Paroxysmal Atrioventricular Block in a Relatively Young Patient with COVID-19

Cardiac involvement has been reported in patients with coronavirus disease 2019 (COVID-19). We herein report a 41-year-old man who presented with recurrent paroxysmal atrioventricular block without showing significant cardiac injuries or comorbidities. The patient was diagnosed with COVID-19 and admitted to our hospital, where he was noted to have paroxysmal atrioventricular block. Cardiac biomarkers, echocardiography, and cardiac magnetic resonance imaging findings were fairly normal. An endomyocardial biopsy performed before the implantation of a permanent pacemaker revealed mild myocardial fibrosis without inflammatory infiltrates. The unusual myocardial involvement of the novel coronavirus was suspected.

Efficacy and safety of left bundle branch area pacing versus right ventricular apex pacing in patients with atrioventricular block: study protocol for a randomised controlled trial

INTRODUCTION

Left bundle branch area pacing (LBBaP) is a relatively new approach for physiologic pacing. A limited number of retrospective clinical studies, featuring small sample sizes, have shown that compared with right ventricular apex pacing (RVAP), the QRS duration of postoperative ECG in LBBaP patients is narrower and the cardiac systolic function is improved. However, there have been no randomised controlled trials (RCTs) evaluating the efficacy and safety of LBBaP in patients with atrioventricular block (AVB). Therefore, the current study intends to address the paucity in RCT data evaluating LBBaP versus RVAP in AVB patients.

ANALYSIS AND METHODS

This study is a single-centre, randomised controlled superiority trial to be conducted at the Cardiac Centre of Beijing Anzhen Hospital. From January 2021 to December 2023, 210 consecutive AVB patients meeting the inclusion criteria and receiving pacemaker implantation will be enrolled. Participants will be randomly divided into an experimental group (LBBaP) and a control group (RVAP) at a 1:1 ratio. The primary outcome is left ventricular ejection fraction (LVEF), which will be assessed by echocardiography. The secondary outcomes in this study are synchrony of left ventricular systole, NT-proBNP, LVEDD, the 6-min walk distance, quality of life (SF-36 scale), all-cause mortality, cardiovascular death events, rehospitalisation rate and major complication rate.

ETHICS AND DISSEMINATION

This study was approved by the Medical Ethics Committee of Beijing Anzhen Hospital (No. 2020021X). The results of the trial will be presented at national and international conferences. We hypothesise that compared with RVAP, LBBaP will be superior for treating patients with AVB. This trial will provide evidence-based suggestion for the majority of electrophysiologists in pacing implantation.

TRIAL REGISTRATION

ChiCTR2000034335.

Three-dimensional mapping for His-bundle pacing in pediatric patients, a case series

INTRODUCTION

Pediatric patients who receive pacemakers may have a lifetime of repeat exposure to fluoroscopy. His bundle pacing may provide better long-term pacing for these patients. To minimize fluoroscopy and for improved localization of the His bundle, we utilized three-dimensional mapping to guide His bundle pacing and we follow-up short-term results.

METHODS

An Octapolar Livewire catheter (Abbott, Minneapolis, USA) was used for mapping and location of the His bundle while 3-dimensional mapping via the EnSite Precision system (Abbott Medical, Abbott Park, IL) was utilized to create a 3-dimensional geometry. The EnSite Precision system also mapped and recorded His bundle signal strengths and earliest ventricular activation or retrograde His bundle activation.

RESULTS

Three patients are presented and followed for 4-5 months. The ages ranged from 10 to 15 years with 1 male patient. Diagnoses including progressive atrioventricular block, alternating bundle branch block and atrioventricular canal defect with complete heart block. All patients received selective His-bundle pacing systems. The range in fluoroscopy time was 6.4 to 9.9 min with 5.64 mGy to 10.18 mGy. Stable lead thresholds, impedances and sensing were present at last follow-up.

CONCLUSIONS

His bundle pacing in our 3 pediatric patients including one with altered His-bundle physiology (case 3 with atrioventricular canal defect) was successful with good short-term follow-up results.

Congenital complete atrioventricular block from literature to clinical approach - a case series and literature review

AIM

Congenital atrioventricular block (CAVB) is an immunological condition, secondary to the transfer of maternal Ig G antibodies from seropositive mothers. Although the presence of these antibodies is high among pregnant women, the preva-lence of this fetal pathology is low. The aim of this paper is to analyze a series of cases with intrauterine diagnosis of CAVB and to present their follow-up protocol.

MATERIAL AND METHOD

In the period between 2013-2020, five fetuses were diagnosed and followed up in the Pediatric Cardiology Clinic. In each of the cases, assessment of the hemodynamic status was done by calculation of the fetal cardiovascular profile score (CVPS). In the last cases the follow-up protocol was supplemented with longitudinal speckle tracking evaluation of the ventricular function.

RESULTS

In the present series, intrauterine death occurred in one case; in another case resumption of atrioventricular conduction was observed. Epicardial pacemaker implantation was required in three of the patients.

CONCLUSION

Completing the evaluation of ventricular function with the longitudinal speckle tracking method in fetuses and newborn patients with congenital atrioventricular block may play an important role in establish-ing therapeutic behavior.

Transcatheter valve-in-valve-in-valve replacement in tricuspid position in a patient with pre-existing permanent dual-chamber pacemaker

Graphic abstract

Case Report: Successful primary percutaneous coronary intervention in octogenarian with acute-on-chronic kidney disease and total atrioventricular block after acute myocardial infarction

Myocardial infarction (MI) is frequently complicated by the worsening of renal function. Undergoing primary percutaneous coronary intervention (PCI) becomes crucial to a patient with ST-segment elevation myocardial infarction (STEMI). With appropriate management of MI, acute-on-chronic kidney disease (ACKD) requiring dialysis post-MI remains an important clinical predictor of elevated in-hospital mortality among patients with MI.  In this study, we reported an octogenarian patient suffering from STEMI with ACKD and total atrioventricular block (TAVB). She underwent insertion of a temporary pacemaker and primary PCI. Renal function was improved after dialysis by decreasing the amount of serum creatinine from 8.1 mg/dL at admission to 1.05 mg/dL after primary PCI and dialysis. Primary PCI should still be considered for patients with acute MI, even though these patients have kidney disease, to save the heart muscle and even indirectly improve the kidney function itself.

Case Report: Successful primary percutaneous coronary intervention in octogenarian with acute-on-chronic kidney disease and total atrioventricular block after acute myocardial infarction

Myocardial infarction (MI) is frequently complicated by the worsening of renal function. Undergoing primary percutaneous coronary intervention (PCI) becomes crucial to a patient with ST-segment elevation myocardial infarction (STEMI). With appropriate management of MI, acute-on-chronic kidney disease (ACKD) requiring dialysis post-MI remains an important clinical predictor of elevated in-hospital mortality among patients with MI.  In this study, we reported an octogenarian patient suffering from STEMI with ACKD and total atrioventricular block (TAVB). She underwent insertion of a temporary pacemaker and primary PCI. Renal function was improved after dialysis by decreasing the amount of serum creatinine from 8.1 mg/dL at admission to 1.05 mg/dL after primary PCI and dialysis. Primary PCI should still be considered for patients with acute MI, even though these patients have kidney disease, to save the heart muscle and even indirectly improve the kidney function itself.

Case Report: Successful primary percutaneous coronary intervention in octogenarian with acute-on-chronic kidney disease and total atrioventricular block after acute myocardial infarction

Myocardial infarction (MI) is frequently complicated by the worsening of renal function. Undergoing primary percutaneous coronary intervention (PCI) becomes crucial to a patient with ST-segment elevation myocardial infarction (STEMI). With appropriate management of MI, acute-on-chronic kidney disease (ACKD) requiring dialysis post-MI remains an important clinical predictor of elevated in-hospital mortality among patients with MI.  In this study, we reported an octogenarian patient suffering from STEMI with ACKD and total atrioventricular block (TAVB). She underwent insertion of a temporary pacemaker and primary PCI. Renal function was improved after dialysis by decreasing the amount of serum creatinine from 8.1 mg/dL at admission to 1.05 mg/dL after primary PCI and dialysis. Primary PCI should still be considered for patients with acute MI, even though these patients have kidney disease, to save the heart muscle and even indirectly improve the kidney function itself.

Remote-only monitoring for patients with cardiac implantable electronic devices: a before-and-after pilot study

BACKGROUND

Outcomes for patients with cardiac implantable electronic devices are better when follow-up incorporates remote monitoring technology in addition to in-clinic visits. For patients with implantable devices, we sought to determine the feasibility, safety and associated health care utilization of remote-only follow-up, along with its effects on patients' quality of life and costs.

METHODS

This multicentre before-and-after pilot study involved patients with new or existing pacemakers or implantable cardioverter defibrillators. The "before" phase of the study spanned the period October 2015 to February 2017; the "after" phase spanned the period October 2016 to February 2018. The exposure was remote-only follow-up in combination with Remote View, a service that facilitates access to device data, allowing device settings to be viewed remotely to facilitate remote programming. Outcomes at 12 months were feasibility (adherence to remote monitoring), safety (rate of adverse events) and health care utilization (remote and in-clinic appointments). We also assessed quality of life, using 3 validated scales, and costs, taking into account both health care system and patient costs.

RESULTS

A total of 176 patients were enrolled. Adherence (defined as at least 1 successful remote transmission during follow-up) was 87% over a mean follow-up of 11.7 (standard deviation 2.2) months. There was a reduction in in-clinic visits at specialized sites among patients with both implantable defibrillators (26 v. 5, p < 0.001, n = 48) and pacemakers (42 v. 10, p < 0.001, n = 51). There was no significant change in visits to community sites for patients with defibrillators (13 v. 17, p = 0.3, n = 48). The composite rate of death, stroke, cardiovascular hospitalization and device-related hospitalization was 7% (n = 164). No adverse events were linked to the intervention. There was no change in quality-of-life scales between baseline and 12 months. Health care costs were reduced by 31% for patients with defibrillators and by 44% for those with pacemakers.

INTERPRETATION

This pilot study showed the feasibility of remote-only follow-up, with no increase in adverse clinical outcomes and no effect on quality of life, but with reductions in costs and health care utilization. These results support progression to a larger-scale study of whether superior effectiveness and reduced cost can be achieved, with preservation of safety, through use of remote-only follow-up.

TRIAL REGISTRATION

ClinicalTrials.gov, no. NCT02585817.

Relation of Prolonged Pacemaker Dependency After Cardiac Surgery to Mortality

Permanent pacemaker implantation (PPI) represents a rare complication after cardiac surgery, with no uniform agreement on timing and no information on follow-up. A multicenter retrospective study was designed to assess pacemaker dependency (PMD) and long-term mortality after cardiac surgery procedures. Between 2004 and 2016, PPI-patients from 18 centers were followed. Time-to-event data were evaluated with semiparametric regression Cox models and semiparametric Fine and Gray model for competing risk framework. Of 859 (0.90%) PPI-patients, 30% were pacemaker independent (PMI) at 6 months. PMD showed higher mortality compared with PMI (10-year survival 80.1% ± 2.6% and 92.2% +2.4%, respectively, log-rank p-value < 0.001) with an unadjusted hazard ratio for death of 0.36 (95% CI 0.20 to 0.65, p< 0.001 favoring PMI) and an adjusted hazard ratio of 0.19 (95% CI 0.08 to 0.45, p< 0.001 with PMD as reference). Crude cumulative incidence function of restored PMI rhythm at follow-up at 6 months, 1 year and 12 years were 30.5% (95% CI 27.3% to 33.7%), 33.7% (95% CI 30.4% to 36.9%) and 37.2% (95% CI 33.8% to 40.6%) respectively. PMI was favored by preoperative sinus rhythm with normal conduction (SR) (HR 2.37, 95% CI 1.65 to 3.40, p< 0.001), whereas coronary artery bypass grafting and aortic valve replacement were independently associated with PMD (HR 0.63, 95% CI 0.45 to 0.88, p = 0.006 and HR 0.807, 95% CI 0.65 to 0.99, p = 0.047 respectively). Time-to-implantation was not associated with increased rate of PMI. Although 30% of PPI-patients are PMI after 6 months, PMD is associated with higher mortality at long term.

Strategy of pacemaker and electrode replacement for superior vena cava stenosis

Cardiac implantable devices are commonly used for superior vena cava stenosis, but there have been few reports of electrode replacement in the stenosed superior vena cava. A 73-year-old man was diagnosed with second-degree type II atrioventricular block and a permanent dual-chamber, rate-modulated pacing pacemaker was implanted 10 years previously. Because of depletion of the pacemaker battery and an increase in the ventricular pacing threshold, replacement of the pacemaker and ventricular electrode was required. During the operation, we found that the patient had severe superior vena cava stenosis on angiography, and this caused obstruction when a common guidewire was used to pass through the superior vena cava. After attempting various methods, we successfully passed through the vascular stenosis with a super slide guidewire and a long sheath, and completed replacement of the pacemaker and ventricular electrode. We summarize the related literature of superior vena cava stenosis related to a cardiac implantable device, and discuss the replacement strategy of this complication and other treatment options.

First-degree atrioventricular block in acute anterior myocardial infarction

BACKGROUND

There is paucity of data regarding the prognostic implications of first-degree atrioventricular block in patients with acute anterior myocardial infarction as a distinct group. The aim of this study was to elucidate the association of prolonged PR interval with hospital clinical outcomes in patients with treated with thrombolysis.

METHODS

Three hundred consecutive patients with a first acute anterior ST-segment elevation myocardial infarction undergoing thrombolysis between October 2017 and March 2018, were retrospectively enrolled in this study. They were divided into two groups based on PR interval on admission: PR interval ≤200 ms, and PR interval > 200 ms. Hospital mortality and complications were compared between the 2 groups.

RESULTS

Of the 300 patients, 26 (8.66%) had first-degree atrioventricular block on initial presentation. Overall, hospital death occurred in 20 (6.66%) patients. Patients with PR interval > 200 ms had a higher hospital mortality rate (26.9%) than those without (4.7%, p < 0.001). In multivariate Cox regression analysis, only left ventricular systolic function and PR interval were independent predictors of hospital mortality (odds ratio = 1.031; 95% confidence interval: 1.008-1.056, p = 0.009 for PR interval).

CONCLUSION

In patients with a first acute anterior ST-segment elevation myocardial infarction treated with thrombolysis, first-degree atrioventricular block was associated with increased hospital mortality and a worse prognosis.

Treatment of atrial fibrillation with third-degree atrioventricular block by pacing His bundle and left bundle branch: Case report

INTRODUCTION

Substantial advances in cardiac pacing technology have been developed in the past decades. However, efforts to improve pacing technology to achieve physiological electrical activity, such as with cardiac resynchronization therapy, are underway. Permanent His bundle pacing, which directly stimulates the His-Purkinje network and electrically activates both ventricles, simulates physiological electric activity in the heart, and has been considered an ideal pacing strategy to treat arrhythmias. For patients with atrial fibrillation complicated by third-degree atrioventricular block (AVB), permanent His bundle pacing is a better option than conventional right ventricular apical or septal pacing, the latter of which may be associated with risks, such as heart failure. However, His bundle pacing exhibits some shortcomings, including elevated pacing threshold, dislocation, and abnormal sensing.

CASE PRESENTATION

A 69-year-old female patient who had atrial fibrillation (AF) complicated by third-degree AVB and who was treated with permanent His bundle pacing combined with left bundle branch pacing.

DIAGNOSIS

AF complicated by third-degree AVB.

INTERVENTIONS

We used the left bundle branch as a backup pacing site to overcome any shortcomings related to permanent His bundle pacing.

OUTCOMES

The patient recovered well without any events.

CONCLUSION

We selected His bundle pacing as the primary pacing, but also used left bundle branch pacing as a backup approach. If His bundle pacing results in an increased sensing threshold, pacing threshold changes, or dislocations, left bundle branch pacing can compensate for dysfunction of permanent deficiencies in His bundle pacing, preserving physiological pacing.

Left bundle branch area pacing - restoring the natural order: A Case Report

INTRODUCTION

Recent studies have shown that His-bundle pacing could be an alternative in patients requiring cardiac resynchronization therapy as it is comparable or better in terms of amelioration of ventricular activation, narrowing of the QRS complex, or clinical outcomes. However, in case of high threshold at the level of His-bundle or inability to correct conduction through a diseased His-Purkinje system other option should be searched like left bundle pacing.

PATIENT CONCERNS

A 77-year-old man presented to the Emergency Department for dizziness and dizziness and lightheadedness due to an intermittent 2:1 atrioventricular block with a QRS complex morphology of a major left branch block.

DIAGNOSIS

Given the documented symptomatic 2:1 AV block, according to the European Guideliness the patient was considered to have a class 1 indication of permanent double chamber cardiostimulation.

INTERVENTIONS

A lead delivery system with a C315 His catheter and a Select Secure 3830 69 cm pacing lead were placed at the His bundle area with important narrowing of the QRS complex but with an unacceptable high threshold. The delivery system was moved towards the apex 1,5 cm and the lead screwed deep into the septum until capture of the left bundle branch was achieved with complete normalization of the conduction troubles.

OUTCOMES

At 3 month follow-up the patient was asymptomatic and the pacing and sensing thresholds remained at same values as during implantation: 0.75/0.4 ms and 14 mV respectively.

CONCLUSION

Left bundle-pacing represents the next step of His-Purkinje system pacing to overcome all difficulties related to His-bundle pacing.

Alpha-Loop for Permanent Pacemaker Implantation in Restrictive Cardiomyopathy

High-grade and complete heart block commonly occurs in adult patients with restrictive cardiomyopathy, and requires aggressive monitoring and prophylactic pacemaker/defibrillator. There are limited data on the procedural details of pacemaker implantation in this group of patients, and as reported, special maneuvers may be required for ventricular lead placement.

Treatment of atypical pacemaker-mediated tachycardia with ablation of the retrograde atrioventricular nodal pathway

A 25-year-old runner received a single-lead, VDD pacemaker after ablation of AV nodal reentrant tachycardia complicated by intermittent AV block. The rate-adaptive AV delay algorithm (RAAV), which shortens the sensed AV interval (SAV) at faster atrial rates, was programmed to provide a physiologic SAV with exercise. She developed repetitive, atypical, long-RP pacemaker-mediated tachycardia (PMT) because the RAAV shortened the antegrade SAV and retrograde conduction occurred over the slow AV nodal pathway. PMT was refractory to usual programming solutions. Using high-density electroanatomic mapping, we were able to ablate the retrograde limb of PMT without further damaging AV conduction.

The risk factors of new-onset atrial fibrillation after pacemaker implantation

OBJECTIVE

The aim of this study was to determine the incidence of newly detected atrial fibrillation (AF) in patients following dual-chamber pacemaker (PPM) implantation and to define the clinical predictors of new-onset AF in a Chinese cohort.

METHODS

A total of 219 patients without documented AF that underwent dual-chamber PPM implantation for sick sinus syndrome (SSS) (n = 88) or atrioventricular block (AVB) (n = 131) were prospectively studied. All patients were invited to follow-up at 1 month, 3 months and 6 months after the pacemaker implantation procedure, and once every 6 months thereafter. An atrial high-rate episode (AHRE) ≥5 min and an atrial rate ≥180 bpm was defined as AF.

RESULTS

During follow-up of 884 ± 180 days, AF was detected in 56 (26%) patients. Using Kaplan-Meier survival curves with Log-rank test, SSS patients with a cumulative percentage of ventricular pacing (Cum % VP) ≥60% had a significantly higher rate of new-onset AF compared to AVB patients (p = 0.026) and SSS patients with Cum % VP <60% (p = 0.018). On multivariate Cox regression analysis, higher Cum % VP independently predicted higher morbidity of newly detected AF (hazard ratio [HR] 1.01; confidence interval [CI] 1.00 ~ 1.02; p = 0.035) among SSS patients. Larger left atrial (LA) dimension was a predictor of newly detected AF (HR 1.06; CI 1.01 ~ 1.14; p = 0.046) in AVB patients.

CONCLUSION

The incidence of AF following dual-chamber PPM implantation was relatively high in this Chinese cohort. High Cum % VP and larger LA dimension could independently predict new-onset AF after dual-chamber PPM implantation in SSS and AVB patients, respectively.

Development of a sheep model of atrioventricular block for the application of novel therapies

Introduction

Sheep have been adopted as a pre-clinical large animal for scientific research as they are good models of cardiac anatomy and physiology, and allow for investigation of pathophysiological processes which occur in the large mammalian heart. There is, however, no defined model of atrioventricular block in sheep to allow for pre-clinical assessment of new cardiac treatment options. We therefore aimed to develop an adult sheep model of atrioventricular block with the focus on future novel applications.

Methods and results

We utilized six sheep to undergo two procedures each. The first procedure involved implantation of a single chamber pacemaker into the right ventricular apex, for baseline assessment over four weeks. The second procedure involved creating atrioventricular block by radiofrequency ablation of the His bundle, before holding for a further four weeks. Interrogation of pacemakers and electrocardiograms determined the persistence of atrioventricular block during the follow up period. Pacemakers were inserted, and atrioventricular block created in 6 animals using a conventional approach. One animal died following ablation of the His bundle, due to procedural complications. Four unablated sheep were assessed for baseline data over four weeks and showed 5.53 ± 1.28% pacing reliance. Five sheep were assessed over four weeks following His bundle ablation and showed continuous (98.89 ± 0.81%) ventricular pacing attributable to persistent atrioventricular block, with no major complications.

Conclusion

We have successfully developed, characterized and validated a large animal model of atrioventricular block that is stable and technically feasible in adult sheep. This model will allow for the advancement of novel therapies, including the development of cell and gene-based therapies.

[Second-degree atrioventricular block caused by Lyme disease]

BACKGROUND

Tick-borne diseases, including Lyme disease, are becoming increasingly common in Europe. Lyme disease has a wide variety of clinical manifestations, as a result of which physicians of diverse disciplines are coming into contact with such patients.

CASE DESCRIPTION

A 58-year-old man was seen at the emergency room with a symptomatic Wenckebach-type second-degree atrioventricular (AV) block and periods of 2:1 AV block. Four weeks previously the patient had noticed a red skin lesion on his left lower leg. Under the working diagnosis of early disseminated Lyme disease with cardiac involvement, treatment with ceftriaxone was started. This diagnosis was supported by a positive Borrelia PCR and culture of a skin biopsy and positive Borreliaserology. The AV conduction disorders resolved completely after 2 weeks of treatment with antibiotics and it was not necessary to implant a pacemaker.

CONCLUSION

A Borrelia infection is a reversible but rare cause of AV conduction disorders. In the event of sudden onset of symptoms or a severe or progressive AV conduction disorder, Lyme carditis should be considered, especially if the medical history or physical examination provides clues for Lyme disease.