The management of cardiac implantable electronic device lead perforations: a multicentre study.

AIMS: Lead perforation is a rare, well-known complication of cardiac implantable electronic device (CIED) implants, whose management is mostly not evidence-based. Main management strategies include conservative approach based on clinical and lead function follow-up vs. routine invasive lead revision approach. This study compared the complications of both strategies by composite endpoint, including recurrent perforation-related symptoms, recurrent pericardial effusion (PEf), lead dysfunction, and device infection during 12 month follow-up. METHODS AND RESULTS: Multicentre retrospective analysis, inquiring data from imaging studies, device interrogation, pericardiocentesis, and clinical charts of patients with suspected perforating leads between 2007 and 2014 in five hospitals. All cases were reviewed by electrophysiologist and defined as definite perforations by suggestive symptoms along with lead perforation on imaging, bloody PEf on pericardiocentesis shortly after implant, or right ventricular (RV) lead non-capture along with diaphragmatic stimulation upon bipolar pacing. Clinical outcomes associated with both management approaches were compared, with respect to the composite endpoint. The study included 48 definitive perforation cases: 22 managed conservatively and 26 via lead revision. Conservative management was associated with an increased composite endpoint compared with lead revision (8/22 vs. 1/26; P = 0.007). The dominant complication among the conservative cohort was appearance of cardiac tamponade during follow-up; 5/6 occurring in cases which presented with no or only mild PEf and were treated by antiplatelets/coagulants during or shortly after CIED implantation. CONCLUSION: A conservative management of CIED lead perforation is associated with increased complications compared with early lead revision. Lead revision may be the preferred management particularly in patients receiving antiplatelets/coagulants.

Cardioversion of pre-excited atrial fibrillation leading to ventricular fibrillation- case report and review of literature.

Pre-excited, fast conducting atrial fibrillation (AF) is a serious life-threatening arrhythmia that requires urgent pharmacological or electrical cardioversion. When anti-arrhythmic medications fail to restore sinus rhythm, biphasic, direct current (DC) cardioversion is required. Appropriate synchronization of the DC shock with the QRS is crucial, however not easily achieved. Since the QRS-T complexes in pre-excited AF are severely distorted, the diagnosis of inaccurate synchronization may be overlooked. Here, we report a unique case where during electrical cardioversion of pre-excited AF with inappropriate synchronization on the T wave inadvertently resulted in ventricular fibrillation (VF), and review the literature.

Alternating trifascicular block and cardiac memory.

We describe a case of a 70year-old woman with effort dyspnea and alternating trifascicular conduction pattern, worsened with exercise to atrioventricular block (AV Block). The alternating conduction at rest resulted in marked T wave changes. We discuss the mechanism of T wave memory changes and the management of exercise-induced AV Block.

Mind the gap.

We present a case of a woman with an asymptomatic intermittent 2:1 atrioventricular block. The baseline ECG showed a wide QRS with right bundle branch block pattern. Measurement of the HV interval during electrophysiological study was normal. During electrophysiological stimulation, a unique pattern of paradoxical conduction was seen. We discuss the mechanism of the paradoxical conduction.

Trends in the Incidence of Cardiovascular Diagnoses and Procedures over the Years 2012-2021 in Israel: The Impact of the COVID-19 Pandemic.

Prior studies found reduced incidences of cardiovascular diagnoses and treatments in the initial phase of the COVID-19 pandemic. However, these studies included a limited number of outcomes and did not consider pre-pandemic trends. This study aimed to describe trends in the incidence of cardiovascular diagnoses and treatments over the years 2012-2021 in Israel and to compare the two years of the COVID-19 period with the preceding 8 years. In this retrospective, population-based study, carried out within Clalit Health Services, the incidence rates of cardiovascular outcomes were calculated for individuals aged ≥ 25 (~2.7 million adults per year) during the first (Y1, 3/2020-2/2021) and second (Y2, 3/2021-2/2022) years of COVID-19 and the 8 years prior (3/2012-2/2020). Declines were observed in Y1 compared to 2019 in all diagnoses and treatments: STEMI (-16.3%; 95% CI: -16.6, -16.1), non-STEMI (-16.4%; -16.6, -16.2), AF (-14.1%; -14.2, -14.0), CHF (-7.8%; -7.9, -7.7), CVA (-5.0%; -5.0, -4.9), catheterization (-64.7%; -65.2, -64.2), CABG (-77.7%; -79.2, -76.2), ablation (-21.2%; -22.0, -20.4), pacemaker implantation (-39.3%; -40.7, -37.9), and defibrillator insertion (-12.5%; -13.1, -12.0). Compared with expected rates based on pre-pandemic trends, observed rates were within expected ranges (CHF, CVA, and ablation), less than expected (STEMI, non-STEMI, AF, catheterization, CABG, and pacemaker insertion), or more than expected (defibrillator insertion). In Y2, STEMI, catheterization, and CABG returned to expected rates; non-STEMI and AF were lower than expected; and CHF, CVA, ablation, and pacemaker and defibrillator implantations were higher than expected. Several cardiovascular diagnoses and treatment trends were interrupted by COVID-19. The long-term consequences of these changes should be considered by health policymakers.

Implantation of cardiac electronic devices in active COVID-19 patients: Results from an international survey.

BACKGROUND: Cardiac implantable electronic device (CIED) implantation rates as well as the clinical and procedural characteristics and outcomes in patients with known active coronavirus disease 2019 (COVID-19) are unknown. OBJECTIVE: The purpose of this study was to gather information regarding CIED procedures during active COVID-19, performed with personal protective equipment, based on an international survey. METHODS: Fifty-three centers from 13 countries across 4 continents provided information on 166 patients with known active COVID-19 who underwent a CIED procedure. RESULTS: The CIED procedure rate in 133,655 hospitalized COVID-19 patients ranged from 0 to 16.2 per 1000 patients (P <.001). Most devices were implanted due to high-degree/complete atrioventricular block (112 [67.5%]) or sick sinus syndrome (31 [18.7%]). Of the 166 patients in the study survey, the 30-day complication rate was 13.9% and the 180-day mortality rate was 9.6%. One patient had a fatal outcome as a direct result of the procedure. Differences in patient and procedural characteristics and outcomes were found between Europe and North America. An older population (76.6 vs 66 years; P <.001) with a nonsignificant higher complication rate (16.5% vs 7.7%; P = .2) was observed in Europe vs North America, whereas higher rates of critically ill patients (33.3% vs 3.3%; P <.001) and mortality (26.9% vs 5%; P = .002) were observed in North America vs Europe. CONCLUSION: CIED procedure rates during known active COVID-19 disease varied greatly, from 0 to 16.2 per 1000 hospitalized COVID-19 patients worldwide. Patients with active COVID-19 infection who underwent CIED implantation had high complication and mortality rates. Operators should take these risks into consideration before proceeding with CIED implantation in active COVID-19 patients.

Arrhythmias Utilizing Concealed Nodoventricular or His-Ventricular Pathways: A Structured Approach to Diagnosis and Management.

OBJECTIVES: This study sought to describe the electrophysiologic characteristics, diagnostic maneuvers, and treatment of a series of arrhythmias using concealed nodoventricular (cNV) or His-ventricular (cHV) pathways. BACKGROUND: Confirming the presence and participation of cNV or cHV pathways in tachyarrhythmias is challenging. METHODS: We present 4 cases of tachycardias with a participatory cNV or cHV pathway. RESULTS: The first patient had a narrow complex tachycardia with ventriculoatrial dissociation. Findings of an entrainment pacing from the right ventricle and fused premature ventricular complexes suggested cNV pathway involvement. The second patient had nonsustained narrow complex tachycardia with more ventricular than atrial complexes. The tachycardia exhibited an anterograde His-right bundle (RB) activation sequence and normal His-ventricular (HV) interval and consistently terminated with fused ventricular extra stimuli, suggesting cNV pathway participation. The third patient had a wide complex tachycardia (WCT) with either a right or left bundle branch block pattern. The WCT showed an eccentric His-RB activation sequence and short HV interval and terminated with fused premature ventricular complexes, suggesting a cHV (or concealed fasciculoventricular) pathway involvement. The fourth patient had a WCT with alternating bundle branch block morphologies with a short HV interval. Entrainment from the basal right ventricle demonstrated fusion and a short postpacing interval, suggesting cHV (or fasciculoventricular) pathway involvement. Ablation at the proximal RB rendered the tachycardia noninducible. CONCLUSIONS: A structured approach can help diagnose and treat cNV or cHV pathways. We emphasize the importance of evaluating both the His-RB activation pattern and HV interval during sinus rhythm and tachycardia as well as the ventricular pacing study.

Direct Admission of Patients With ST-Segment-Elevation Myocardial Infarction to the Catheterization Laboratory Shortens Pain-to-Balloon and Door-to-Balloon Time Intervals but Only the Pain-to-Balloon Interval Impacts Short- and Long-Term Mortality.

Background Shortening the pain-to-balloon (P2B) and door-to-balloon (D2B) intervals in patients with ST-segment-elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention (PPCI) is essential in order to limit myocardial damage. We investigated whether direct admission of PPCI-treated patients with STEMI to the catheterization laboratory, bypassing the emergency department, expedites reperfusion and improves prognosis. Methods and Results Consecutive PPCI-treated patients with STEMI included in the ACSIS (Acute Coronary Syndrome in Israel Survey), a prospective nationwide multicenter registry, were divided into patients admitted directly or via the emergency department. The impact of the P2B and D2B intervals on mortality was compared between groups by logistic regression and propensity score matching. Of the 4839 PPCI-treated patients with STEMI, 1174 were admitted directly and 3665 via the emergency department. Respective median P2B and D2B were shorter among the directly admitted patients with STEMI (160 and 35 minutes) compared with those admitted via the emergency department (210 and 75 minutes, P<0.001). Decreased mortality was observed with direct admission at 1 and 2 years and at the end of follow-up (median 6.4 years, P<0.001). Survival advantage persisted after adjustment by logistic regression and propensity matching. P2B, but not D2B, impacted survival (P<0.001). Conclusions Direct admission of PPCI-treated patients with STEMI decreased mortality by shortening P2B and D2B intervals considerably. However, P2B, but not D2B, impacted mortality. It seems that the D2B interval has reached its limit of effect. Thus, all efforts should be extended to shorten P2B by educating the public to activate early the emergency medical services to bypass the emergency department and allow timely PPCI for the best outcome.

Hypoxia causes connexin 43 internalization in neonatal rat ventricular myocytes.

Gap junctions produce low resistance pathways between cardiomyocytes and are major determinants of electrical conduction in the heart. Altered distribution and function of connexin 43 (Cx43), the major gap junctional protein in the ventricles, can slow conduction, and thus contribute to arrhythmogenesis in experimental models such as ischemic rat heart and pacing-induced atrial fibrillation. The mechanisms underlying reduced gap junctional density and conductance during ischemia may involve decreased Cx43 synthesis, increased degradation and/or Cx43 migration into areas which do not contribute to intercellular communication. To test more rigorously the hypothesis that hypoxia resulting from ischemia causes Cx43 internalization, we infected neonatal rat ventricular myocytes (NRVM) with a Cx43-GFP chimera, which enabled us to investigate by means of confocal microscopy the effect of hypoxia (1% O2 for 5 h) on Cx43 distribution in live cardiomyocytes. Importantly, this protocol permitted each culture to serve as its own control. To this end we used life confocal microscopy analysis to determine in the same pair of myocytes the effects of hypoxia on Cx43-GFP distribution at the gap junctional (GJ) and non-GJ areas. In support of this hypothesis, we found that compared to normoxia, 5 h of hypoxia reduced the Cx43-GFP signal at the GJ areas (defined as the border area) and caused a corresponding increase in the Cx43-GFP signal at the non-border areas, thus providing an additional explanation for the intercellular uncoupling during ischemic conditions.

Modern Stents: Where Are We Going?

Coronary artery stenting is the treatment of choice for patients requiring coronary angioplasty. We describe the major advancements with this technology. There have been significant developments in the design of stents and adjunctive medical therapies. Newer-generation drug-eluting stents (DES) have almost negligible restenosis rates and, when combined with proper anti-platelet treatment and optimal deployment, a low risk of stent thrombosis. The introduction of newer-generation DES with thinner stent struts, novel durable or biodegradable polymer coatings, and new antiproliferative agents has further improved the safety profile of early-generation DES. In parallel the effectiveness has been kept, with a significant reduction in the risk of target lesion revascularization compared with the early-generation DES. However, to date, the development of completely bioresorbable vascular scaffolds has failed to achieve further clinical benefits and has been associated with increased thrombosis. Newer-generation DES-including both durable polymer as well as biodegradable polymer-have become the standard of care in all patient and lesion subsets, with excellent long-term results.

Dual-Antithrombotic Therapy With DOACs After Acute Coronary Syndrome or Percutaneous Coronary Intervention in Atrial Fibrillation: A Meta-analysis of Randomized Controlled Trials.

BACKGROUND: The choice of antithrombotic therapy for atrial fibrillation (AF) patients who have an acute coronary syndrome (ACS) or have undergone percutaneous coronary intervention (PCI) is challenging. We aimed to assess outcomes between dual-antithrombotic therapy with the use of direct-acting oral anticoagulants (DOACs) plus an antiplatelet agent (dual therapy) compared with warfarin plus 2 antiplatelet agents (triple therapy) for AF patients after PCI or with ACS. METHODS: Systematic searches of multiple major databases were performed from their inception through September 2019. We included only randomized controlled trials. Odds ratios (ORs) were pooled with the use of a random-effects model. RESULTS: We identified 4 randomized controlled trials, which included 7168 patients. Compared with triple-antithrombotic therapy with warfarin, dual-antithrombotic therapy with DOACs was associated with a significant reduction in major bleeding (OR 0.56, 95% confidence interval [CI] 0.38-0.82; P = 0.003) as well as major bleeding or clinically relevant nonmajor bleeding (OR 0.53, 95% CI 0.38-0.75; P < 0.001). The rate of composite of death and ischemic events (stroke and myocardial infarction) was not statistically different between groups (OR 1.21, 95% CI 0.99-1.49; P = 0.06). There was no significant difference between groups in the rate of death (OR 1.20, 95% CI 0.95-1.53; P = 0.13). CONCLUSIONS: In patients with AF and recent ACS or PCI, the use of dual-antithrombotic therapy with DOACs was associated with less major bleeding and less major bleeding or clinically relevant nonmajor bleeding compared with triple therapy. The use of dual therapy also showed nonsignificantly higher composite of death and ischemic events but no difference in mortality.

Complex Re-Entrant Arrhythmias Involving the His-Purkinje System: A Structured Approach to Diagnosis and Management.

OBJECTIVES: This study sought to characterize the presentations, electrophysiological features and diagnostic maneuvers for a series of unique arrhythmias involving the HPS. BACKGROUND: By virtue of its unique anatomy and ion channel composition, the His-Purkinje system (HPS) is prone to a variety of arrhythmic perturbations. METHODS: The authors present a collaborative multicenter case series of 6 patients with HPS-related arrhythmias. All patients underwent electrophysiological studies using standard multipolar catheters. RESULTS: In 3 patients, both typical and reverse bundle branch re-entry were seen, with 1 patient demonstrating "figure of 8" re-entry likely involving the septal fascicle. One patient presented with systolic dysfunction associated with a high premature ventricular complex burden, with the mechanism being bundle-to-bundle re-entrant beats masquerading as dual response to a single sinus impulse. Two patients were diagnosed with interfascicular re-entry. Diagnosis was aided by careful assessment of HV interval in sinus rhythm and ventricular tachycardia, multipolar catheters to assess the activation sequence of the His-right bundle branch, and fascicles and entrainment of different components of the HPS. Cure of the arrhythmia was achieved by ablation of the right bundle branch block in 3 patients, the left septal fascicle in 2 patients, and the left posterior fascicle in 1 patient. CONCLUSIONS: Proper diagnosis of re-entrant arrhythmias involving the HPS may prove challenging. We emphasize a structured approach for diagnosis and effective therapy.

Natural History and Risk Stratification in Andersen-Tawil Syndrome Type 1.

BACKGROUND: Andersen-Tawil Syndrome type 1 (ATS1) is a rare arrhythmogenic disorder, caused by loss-of-function mutations in the KCNJ2 gene. We present here the largest cohort of patients with ATS1 with outcome data reported. OBJECTIVES: This study sought to define the risk of life-threatening arrhythmic events (LAE), identify predictors of such events, and define the efficacy of antiarrhythmic therapy in patients with ATS1. METHODS: Clinical and genetic data from consecutive patients with ATS1 from 23 centers were entered in a database implemented at ICS Maugeri in Pavia, Italy, and pooled for analysis. RESULTS: We enrolled 118 patients with ATS1 from 57 families (age 23 ± 17 years at enrollment). Over a median follow-up of 6.2 years (interquartile range: 2.7 to 16.5 years), 17 patients experienced a first LAE, with a cumulative probability of 7.9% at 5 years. An increased risk of LAE was associated with a history of syncope (hazard ratio [HR]: 4.54; p = 0.02), with the documentation of sustained ventricular tachycardia (HR 9.34; p = 0.001) and with the administration of amiodarone (HR: 268; p < 0.001). The rate of LAE without therapy (1.24 per 100 person-years [py]) was not reduced by beta-blockers alone (1.37 per 100 py; p = 1.00), or in combination with Class Ic antiarrhythmic drugs (1.46 per 100 py, p = 1.00). CONCLUSIONS: Our data demonstrate that the clinical course of patients with ATS1 is characterized by a high rate of LAE. A history of unexplained syncope or of documented sustained ventricular tachycardia is associated with a higher risk of LAE. Amiodarone is proarrhythmic and should be avoided in patients with ATS1.

Identifying Factors That Predict the Prescription of Non-vitamin K Antagonist Oral Anticoagulants in Older Individuals With Atrial Fibrillation.

OBJECTIVES: Factors that influence decision of non-vitamin K antagonist oral anticoagulants (NOACs) use among older atrial fibrillation (AF) patients in long-term care (LTC) facilities have not been well studied. The aim of this study was to assess whether increased frailty influenced physicians to prescribe NOACs over warfarin. DESIGN: We retrospectively reviewed the electronic medical record (EMR) and pharmacy data of 25 LTC facilities in Ontario, Canada, in May 2015. The diagnosis of AF was ascertained from EMR and confirmed by complete chart review of a random sample of the cohort. A score of ≥2 on the Changes in Health, End-stage disease, Signs, and Symptoms (CHESS) scale was used as a surrogate marker of frailty. MEASURES: Multivariable logistic regression model was used to assess whether a higher frailty score is associated with the use of NOACs in comparison to warfarin, independent of potential patient-level confounders. SETTING AND PARTICIPANTS: In total, 3378 active residents were assessed in 25 LTC facilities. All the residents were ≥65 years old. We identified 433 residents with AF; 273 (63%) AF residents were on anticoagulation therapy and included in the analysis. RESULTS: Residents were more often treated with NOACs (n = 159; 58%) in comparison to warfarin (n = 114; 42%). A CHESS score of ≥2 increased the odds of prescribing NOACs by 2.46 times [95% confidence interval (CI) 1.11, 5.49; P = .03] when adjusted for important patient-level factors. Patients with hypertension had a trend of increased NOAC prescriptions but did not reach statistical significance [odds ratio 2.1 (95% CI 0.91, 4.81), P = .08]. None of the patient-level factors were associated with NOAC prescriptions. CONCLUSIONS AND IMPLICATIONS: In this real world cohort of AF patients in LTC who are prescribed an oral anticoagulation therapy, a higher CHESS score (≥2) is associated with increased use of NOACs in comparison to warfarin.

Optimal Timing for Coronary Intervention in Patients With Transient ST-Elevation Myocardial Infarction.

STEMI patients admitted urgently to the hospital but experience early complete resolution of both ischemic symptoms and ST-elevations on the electrocardiogram are diagnosed as transient STEMI (TSTEMI). Current evidence indicates that primary intervention is plausible but in certain circumstances intervention can be delayed. We sought to examine whether there is a time limit to such a delay that may affect long-term outcome. Study population included prospectively admitted TSTEMI patients whose demographics, pertinent medical history, and clinical and angiographic features were recorded. Study patients were divided by the median time interval from admission to intervention and their characteristics and long-term survival were compared. Study population comprised 260 consecutive patients (age: 57±10 years, men: 84%) diagnosed as TSTEMI who were included from January 2000 to June 2019, which represent 6% of all STEMI patients. Coronary angiography was performed in 254 patients. The median time interval from admission to angiography was 17 hours (IQR: 7.2 to 38.7 hours). Early (<17 hours from admission) and late (>17 hours from admission) study groups were comparable. One patient died during admission and 41 throughout the long follow-up period of 8.5 ± 5.2 years (median: 8.2 years, IQR: 3.4 to 13.1). Mortality of early-treated TSTEMI patients (11.2%) was significantly lower than of the late-treated patients (21.6%, p <0.04). The Kaplan-Meier curve demonstrated a clear tendency toward improved survival in early-treated TSTEMI patients (p <0.09). In conclusion, the present data suggest that TSTEMI patients should be treated, if not by primary coronary intervention, then at least within 17 hours from admission to achieve better long-term outcome.

On the diagnosis of wide QRS tachycardia.

Class IC antiarrhythmic drugs may be pro-arrhythmic. The diagnosis of the exact nature of the arrhythmia may be challenging. In most case, these drugs should be stopped regardless of the type of the arrhythmia.