Mechanisms of persistent atrial fibrillation and recurrences within 12 months post-ablation: Non-invasive mapping with electrocardiographic imaging

INTRODUCTION: Catheter ablation of persistent AF has not been consistently successful in terminating AF or preventing arrhythmia recurrences. Non-invasive Electrocardiographic Imaging (ECGI) can help to understand recurrences by mapping the mechanisms of pre-ablation AF and comparing them with the patterns of recurrent arrhythmias in the same patient. METHODS: Seventeen persistent AF patients underwent ECGI before their first catheter ablation. Time-domain activation maps and phase progression maps were obtained on the bi-atrial epicardium. Location of arrhythmogenic drivers were annotated on the bi-atrial anatomy. Activation and phase movies were examined to understand the wavefront dynamics during AF. Eight patients recurred within 12 months of ablation and underwent a follow-up ECGI. Driver locations and movies were compared for pre- and post-ablation AF. RESULTS: A total of 243 focal drivers were mapped during pre-ablation AF. 62% of the drivers were mapped in the left atrium (LA). The pulmonary vein region harbored most of the drivers (43%). 35% of the drivers were mapped in the right atrium (RA). 59% (10/17) and 53% (9/17) of patients had repetitive sources in the left pulmonary veins (LPV) and left atrial appendage (LAA), and the lower half of RA, respectively. All patients had focal drivers. 29% (5/17) of patients had macro-reentry waves. 24% (4/17) of patients had rotors. Activation patterns during persistent AF varied from single macro-reentry to complex activity with multiple simultaneous wavefronts in both atria, resulting in frequent wave collisions. A total of 76 focal driver activities were mapped in 7/8 patients during recurrence. 59% of the post-ablation AF drivers were mapped in the LA. The pulmonary vein region harbored 50% of total drivers. 39% of sources were mapped in the RA. AF complexity remained similar post-ablation. 58% (44/76) of pre-ablation sources persisted during recurrence. 38% (3/8) of patients had macro-reentry and one patient had rotors. CONCLUSION: ECGI provides patient-specific information on mechanisms of persistent AF and recurrent arrhythmia. More than half pre-ablation sources repeated during post-ablation recurrence. This study provides direct evidence for drivers that persist days and months after the ablation procedure. Patient-tailored bi-atrial ablation is needed to successfully target persistent AF and prevent recurrence. ECGI can potentially predict recurrence and assist in choice of therapy

Implementation of a screening program for patients at risk for posttraumatic stress disorder

Introduction Implantable cardioverter defibrillator (ICD) recipients who suffer from posttraumatic stress disorder (PTSD) are known to be associated with significant cardiac-specific mortality. Clinical observations suggest that PTSD is frequently undetected in ICD recipients followed up at electrophysiology (EP) outpatient clinics. Early recognition of PTSD is important to reduce the risk of serious manifestations on patient outcomes. Methods All ICD recipients aged 19 years or older at the Washington University School of Medicine (WASHU) EP clinic, a large urban EP clinic, were invited to participate in the project. An informed consent letter with an attached primary care: posttraumatic stress disorder (PC: PTSD) survey was offered to the participants who met the inclusion criteria. Those who completed the survey were included in the project. Individuals with positive survey result were offered a referral to mental health services. Comparisons between PTSD and non-PTSD patients were done using a two-sample t -test for continuous variables. Using Fisher's exact test, PTSD prevalence was compared to the study by Ladwig et al in which prevalence was determined as the proportion of patients with positive findings of PTSD ( n = 38/147). All analyses were conducted using SAS v9.4. The proportion of patients having PTSD was determined and an exact 95% confidence interval was evaluated based on the binomial distribution. Results Using a convenience sample, 50 ICD recipients (33 males and 17 females) were enrolled. The project had a 30-day outcome period. Nine (18%) of the 50 participants had positive PC: PTSD findings and all these nine participants were referred to a mental health specialist. The current project demonstrated an 18% (9/50) PTSD prevalence rate when compared to a 26% (38/147) prevalence rate in the study by Ladwig et al ( P = 0.34). Although this project did not demonstrate 20% PTSD prevalence rate, as hypothesized, the 18% PTSD prevalence rate is consistent with previous research. Conclusion The prevalence of PTSD noted in the current project is consistent with previous research and validates underrecognition of PTSD in ICD patients. Offering a referral to all ICD recipients at EP clinic visits with a positive PC: PTSD screening to a mental health specialist is an important step in reducing the risk of serious manifestations on patient outcomes