Intramural needle ablation or repeated standard ablation in patients referred for repeat ablation of scar-related ventricular tachycardia.

INTRODUCTION: When ventricular tachycardia (VT) recurs after standard RF ablation (sRFA) some patients benefit from repeat sRFA, whereas others warrant advanced methods such as intramural needle ablation (INA). Our objectives are to assess the utility of repeat sRFA and to clarify the benefit of INA when repeat sRFA fails in patients with VT due to structural heart disease. METHODS: In consecutive patients who were prospectively enrolled in a study for INA for recurrent sustained monomorphic VT despite sRFA, repeat sRFA was considered first. INA was performed during the same procedure if repeat sRFA failed or no targets for sRFA were identified. RESULTS: Of 85 patients enrolled, acute success with repeat sRFA was achieved in 30 patients (35%), and during the 6-month follow-up, 87% (20/23) were free of VT hospitalization, 78% were free of any VT, and 7 were lost to follow-up. INA was performed in 55 patients (65%) after sRFA failed, or no endocardial targets were found abolished or modified inducible VT in 35/55 patients (64%). During follow-up, 72% (39/54) were free of VT hospitalization, 41% were free of any VT, and 1 was lost to follow-up. Overall, 59 out of 77 (77%) patients were free of hospitalization and 52% were free of any VT. Septal-origin VTs were more likely to need INA, whereas RV and papillary muscle VTs were less likely to require INA. CONCLUSIONS: Repeat sRFA was beneficial in 23% (18/77) of patients with recurrent sustained VT who were referred for INA. The availability of INA increased favorable outcomes to 52%.

Safety and Efficacy of Ultrasound-Guided Sympathetic Blockade by Proximal Intercostal Block in Electrical Storm Patients.

BACKGROUND: Electrical storm (ES) patients who fail standard therapies have a high mortality rate. Previous studies report effective management of ES with bedside, ultrasound-guided percutaneous stellate ganglion block (SGB). We report our experience with sympathetic blockade administered via a novel alternative approach: proximal intercostal block (PICB). Compared with SGB, this technique targets an area typically free of other catheters and support devices, and may pose less strict requirements for anticoagulation interruption, along with lower risk of focal neurological side effects. OBJECTIVES: The authors sought to describe the safety and efficacy of PICB in patients with refractory ES. METHODS: We reviewed our institutional data on ES patients who underwent PICB between January 2018 and February 2023 to analyze procedural safety and short- and long-term outcomes. RESULTS: A total of 15 consecutive patients with ES underwent PICB during this period. Of those, 11 patients (73.3%) were maintained on PICB alone, and 4 patients (26.6%) were maintained on combined block with SGB and PICB. Overall, 72.7% patients who were maintained on PICB alone and 77.8% patients who were maintained on bilateral PICB had excellent arrhythmia suppression. After PICB, implantable cardioverter-defibrillator therapies were significantly reduced (P < 0.05), with 93.3% of patients receiving PICB having no implantable cardioverter-defibrillator shock until discharge or heart transplant. Anticoagulation was continued in all patients and there were no procedure-related complications. Apart from mild transient neurological symptoms seen in 3 patients, no significant neurological or hemodynamic sequelae were observed. CONCLUSIONS: In patients with refractory ES, continuous PICB provided safe and effective sympathetic block (77.8% ventricular arrhythmia suppression), achievable without interruption of anticoagulation, and without significant side effects.

Evaluation of organized atrial arrhythmias after cryptogenic stroke.

Background: Long-term rhythm monitoring to detect atrial fibrillation (AF) following a cryptogenic stroke (CS) is well established. However, the burden of organized atrial arrhythmias in this population is not well defined. Objective: The purpose of this study was to assess the incidence and risk factors for organized atrial arrhythmias in patients with CS. Methods: We evaluated all patients with CS who received an insertable cardiac monitor (ICM) between October 2014 and April 2020. All ICM transmissions categorized as AF, tachycardia, or bradycardia were reviewed. We evaluated the time to detection of organized AF and the combination of either organized atrial arrhythmia or AF. Results: A total of 195 CS patients with ICMs were included (51% men; mean age 66 ± 12 years; mean CHA2DS2-VASC score 4.6). Over mean follow-up of 18.9 ± 11.2 months, organized atrial arrhythmias lasting ≥30 seconds were detected in 45 patients (23%), of whom 62% did not have AF. Seventeen patients had both organized atrial arrhythmia and AF, and another 21 patients had AF only. Compared to those with normal left atrial size, patients with left atrial enlargement had a higher adjusted risk for development of atrial arrhythmias (mild left atrial enlargement: hazard ratio 1.99; 95% confidence interval 1.06-3.75; moderate/severe left atrial enlargement: hazard ratio 3.06; 95% confidence interval 1.58-5.92). Conclusion: Organized atrial arrhythmias lasting ≥30 seconds are detected in nearly one-fourth of CS patients. Two-thirds of these patients did not have AF. Further studies are required to evaluate the impact of organized atrial arrhythmias on recurrent stroke risk.

Worldwide Experience With an Irrigated Needle Catheter for Ablation of Refractory Ventricular Arrhythmias: Final Report.

BACKGROUND: We previously reported feasibility of irrigated needle ablation (INA) with a retractable 27-G end-hole needle catheter to treat nonendocardial ventricular arrhythmia substrate, an important cause of ablation failure. OBJECTIVES: The purpose of this study was to report outcomes and complications in our entire INA-treated population. METHODS: Patients with recurrent sustained monomorphic ventricular tachycardia (VT) or high-density premature ventricular contractions (PVCs) despite radiofrequency ablation were prospectively enrolled at 4 centers. Endpoints included a 70% decrease in VT frequency or PVC burden decrease to <5,000/24 h at 6 months. RESULTS: INA was performed in 111 patients (median: 2 failed prior ablations, 71% nonischemic heart disease, and left ventricular ejection fraction 36% ± 14%). INA acutely abolished targeted PVCs in 33 of 37 patients (89%), and PVCs were reduced to <5,000/day in 29 patients (78%). During 6-month follow-up, freedom from hospitalization was observed in 50 of 72 patients with VT (69%), and improvement or abolition of VT occurred in 47%. All patients received multiple INA applications, with more in the VT group than in the PVC group (median: 12 [IQR: 7-19] vs 7 [5-15]; P < 0.01). After INA, additional endocardial standard radiofrequency ablation was required in 23% of patients. Adverse events included 4 pericardial effusions (3.5%), 3 cases of (anticipated) atrioventricular block (2.6%), and 3 heart failure exacerbations (2.6%). During 6-month follow-up, 5 deaths occurred; none were procedure-related. CONCLUSIONS: INA achieves improved arrhythmia control in 78% of patients with PVCs and avoids hospitalization in 69% of patients with VT refractory to standard ablation at 6-month follow-up. Procedural risks are acceptable. (Intramural Needle Ablation for Ablation of Recurrent Ventricular Tachycardia, NCT01791543; Intramural Needle Ablation for the Treatment of Refractory Ventricular Arrhythmias, NCT03204981).

Safety and Efficacy of Cryoablation for Right Ventricular Moderator Band-Papillary Muscle Complex Ventricular Arrhythmias.

BACKGROUND: The right ventricular moderator band and papillary muscle (RV MB-PM) complex is an uncommon source of ventricular arrhythmias (VAs). Success rates following the ablation of intracavity structures are lower than for other sites of origin of VAs because of challenging catheter stability and a tendency for hemodynamically unstable automaticity when radiofrequency (RF) is delivered. OBJECTIVES: This study sought to describe the institutional experience of RV MB-PM VAs across a 2-year period and compare the outcomes from ablations performed using RF ablation and cryoablation. METHODS: Electronic health records of patients who underwent catheter ablation of RV MB-PM arrhythmias between January 2018 and November 2021 were reviewed, including imaging, intraprocedural data, and follow-up. RESULTS: Eleven patients underwent ablation of RV MB-PM arrhythmias throughout the duration of the study. Five patients underwent catheter ablation with RF, and 6 patients underwent cryoablation. Three patients in the cryoablation group had previous attempted ablation with RF. Four patients in the RF group and 4 patients in the cryoablation group had structurally abnormal hearts. Acute VA suppression was achieved in 4 of 5 patients with RF and 6 of 6 patients with cryoablation. During follow-up, the rate of arrhythmia recurrence was lower in the cryoablation group (HR: 0.12; 95% CI: 0.016-0.90; P = 0.0396). CONCLUSIONS: Compared to RF, cryoablation offers improved catheter stability and reduced propensity for automaticity during ablation. The use of cryoablation as a first-line strategy is reasonable when RV MB-PM origin of premature ventricular contractions is suspected.

Failure of Complete Endothelialization of a Watchman Device 3 Years Post-Implantation.

We report an unusual case of incomplete endothelialization of the Watchman device >3 years after its implantation. Animal data suggest that device endothelialization occurs ∼45 days post-implantation; however, data on humans are lacking. Guidelines on anticoagulation are based on expectation from animal studies. (Level of Difficulty: Advanced.).

Atrioventricular and Sinus Node Dysfunction in Stable COVID-19 Patients.

There are now well-documented cardiac complications of COVID-19 infection which include myocarditis, heart failure, and acute coronary syndrome resulting from coronary artery thrombosis or SARS-CoV-2-related plaque ruptures. There is growing evidence showing that arrhythmias are also one of the major complications. We report two patients with no known history of cardiac conduction disease who presented with COVID-19 symptoms, positive SARS-CoV-2 infection, and developed cardiac conduction abnormalities. Cardiac conduction system disease involving the sino-atrial (SA) node and atrioventricular (AV) node could be a manifestation of SARS-CoV-2 infection.

Hypoglycemia-associated In-stent Thrombosis: Are We Doing Too Much?

Diabetes mellitus is one of the most common modifiable risk factors for coronary artery disease, and its prevalence is rising globally. Persistent hyperglycemia has a well-established cardiovascular risk, and its treatment plays an important role in the prevention of future cardiovascular events. While we improved microvascular complications such as retinopathy, nephropathy, and neuropathy by stringent blood glucose control, the cardiovascular morbidity and mortality in diabetics remain high. Hypoglycemia, on the other hand, is an important side effect of pharmaceutical blood glucose control, especially those who are treated with insulin. Here, we report the case of a 38-year-old man with type 1 diabetes presenting twice with acute ST-elevation myocardial infarction, both in the setting of documented hypoglycemia. There are reported cases of acute cardiovascular events or silent myocardial ischemia associated with hypoglycemia, and we wish to raise awareness for clinicians who treat this special population of patients.