Davis, Nathaniel E

Abstract Aims Catheter ablation is commonly performed in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) for management of ventricular arrhythmias (VAs). The impact of catheter ablation on cardiac function is unknown. The aim is to assess the impact of catheter ablation for VAs on cardiac function in patients with ARVC. Methods and results This retrospective study included consecutive patients with ARVC who underwent catheter ablation for VAs. Cardiac and valvular functions were assessed on pre- and post-procedure cardiac imaging. The severities of tricuspid regurgitation, pulmonic regurgitation, right ventricular (RV) enlargement, and RV systolic dysfunction was graded as absent (=0), mild (=1), mild-moderate (=2), moderate (=3), moderate-severe (=4), or severe (=5). Thirty-four patients were included. Median age at the time of ablation was 49 [inter-quartile range (IQR), 23] years, and 10 (29%) patients were female. After a median follow-up of 1 (IQR, 0) day, 11 (34%) patients had worsening RV function, and 4 (12%) patients had worsening left ventricular ejection fraction (LVEF) >5%. Five (15%) patients required inotropic support. After a median follow-up of 6.5 (IQR, 6.4) months, 20 (59%) patients had repeat transthoracic echocardiograms. Among patients with worsening RV function post-ablation, one-sixth (17%) had improvement in the RV function at follow-up. In contrast, among patients who had an acute drop in LVEF post-ablation, two-thirds (67%) had improvement at follow-up. Conclusion Right ventricular dysfunction following catheter ablation in patients with ARVC is common, affecting one-third of patients. Patients undergoing catheter ablation of VAs should be counselled on the potential negative impact of ablation on cardiac function.

Atrial fibrillation (AF) and cancer are increasingly recognized as interrelated conditions, with cancer patients showing elevated incidences of AF, and there is evidence that AF may sometimes precede cancer diagnoses. This comprehensive review investigates the epidemiology, pathophysiology, and management challenges associated with AF in cancer patients. Epidemiologically, several cancers are more closely related to increased rates of AF, including lung, colorectal, gastrointestinal, and hematologic malignancies. Mechanistically, both AF and cancer share pathophysiological pathways centered on inflammation, oxidative stress, and common cardiovascular risk factors, such as hypertension, obesity, and diabetes. The inflammatory microenvironment in tumors, marked by increased cytokines and growth factors, promotes atrial remodeling and AF susceptibility. Elevated reactive oxygen species (ROS) levels, driven by the metabolic demands of cancer, further contribute to atrial fibrosis and structural changes. Moreover, many anticancer treatments exacerbate AF risk. Management of AF in cancer patients presents many unique challenges and requires a multidisciplinary approach. Rate and rhythm control strategies are complicated by potential drug–drug interactions and limited data surrounding early implementation of rhythm control strategies in cancer patients. Interventional approaches such as catheter ablation, though effective in maintaining sinus rhythm, carry significant perioperative risk in patients with malignancy. Stroke prevention with anticoagulants is essential but requires cautious administration to avoid heightened bleeding risks, particularly in patients undergoing chemotherapy. Further, the limited applicability of standard risk stratification tools like CHA2DS2-VASc in this population complicate decisions regarding anticoagulation. This review highlights the bidirectional relationship between AF and cancer, the difficulties in management, and the critical need for further research in this field.

Introduction: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic disorder characterized by fibrofatty replacement of myocardial tissue, creating areas of electrical heterogeneity and increasing the risk of ventricular arrhythmias (VAs) and sudden cardiac death (SCD). Catheter ablation is commonly performed in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) for management of ventricular arrhythmias (VAs). Whether catheter ablation affects cardiac function post-procedurally is uncertain. Research Question: Does catheter ablation for ARVC result in acute change in cardiac function? Goals/Aims: To assess the impact of catheter ablation for VAs on cardiac function in the acute post-procedure setting. Methods: This retrospective study included patients with ARVC who underwent catheter ablation for VAs at Mayo Clinic. Cardiac function was assessed on pre- and post-procedure transthoracic echocardiograms (TTEs). Post-procedure TTEs were obtained within 4 weeks after the ablation procedure. Right ventricular (RV) enlargement and systolic dysfunction were evaluated as continuous variables (0=none, 1=mild, 2=mild-moderate, 3=moderate, 4=moderate-severe, 5=severe). Results: The study included 32 patients who underwent a total of 44 ablations. Mean age at the time of ablation was 49±16 years, and 24 (75%) were male. After a mean follow-up duration of 2.6±5.5 days, there was a significant worsening in mean RV dysfunction (1.6±1.5 to 2.0±1.4, P = 0.001). There were no significant changes in mean left ventricular ejection fraction (LVEF), left ventricular (LV) dimensions, and RV size. 6 (14%) patients had a >5% decline in LVEF, and 14 (32%) patients had worsening RV function. Transient inotropic support was required in 4 (9%) patients. Conclusion(s): This study is the first to assess the acute impact of catheter ablation for VAs on cardiac function in ARVC patients. These results underscore the importance of careful post-procedure monitoring and planning of the ablation target in these patients to avoid excessive ablation and therefore impairment in cardiac function.

Description of Cases: Case 1: A 72 year old male with atrial fibrillation (AF) and tachy-brady syndrome underwent Micra implantation. On post-procedure day 2, pacing thresholds were unacceptably elevated. A new Micra device was deployed; subsequently, a microsnare was placed through the Micra delivery catheter and the docking button of the old Micra was successfully snared (Figure A). The old Micra was then captured over the delivery catheter and removed from the body. Case 2: A 76 year old male underwent Micra implantation and AV node ablation for AF with persistent tachycardia. One month later, he presented with heart failure and interval decrease in ejection fraction from 66% to 33%. After biventricular leads were implanted, an Agilis catheter was advanced towards the Micra. The docking button was successfully snared with a gooseneck snare (Figure B), and the Micra was extracted with gentle traction. Case 3: A 76 year old male with complete heart block and longstanding persistent AF received a Micra. Nine months later, he presented with heart failure and interval decrease in ejection fraction from 55% to 25%. A defibrillator lead was implanted but no suitable CS branch was identified. The Aveir retrieval catheter was advanced and the Micra docking button was captured with the triloop snare (Figure C). The protective sleeve was advanced over the Micra and it was successfully removed. Subsequently, a left bundle area lead was placed. Discussion: Although uncommon, extraction of the tined leadless pacemaker (Micra) may be indicated at times. As rates of implantation continue to increase, establishing uniform procedures for extraction becomes increasingly important. These three cases highlight unique options for Micra extraction, and the feasibility of each approach. However, a dedicated tool and protocol would be ideal for patient safety and consistency. No complications occurred with the above cases.