Complete Atrioventricular Block Research Articles

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

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). 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). 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. 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.

Feasibility of a novel atrial mechanical sensing method for leadless atrioventricular synchronous pacing.

Few studies have demonstrated a high degree of atrioventricular (AV) synchrony with a new leadless pacemaker called Micra AV. Our group previously reported a new and unique sensing method. We believe that this novel sensing method, "Simplified A3 method,"might facilitate better AV synchrony than a conventional sensing method in almost all cases with Micra AV implantation. We conducted a non-randomized retrospective study comparing the two pacing methods at two centers. From December1,2021 to October 31, 2022, Micra AV was implanted for 32 patients at the two centers. Twenty of the 32 patients with sinus rhythm and complete AV block were included in this study. In Group 1, the conventional setting was programmed as follows: auto A3 threshold, auto A3 window-end (WE), and auto A4 threshold turned on during hospitalization. In Group 2, the "Simplified A3 method" was programmed as follows: auto A3 threshold and auto A3WE turned off. Instead, an intentionally prolonged A3WE (850-1000 ms) and low A3 threshold (A3 signal amplitude + 0.5-1.0 m/s2) were programmed. Twenty patients were analyzed. In Group 2, AV synchrony (%AMVp) was significantly higher at the first outpatient clinic (63.0 ± 5.7% vs 81.0 ± 4.2%, p = .03). A3 threshold was significantly lower in Group 2 (5.9 ± 0.7 m/s2, p < .05 vs 2.3 ± 0.5 m/s2, p < .05). Our novel sensing method might be a more feasible sensing method for obtaining higher AV synchrony than the conventional algorithm.

Prevalence of neonatal lupus in a small group of antibody-carrying mothers and frequency of complete atrioventricular block.

Neonatal lupus (NL) is extremely rare and is caused by the transplacental passage of maternal IgG autoantibodies against Ro, La, and/or RNP proteins into the fetal circulation, which can cause congenital complete atrioventricular block (CCAB), permanent skin lesions, and liver involvement. To know the prevalence of NL in patients with CCAB and the clinical course in long-term follow-up. From January 1992 to December 2017, patients with CCAB were included. The presence of anti-SSA/Ro and anti-SSB/La antinuclear antibodies in maternal serum confirmed NL. Eight patients were included with a follow-up of 10 ± 6 years; NL was concluded in 62.5%; two were male. One of them was diagnosed in utero, two at birth, and a pacemaker was implanted in them, one at 12 years of age and another at 15. The other two cases were diagnosed at 18 and 26 years of age, and permanent pacemakers were implanted 8 and 5 years later, respectively. In one case, a definitive pacemaker was not implanted in a newborn with only 1 year of follow-up. At delivery, 60% of the mothers were free of rheumatic disease, and altogether, they all had 19 children; none of them presented NL manifestations. CCAB is rare and frequently associated with a maternal autoimmune disease, practically all of them will require a definitive pacemaker at some point in their lives.

Downregulation of SIRT1 and GADD45G genes and left atrial fibrosis induced by right ventricular dependent pacing in a complete atrioventricular block pig model.

The molecular and genetic mechanisms underlying left atrial (LA) enlargement and atrial fibrosis following right ventricular (RV) dependent pacing remain unclear. Our objective was to investigate genetic expressions in the LA of pigs subjected to RV pacing for atrioventricular block (AVB), as well as to identify the differential gene expressions affected by biventricular (BiV) pacing. We established an AVB pig model and divided the subjects into three groups: a sham control group, an RV pacing group, and a BiV pacing group. Differential expression genes (DEGs) analyses conducted through next-generation sequencing (NGS) and enrichment analyses were employed to identify genes with altered expression in the LA myocardium. The RV pacing group showed a significant increase in extracellular fibrosis in the LA myocardium compared to the control group. NGS analysis revealed suppressed expression of the sirtuin signaling pathway in the RV pacing group. Among the DEGs within this pathway, GADD45G was found to be downregulated in the RV pacing group and upregulated in the BiV pacing group. Remarkably, the BiV pacing group exhibited elevated levels of GADD45G protein. In our study, we observed significant downregulation of SIRT1 and GADD45G genes, which are associated with the sirtuin signaling pathway, in the LA myocardium of the RV pacing group when compared to the control group. Moreover, these genes, which were downregulated in the RV pacing group, displayed a noteworthy upregulation in the BiV pacing group when compared to the RV pacing group.

ОСОБЕННОСТИ ДИАГНОСТИКИ И ВЕДЕНИЯ ПАЦИЕНТКИ С СИНДРОМОМ ФРЕДЕРИКА (КЛИНИЧЕСКОЕ НАБЛЮДЕНИЕ)

Description of a clinical case. The article presents a clinical observation of a 77-year-old patient with newly diag-nosed Frederick’s syndrome, which is a combination of a permanent form of atrial fibrillation and complete atrioven-tricular block. An exacerbation of chronic pancreatitis was the reason for hospitalization of the patient. The patient had no complaints of bradycardia or syncope, but treatment of the underlying disease was difficult due to the development of acute kidney injury against the background of chronic kidney disease and uncompensated chronic heart failure. The cause of the development of Frederick’s syndrome was pronounced myocardium remodeling due to diseases that make up the classic complex of metabolic syndrome – coronary heart disease, arterial hypertension, type 2 dia-betes mellitus and obesity. Conclusion. The analysis of a few domestic and foreign literature sources showed that the development of Frederick’s syndrome is associated with a worsening prognosis and the development of various complications, which is usually underestimated by attending physicians. Taking into account the difficulties of diagnosis and management of patients with this pathology, it is necessary to be wary of the development of Frederick’s syndrome, especially in comorbid elderly and senile patients. Timely medical correction and referral of the patient for surgical treatment will improve the prognosis and reduce mortality in patients with atrial fibrillation.

Reversal of complete atrioventricular block in dialysis patients following parathyroidectomy: A case report

BACKGROUND Refractory secondary hyperparathyroidism (SHPT) is a common complication observed in patients with end-stage renal disease and can result in ectopic calcification. Metastatic calcification involving the heart valves and the conduction system can easily lead to arrhythmias, including atrioventricular block. This case report describes a maintenance hemodialysis patient with refractory SHPT resulting in a complete atrioventricular block (CAVB), which was eventually reversed to a first-degree atrioventricular block. CASE SUMMARY We present the case of a 31-year-old Asian female who was receiving maintenance hemodialysis because of lupus nephropathy. She developed SHPT, and an electrocardiogram revealed a first-degree atrioventricular block. Then, she underwent parathyroidectomy (PTX) with autotransplantation. Unfortunately, a few years later, she developed SHPT again, and an electrocardiogram revealed a CAVB. A few years after the second PTX surgery, the calcification of the left atrium and left ventricle improved, and her CAVB was reversed. CONCLUSION This case revealed that metastatic cardiac calcification can result in complete atrioventricular blockage. Following parathyroid surgery, calcification of the cardiac conduction system improved, leading to reversal of the atrioventricular block. It is important for dialysis patients to optimize intact parathyroid hormone therapy and pay attention to calcification metastasis.

Usefulness of endomyocardial biopsy using three-dimensional delivery system for the diagnosis of cardiac amyloidosis with complete atrioventricular block after transcatheter aortic valve implantation.

Usefulness of endomyocardial biopsy using three-dimensional delivery system for the diagnosis of cardiac amyloidosis with complete atrioventricular block after transcatheter aortic valve implantation.

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).

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. 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. 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. 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.

Mechanisms of torsades de pointes: an update.

Torsades de Pointes (TdP) refers to a polymorphic ventricular tachycardia (VT) with undulating QRS axis that occurs in long QT syndrome (LQTS), although the term has been used to describe polymorphic ventricular tachyarrhythmias in which QT intervals are not prolonged, such as short-coupled variant of TdP currently known as short-coupled ventricular fibrillation (VF) and Brugada syndrome. Extensive works on LQTS-related TdP over more than 50 years since it was first recognized by Dessertennes who coined the French term meaning "twisting of the points", have led to current understanding of the electrophysiological mechanism that TdP is initiated by triggered activity due to early afterdepolarization (EAD) and maintained by reentry within a substrate of inhomogeneous repolarization. While a recently emerging notion that steep voltage gradients rather than EADs are crucial to generate premature ventricular contractions provides additions to the initiation mode, the research to elucidate the maintenance mechanism hasn't made much progress. The reentrant activity that produces the specific form of VT is not well characterized. We have conducted optical mapping in a rabbit model of electrical storm by electrical remodeling (QT prolongation) due to chronic complete atrioventricular block and demonstrated that a tissue-island with prolonged refractoriness due to enhanced late Na+ current (INa-L) contributes to the generation of drifting rotors in a unique manner, which may explain the ECG characteristic of TdP. Moreover, we have proposed that the neural Na+ channel NaV1.8-mediated INa-L may be a new player to form the substrate for TdP. Here we discuss TdP mechanisms by comparing the findings in electrical storm rabbits with recently published studies by others in simulation models and human and animal models of LQTS.

Feasibility of cardiac magnetic resonance imaging in temporary permanent pacemaker implants in pediatric myocarditis and complete atrioventricular block.

Diagnosing myocarditis in children presenting with complete AV block (CAVB) is challenging. Temporary permanent pacing support using standard transvenous active fixation lead can be inserted percutaneously until recovery. However, access to cardiac magnetic resonance (CMR) imaging may be limited due to safety concerns. We report three cases where CMR was performed using temporary permanent pacemaker insitu. We evaluated the effect of device artefacts on image quality and examined any instances of device malfunction. In children with CAVB and myocarditis, a temporary permanent pacemaker can provide reliable pacing until recovery, and CMR can be safely performed with the implanted pacemaker without compromising image quality.

Association Between ECG Abnormalities and Mortality in a Low-Risk Population.

The ECG is a simple, noninvasive screening method for cardiovascular disease and arrhythmia. The impact of ECG abnormality on mortality is not certain in low-risk populations. To address this, we evaluated the association between ECG abnormality and mortality. We retrospectively assessed baseline ECG and all-cause mortality and cardiovascular mortality in 660 383 patients presenting for medical check-ups. Baseline ECG abnormalities were classified according to the Minnesota Code. Among the total 660 383 participants, 23 609 (3.6%) had major and 110 038 (16.7%) had minor ECG abnormalities. All-cause mortality occurred in 7751 patients (1.1%) and cardiovascular mortality in 1180 (0.18%) over a median follow-up period of 8.8 years. Major ECG abnormalities were associated with all-cause mortality (hazard ratio [HR], 1.11 [95%, 1.03-1.2]) and cardiovascular mortality (HR, 1.92 [95% CI, 1.63-2.27]) compared with no ECG abnormalities. All-cause mortality was associated with right atrial enlargement (HR, 2.11 [95% CI, 1.1-4.07]), left atrial enlargement (HR, 1.76 [95% CI, 1.1-2.84]), sinus tachycardia (HR, 1.52 [95% CI, 1.15-2.01]), complete atrioventricular block (HR, 2.1 [95% CI, 1.05-4.2]), atrial fibrillation (HR, 1.52 [95% CI, 1.26-1.84]), and left ventricular hypertrophy (HR, 1.15 [95% CI, 1.02-1.3]). Cardiovascular mortality was associated with left atrial enlargement (HR, 4.52 [95% CI, 2.15-9.5]), atrial fibrillation (HR, 3.22 [95% CI, 2.33-4.46]), left ventricular hypertrophy (HR, 1.72 [95% CI, 1.35-2.19]), major Q-wave abnormality (HR, 1.6 [95% CI, 1.08-2.39]), and major ST-T abnormality (HR, 1.76 [95% CI, 1.01-3.04]). ECG abnormalities, including left atrial enlargement, left ventricular hypertrophy, atrial fibrillation, and major Q-wave and ST-T abnormalities, were associated with cardiovascular mortality in a low-risk population.

[Short history of the DC-Catheter-Ablation].

Direct current (DC) catheter ablation in 5patients aiming to interrupt rapid atrioventricular (AV) conduction with atrial fibrillation and subsequent pacemaker implantation was first published by M.M.Scheinman etal. (San Francisco, CA, USA) in 1982. In Germany, L.Seipel, G.Breithardt, and M.Borggrefe reported their first experience with DC catheter ablation in 1984, followed by the group in Bonn (M.Manz and B.Lüderitz) in 1985. The first international DC catheter ablation registry, which also included four German centers, reported DC catheter ablation results of 127 patients in 24centers in 1984. Complete AV block was achieved in 71% patients. In 1992, the Hannover group (H‑J.Trappe, H.Klein and J.Huang) reported results of DC catheter ablation of AV conduction performed between 1983 and 1990 in 100 patients (86% with rapid atrial fibrillation, 14% with AV-node reentry tachycardias). The first successful DC catheter ablation in apatient with Wolff-Parkinson-White (WPW) syndrome was reported in 1985 by F.Morady etal. (San Francisco, CA, USA). In 1987, M.Borggrefe etal. were the first to report aswitch from DC catheter ablation to ahigh-frequency (HF) catheter ablation procedure in apatient with WPW syndrome. The use of DC catheter ablation to treat ventricular tachycardia (VT) was described by G.O.Hartzler (Kansas City, MO, USA) in 3patients in 1983. M.Borggrefe etal. (1989) reported on 24patients who underwent DC catheter ablation for VT. Of those, 17patients did not have VT recurrence within the following 14months. In 1994, the Hannover group (H-JTrappe, H.Klein) published their 5‑year long-term results of DC catheter ablation of VT in 51patients. VT recurrence occurred in 57% patients and overall mortality was also high (16%). Acomparison of DC catheter ablation with HF catheter ablation for recurrent VT was reported in 1994 by G.Gonska etal. (Göttingen, Germany). After 2years follow-up, success rates were not found to be significantly different.

Complete atrioventricular block in an adolescent with acute rheumatic fever: a case report

Acute rheumatic fever (ARF) is an autoimmune, multiorgan inflammatory disease that occurs in genetically susceptible individuals after group A-hemolytic streptococcal infection. Carditis and polyarthritis are the most common symptoms of ARF. Repeated streptococcal infections can cause recurrent valvulitis and valvular heart disease.&#x0D; Prolonged atrioventricular conduction (first-degree heart block) is a well-known symptom of ARF, occurring in one-fifth to three-fifths of patients. This condition is a minor criterion for diagnosing ARF based on Jones's criteria. Advanced conduction delay, such as a second-degree or a complete atrioventricular (AV) block, is a rare condition of ARF that can occur before symptoms like carditis, polyarthritis, and Sydenham chorea appear. We present a case of ARF in an adolescent with complete AV block.

Atrioventricular block secondary to transient causes and long-term recurrence after an index event.

Atrioventricular block (AVB) secondary to transient causes can recover with its correction. However, studies assessing predictors of recovery and long-term recurrence are lacking. Patients with advanced or complete AVB who had a reversible cause admitted in a single expert center were retrospectively studied. Patients with AVB secondary to acute coronary syndromes were excluded from analysis. In a population of 162 patients, the main factors associated with recovery of rhythm without a permanent pacemaker (PPM) implantation were the presence of chronic kidney disease (CKD) on dialysis (OR 7.6; CI 95% 1.2-47.5 (p=.03)); greater serum potassium levels (OR 2.3; CI 95% 1.28-4.0 (p<.01)), higher dosage of bradycardic drugs (OR 2.2; CI 95% 1.13-4.4 (p=.02)), the association between different bradycardic drugs (OR 9.0; CI 95% 2.02-40.3 (p<.01)) and between drug therapy and hyperkaliemia (OR 5.2; CI 95% 1.8-15.1 (p<.01)). There was an overall high burden of conductions abnormalities which did not correlate with recovery of rhythm (OR 0.5; CI 95% 0.19-1.5 (p=.23)). In 29 patients (17.9%) there was a correction of the AVB. During a maximum follow-up of 130 months, 24 patients (82.8%) had a recurrence which warranted a PPM. In the overall cohort only five patients (3%) had sustained recovery of rhythm. Recovery of AVB was mainly observed with higher doses of drug therapy, higher serum potassium levels or a combination of factors and regardless of baseline conduction abnormalities. The high rate of recurrence during follow-up warrants a close follow-up or PPM implantation at index admission.

Right anterior mini-thoracotomy aortic valve replacement versus transcatheter aortic valve implantation in octogenarians: a single center experience: a retrospective study.

The aim of this study was to compare the early outcomes of octogenarians undergoing minimally invasive right anterior mini-thoracotomy aortic valve replacement (RAT-AVR) with those undergoing transcatheter aortic valve implantation (TAVI) for aortic valve disease. In this single-center retrospective study, data were collected from octogenarians before and after RAT-AVR and TAVI between January 2021 and July 2022. Short-term outcomes, including the length of hospital stay, in-hospital mortality, all-cause mortality, and other major postoperative complications, were compared and analyzed. There were no significant differences in in-hospital mortality, stroke, acute kidney dysfunction requiring renal replacement therapy, length of intensive care unit stay, or length of hospital stay. However, the TAVI group had a higher incidence of permanent pacemaker insertion (10% vs. 0%, p=0.54) and paravalvular leaks (75% vs. 0%, p<0.001). In the present study on octogenarians, both TAVI and RAT-AVR showed comparable short-term results. Although both procedures were considered safe and effective in the selected group, RAT-AVR had a lower incidence of complete atrioventricular block and paravalvular regurgitation.

Pembrolizumab-induced myocarditis with complete atrioventricular block and concomitant myositis in a metastatic bladder cancer patient: a case report and review of the literature

BackgroundThe cardiovascular system is among the least systems affected by immune-related adverse events. We report a rare life-threatening case of pembrolizumab-induced myocarditis with complete atrioventricular block and concomitant myositis in a metastatic bladder cancer patient.Case presentationAn 82-year-old Caucasian female with invasive urothelial carcinoma, started on first-line pembrolizumab, was admitted four days after receiving her second dose for severe asthenia, diffuse muscle aches, neck pain, and lethargy. In the emergency department, she had several episodes of bradycardia reaching 40 beats per minute associated with general discomfort and fatigue. Electrocardiography showed a third-degree atrioventricular heart block, while the patient remained normotensive. Cardiac damage parameters were altered with elevated levels of creatine phosphokinase of 8930 U/L, suggestive of immune checkpoint inhibitor-induced myositis, and troponin T of 1.060 ng/mL. Transthoracic echocardiography showed a preserved ejection fraction. Pembrolizumab-induced myocarditis was suspected. Therefore, treatment was initiated with high-dose glucocorticoids for 5 days, followed by a long oral steroid taper. A pacemaker was also implanted. Treatment resulted in the resolution of heart block and a decrease in creatine phosphokinase to the normal range.ConclusionLife-threatening cardiac adverse events in the form of myocarditis may occur with pembrolizumab use, warranting vigilant cardiac monitoring. Troponin monitoring in high-risk patients, along with baseline echocardiography may help identify this complication promptly to prevent life-threatening consequences.

Monitoring of Women with Anti-Ro/SSA and Anti-La/SSB Antibodies in Germany-Status Quo and Intensified Monitoring Concepts.

Background: The fetuses of pregnant women affected by anti-Ro/anti-La antibodies are at risk of developing complete atrioventricular heart block (CAVB) and other potentially life-threatening cardiac affections. CAVB can develop in less than 24 h. Treatment with anti-inflammatory drugs and immunoglobulins (IVIG) can restore the normal rhythm if applied in the transition period. Routine weekly echocardiography, as often recommended, will rarely detect emergent AVB. The surveillance of these pregnancies is controversial. Home-monitoring using a hand-held Doppler is a promising new approach. Methods: To obtain an overview of the current practice in Germany, we developed a web-based survey sent by the DEGUM (German Society of Ultrasound in Medicine) to ultrasound specialists. With the intention to evaluate practicability of home-monitoring, we instructed at-risk pregnant women to use a hand-held Doppler in the vulnerable period between 18 and 26 weeks at our university center. Results: There are trends but no clear consensus on surveillance, prophylaxis, and treatment of anti-Ro/La positive pregnant between specialists in Germany. Currently most experts do not offer home-monitoring but have a positive attitude towards its prospective use. Intensified fetal monitoring using a hand-held Doppler is feasible for pregnant women at risk and does not lead to frequent and unnecessary contact with the center. Conclusion: Evidence-based guidelines are needed to optimize the care of anti-Ro/La-positive pregnant women. Individual risk stratification could help pregnancy care of women at risk and is welcmed by most experts. Hand-held doppler monitoring is accepted by patients and prenatal medicine specialists as an option for intensified monitoring and can be included in an algorithm for surveillance.

Staged therapeutic surgery for progressive pulmonary regurgitation and pacemaker induced cardiomyopathy after the tetralogy of fallot repair

BackgroundRecently, improvements in the repair of tetralogy of Fallot have increased the need for reoperation in adulthood, and it’s not rare that these reoperation candidates suffer from biventricular failure. However, there are no firm treatment guidelines, and each country, and even each facility, treats each case individually.Case presentationWe report the successful staged treatment of pulmonary regurgitation and pacemaker-induced cardiomyopathy with biventricular failure in adulthood in a case of complete atrioventricular block after tetralogy of Fallot repair in childhood. We planned a staged therapeutic strategy with preoperative left ventricular volume reduction with medication, following surgical pulmonary valve replacement concomitant epicardial lead implantation on the lateral basal wall, placed just beneath the generator pocket through 3rd intercostal space. in addition to postoperative intervention with a defibrillator to adjust cardiac resynchronization therapy, resulted in improvement of symptoms.ConclusionIn a patient with biventricular failure after TOF repair, a staged treatment strategy involving medication, PVR, and CRT with a combination of epicardial and intravenous leads could be a useful treatment worth trying before heart transplantation.

Effect of His Bundle Pacing on Abnormal Myocardial Fatty Acid and Glucose Metabolism Induced by Right Ventricular Pacing.

Metabolic disorder is noted for pacing-induced cardiomyopathy. The benefits of His bundle pacing over right ventricular (RV) pacing in preventing pacing-induced cardiomyopathy from a metabolic perspective are yet to be fully understood. Three pig groups were established for this study: sham control, RV pacing (RV pacing for 6 months), and His pacing (RV pacing for 6 months, followed by His bundle pacing for 3 months). Complete atrioventricular block was created in the last 2 groups. Left ventricular function and dyssynchrony were assessed via echocardiography, while proteins linked to metabolism, endoplasmic reticulum stress, and inflammation in left ventricular myocardium were examined. The RV pacing group had significantly more left ventricular mechanical dyssynchrony compared with the other groups. The RV pacing group exhibited triglyceride and diacylglycerol accumulation in cardiomyocytes and higher expression of binding immunoglobulin protein and tumor necrosis factor-α than the other groups. Additionally, the expression of CD36 was activated, while the expression of hormone-sensitive lipase was downregulated in the RV pacing group compared with the His pacing and sham control groups. Furthermore, the expressions of GLUT4 and pyruvate dehydrogenase were higher in the RV pacing group than the sham control and His pacing groups. Notably, the abnormal fatty acid and glucose metabolic pathways in the left ventricular myocardium during RV pacing could be corrected by His bundle pacing. His bundle pacing can mitigate the abnormal metabolism disorders, endoplasmic reticulum stress, and inflammation induced during RV pacing and may contribute to the superiority of conduction system pacing over RV pacing in reducing heart failure hospitalization.

Racial disparities among patients with cardiac sarcoidosis and arrhythmias in the United States: A propensity matched-analysis from the national inpatient sample database 2016-2020

BackgroundCardiac sarcoidosis (CS) is frequently associated with conduction abnormalities and arrhythmias. In this study, we aim to evaluate racial disparities in the frequency of arrhythmias, and associated co-morbidities, among patients with CS. MethodsWhite and African American (AA) patients diagnosed with CS were identified and compared from the 2016-2020 National Inpatient Sample (NIS) database whilst adjusting for confounders via logistic regression models. ResultsA total of 7,935 patients with CS were included in the study. The propensity-matched sample comprised of 5,570 patients, of whom 2,785 were White and 2,785 were AA. AA patients had a longer mean length of hospital stay (LOS) (7.84 vs. 6.94, p<0.01), a higher mean Charlson Comorbidity Index (CCI) score (3.10 vs. 2.84, p<0.01), and significantly higher incidences of cardiogenic shock [(9.2% vs 6.3%, p<0.01), aOR 1.45 (95% CI 1.17-1.78), p<0.01] and acute kidney injury (AKI) [(34.3% vs. 26.9%, p<0.01), aOR 1.41 (95% CI 1.24-1.61), p<0.01]. From an arrhythmia perspective, AA CS patients were shown to have a lower frequency of: (1) ventricular tachycardia (32.5% vs. 37.9%, p<0.01), (2) ventricular fibrillation (5.4% vs.7.2%, p<0.01), (3) first-degree AV block (1.8% vs. 4.1%, p<0.01), (4) complete AV block (6.3% vs. 14.2%, p<0.01), and (5) atrial fibrillation (31.8% vs. 34.8%, p=0.016) when compared to Whites with CS. Mortality remained higher for AAs (3.8% vs. 2.7%, p=0.024). ConclusionOur study demonstrates a higher incidence of cardiac arrhythmias among White patients but a higher incidence of cardiogenic shock, AKI, mean LOS, and mortality among AA patients with cardiac sarcoidosis.