Wide Antral Circumferential Re-Ablation for Recurrent Atrial Fibrillation after Prior Pulmonary Vein Isolation Guided by High-Density Mapping Increases Freedom from Atrial Arrhythmias.

Performing repeated pulmonary vein isolation (re-PVI) after recurrent atrial fibrillation (AF) following prior PVI is a standard procedure. However, no consensus exists regarding the most effective approach in redo procedures. We assessed the efficacy of re-PVI using wide antral circumferential re-ablation (WACA) supported by high-density electroanatomical mapping (HDM) as compared to conventional re-PVI. Consecutive patients with AF recurrences showing true PV reconnection (residual intra-PV and PV antral electrical potentials within the initial ablation line) or exclusive PV antral potentials (without intra-PV potentials) in the redo procedure were prospectively enrolled and received HDM-guided WACA (Re-WACA group). Conventional re-PVI patients treated using pure ostial gap ablation guided by a circular mapping catheter served as a historical control (Re-PVI group). Patients with durable PVI and no antral PV potentials were excluded. Arrhythmia recurrences ≥30 s were calculated as recurrences. In total, 114 patients were investigated (Re-WACA: n = 56, 68 ± 10 years, Re-PVI: n = 58, 65 ± 10 years). There were no significant differences in clinical characteristics including the AF type or the number of previous PVIs. In the Re-WACA group, 11% of patients showed electrical potentials only in the antrum but not inside any PV. At 402 ± 71 days of follow-up, the estimated freedom from arrhythmia was 89% in the Re-WACA group and 69% in the Re-PVI group (p = 0.01). Re-WACA independently predicted arrhythmia-free survival (HR = 0.39, 95% CI 0.16-0.93, p = 0.03), whereas two previous PVI procedures predicted recurrences (HR = 2.35, 95% CI 1.20-4.46, p = 0.01). The Re-WACA strategy guided by HDM significantly improved arrhythmia-free survival as compared to conventional ostial re-PVI. Residual PV antral potentials after prior PVI are frequent and can be easily visualized by HDM.

Clinical Impact of Circulating Galectin-3 on Ventricular Arrhythmias and Heart Failure Hospitalization Independent of Prior Ventricular Arrhythmic Events in Patients with Implantable Cardioverter-defibrillators.

Objective For risk stratification of sudden cardiac death in patients with structural heart disease, more precise predictors in addition to left ventricular ejection fraction (LVEF) are clinically needed. The present study assessed the utility of galectin-3 as an independent indicator for the prognosis of heart failure patients with implantable cardioverter-defibrillators (ICD). Methods The study population consisted of 91 consecutive patients who underwent a routine ICD checkup in our ICD outpatient clinic. Circulating galectin-3 was assessed using a commercially available enzyme-linked immunosorbent assay kit. The enrolled patients were prospectively followed. The primary endpoint was defined as the occurrence of appropriate ICD therapy (AIT), and the secondary endpoint was defined as the occurrence of unplanned overnight hospitalization due to decompensated heart failure (dHF). Results During a mean follow-up of 472±107 days, AIT occurred in 18 patients (20%). Unplanned hospitalizations due to dHF were noted in 12 patients (13%). A receiver-operative characteristics analysis demonstrated a sensitivity of 83% and specificity of 68% for AIT occurrences with a galectin-3 cut-off value of 13.1 ng/mL (area under the curve =0.82). A Kaplan-Meier analysis demonstrated that patients with galectin-3 >13.1 ng/mL had significantly higher incidences of AIT as compared to those with lower galectin-3 (log-rank, p<0.001). This significance was also observed in both subgroup analyses with ischemic and non-ischemic etiology. Cox regression demonstrated that higher galectin-3 was an independent predictor of AIT and dHF, even after adjusting for previous arrhythmic events. Conclusion The circulating galectin-3 level can be used as a clinical indicator of subsequent occurrence of ventricular arrhythmic events and decompensated heart failure, regardless of a history of ventricular arrhythmias.

Performance of a convolutional neural network derived from an ECG database in recognizing myocardial infarction.

Artificial intelligence (AI) is developing rapidly in the medical technology field, particularly in image analysis. ECG-diagnosis is an image analysis in the sense that cardiologists assess the waveforms presented in a 2-dimensional image. We hypothesized that an AI using a convolutional neural network (CNN) may also recognize ECG images and patterns accurately. We used the PTB ECG database consisting of 289 ECGs including 148 myocardial infarction (MI) cases to develop a CNN to recognize MI in ECG. Our CNN model, equipped with 6-layer architecture, was trained with training-set ECGs. After that, our CNN and 10 physicians are tested with test-set ECGs and compared their MI recognition capability in metrics F1 (harmonic mean of precision and recall) and accuracy. The F1 and accuracy by our CNN were significantly higher (83 ± 4%, 81 ± 4%) as compared to physicians (70 ± 7%, 67 ± 7%, P < 0.0001, respectively). Furthermore, elimination of Goldberger-leads or ECG image compression up to quarter resolution did not significantly decrease the recognition capability. Deep learning with a simple CNN for image analysis may achieve a comparable capability to physicians in recognizing MI on ECG. Further investigation is warranted for the use of AI in ECG image assessment.

Clinical significance of precedent asymptomatic non-sustained ventricular tachycardias on subsequent ICD interventions and heart failure hospitalization in primary prevention ICD patients.

BACKGROUND: The prognostic implications of non-sustained ventricular tachycardia (NSVT) and their significance as therapeutic targets in patients without prior sustained ventricular arrhythmias remain undetermined. The aim of this study was to investigate the prognostic significance of asymptomatic NSVT in patients who had primary prevention implantable cardioverter-defibrillator (ICD) implantation due to ischemic or non-ischemic cardiomyopathy (ICM, NICM). METHODS: We enrolled 157 consecutive primary prevention ICD patients without previous appropriate ICD therapy (AIT). Patients were allocated to two groups depending on the presence or absence of NSVT in a 6-month period prior to enrollment. The incidence of AIT and unplanned hospitalization due to decompensated heart failure (HF) were assessed during follow-up. RESULTS: In 51 patients (32%), precedent NSVT was documented. During a median follow-up of 1011 days, AIT occurred in 36 patients (23%) and unplanned HF hospitalization was observed in 32 patients (20%). In precedent NSVT patients, the incidence of AIT and unplanned HF hospitalization was significantly higher as compared to patients without precedent NSVT (AIT: 29/51 [57%] vs. 7/106 [7%], P < 0.001, log-rank; HF hospitalization: 16/51 [31%] vs. 16/106 [15%], P = 0.043, log-rank). Cox-regression demonstrated that precedent NSVT independently predicted AIT (P < 0.0001). In subgroup analyses, precedent NSVT predicted AIT in both ICM and NICM (P < 0.0001, P = 0.020), but predicted HF hospitalization only in patients with ICM (P = 0.0030). CONCLUSIONS: Precedent non-sustained VT in patients with primary prevention ICDs is associated with subsequent appropriate ICD therapies, and is an independent predictor of unplanned heart failure hospitalizations in patients with ischemic cardiomyopathy.

Fluoroscopy integrating technology in a 3D mapping system during ablation of atrial arrhythmias: first experiences.

INTRODUCTION: Ablation of the cavotricuspid isthmus (CTI) in patients with atrial flutter (AFL) and pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF) are both common therapies. As the demand for ablative treatments rises, total radiation exposure times of staff increase concomitantly. Here, we report on our first experiences with a new fluoroscopy integrating system (FIS) integrated into a current 3D mapping system (3DMS). MATERIAL AND METHODS: The study population consisted of 59 consecutive patients who underwent PVI or CTI ablation (26 and 33 patients with and without FIS respectively). Total procedure time (PT), fluoroscopy exposure time (FT) and dose-area product (DAP) were monitored. RESULTS: All procedures were successfully completed without major complications. Employing FIS in the PVI group, FT and DAP were both significantly reduced after completing a short learning curve of 6 cases (respectively 361.6 ±181 s vs. 530.3 ±156.7 s, p = 0.039; 801.9 ±439.15 cGycm² vs. 1495 ±435.2 cGycm², p = 0.002). Mean PT was not significantly affected (121 ±26.7 min vs. 135.6 ±23.2 min, p = 0.21). The same holds true for CTI ablation: FT (99.29 ±51.4 s vs. 153.9 ±76.6 s, p = 0.022) and DAP (269 ±128.7 cGycm² vs. 524.3 ±288.4 cGycm², p = 0.002) were significantly reduced, leaving PT not significantly affected (29.5 ±10 min vs. 35.2 ±16.3 min, p = 0.23). CONCLUSIONS: The introduction of the new FIS with a current 3DMS results in a significant reduction of both the total FT and DAP without affecting PT. The initial learning curve for adopting this method is considerably short.

High Incidence of Atrial Fibrillation After Embolic Stroke of Undetermined Source in Posterior Cerebral Artery Territory.

BACKGROUND: Subclinical atrial fibrillation is one possible cause of embolic stroke of undetermined source (ESUS). It remains to be elucidated if a specific infarction site has a predictive value for detecting subclinical atrial fibrillation. We aimed to investigate the predictive value of infarction site in patients with ESUS for the detection of atrial tachyarrhythmia (AT) using an insertable cardiac monitor. METHODS AND RESULTS: Consecutive 146 patients (84 men; aged 62±12 years) underwent insertable cardiac monitor implantation after diagnosis of ESUS. The detection of AT >30 seconds was evaluated. The ESUS infarction sites were categorized into internal carotid artery and vertebral artery (VA) territories, with ophthalmic artery, anterior cerebral artery, and middle cerebral artery as internal carotid artery subterritories, and posterior cerebral artery and other vertebrobasilar arteries as VA subterritories. During a median follow-up of 387 days, AT was detected in 33 patients (23%). Subclinical AT detection was significantly more frequent after VA territorial infarction opposed to internal carotid artery infarction (20/57 [35%] versus 13/89 [15%]; P=0.0039). Kaplan-Meier analysis demonstrated a significantly higher AT detection rate after VA infarction (log-rank, P=0.0076). Regression analysis revealed that VA territorial infarction, and particularly posterior cerebral artery area infarction, was an independent predictor of AT detection. CONCLUSIONS: Patients with ESUS in the posterior cerebral artery territory had a higher rate of subclinical AT detection than those with other infarct localizations. Our data suggest that the possible usefulness of ESUS site to identify candidates for direct oral anticoagulation should be confirmed in future research.

Low Incidence of Esophageal Lesions After Pulmonary Vein Isolation Using Contact-Force Sensing Catheter Without Esophageal Temperature Probe.

Pulmonary vein isolation (PVI) is a cornerstone therapy for atrial fibrillation (AF). Although severe complications are rather rare, the development of an atrio-esophageal fistula (AEF) is a fatal complication with a very high mortality even after surgical treatment. The use of esophageal temperature probes (ETP) during PVI may protect the esophagus but it is still under debate since the ETP may also lead to esophageal lesions. The aim of this study was to evaluate the clinical safety of PVI using contact-force (CF) sensing catheter without esophageal temperature monitoring.We investigated 70 consecutive patients who underwent point-by-point PVI without usage of ETP and who underwent esophago-gastro-duodenoscopy (EGD) with detailed evaluation of the esophagus after the index PVI procedure. The operator attempted to keep CF within the 10-40 g range. The incidences of esophageal lesions (EDEL) detected by endoscopy were then analyzed.Two of 70 patients (2.9%) showed EDEL consisting of one longitudinal ulcer-like erythematous lesion with fibrin and a different one consisting of a round-shaped lesion surrounded by erythema and petechial hemorrhage. All EDEL healed within two weeks under high proton-pump inhibitor therapy without developing AEF as proven by a second EGD of the esophagus.Point-by-point PVI without usage of ETP showed a low incidence of EDEL (2.9%); atrio-esophageal fistula was absent. Further studies on the necessity of ETP under CF control are necessary.

One-Year Success Rate of Pulmonary Vein Isolation Using a Novel Irrigated Multipolar Mapping and Ablation Catheter With Reduced Power Settings.

The use of a novel irrigated multipolar ablation and mapping catheter for pulmonary vein isolation in patients with atrial fibrillation (AF) has demonstrated reasonable acute success rates and short procedure times, however, long-term outcome data are limited. The aim of this study was to analyze the long-term efficacy of this novel ablation system utilizing a reduced power setting for safety purposes.A total of 89 patients with paroxysmal (63 of 89 patients; 71%) or persistent AF underwent PVI with a reduced power setting of maximum 20 Watts (W) unipolar radiofrequency energy and 30 seconds in duration. In cases of persistent AF, atrial substrate ablation was performed additionally. Follow-up was based on outpatient clinic visits at 3, 6, and 12 months and included 5-day Holter ECGs. All of the 347 identified pulmonary veins were successfully isolated. Mean procedure times in PVI and PVI plus substrate ablation were 102 ± 25 minutes and 126 ± 32 minutes, respectively, applying a mean total radiofrequency time of 14 ± 6 minutes and 19 ± 9 minutes. Mean fluoroscopy time was 17 ± 8 minutes and 18 ± 6 minutes, respectively. Follow-up was available for all 89 patients. At one-year follow-up, 44 (70%) patients with paroxysmal AF and 11 (42%) patients with persistent AF remained in stable sinus rhythm after a singleprocedure and off antiarrhythmic drugs.The use of a novel irrigated multipolar ablation catheter with a reduced power setting is safe and feasible, and demonstrates a one-year success rate of 70% in paroxysmal AF and 42% in persistent AF.

Reduction of Fluoroscopic Exposure Using a New Fluoroscopy Integrating Technology in a 3D-Mapping System During Pulmonary Vein Isolation With a Circular Multipolar Irrigated Catheter.

Pulmonary vein isolation (PVI) is a cornerstone therapy in patients with atrial fibrillation (AF). With increasing numbers of PVI procedures, demand arises to reduce the cumulative fluoroscopic radiation exposure for both the physician and the patient. New technologies are emerging to address this issue. Here, we report our first experiences with a new fluoroscopy integrating technology in addition to a current 3D-mapping system. The new fluoroscopy integrating system (FIS) with 3D-mapping was used prospectively in 15 patients with AF. Control PVI cases (n = 37) were collected retrospectively as a complete series. Total procedure time (skin to skin), fluoroscopic time, and dose-area-product (DAP) data were analyzed. All PVI procedures were performed by one experienced physician using a commercially available circular multipolar irrigated ablation catheter. All PVI procedures were successfully undertaken without major complications. Baseline characteristics of the two groups showed no significant differences. In the group using the FIS, the fluoroscopic time and DAP were significantly reduced from 571 ± 187 seconds versus 1011 ± 527 seconds (P = 0.0029) and 4342 ± 2073 cGycm(2) versus 6208 ± 3314 cGycm(2) (P = 0.049), respectively. Mean procedure time was not significantly affected and was 114 ± 31 minutes versus 104 ± 24 minutes (P = 0.23) by the FIS.The use of the new FIS with the current 3D-mapping system enables a significant reduction of the total fluoroscopy time and DAP compared to the previous combination of 3D-mapping system plus normal fluoroscopy during PVI utilizing a circular multipolar irrigated ablation catheter. However, the concomitant total procedure time is not affected. Thus, the new system reduces the radiation exposure for both the physicians and patients.

Wearable sensors in syncope management.

Syncope is a common disorder with a lifetime prevalence of about 40%. Implantable cardiac electronic devices, including implantable loop recorders (ILR) and implantable cardioverter-defibrillators (ICD), are well established in syncope management. However, despite the successful use of ILR and ICD, diagnosis and therapy still remain challenging in many patients due to the complex hemodynamic interplay of cardiac and vascular adaptations during impending syncopes. Wearable sensors might overcome some limitations, including misdiagnosis and inappropriate defibrillator shocks, because a variety of physiological measures can now be easily acquired by a single non-invasive device at high signal quality. In neurally-mediated syncope (NMS), which is the most common cause of syncope, advanced signal processing methodologies paved the way to develop devices for early syncope detection. In contrast to the relatively benign NMS, in arrhythmia-related syncopes immediate therapeutical intervention, predominantly by electrical defibrillation, is often mandatory. However, in patients with a transient risk of arrhythmia-related syncope, limitations of ICD therapy might outweigh their potential therapeutic benefits. In this context the wearable cardioverter-defibrillator offers alternative therapeutical options for some high-risk patients. Herein, we review recent evidence demonstrating that wearable sensors might be useful to overcome some limitations of implantable devices in syncope management.

Feasibility of pulse presence and pulse strength assessment during head-up tilt table testing using an accelerometer located at the carotid artery.

Neurally mediated syncope (NMS) is a disorder of the autonomic regulation of postural tone, which is characterized by hypotension and/or bradycardia, resulting in cerebral hypo-perfusion and finally in a sudden loss of consciousness. Prediction of an impending NMS requires detection of pulse presence to derive heart rate (HR) as well as to assess the pulse strength (PS) related to systolic blood pressure (SBP) preferably from a single body location only. This paper analyses the basic feasibility of using a single accelerometer positioned above the common carotid artery to assess pulse strength and pulse rate towards NMS prediction. A physical model has been investigated to gain insights into expected signal morphologies and potential feature candidates vs. hemodynamic parameters such as SBP, pulse pressure (PP) and PR relevant for NMS detection. Model results are compared with first measurements obtained in a head-up tilt table test (HUTT) from a patient during impending syncope. We show that an accelerometer positioned at the carotid artery is a potential approach offering a valuable tool in syncope management.

Genetic variants of the bile salt export pump: inducers and modifiers of liver diseases.

The bile salt export pump (BSEP, ABCB11) is the major transporter protein for the excretion of bile salts into bile. Here we describe a spectrum of BSEP-dependent effects on the course of liver diseases, and present two mutations that differentially affect total bile acid output and the biliary bile acid profile. According to the clinical course of affected children, low bile acid output but a normal profile was less harmful than higher output in combination with changes in the ratio of chenodeoxycholic acid to cholic acid. On the other hand, the common BSEP polymorphism V444A (c.1331T>C; allele frequency 65%) emerged as an independent predictor of the success rate in patients with chronic hepatitis C treated with pegylated interferon/ribavirin. This association between bile acid transport and hepatitis C may be due to interference of bile acids with viral replication, interferon signaling or antiviral proteins.