip for mimicking a single Rh nanoparticle and field electron microscopy for in situ monitoring, we demonstrate a La-mediated local catalytic effect. The oscillatory mode of the reaction provides a tool for studying the interplay between different types of reaction pacemakers, i.e., specific local surface atomic configurations that initiate kinetic transitions. The presence of La shifts the bistable reaction states, changes the oscillation pattern and deactivates one of two pacemaker types for the La-free surface. The observed effects originate from the La-enhanced oxygen activation on the catalyst. The experimental observations are corroborated by micro-kinetic model simulations comprising a system of 25 coupled oscillators.

Pacing-Induced Cardiomyopathy in Leadless and Traditional Pacemakers: A Single-Center Retrospective Analysis.

Pacing-induced cardiomyopathy (PICM) is a clinical syndrome that is characterized by a drop in the left ventricular ejection fraction (LVEF) due to chronic high-burden right ventricular (RV) pacing. It has been postulated that leadless pacemakers (LPs) cause decreased risk of PICM compared to transvenous pacemakers (TVPs), but the exact risk reduction is unknown. We performed a single-center retrospective analysis of adults who received an LP or TVP between January 1, 2014, and April 1, 2022, and had echocardiograms before and after the pacemaker implant. This study's outcomes were the RV pacing percentage, change in EF, the need for cardiac resynchronization therapy (CRT) upgrade, and follow-up duration. A Wilcoxon rank-sum test calculated the change in EF. RV time, defined as the duration from pacemaker placement to the follow-up echocardiogram in months multiplied by the RV pacing percentage, served as a surrogate for how long the RV was paced. A total of 614 patients were screened, and 198 patients were included in the study, where 72 received LP and 126 received TVP. The median follow-up was 480 days. The average of the reported RV percentage pacing was 63.43% for LP and 71.30% for TVP (p=0.14). The incidence of PICM and CRT upgrade was 44% and 9.7%in the LP group and37% and 9.5%in the TVP group(p=0.3 and p>0.9), respectively. After accounting for age, sex, LP versus TVP, atrioventricular nodal ablation, RV pacing percentage, and follow-up duration, univariate analysis showed that RV time was significantly different between the two types of pacemakers (13.54 ± 14.21 months (LP) versus 9.26 ± 13.95 months (TVP), p=0.009). The difference in RV time between patients who underwent CRT upgrade and those who did not was statistically insignificant (12.11 ± 14.47 months (no CRT) versus 9.19 ± 12.00 months (CRT), p=0.5). This analysis demonstrated that the incidence of PICM was high in both groups (44% (LP) versus 37% (TVP)), despite significantly more RV time in patients with LP. There was no difference in CRT upgrade between LP and TVP.

“Challenges” During Leadless Pacemaker Implantation

Leadless pacemaker (LP) is a new type of pacemaker that integrates generator and leads, and has become an effective alternative to traditional transvenous pacemakers. It can be used for difficult or complicated situations of traditional pacemaker implantation, such as subclavian vein occlusion, traditional pacemaker pocket infection, lead fracture, and multiple pacemaker replacements. Because no pockets and leads are required, LPs eliminate pocket- and lead-related complications compared to traditional pacemakers. Multiple studies have demonstrated its reliable safety and efficacy. Compared with traditional pacemakers, due to the different implantation methods, the difficulties encountered during the implantation process are also different. This article reviews the difficulties that may be encountered during leadless implantation and looks forward to the future of leadless pacemakers.

Reducing cardiac tamponade caused by temporary pacemaker perforation in transcatheter aortic valve replacement

BackgroundCardiac tamponade caused by temporary right ventricular (RV) pacemaker perforation is a rare but serious complication in transcatheter aortic valve replacement (TAVR). AimsTo study the incidence of temporary pacemaker related cardiac tamponade in TAVR, and the relation to the type of pacemaker lead used in periprocedural temporary transvenous pacing. MethodsA single center registry of transfemoral TAVRs in 2014–2020. Main inclusion criterion was peri-operative use of a temporary RV pacing lead. Main exclusion criteria were a preoperatively implanted permanent pacemaker or the exclusive use of left ventricular guidewire pacing. Incident cardiac tamponade was classified as pacemaker lead related, or other. Patients were grouped according to type of temporary RV pacing wire. Results810 patients were included (age 80.5 ± 7.3 [mean ± standard deviation], female 319, 39.4%). Of these, 566 (69.9%) received a standard RV temporary pacing wire (RV-TPW), and 244 (30.1%) received temporary RV pacing through a permanent, passive pacemaker lead (RV-TPPL). In total, 18 (2.2%) events of cardiac tamponade occurred, 12 (67%) were pacemaker lead related. All pacemaker lead-related cardiac tamponades occurred in the group who received a standard RV-TPW and none in the group who received RV-TPPL (n = 12 [2.1%] vs. n = 0 [0%], p = 0.022). No difference in cardiac tamponade due to other causes was seen between the groups (p = 0.82). ConclusionsThe use of soft-tip RV-TPPL was associated with a lower risk of pacemaker related cardiac tamponade in TAVR. When perioperative pacing is indicated, temporary RV-TPPL may contribute to a significant reduction of cardiac tamponade in TAVR.

Clinical outcome for heart failure hospitalizations in patients with leadless pacemaker.

IntroductionThe long‐term performance of leadless pacemaker (LPM) has not been well evaluated.MethodsBetween September 2017 and January 2021, 929 consecutive patients who underwent pacemaker implantation were grouped according to the types of pacemakers: LPM (LPM group, n = 368) and conventional pacemaker (PM group, n = 561).ResultsThe median follow‐up duration was 1.7 years (interquartile range 0.8–2.6 years). Hospitalization rate for heart failure in the LPM group was 9.3%, 15.6%, and 21.6% at 1, 2, 3 years, respectively. The LPM group had a significantly higher adjusted heart failure hospitalization risk than the PM group [hazard ratio (HR) 1.70, 95% confidence interval (CI) 1.09–2.64, p = .01]. More patients with symptomatic bradycardia caused by sinus node dysfunction (SND) in the LPM group (n = 150) were admitted to the hospital for heart failure compared to those in the PM group (n = 219) (HR 2.02, 95%CI 1.04–3.90, p = .03), whereas no significant difference was observed between the two groups in the patients with bradycardia caused by atrial fibrillation (LPM group, n = 71; PM group, n = 18) or atrioventricular block (LPM group, n = 147; PM group, n = 324).ConclusionsPatients who received LPM implantation had greater hospitalization risk for heart failure, compared to those who received conventional pacemaker implantation. The increased risk was mainly attributed to patients with SND.

Ca2+ Signaling Is the Basis for Pacemaker Activity and Neurotransduction in Interstitial Cells of the GI Tract.

Years ago gastrointestinal motility was thought to be due to interactions between enteric nerves and smooth muscle cells (SMCs) in the tunica muscularis. Thus, regulatory mechanisms controlling motility were either myogenic or neurogenic. Now we know that populations of interstitial cells, c-Kit+ (interstitial cells of Cajal or ICC), and PDGFRα+ cells (formerly "fibroblast-like" cells) are electrically coupled to SMCs, forming the SIP syncytium. Pacemaker and neurotransduction functions are provided by interstitial cells through Ca2+ release from the endoplasmic reticulum (ER) and activation of Ca2+-activated ion channels in the plasma membrane (PM). ICC express Ca2+-activated Cl- channels encoded by Ano1. When activated, Ano1 channels produce inward current and, therefore, depolarizing or excitatory effects in the SIP syncytium. PDGFRα+ cells express Ca2+-activated K+ channels encoded by Kcnn3. These channels generate outward current when activated and hyperpolarizing or membrane-stabilizing effects in the SIP syncytium. Inputs from enteric and sympathetic neurons regulate Ca2+ transients in ICC and PDGFRα+ cells, and currents activated in these cells conduct to SMCs and regulate contractile behaviors. ICC also serve as pacemakers, generating slow waves that are the electrophysiological basis for gastric peristalsis and intestinal segmentation. Pacemaker types of ICC express voltage-dependent Ca2+ conductances that organize Ca2+ transients, and therefore Ano1 channel openings, into clusters that define the amplitude and duration of slow waves. Ca2+ handling mechanisms are at the heart of interstitial cell function, yet little is known about what happens to Ca2+ dynamics in these cells in GI motility disorders.

Cardioneuroablation for recurrent vasovagal syncope: Important questions need to be answered

Vasovagal reflex syncope (VVS) is the most common cause of transient loss of consciousness in any setting and at all ages. Although the reflex is benign and occurs in otherwise healthy persons, the morbidity and injuries resulting from VVS can be major. In patients with frequent and burdensome cardioinhibitory VVS, cardiac pacemakers have been implanted. Cardiac pacing does seem to be beneficial for some patients, but patient selection and types of pacemakers are debated.1,2 More recently, cardioneuroablation (CNA) procedures have emerged as a novel therapy for VVS, and positive results in small open-label cohort studies have been reported.

Pacemaker use for the treatment of reflex-mediated syncope: 40-year experience at a single paediatric institution.

Reflex-mediated syncope occurs in 15% of children and young adults. In rare instances, pacemakers are required to treat syncopal episodes associated with transient sinus pauses or atrioventricular block. This study describes a single centre experience in the use of permanent pacemakers to treat syncope in children and young adults. Patients with significant pre-syncope or syncope and pacemaker implantation from 1978 to 2018 were reviewed. Data collected included the age of presentation, method of diagnosis, underlying rhythm disturbance, age at implant, type of pacemaker implanted, procedural complications and subsequent symptoms. Fifty patients were identified. Median age at time of the first syncopal episode was 10.2 (range 0.3-20.4) years, with a median implant age of 14.9 (0.9-34.3) years. Significant sinus bradycardia/pauses were the predominant reason for pacemaker implant (54%), followed by high-grade atrioventricular block (30%). Four (8%) patients had both sinus pauses and atrioventricular block documented. The majority of patients had dual-chamber pacemakers implanted (58%), followed by ventricular pacemakers (38%). Median follow-up was 6.7 (0.4-33.0) years. Post-implant, 4 (8%) patients continued to have syncope, 7 (14%) had complete resolution of their symptoms, and the remaining reported a decrease in their pre-syncopal episodes and no further syncope. Twelve (24%) patients had complications, including two infections and eight lead malfunctions. Paediatric patients with reflex-mediated syncope can be treated with pacing. Complication rates are high (24%); as such, permanent pacemakers should be reserved only for those in whom asystole from sinus pauses or atrioventricular block has been well documented.

Применение местных гемостатических препаратов для профилактики гематом ложа электрокардиостимулятора

BACKGROUND: Prevention of pacemaker pocket hematoma is an urgent problem of modern cardiovascular surgery. A method of prevention of hematomas may be application of local hemostatic agents. One of such means is incomplete silver salt of polyacrylic acid, registered in the Russian Federation as a medical product under the trade name “Hemoblock”. AIM: To evaluate the efficacy and safety of partial silver salt of polyacrylic acid (Hemoblock®) as a hemostatic drug for prophylaxis of pacemaker (PM) pocket hematoma. MATERIALS AND METHODS: The study included 29 patients (18 men) with average age of 72.8 ± 9.8 years and indications for PM implantation. The patients were divided into 2 groups, partial silver salt of polyacrylic acid was used during the PM implantation in group A, 0.9% NaCl solution was used in group B. Anticoagulant therapy was not cancelled. In the postoperative period, patients underwent a daily examination by a surgeon, on the 3th–5th day — an ultrasound of soft tissues in the area of the PM pocket to diagnose hemorrhagic complications. After 1 month, a control examination of the postoperative wound and an assessment of the PM function were performed. RESULTS: In 1 (6.3%) patient in group B, a PM pocket hematoma was found which required drainage in the dressing room and increased the period of hospitalization after surgery to 7 days. Soft tissue imbibition with blood was observed in 9 (56.3%) group B patients. No PM pocket hematomas and imbibition of soft tissues were observed in group A. PM implantation with uninterrupted anticoagulant therapy without the use of hemostatic agents increases the risk of soft tissue imbibition with blood by 2.3 times (p = 0.001, r = 0.605, RR 2.3, 95% CI 1.3–4). Age, gender, body mass index, body surface area, left ventricular ejection fraction, type of anticoagulation therapy, indication for PM implantation, type of PM, and the peculiarities of the operation did not influence the risk of development of PM pocket hematoma or soft tissue imbibition with blood (p > 0.05). CONCLUSION: The use of a partial silver salt of polyacrylic acid (Hemoblock®) can reduce the risk of development of hematomas and soft tissue imbibition with blood in the area of the pacemaker pocket and does not lead to the development of infectious complications and allergic reactions.

B-PO03-026 SYNCHRONIZATION BETWEEN CARDIAC INTERVALS IN HEALTHY SUBJECTS AND SUBJECTS WITH PACEMAKERS.

The heart rate variability (HRV) makes it possible to maintain the homeostasis of the cardiovascular system, allowing its adaptation to multiple stimuli. Many studies have shown that cardiac pacing above 40% increases the risk of developing ventricular remodeling, with adverse consequences for the ejection fraction. This effect persists beyond the refinement achieved so far in these devices. In this work we show a possible cause for this persistence. To we show the desynchronization that occurs between the various stages of the cardiac cycle in patients with pacemakers due to the current design of these devices. We examined Holter recordings of healthy adult subjects with pacemakers. The time series of the various cardiac intervals were analyzed in the frequency domain. Figure 1a shows the synchronization of the cardiac cycle for healthy individuals. All the intervals that include the TP interval are synchronized with each other, have the same autocorrelation function, and the same cross-correlation function. The other subintervals are synchronized with each other so that the variability of the TP interval is transferred to the RR interval. Figure 1b,c shows the effect of a VVI pacemaker. The RR interval is set in a fixed duration, the RT interval is specific to the patient, and therefore the TR interval is altered. Figure 1d,e,f schematically shows the effect of the other types of pacemakers. Therefore, setting any cardiac subinterval alters the timing of the entire cardiac cycle. We show that the synchronization within the cardiac cycle is altered in current pacemakers. This temporal phenomenon is not related to stimulation sequence.

Trends and Profile of Permanent Pacemaker Implantation in Nepal. Experience From Tertiary Cardiac Center (SGNHC) From 2001 to 2020.

Background and Aims: The number of pacemaker implantation is increasing at various centres of Nepal with increase in cardiac services. However, there are few data available regarding the pacemaker implantation in Nepal. This study intend to focus and study trends and profile of permanent pacemaker implantation (PPI) of 19 years experience at the referral tertiary cardiac center which will reflect intended objective of this study.
 Methods: This was a retrospective cross sectional study done at Shahid Gangalal National Heart Centre (SGNHC). The data of the patient who underwent PPI from 2001 November to 2020 August were reviewed. Patients data including age, sex, indication for pacing, mode of pacing, type of pacemaker implanted, implantation parameters such as lead impedence and threshold were recorded and analyzed.
 Results: A total of 3631 pacemaker implantation were performed at SGNHC from 2001 November to 2020 August. Among the total patients, 59.4% were male with mean age of 65.2±15.2 years. The most common indication was degenerative complete heart block (74.8%). Sick sinus syndrome (8.2%) was the second most common indication of pacing. The single chamber were implanted in 93.3% cases and dual chamber in 6.7% cases. VVIR was the most common mode of implantation in 93.1% cases, followed by DDDR (6.7%). AAIR (0.1%) and VDD in 0.1% cases. The total number of pacemaker implanted yearly in SGNHC has increased since the early year of implantation. During the early years most of the pacemakers were Single chamber (VVI) pacemaker and the implantation of dual chamber pacemaker increased gradually from year 2010 onwards. After the year 2010 the implantation of dual chamber pacemaker has increased significantly compared to prior to 2010 (p= 0.001). There were no gender differences in use of single chamber and dual chamber implantation during this period. (p value = 0.489). The dual chamber were implanted mostly in age group less than 65 year compared to more than 65 years (P value = 0.001). 
 Conclusion: There is gradual increase in the number of pacemaker implantation yearly at SGNHC and since 2010 there is also increase in number of dual chamber pacemaker implantation though the single chamber pacemaker outnumbered the dual chamber implantation.