The PhysioVP-AF study, a randomized controlled trial to assess the clinical benefit of physiological ventricular pacing vs. managed ventricular pacing for persistent atrial fibrillation prevention in patients with prolonged atrioventricular conduction: design and rationale.

AIMS: In patients with prolonged atrioventricular (AV) conduction and pacemaker (PM) indication due to sinus node disease (SND) or intermittent AV-block who do not need continuous ventricular pacing (VP), it may be difficult to determine which strategy to adopt. Currently, the standard of care is to minimize unnecessary VP by specific VP avoidance (VPA) algorithms. The superiority of this strategy over standard DDD or DDD rate-responsive (DDD/DDDR) in improving clinical outcomes is controversial, probably owing to the prolongation of the atrialventricular conduction (PR interval) caused by the algorithms. Conduction system pacing (CSP) may offer the most physiological-VP approach, providing appropriate AV conduction and preventing pacing-induced dyssynchrony. METHODS AND RESULTS: PhysioVP-AF is a prospective, controlled, randomized, single-blind trial designed to determine whether atrial-synchronized conduction system pacing (DDD-CSP) is superior to standard DDD-VPA pacing in terms of 3-year reduction of persistent-AF occurrence. Cardiovascular hospitalization, quality-of-life, and safety will be evaluated. Patients with indication for permanent DDD pacing for SND or intermittent AV-block and prolonged AV conduction (PR interval > 180 ms) will be randomized (1:1 ratio) to DDD-VPA (VPA-algorithms ON, septal/apex position) or to DDD-CSP (His bundle or left bundle branch area pacing, AV-delay setting to control PR interval, VPA-algorithms OFF). Approximately 400 patients will be randomized in 24 months in 13 Italian centres. CONCLUSION: The PhysioVP-AF study will provide an essential contribution to patient management with prolonged AV conduction and PM indication for sinus nodal disease or paroxysmal 2nd-degree AV-block by determining whether CSP combined with a controlled PR interval is superior to standard management that minimizes unnecessary VP in terms of reducing clinical outcomes.

Electroanatomic voltage mapping for tissue characterization beyond arrhythmia definition: A systematic review.

Three-dimensional (3D) reconstruction by means of electroanatomic mapping (EAM) systems, allows for the understanding of the mechanism of focal or re-entrant arrhythmic circuits, which can be identified by means of dynamic (activation and propagation) and static (voltage) color-coded maps. However, besides this conventional use, EAM may offer helpful anatomical and functional information for tissue characterisation in several clinical settings. Today, data regarding electromechanical myocardial viability, scar detection in ischaemic and nonischaemic cardiomyopathy and arrhythmogenic right ventricle dysplasia (ARVC/D) definition are mostly consolidated, while emerging results are becoming available in contexts such as Brugada syndrome and cardiac resynchronisation therapy (CRT) implant procedures. As part of an invasive procedure, EAM has not yet been widely adopted as a stand-alone tool in the diagnostic path. We aim to review the data in the current literature regarding the use of 3D EAM systems beyond the definition of arrhythmia.

Left ventricle pacing challenges in cardiac resynchronization therapy systems.

Left ventricle (LV) pacing can be considered peculiar due to its different lead/tissue interface (epicardial pacing) and the small vein wedging lead locations with less reliable lead stability. The current technologies available for LV capture automatic confirmation adopt the evoked response (ER), as well as "LV pace to right ventricular (RV) sense" algorithms. The occurrence of anodal RV capture is today completely solved by the use of bipolar LV leads, while intriguing data are recently published regarding the unintentional LV anodal capture beside the cathodal one, which may enlarge the front wave of cardiac resynchronization therapy (CRT) delivery. The LV threshold behavior over time leading to ineffective CRT issues (subthreshold stimulation or concealed loss of capture), the extracardiac capture with phrenic nerve stimulation (PNS), the flexible electronic cathode reprogramming and the inadequate CRT delivery related to inadequate AV and VV pace timing (and its management by LV "dromotropic pace-conditioning") are discussed. Moreover, recently, His bundle pacing (HBP) and left bundle branch pacing (LBBP) have shown growing interest to prevent pacing-induced cardiomyopathy as well as for direct intentional CRT. The purpose of the present review is to explore these new challenges regarding LV pacing starting from old concepts.

Electroanatomic voltage mapping and characterisation imaging for "right ventricle arrhythmic syndromes" beyond the arrhythmia definition: a comprehensive review.

Three-dimensional (3D) reconstruction by means of electroanatomic mapping (EAM) systems, allows for the understanding of the mechanism of focal or re-entrant arrhythmic circuits along with pacing techniques. However, besides this conventional use, EAM may offer helpful anatomical and functional information. Data regarding electromechanical scar detection in ischaemic (and nonischaemic) cardiomyopathy are mostly consolidated, while emerging results are becoming available in contexts such as arrhythmogenic right ventricular dysplasia (ARVC/D) definition and Brugada syndrome. As part of an invasive procedure, EAM has not yet been widely adopted as a stand-alone tool in the diagnostic path. We aim to review the current literature regarding the use of 3D EAM systems for right ventricle (RV) functional characterisation beyond the definition of arrhythmia.

Transcatheter ablation of the atrioventricular junction in refractory atrial fibrillation: A clinicopathological study.

BACKGROUND: Catheter ablation of the specialized atrioventricular junction (AVJ) with a right-side approach is an effective therapy for refractory atrial fibrillation with fast ventricular rate. Our aim is to assess the efficacy of the procedure in a single center experience and investigate the histologic findings of AVJ after catheter ablation. METHODS: A) Analysis of AVJ ablation efficacy in a consecutive series of patients with refractory atrial fibrillation; B) Histopathologic study of the conduction system by serial section technique and clinical-electrophysiologic correlation in four patients who underwent AVJ ablation. RESULTS: A) Right-sided AVJ ablation was successful in all 87 consecutive patients (mean procedural time 19.2±17.9 min). Energy applications ranged from 1 to 27 (mean 5.8±5.1) with eight patients (9%) requiring > 15 applications. B) Fibrotic disruption of atrioventricular (AV) node and/or His bundle interruption was found in three cases with previous AVJ ablation. In the case requiring a left side approach, the compact AV node and common His bundle appeared undamaged whereas extensive fibrosis of the summit of the ventricular septum, branching His bundle and proximal bundle branches was found. Noteworthy, a continuity between the septal and anterior tricuspid valve leaflets was present. CONCLUSION: Our data confirm that the ideal site for ablation of the specialized AVJ is the AV node. In selected cases with unsuccessful AV node ablation, a shift towards the His bundle is needed. A continuity between the septal and anterior leaflets of the tricuspid valve may protect the His bundle as to require multiple shocks and prolong the procedure.

Daily Exposure to Air Pollution Particulate Matter Is Associated with Atrial Fibrillation in High-Risk Patients.

Several epidemiological studies found an association between acute exposure to fine particulate matter of less than 2.5 µm and 10 µm in aerodynamic diameter (PM2.5 and PM10) and cardiovascular diseases, ventricular fibrillation incidence and mortality. The effects of pollution on atrial fibrillation (AF) beyond the first several hours of exposure remain controversial. A total of 145 patients with implantable cardioverter-defibrillators (ICDs), cardiac resynchronization therapy defibrillators (ICD-CRT), or pacemakers were enrolled in this multicentric prospective study. Daily levels of PM2.5 and PM10 were collected from monitoring stations within 20 km of the patient's residence. A Firth Logistic Regression model was used to evaluate the association between AF and daily exposure to PM2.5 and PM10. Exposure levels to PM2.5 and PM10 were moderate, being above the World Health Organization (WHO) PM2.5 and PM10 thresholds of 25 µg/m3 and 50 µg/m3, respectively, on 26% and 18% of the follow-up days. An association was found between daily levels of PM2.5 and PM10 and AF (95% confidence intervals (CIs) of 1.34-2.40 and 1.44-4.28, respectively) for an increase of 50 µg/m3 above the WHO threshold. Daily exposure to moderate PM2.5 and PM10 levels is associated with AF in patients who are not prone to AF.

Insights on arrhythmia termination and type 2 breaks after ICD therapy delivery.

Introduction of anti-tachycardia pacing (ATP) therapy and longer detection intervals delivery have allowed to safely reduce unnecessary shocks, improving survival and quality of life in implantable cardioverter defibrillator (ICD) patients. However, there are still outstanding issues, especially regarding the mode of arrhythmias termination after ATP or shock delivery. Regardless of ICD therapy efficacy, the arrhythmia interruption does not always occur abruptly, indeed both nonsustained tachy- or bradyarrhythmias have been described after ICD therapy delivery, being the former classified as type 2 interruption. Several physiopathological mechanisms have been suggested to be responsible for this phenomenon. Our aim is to review current data on postshock and post-ATP arrhythmias and to give insights on their possible mechanisms.

Left ventricle automatic pacing threshold management in CRT systems: A comprehensive review.

Modern cardiac resynchronization therapy (CRT) device-based threshold detection enables capture management and voltage output adjusting to combine consistent left ventricular (LV) pacing with acceptable battery drainage. The current technologies available for LV capture automatic confirmation in most cases require the evoked response, as well as "LV pace to right ventricular sense" algorithms. The LV pacing percentage counter may overestimate the CRT delivery which may be reduced due to pacing inhibition (by sensed LV activation) or inadequate capture due to subthreshold current or pacing into refractory tissue. Moreover, the LV threshold at implant and its behavior over time (as a marker of electrical viability) and the ineffective CRT issues (subthreshold stimulation or concealed loss of capture) are discussed. The purpose of the present review is to explore these new challenges regarding LV pacing automatic management.

Cardiac implantable electronic device remote monitoring in a large cohort of patients and the need for planning.

Aim: The remote monitoring (RM) of cardiac implantable electronic devices (CIED) is standard of care. We describe an organizational and projection RM workload model. Methods: At the time of the analysis (2015), 3995 CIED patients were followed-up; 1582 (40.5%) with RM. All RM transmissions (Tx) have been gathered in five event types. Results: We received 10,406 Tx, classified as: 128 (1.2%) red alerts, 141 (1.3%) atrial fibrillation episodes, 1944 (18.6%) yellow alerts, 403 (3.9%) lost Tx (disconnected/noncompliant patients) and 7790 (75.0%) Tx 'OK' (un-eventful Tx). At the time of 100% of remote CIED managed, we can expect a total of 25,990 Tx/year. Conclusion: We provide a descriptive analysis of remote monitoring management and workload estimation in a large cohort of CIED patients.

Ventricular tachycardia oversensing in S-ICD patients: Case-based brief review.

A 76-year-old woman with permanent atrial fibrillation and a mechanical aortic valve came to our attention. Echocardiography showed a 50-55% ejection fraction (EF) with good prosthesis performance. For symptomatic bradyarrhythmia, she received a VVI pacemaker (Proponent MRI L2010 model; Boston Scientific.). During follow-up, frequent symptomatic (presyncopal) episodes of nonsustained episodes of ventricular tachycardia (VT) were detected. Amiodarone proved unsuccessful; she was then offered an upgrade to an implantable cardioverter defibrillator (ICD) and a subcutaneous ICD (S-ICD) was chosen by the patient. A few weeks later, two sustained VT were detected and effectively treated with 80-J shock delivery. In both cases, device interrogation revealed a VT rate around 163 bpm (370 ms cycle length), below the lowest device detection cutoff. The report is a case-based review.

Single-center experience with wearable cardioverter-defibrillator as a bridge before definitive ICD implantation.

BACKGROUND: The wearable cardioverter-defibrillator (WCD) has been approved for patients with poor left ventricular ejection fraction (LVEF) who are at risk of sudden arrhythmic death for a limited period but are not candidates for a definitive implantable cardioverter-defibrillator (ICD). The present study sought to retrospectively analyse our single-centre experience. METHODS AND RESULTS: All consecutive WCDs applied between April 2017 and September 2018 in our centre were enrolled. An exercise test was performed in all patients in order to evaluate the absence of false detection of ventricular arrhythmias by the device. A total of 16 patients (57.7 ± 14.8 years old; 75% males) were taken into consideration for the analysis. Mean LVEF was 32 ± 11% at diagnosis and 42 ± 10% at last follow-up (mean, 3.1 ± 1.7 months; median, 3 months). At the end of the "wearing period" 11/16 patients (69%) did not have ICD implant indications and only 5 (31%) underwent ICD implantation. Neither appropriate nor appropriate shocks occurred during the follow up. CONCLUSIONS: The WCD represents a useful tool to bridge a temporarily increased risk for sudden cardiac death. The proportion of patients with an improvement of LVEF> 35% beyond the WCD-application period was considerable.

Safety steps for a non-fluoroscopic approach in right-sided electrophysiology procedures: A point of view.

BACKGROUND: Electro-anatomic 3D mapping systems enable the fluoroscopy (FL) exposure to be reduced. In right-heart supraventricular tachycardia (SVT) procedures, FL could potentially be avoided. Our aim was to discuss some steps focusing on safety. METHODS AND RESULTS: The patient cohort comprised 70 consecutive SVT patients who underwent electrophysiologic (EP) catheterization. FL was routinely avoided in all cases (54.2% males, age 57.2 ±â€¯13.3 years): 51 ablations and 19 EP study procedures. The Carto®3 (Biosense Webster) mapping system was used in 17/70 cases (24.3%), and the EnSite Precision™ (Abbott) system in the remaining 53/70 (75.7%). The mean procedure time was 94.1 ±â€¯33.2 min; no FL was used. No major complications occurred. Acute procedural success was achieved in all 51 patients who underwent ablation. Over 3-month follow-up, arrhythmia recurred in 1 patient. There were no significant differences in procedural times between the two mapping systems, except for the time dedicated to the full geometry creation, which was longer for the EnSite Precision™ system: 10 min (8.5-15 IQR) vs 8 min (5-10 IQR) for the Carto® system (p < 0.001) mainly due to the sub-diaphragmatic navigation. The following procedural steps were considered critical in order to safely avoid FL use: "loop" advancing of catheters, the use of a fixed intracardiac reference, His signal landmark centered maps and the careful acquisition of sub-diaphragmatic extracardiac geometry. CONCLUSIONS: A routine zero X-ray approach by means of electro-anatomic 3D mapping systems is safe and effective in right-atrium procedures. Some ad-hoc discussed procedural steps may enhance safety.

Predictors of Zero X-Ray Ablation for Supraventricular Tachycardias in a Nationwide Multicenter Experience.

BACKGROUND: This multicenter, prospective study evaluated the determinants of zero-fluoroscopy (ZFL) ablation of supraventricular tachycardias. METHODS AND RESULTS: Four hundred thirty patients (215 male, 55.4±22.1 years) with indication to electrophysiological study or ablation of supraventricular tachycardias were enrolled. All participating physicians agreed to follow the as low as reasonably achievable policy. A procedure was defined as ZFL when no fluoroscopy was used. The total fluoroscopy time inversely correlated to the number of procedures previously performed by each operator since study start (r=-0.112; P=0.02). Two hundred eighty-nine procedures (67.2%) were ZFL; multivariable analysis identified as predictors of ZFL: procedure after the 30th for each operator, compared with procedures up to the ninth (P=0.011; hazard ratio, 3.49; 95% confidence interval [CI], 1.79-6.80); the type of arrhythmia (P=0.031; electrophysiological study and atrioventricular nodal reentry tachycardia ablation having the highest probability of ZFL; hazard ratio, 6.87; 95% CI, 2.08-22.7 and hazard ratio, 2.02; 95% CI, 1.04-3.91, respectively); the operator's (P=0.002) and patient's age (P=0.009). Among operators, achievement of ZFL varied from 0% to 100%; 8 (22.8%) operators achieved ZFL in <25% of their procedures; 17 (48.6%) operators achieved ZFL in >75% of their procedures. The probability of ZFL increased by 2.8% (hazard ratio, 0.98; 95% CI, 0.97-0.99) as patient's age decreased by 1 year. Acute procedural success was obtained in all cases. CONCLUSIONS: The use of 3-dimensional mapping system completely avoided the use of fluoroscopy in most cases, with very low fluoroscopy time in the remaining and high safety and effectiveness profiles. Achievement of ZFL was predicted by the type of arrhythmia, operator's experience, and patient's age.

Prediction of mortality in patients with implantable defibrillator using CHADS2 score: data from a prospective observational investigation.

BACKGROUND: CHADS2 (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, previous stroke/TIA) score has been validated as a risk stratification score to predict stroke in patients with atrial fibrillation (AF). The objective of this analysis was to assess whether patient risk factors, in particular CHADS2 score, identified patients at risk of mortality. METHODS: 821 patients with an implantable cardioverter defibrillator were prospectively followed-up in 11 cardiology centers. Patients were grouped in 3 groups according to pre-specified risk classes: low (CHADS2 = 0), moderate (CHADS2 = 1, 2), and high (CHADS2 = 3-6). Information on clinical status and events, were collected during scheduled and unscheduled follow-up visits. Deaths were retrieved from medical records, or through the Regional Office of Vital Statistics. RESULTS: Over a mean follow-up of 44±26 months, 135 deaths occurred in the overall population: 6 (7.7%) in the low-risk population, 69 (13.8%) in moderate-risk patients and 60 (24.6%) in high-risk patients. Kaplan-Meier estimated of patient survival were significantly different in 3 patients groups (93.0%, 90.1%, 78.5% in low, moderate and high risk patients respectively, at 4 years P<0.001). A sub-analysis on patients without history of AF showed similar results. Multivariate regression analysis adjusted for baseline characteristics confirmed the high risk status (HR 1.88, 95% CI 1.27-2.80; P = 0.002) as an independent predictor of mortality adjusted for the baseline characteristics. CONCLUSIONS: In our multicenter research, the long-term mortality was higher in patients with high CHADS2 score than in those with lower risk score regardless the presence of history of AF. CHADS2 score could be considered a toll to predict all causes mortality.

Association between air pollution and ventricular arrhythmias in high-risk patients (ARIA study): a multicentre longitudinal study.

BACKGROUND: Although the effects of air pollution on mortality have been clearly shown in many epidemiological and observational studies, the pro-arrhythmic effects remain unknown. We aimed to assess the short-term effects of air pollution on ventricular arrhythmias in a population of high-risk patients with implantable cardioverter-defibrillators (ICDs) or cardiac resynchronisation therapy defibrillators (ICD-CRT). METHODS: In this prospective multicentre study, we assessed 281 patients (median age 71 years) across nine centres in the Veneto region of Italy. Episodes of ventricular tachycardia and ventricular fibrillation that were recorded by the diagnostic device were considered in this analysis. Concentrations of particulate matter of less than 10 µm (PM10) and less than 2·5 µm (PM2·5) in aerodynamic diameter, carbon monoxide, nitrogen dioxide, sulphur dioxide, and ozone were obtained daily from monitoring stations, and the 24 h median value was considered. Each patient was associated with exposure data from the monitoring station that was closest to their residence. Patients were followed up for 1 year and then scheduled to have a closing visit, within 1 more year. This study is registered with ClinicalTrials.gov, number NCT01723761. FINDINGS: Participants were enrolled from April 1, 2011, to Sept 30, 2012, and follow-ups (completed on April 5, 2014) ranged from 637 to 1177 days (median 652 days). The incidence of episodes of ventricular tachycardia and ventricular fibrillation correlated significantly with PM2·5 (p<0·0001) but not PM10. An analysis of ventricular fibrillation episodes alone showed a significant increase in risk of higher PM2·5 (p=0·002) and PM10 values (p=0·0057). None of the gaseous pollutants were significantly linked to the occurrence of ventricular tachycardia or ventricular fibrillation. In a subgroup analysis of patients with or without a previous myocardial infarction, only the first showed a significant association between particulate matter and episodes of ventricular tachycardia or ventricular fibrillation. INTERPRETATION: Particulate matter has acute pro-arrhythmic effects in a population of high-risk patients, which increase on exposure to fine particles and in patients who have experienced a previous myocardial infarction. The time sequence of the arrhythmic events suggests there is an underlying neurally mediated mechanism. From a clinical point of view, the results of our study should encourage physicians to also consider environmental risk when addressing the prevention of arrhythmic events, particularly in patients with coronary heart disease, advising them to avoid exposure to high levels of fine particulate matter. FUNDING: There was no funding source for this study.

Twelve-year follow-up of catheter ablation for atrial fibrillation: A prospective, multicenter, randomized study.

BACKGROUND: Randomized and controlled studies have reported the effect of catheter ablation (CA) for atrial fibrillation (AF) over a follow-up of 12-24 months. OBJECTIVE: We report on the effect of CA plus antiarrhythmic drugs in comparison with antiarrhythmic drugs alone on the maintenance of sinus rhythm over 12-year follow-up. METHODS: We extended the follow-up duration of the 137 patients who were enrolled in the Catheter Ablation for the Cure of Atrial Fibrillation Study between February 1, 2002, and June 30, 2003, and randomized to antiarrhythmic drugs (control group) or antiarrhythmic drugs plus CA (ablation group). The primary end point was time to first symptomatic or asymptomatic recurrence of atrial arrhythmia lasting >30 seconds during follow-up. RESULTS: During follow-up, 19 of 68 (27.9%; 95% confidence interval [CI] 18.7%-39.6%) ablation group patients and 3 of 69 (4.3%; 95% CI 1.49%-12.0%) control group patients did not experience any relapse of atrial tachyarrhythmia (P < .001). The Kaplan-Meier analysis performed to determine the probability of survival free from atrial arrhythmias showed a statistical difference in favor of the ablation group (log-rank, P < .001). The effect of CA was consistent in both patients with paroxysmal AF and those with persistent AF. In the multivariate Cox regression analysis, belonging to the control group (hazard ratio 2.95; 95% CI 1.896-4.726; P < .001) and longer time since first AF episode (hazard ratio 1.004; 95% CI 1.002-1.084; P = .041) were predictors of atrial tachyarrhythmia recurrence. CONCLUSION: In patients with paroxysmal and persistent AF, CA significantly increased time to first recurrence of atrial arrhythmias during 12-year follow-up.

Long-term clinical outcome of patients who failed catheter ablation of atrial fibrillation.

AIMS: Left atrial ablation fails to prevent symptomatic recurrences of atrial fibrillation (AF) in 20-30% of patients up to 3 years of follow-up despite multiple procedures. Data are lacking on the long-term clinical outcome of those patients for whom the decision was taken to renounce performing further ablation procedures. METHODS AND RESULTS: In this multicentre study, 218 (34%) of 631 consecutive patients, who had undergone AF catheter ablation in the years 2001-11 for drug-refractory symptomatic AF, had symptomatic AF recurrences after 1.5 ± 0.6 procedures. Their long-term clinical outcome was assessed in March 2012 (minimum follow-up 1 year). At a mean of 5.1 ± 2.6 years since their last ablation, 82 (38%) patients improved, 103 (47%) remained unchanged and 33 (15%) worsened, but only 17 (8%) had such a severe impairment of their quality of life as to require atrioventricular junction ablation and pacing (#13) or cardiac surgery (#4); 22 (10%) patients had had adverse clinical events (death in five, heart failure in five, stroke and transient ischaemic cerebral attack in four, severe haemorrhage in four, pacemaker or implantable cardioverter-defibrillator implantation in seven) and 98 (45%) patients had developed permanent AF. Compared with patients without permanent AF, fewer patients with permanent AF improved (3% vs. 66%, P = 0.001) and more got worse (28% vs. 5%, P = 0.001). At multivariable logistic regression, single ablation procedure, left atrial diameter, persistent AF and time from the last ablation were independent predictors of permanent AF. CONCLUSION: More than 5 years after a failed AF ablation, a small minority of patients had such an impaired quality of life as to require non-pharmacological interventions. Almost half developed permanent AF, which significantly impaired quality of life. Permanent AF was more common in patients who had left atrial enlargement, history of persistent AF, longer follow-up, and had performed a single ablation procedure, thus hypothesizing that reablation could reduce the chronicization of arrhythmia. A low risk of stroke was observed in the long-term follow-up.

Morphology of right atrial appendage for permanent atrial pacing and risk of iatrogenic perforation of the aorta by active fixation lead.

BACKGROUND: Permanent atrial pacing usually involves lead placement in the right atrial appendage (RAA). Anatomical studies addressing features predisposing to complications are scanty. OBJECTIVE: To assess the morphology of RAA in the perspective of pacing, including the morphology of tenia sagittalis (TS) and the spatial relationship with the aorta. METHODS: The gross anatomy of the RAA has been analyzed in a consecutive series of 100 hearts following a case of iatrogenic perforation of the aorta by active fixation lead located in the RAA. Transmural RAA sections were taken from 40 hearts to assess the wall thickness at the level of pectinate muscles (PMs) and of inter-PMs spaces and the distance between adjacent PMs. RESULTS: The TS was present in 90% of cases (single trunk, 76%; double trunk, 13%; and triple trunk, 1%), demarcating the proximal antral RAA region (facing the adjacent aorta) from the distal saccular RAA region (facing the pulmonary infundibulum). The RAA free wall in the inter-PMs spaces is usually paper-thin and translucent. Histomorphometric analysis reveals that the RAA wall mean thickness was 1.38 ± 0.05 mm (range 0.64-4.25 mm) at the level of PMs and 0.39 ± 0.23 mm (range 0.09-1.05 mm) at the level of inter-PMs spaces. The mean distance between adjacent PMs was 0.88 ± 0.99 mm (range 0.04-4.12 mm). CONCLUSION: In 90% of hearts, a well-defined TS separates the distal saccular from the proximal antral RAA, the latter being closely adjacent to the ascending aorta. The paper-thin wall between PMs is potentially at risk of perforation, and aortic injury could occur when active fixation leads are anchored in the antral RAA, as demonstrated in an iatrogenic fatal case.

Improving atrial fibrillation detection in patients with implantable cardiac devices by means of a remote monitoring and management application.

BACKGROUND: Atrial fibrillation (AF) is common in patients with cardiac implantable electronic devices (CIED) and has been associated with an increased stroke risk. The aim of our project was to assess the clinical value of a web-based application, Discovery Link AFinder, in improving AF detection in CIED patients. METHODS AND RESULTS: Seven Italian hospitals performed an observational study consisting of four phases. During phase 1, expert nurses and cardiologists prospectively followed-up CIED patients via in-hospital examinations and remote monitoring, and classified clinically relevant events, particularly AF occurrence. During phase 2, Discovery Link AFinder was exploited to identify patients who had suffered AF in the previous 12 months through the systematic scanning of device data remote transmissions. Phases 3 and 4 were repetitions of phases 1 and 2, respectively, and were implemented 6 months after the previous phases. A total of 472 consecutive patients were included in phase 1; AF occurred in 170 patients, 61 of whom were identified as new AF patients. Evidence of AF during this phase prompted prescription of oral anticoagulation (OAC) therapy in 30 patients. In phase 2, AFinder uncovered new AF, unidentified in phase 1, in 54 patients and prompted implementation of OAC therapy in 11 patients. During phase 3, 30 new AF patients were identified by means of remote monitoring, while during phase 4, a further three AF patients were identified by AFinder only. CONCLUSIONS: The AFinder web-based software, applied on top of standard in-hospital and remote monitoring, improved AF detection and enabled OAC treatment to be undertaken.