Worldwide survey on implantation of and outcomes for conduction system pacing with His bundle and left bundle branch area pacing leads.

BACKGROUND: Adoption and outcomes for conduction system pacing (CSP), which includes His bundle pacing (HBP) or left bundle branch area pacing (LBBAP), in real-world settings are incompletely understood. We sought to describe real-world adoption of CSP lead implantation and subsequent outcomes. METHODS: We performed an online cross-sectional survey on the implantation and outcomes associated with CSP, between November 15, 2020, and February 15, 2021. We described survey responses and reported HBP and LBBAP outcomes for bradycardia pacing and cardiac resynchronization CRT indications, separately. RESULTS: The analysis cohort included 140 institutions, located on 5 continents, who contributed data to the worldwide survey on CSP. Of these, 127 institutions (90.7%) reported experience implanting CSP leads. CSP and overall device implantation volumes were reported by 84 institutions. In 2019, the median proportion of device implants with CSP, HBP, and/or LBBAP leads attempted were 4.4% (interquartile range [IQR], 1.9-12.5%; range, 0.4-100%), 3.3% (IQR, 1.3-7.1%; range, 0.2-87.0%), and 2.5% (IQR, 0.5-24.0%; range, 0.1-55.6%), respectively. For bradycardia pacing indications, HBP leads, as compared to LBBAP leads, had higher reported implant threshold (median [IQR]: 1.5 V [1.3-2.0 V] vs 0.8 V [0.6-1.0 V], p = 0.0008) and lower ventricular sensing (median [IQR]: 4.0 mV [3.0-5.0 mV] vs. 10.0 mV [7.0-12.0 mV], p < 0.0001). CONCLUSION: In conclusion, CSP lead implantation has been broadly adopted but has yet to become the default approach at most surveyed institutions. As the indications and data for CSP continue to evolve, strategies to educate and promote CSP lead implantation at institutions without CSP lead implantation experience would be necessary.

Risk Mitigation of Pacemaker Pocket Erosion in Thin Patients.

The aging population, particularly the thin and frail, has an increased risk of long-term cardiac implantable electronic device complications. This case is that of an elderly, thin-skinned patient who presented with a pacemaker pocket erosion 4 years after elective generator change, potentiated by a small pocket size with a superficial suture fixating the generator in the subcutaneous pocket. The risk for device erosion may have been mitigated during the generator change by increasing the size of the pocket, using a submuscular pocket, and potentially an absorbable antibacterial envelope. Fixation of the generator is considered optional.

Le risque de complications liées aux dispositifs électroniques cardiaques implantables est plus grand à long terme au sein de la population vieillissante, particulièrement chez les personnes minces et fragiles. Nous présentons ici le cas d'un patient âgé, à la peau fine, qui, quatre ans après le remplacement non urgent du générateur de son stimulateur cardiaque, a présenté une érosion de la loge du boîtier aggravée par la petite taille de celle-ci. Une suture superficielle fixait le générateur dans la loge sous-cutanée. Le risque d'érosion de la loge du boîtier aurait pu être atténué par l'augmentation de la taille de la loge lors du remplacement du générateur, par le recours à une loge sous-musculaire, et peut-être par l'utilisation d'une enveloppe antibactérienne résorbable. La fixation du générateur est jugée facultative.

Quality of Life and Health Care Utilization in the CIRCA-DOSE Study.

OBJECTIVES: This study evaluated the impact of contact force-guided radiofrequency ablation versus cryoballoon ablation on quality of life and health care utilization. BACKGROUND: Traditional outcome parameters, such as arrhythmia-free survival, are insufficient to evaluate the clinical impact of atrial fibrillation (AF), as it fails to the capture patient- and health system-level differences in treatment approaches. METHODS: The CIRCA-DOSE (Cryoballoon Vs. Contact-Force Atrial Fibrillation Ablation) study randomly assigned 346 patients with drug-refractory paroxysmal AF to contact force-guided radiofrequency or cryoballoon ablation. Health-related quality-of-life (HRQOL) was assessed at baseline, and at 6 and 12 months post-ablation using a disease-specific and generic HRQOL instruments. Health care utilization (hospitalization, emergency department visits, and cardioversion) and antiarrhythmic drug use for the 12 months preceding ablation was compared with the 12 months following ablation. RESULTS: Disease-specific and generic HRQOL was moderately to severely impaired at baseline and improved significantly at 6 and 12 months of follow-up (median improvement in AFEQT [Atrial Fibrillation Effect on QualiTy of Life] score 32.4 [interquartile range: 17.7 to 48.9]). When compared with the 12 months pre-ablation, the proportion and absolute number of cardioversions decreased significantly (41.1% vs. 10.1% of patients, 137 vs. 35 events; p < 0.0001). Similar significant reductions in emergency department visits (66.7% vs. 25.1% of patients, 224 vs. 87 events; p < 0.0001), and hospitalizations (25.5% vs. 14.5% of patients, 86 vs. 50 events; p < 0.001) were observed. There were no significant differences between randomized groups. CONCLUSIONS: In this multicenter randomized trial, catheter ablation with advanced-generation technologies resulted in a significant improvement in HRQOL and a significant reduction in health care utilization in the year following AF ablation. (Cryoballoon vs. Irrigated Radiofrequency Catheter Ablation [CIRCA-DOSE]; NCT01913522).

Clinical assessment of AF pattern is poorly correlated with AF burden and post ablation outcomes: A CIRCA-DOSE sub-study.

BACKGROUND: Contemporary guidelines recommend that atrial fibrillation (AF) be classified into paroxysmal and persistent AF based on clinical assessment, with these categorizations forming the basis of therapeutic recommendations. While pragmatic, clinical assessment may introduce misclassification errors, which may impact treatment decisions. We sought to determine the relationship between AF classification, baseline AF burden, and post-ablation arrhythmia outcomes. DESIGN: The current study is a sub-analysis of a prospective, parallel-group, multicenter, single-blinded randomized clinical trial. All 346 patients enrolled in CIRCA-DOSE received an implantable cardiac monitor a median of 72 days prior to ablation. AF was classified as low burden paroxysmal, high burden paroxysmal, or persistent based on clinical assessment prior to device implantation. Prior to ablation patients were re-classified using the same definitions based on device monitoring data. Correlation between classifications, AF burden, and post-ablation arrhythmia outcomes were assessed. RESULTS: There was poor agreement between clinical and device-based AF classification (Cohen's kappa: 0.192). AF classification derived from pre-ablation continuous monitoring reflected baseline and post-ablation AF burden with greater accuracy and with less overlap between the AF classes (P < 0.01 for all categorical comparisons). Patients objectively classified as "Low Burden" paroxysmal by continuous monitoring data had significantly greater freedom from recurrent AF/AT/AFL compared to those classified as "High Burden" paroxysmal (hazard ratio [HR] 0.57 for AF/AT/AFL recurrence) or persistent AF (HR 0.19 for AF/AT/AFL recurrence). CONCLUSIONS: Classification of AF pattern based on pre-ablation continuous cardiac rhythm monitoring better predicted AF burden and freedom from recurrent AF post ablation. Despite the use of standardized definitions, classification of AF based on clinical assessment did not predict baseline AF burden, post ablation AF burden, or freedom from recurrent AF post ablation. TRIAL REGISTRATION: ClinicalTrials.govNCT01913522.

Evaluation of common suturing techniques to secure implantable cardiac electronic device leads: Which strategy best reduces the lead dislodgement risk?

Summary: Implantable cardiac electronic device lead dislodgment is a relatively common complication and carries significant comorbidities. A potential cause of lead dislodgement includes inadequate anchoring along the lead suture sleeve at the venous insertion site. We assessed which of the 3 commonly applied knot-tying techniques results in the most effective anchoring of a pacing lead along its suture sleeve, which could be associated with minimized lead motion postimplant. Following controlled traction force measurements, the anchor knot technique offered the greatest amount of lead stability when compared with the simple knot and the looping knot techniques.

The use of dronedarone for recurrent ventricular tachycardia: a case report and review of the literature.

BACKGROUND: Dronedarone is a benzofuran derivative resembling amiodarone that was intended to reduce the iodine-associated tissue deposition and organ toxicity seen with the latter. The utility of dronedarone for patients with ventricular arrhythmias has not been thoroughly evaluated. We present our experience with its use to treat refractory ventricular tachycardia storm and review the literature. CASE PRESENTATION: An 85 year-old gentleman with multiple medical comorbidities including ischemic and non-ischemic cardiomyopathy with severe biventricular systolic dysfunction presented with ventricular tachycardia storm. Therapeutic options were limited given his frail medical status, failures of sotalol, mexilitine, and catheter ablation therapies along with drug-toxicities from amiodarone. Dronedarone was thus considered as off-label use following informed consent. The patient unfortunately developed fatal multisystem organ failure including acute severe hepatotoxicity from dronedarone. CONCLUSION: Novel therapies for drug-refractory ventricular arrhythmias are long overdue given the limitations of available pharmacologic and non-pharmacologic options. Off-label use of antiarrhythmic agents such as dronedarone is considered a treatment of last-resort in patients who otherwise have no therapeutic options. Given the paucity of reported cases regarding dronedarone for the treatment of ventricular tachyarrhythmias, no conclusive recommendations can be made at this time aside from words of caution. Despite the potential ventricular antiarrhythmic effects of dronedarone, careful patient evaluation is required to identify those at greatest risk of drug-related adverse events particularly in those patients with significant comorbidities such as advanced hepatic, renal, and cardiovascular disease.

The utility of pocket-sized echocardiography to assess left ventricular systolic function prior to permanent pacemaker implantation.

BACKGROUND: A subset of patients receiving first-time permanent pacemakers (PPM) may also benefit from an implantable cardioverter defibrillator (ICD) based on the presence of left ventricular systolic dysfunction (LVSD). Routine screening using pocket-sized echocardiography (PSE) may be useful in identifying such patients. OBJECTIVE: To determine whether PSE can be used by an inexperienced sonographer to adequately screen for LVSD in a patient population receiving a first-time PPM. METHODS: A sonographic trainee (medical student) acquired images using PSE, which were then evaluated by an experienced echocardiologist for both image quality and presence of LVSD. The sensitivity and specificity of assessment by the inexperienced sonographer was compared to the level 3 echocardiologist. RESULTS: The patient population included 71 individuals (66% male, mean age 77 ± 12 years). Interpretable images where left ventricular ejection fraction (LVEF) could be adequately assessed were obtained in 93% of the patient population. As compared with the echocardiologist, the sonographic trainee had a sensitivity of 60% and a specificity of 98% in detecting LVSD. CONCLUSIONS: For patients receiving first-time PPM, the use of PSE by a sonographic trainee combined with interpretation by an experienced imaging cardiologist can triage for the need to perform standard transthoracic echocardiography (sTTE) by determining the presence of LVSD.

Troubleshooting during a challenging high-risk pacemaker lead extraction: a case report and review of the literature.

BACKGROUND: The use of cardiac implantable electrical devices continues to increase with the validation of new beneficial indications. While the risks of device implantation decreased significantly over time, significant risk remains associated with their extraction when indicated. A high-risk pacemaker lead extraction case is described, wherein a chronically implanted lead that had perforated the right atrium was successfully removed without the need for cardiopulmonary bypass. In this report we share our approach to this challenging extraction case and describe an infrequently utilized off-pump hybrid technique that we term the "lead-inverting stitch". CASE PRESENTATION: A 74 year-old Caucasian woman with complete heart block and remote pacemaker implantation presents with a swollen and erythematous infected pacemaker pocket necessitating device extraction. Chest computerized tomographic imaging revealed a chronically perforating right atrial lead tip approximately 2 cm within the pericardial space. A successful hybrid transvenous and open surgical extraction approach was undertaken without the need for cardiopulmonary bypass; this was made possible due to a successfully positioned "lead-inverting stitch". CONCLUSION: Implantable cardiac electrical device infections are amongst the most dreaded post implant complications. Risks of device extraction are further complicated in cases of chronic lead perforations. Extraction strategies that avoid cardiopulmonary bypass initiation are preferred.

Getting by with less - the "frugal tie".

The ability to tie surgical knots efficiently and effectively is an essential surgical skill for medical procedures, especially pacemaker implantation. Device generators and their leads need to be safely anchored with sutures during implantation to prevent dislodgement and inadequate packaging in the pacemaker pocket. With most knot tying techniques, a generous amount of suture slack is required. We introduce a new technique that is a variation of the 2-handed surgical square knot and the 1-handed surgeon's knot that allows one to finish or tie a knot when left with little slack.

Non-invasive bedside assessment of central venous pressure: scanning into the future.

BACKGROUND: Noninvasive evaluation of central venous pressure (CVP) can be achieved by assessing the Jugular Venous Pressure (JVP), Peripheral Venous Collapse (PVC), and ultrasound visualization of the inferior vena cava. The relative accuracy of these techniques compared to one another and their application by trainees of varying experience remains uncertain. We compare the application and utility of the JVP, PVC, and handheld Mini Echo amongst trainees of varying experience including a medical student, internal medicine resident, and cardiology fellow. We also introduce and validate a new physical exam technique to assess central venous pressures, the Anthem sign. METHODS: Patients presenting for their regularly scheduled echocardiograms at the hospital echo department had clinical evaluations of their CVP using these non-invasive bedside techniques. The examiners were blinded to the echo results, each other's assessments, and patient history; their CVP estimates were compared to the gold standard level 3 echo-cardiographer's estimates at the completion of the study. RESULTS: 325 patients combined were examined (mean age 65, s.d. 16 years). When compared to the gold standard of central venous pressure by a level 3 echocardiographer, the JVP was the most sensitive at 86%, improving with clinical experience (p<0.01). The classic PVC technique and Anthem sign had better specificity compared to the JVP. Mini Echo estimates were comparable to physical exam assessments. CONCLUSIONS: JVP evaluation is the most sensitive physical examination technique in CVP assessments. The PVC techniques along with the newly described Anthem sign may be of value for the early learner who still has not mastered the art of JVP assessment and in obese patients in whom JVP evaluation is problematic. Mini Echo estimates of CVPs are comparable to physical examination by trained clinicians and require less instruction. The use of Mini Echo in medical training should be further evaluated and encouraged.

Absent right and persistent left superior vena cava: troubleshooting during a challenging pacemaker implant: a case report.

BACKGROUND: Venous anomalies of the thorax can occur in isolation or in association with complex congenital heart disease. The incidence of an absent right superior vena cava in the setting of a persistent left superior vena cava is very rare in the general population with only a dozen cases documented in the medical literature. Such venous anomalies can make for very challenging electronic cardiac device implantation. We report our challenging dual chamber pacemaker implant in a patient with such complex anatomy and focus on our implantation technique that helped achieve adequate lead positioning. CASE PRESENTATION: A 73-year-old Caucasian female with degenerative complete heart block presented for dual chamber permanent pacemaker implant. Lead implantation was very challenging due to abnormal and rare vena cava anatomy; a persistent left superior vena cava drained directly into the coronary sinus and the right brachiocephalic vein drained directly into the left persistent superior vena cava as the patient had an absent right superior vena cava . Adequate right ventricular lead positioning was achieved following numerous lead-stylet manipulations and careful looping in the atria to redirect its trajectory to the ventricular apex. CONCLUSION: Abnormal superior vena cava development is uncommon and can lead to technical challenges when venous access is required during various interventional procedures. Pre-operative imaging can help identify such challenging anatomy allowing appropriate operative planning; careful patient selection is warranted for venography given the risk of contrast nephrotoxicity.

Eosinophilic myocarditis: two case reports and review of the literature.

BACKGROUND: Eosinophilic myocarditis is a rare and often under-diagnosed subtype of myocarditis with only around 30 cases published in the medical literature. In this article we present two patients with eosinophilic myocarditis with the aim to demonstrate the often elusive nature of the disease and present the current scientific literature on this topic. CASE PRESENTATION: A 76 years old Caucasian gentleman and a 36 years old Aboriginal gentleman both presenting with heart failure symptoms were eventually diagnosed with eosinophilic myocarditis after extensive evaluation. Their presentation, assessment, and medical management is explored in this article. CONCLUSIONS: Eosinophilic myocarditis remains a rare and likely under-diagnosed subtype of myocarditis. The key features of this disease include myocardial injury in the setting of non-contributory coronary artery disease. Endomyocardial biopsy remains the definitive gold standard for diagnosis of noninfectious eosinophilic myocarditis. Non-invasive cardiac imaging in the setting of peripheral eosinophilia can be strongly suggestive of eosinophilic myocarditis with potential for earlier diagnosis. Failure to diagnose eosinophilic myocarditis and the delay of therapy may lead to irreversible myocardial injury. Therapies for this disease have yet to be validated in large prospective studies.

Successful ablation of idiopathic left ventricular tachycardia in an adult patient during extracorporeal membrane oxygenation treatment.

Idiopathic ventricular tachycardia (VT) is usually a benign arrhythmia with good prognosis that can be managed with antiarrhythmic agents and is often cured using ablation. There is, however, a malignant potential in a subset of patients with idiopathic VT as was the case for our patient whom we discuss in this case report. After a review of the medical literature, and to our knowledge, this is the first case of a successful idiopathic VT ablation in an adult while extracorporeal membrane oxygenation was being used.

Reduced hospitalizations in severe, refractory congestive heart failure with peritoneal dialysis: a consecutive case series.

BACKGROUND: Peritoneal dialysis (PD) for long-term management of diuretic resistant volume overload in heart failure (HF) may provide potential benefit with few adverse consequences. We examined the impact of PD on clinical status hospitalizations, and complications of therapy in severe end-stage HF. METHODS: A consecutive case series of 10 transplant ineligible patients receiving PD solely for HF volume management between 2007 and 2011 was evaluated with clinical data reviewed pre- and post-PD initiation. RESULTS: The mean ejection fraction (EF) pre-PD was 24.5 ± 6.0% with the majority of patients having NYHA class IIIB symptoms and moderate-severe right ventricular dysfunction. 9/10 patients were Stage 3 chronic kidney disease (CKD) or worse. After PD initiation, average weight loss was almost 7 kg (p = 0.016) with improvement in diuretic response, peripheral edema, and functional class. There was a significant decrease in re-hospitalization from an average of 3.2 ± 2.5 to 0.1 ± 0.3 admissions per patient (p = 0.007) and reduced average length of stay from 37 ± 36.7 to 0.78 ± 2.3 days (p = 0.019). SUMMARY: Objective criteriabased institution of PD for the treatment of diuretic refractory severe-end-stage HF was well tolerated and demonstrated favorable outcomes; these included improved clinical status, reduced hospitalizations and length of stay, with very few and easily treatable PDrelated complications. PD appears to be a viable option in refractory, end-stage congestive heart failure (CHF).

Cardiac lipofibromatosis.

We present a case of cardiac lipofibromatosis associated with atrial fibrillation and complete heart block requiring permanent pacemaker implantation. Multimodality cardiac imaging including transthoracic echocardiography and cardiac magnetic resonance were useful for tissue characterization of this rare cardiac diagnosis.

Integrative approach to quality assessment of medical journals using impact factor, eigenfactor, and article influence scores.

BACKGROUND: Impact factor (IF) is a commonly used surrogate for assessing the scientific quality of journals and articles. There is growing discontent in the medical community with the use of this quality assessment tool because of its many inherent limitations. To help address such concerns, Eigenfactor (ES) and Article Influence scores (AIS) have been devised to assess scientific impact of journals. The principal aim was to compare the temporal trends in IF, ES, and AIS on the rank order of leading medical journals over time. METHODS: The 2001 to 2008 IF, ES, AIS, and number of citable items (CI) of 35 leading medical journals were collected from the Institute of Scientific Information (ISI) and the http://www.eigenfactor.org databases. The journals were ranked based on the published 2008 ES, AIS, and IF scores. Temporal score trends and variations were analyzed. RESULTS: In general, the AIS and IF values provided similar rank orders. Using ES values resulted in large changes in the rank orders with higher ranking being assigned to journals that publish a large volume of articles. Since 2001, the IF and AIS of most journals increased significantly; however the ES increased in only 51% of the journals in the analysis. Conversely, 26% of journals experienced a downward trend in their ES, while the rest experienced no significant changes (23%). This discordance between temporal trends in IF and ES was largely driven by temporal changes in the number of CI published by the journals. CONCLUSION: The rank order of medical journals changes depending on whether IF, AIS or ES is used. All of these metrics are sensitive to the number of citable items published by journals. Consumers should thus consider all of these metrics rather than just IF alone in assessing the influence and importance of medical journals in their respective disciplines.