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.

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.

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.

Seasonal trends in atrial fibrillation episodes and physical activity collected daily with a remote monitoring system for cardiac implantable electronic devices.

BACKGROUND: Remote monitoring (RM) of cardiac implantable electronic devices is an ideal experimental model to evaluate long-term trends of physiological and clinical data automatically collected from large patient cohorts. OBJECTIVES: We studied data of atrial fibrillation (AF) and physical activity (PA) transmitted daily during 3.5years from a subgroup of patients enrolled in the HomeGuide trial, a previously conducted study on patients routinely followed with a RM system transmitting clinical and diagnostic data daily. METHODS: We selected 988 patients (80% male, mean age 68±11) implanted with a pacemaker (16%) or an implantable defibrillator and provided with atrial sensing and movement sensors. Remotely transmitted data were processed in order to obtain AF incidence and time of PA in the form of collective time series daily sampled. RESULTS: We found that both PA and AF incidence clearly showed seasonal trends with an annual period and inverse correlation. In a first-order autoregressive model the regression coefficient of daily activity to AF incidence was -0.64 (standard error, 0.18, p<0.0001), while the cross-correlation coefficient reached its maximum values at ±180day lags. AF incidence was 14.4% higher and PA was 14.7% lower in winters than in summers (p<0.0001 for both comparisons). Power spectral analysis revealed weekly periodicity in the PA series (corresponding to festivity rest) but not in the AF incidence. CONCLUSIONS: RM data collected daily from a relatively large patient cohort revealed marked seasonal trends in AF incidence and PA with opposite behavior in winters and summers.

Three-Dimensional Electroanatomic Mapping System-Enhanced Cardiac Resynchronization Therapy Device Implantation: Results From a Multicenter Registry.

INTRODUCTION: Cardiac resynchronization therapy (CRT) device implantation guided by an electroanatomic mapping system (EAMS) is an emerging technique that may reduce fluoroscopy and angiography use and provide information on coronary sinus (CS) electrical activation. We evaluated the outcome of the EAMS-guided CRT implantation technique in a multicenter registry. METHODS: During the period 2011-2014 we enrolled 125 patients (80% males, age 74 [71-77] years) who underwent CRT implantation by using the EnSite system to create geometric models of the patient's cardiac chambers, build activation mapping of the CS, and guide leads positioning. Two hundred and fifty patients undergoing traditional CRT implantation served as controls. Success and complication rates, fluoroscopy and total procedure times in the overall study population and according to center experience were collected. Centers that performed ≥10 were defined as highly experienced. RESULTS: Left ventricular lead implantation was successful in 122 (98%) cases and 242 (97%) controls (P = 0.76). Median fluoroscopy time was 4.1 (0.3-10.4) minutes in cases versus 16 (11-26) minutes in controls (P < 0.001). Coronary sinus angiography was performed in 33 (26%) cases and 208 (83%) controls (P < 0.001). Complications occurred in 5 (4%) cases and 17 (7%) controls (P = 0.28). Median fluoroscopy time (median 11 minutes vs. 3 minutes, P < 0.001) and CS angiography rate (55% vs. 21%, P < 0.001) were significantly higher in low experienced centers, while success rate and complications rate were similar. CONCLUSIONS: EAMS-guided CRT implantation proved safe and effective in both high- and low-experienced centers and allowed to reduce fluoroscopy use by ≈75% and angiography rate by ≈70%.

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.

Stroke incidence in patients with cardiac implantable electronic devices remotely controlled with automatic alerts of atrial fibrillation. A sub-analysis of the HomeGuide study.

BACKGROUND: Remote Monitoring (RM) of cardiac implantable electronic devices (CIEDs) is recommended in management of Atrial Fibrillation (AF), which is a recognized risk factor for thromboembolism. We tried to elucidate whether stroke incidence observed in a large, remotely monitored population was consistent with the CHA2DS2VASc risk profile. METHODS: Data from 1650 patients [76% male, age 72 (63-68), CHA2DS2VASc score 3.0 (2.0-4.0)] enrolled during the HomeGuide study and monitored with a daily-transmission RM system providing automatic alerts for AF, were analysed. Of those, 25% had a pacemaker and 75% an implantable cardioverter defibrillator with or without cardiac resynchronization. Estimations of the expected thromboembolic events were based on the population CHA2DS2VASc score profile used in a computer-simulated Markov model. RESULTS: Eight thromboembolic events were observed with a 4-year cumulative stroke rate of 0.8% (confidence interval, 0.4%-1.5%). Simulations returned from 18.7 to 17.1 expected events, depending on the AF duration assumed to trigger anticoagulation (one-sample log-rank p<0.03). During the study period, 681 (84%) AF episodes and 129 (16%) atrial tachycardias were detected in 291 patients (18%): 93% of episodes were detected remotely in 269 patients, 66% of whom had no history of AF. Medical interventions were necessary in 305 episodes, 85% of which were detected remotely. Reaction time was 1 (0-6) days for remotely-detected episodes and 33 (14-121) days for episodes detected in clinic (p<0.0001). CONCLUSIONS: In a large CIED population followed remotely for up to 4years, the incidence of thromboembolic events was less than half the estimations based on the CHA2DS2VASc risk profile.

Association between ventricular pacing and persistent atrial fibrillation in patients indicated to elective pacemaker replacement: Results of the Prefer for Elective Replacement MVP (PreFER MVP) randomized study.

BACKGROUND: Pacing in the right ventricle can cause a variety of detrimental effects, including atrial tachyarrhythmias (atrial tachycardia [AT]/atrial fibrillation [AF]). OBJECTIVE: The purpose of this study was to evaluate the incidence and predictors of persistent AT/AF in patients with long-term exposure to ventricular pacing. METHODS: In a multicenter international trial, 605 patients (age 75 ± 11 years, 240 women) referred for replacement of an implanted pacemaker or implantable cardioverter-defibrillator (ICD), with a history of high-percentage (>40%) ventricular pacing, were randomly allocated to standard dual-chamber pacing or managed ventricular pacing (MVP), a pacing modality that minimizes ventricular pacing. The main end-point of this secondary analysis of the PreFER MVP randomized study was persistent AT/AF, defined as ≥7 consecutive days with AT/AF or AT/AF interrupted by atrial cardioversion or AT/AF present during 2 consecutive follow-up visits. RESULTS: Persistent AT/AF was observed in 71 patients (11.7%) after 2 years of follow-up. At multivariable Cox regression analysis, prior AT/AF (hazard ratio [HR] 2.85, 95% confidence interval [CI] 1.20-6.22, P = .017) and ventricular pacing percentage, estimated in the first 3 months, ≥10% (HR 3.24, 95% 95% CI 1.13-9.31, P = .029) were independent predictors for persistent AT/AF. MVP was associated with persistent AT/AF risk (HR 3.41, 95% 95% CI 1.10-10.6, P = .024) in the subgroup of patients with baseline long PR interval (PR >230 ms) but not in the whole population. CONCLUSION: In pacemaker and ICD replacement patients, a high percentage of ventricular pacing is associated with higher risk of persistent AT/AF. Use of algorithms that minimize right ventricular pacing may benefit patients with normal spontaneous AV conduction but should be evaluated with caution in patients with long PR interval.

Multicentre comparison Of shock efficacy using single-vs. Dual-coil lead systems and Anodal vs. cathodaL polarITY defibrillation in patients undergoing transvenous cardioverter-defibrillator implantation. The MODALITY study.

PURPOSE: An optimal active-can lead configuration during implantable cardioverter defibrillator (ICD) placement is important to obtain an adequate defibrillation safety margin. The purpose of this multicenter study was to evaluate the rate of the first shock success at defibrillation testing according to the type of lead implant (single vs. dual coil) and shock polarity (cathodal and anodal) in a large series of consecutive patients who received transvenous ICDs. METHODS: This was a multicenter study enrolling 469 consecutive patients. Single- versus dual-coil leads and cathodal versus anodal polarity were evaluated at defibrillation testing. In all cases, the value of the energy for the first shock was set to 20 J less than the maximum energy deliverable from the device. RESULTS: A total of 469 patients underwent defibrillation testing: 158 (34 %) had dual-coil and 311 (66 %) had single-coil lead systems configuration, 254 (54 %) received anodal shock and 215 (46 %) received cathodal shock. In 35 (7.4 %) patients, the shock was unsuccessful. No significant differences in the outcome of defibrillation testing using single- versus dual-coil lead were observed but the multivariate analysis showed an increased risk of shock failure using cathodal shock polarity (OR 2.37, 95 % CI 1.12-5.03). CONCLUSIONS: Both single- and dual-coil transvenous ICD lead systems were associated with high rates of successful ICD implantation, and we found no significant differences in ventricular arrhythmias interruption between the two ICD lead systems configuration. Instead, anodal defibrillation was more likely to be successful than cathodal defibrillation.

Manpower and outpatient clinic workload for remote monitoring of patients with cardiac implantable electronic devices: data from the HomeGuide Registry.

BACKGROUND: This study aimed to assess manpower and resource consumption of the HomeGuide workflow model for remote monitoring (Biotronik Home Monitoring [HM], Biotronik SE & Co. KG, Berlin, Germany) of cardiac implantable electronic devices in daily clinical practice. METHODS: The model established a cooperative interaction between a reference nurse (RN) for ordinary management, and a responsible physician (RP) for medical decisions in each outpatient clinic. RN reviewed remote transmissions and alerts, addressing critical cases to the RP. RESULTS: A total of 1,650 patients were enrolled in 75 sites: 25% pacemakers (PM), 22% dual-, 27% single-chamber implantable defibrillators (ICD), 2% PM with cardiac resynchronization therapy (CRT), and 24% ICD-CRT. During a median follow-up of 18 (10-31) months, 3,364 HM sessions were performed (74% by the RN, 26% by the RP) to complete 18,478 remote follow-ups. Median duration of remote follow-ups was 1.2 (0.6-2.0) minutes, corresponding to a manpower of 43.3 (4.2-94.8) minutes/month every 100 patients for nurses and 10.2 (0.1-31.1) for physicians (P < 0.0001). RN submitted 15% of remote transmissions to RP, who decided unscheduled follow-ups in 12% of the cases. The median manpower for phone calls was 1.9 (0.8-16.5) minutes/month every 100 contacted patients. There were 2.84 in-hospital visits/patient, 0.46 of which triggered by HM findings. A cumulative per-patient HM follow-up time of 15.4 minutes (20% of total follow-up time) allowed remote detection of 73% of actionable events. CONCLUSIONS: HM implemented in the HomeGuide workflow model required <1 hour/month every 100 patients to detect the majority of actionable events with limited administrative workload.

Managed ventricular pacing compared with conventional dual-chamber pacing for elective replacement in chronically paced patients: results of the Prefer for Elective Replacement Managed Ventricular Pacing randomized study.

BACKGROUND: Several studies have shown that unnecessary right ventricular pacing has detrimental effects. OBJECTIVE: To evaluate whether minimization of ventricular pacing as compared with standard dual-chamber pacing (DDD) improves clinical outcomes in patients referred for pacemaker or implantable cardioverter-defibrillator (ICD) replacement. METHODS: In an international single-blind, multicenter, randomized controlled trial, we compared DDD with managed ventricular pacing (MVP), a pacing mode developed to minimize ventricular pacing by promoting intrinsic atrioventricular conduction. We included patients referred for device replacement with >40% ventricular pacing, no cardiac resynchronization therapy upgrade indication, no permanent atrial fibrillation (AF), and no permanent complete atrioventricular block. Follow-up was for 2 years. The primary end point was cardiovascular hospitalization. The intention-to-treat analysis was performed by using Kaplan-Meier method and the log-rank test. RESULTS: We randomized 605 patients (556 referred for pacemaker and 49 referred for ICD replacement; mean age 75 ± 11 years; 365 [60%] men, at 7.7 ± 3.3 years from first device implantation) to MVP (n = 299) or DDD (n = 306). We found no significant differences in the primary end point cardiovascular hospitalization (MVP: 16.3% vs DDD: 14.5%; P = .72) and the secondary end point persistent AF (MVP: 15.4% vs DDD: 11.2%; P = .08), permanent AF (MVP: 4.1% vs DDD: 3.1%; P = .44), and composite of death and cardiovascular hospitalization (MVP: 23.9% vs DDD: 20.2%; P = .48). MVP reduced right ventricular pacing (median 5% vs 86%; Wilcoxon, P < .0001) as compared with DDD. CONCLUSIONS: In patients referred for pacemaker and ICD replacement with clinically well-tolerated long-term exposure to >40% ventricular pacing in the ventricle, a strategy to minimize ventricular pacing is not superior to standard DDD in reducing incidence of cardiovascular hospitalizations.

Effectiveness of remote monitoring of CIEDs in detection and treatment of clinical and device-related cardiovascular events in daily practice: the HomeGuide Registry.

AIMS: The HomeGuide Registry was a prospective study (NCT01459874), implementing a model for remote monitoring of cardiac implantable electronic devices (CIEDs) in daily clinical practice, to estimate effectiveness in major cardiovascular event detection and management. METHODS AND RESULTS: The workflow for remote monitoring [Biotronik Home Monitoring (HM)] was based on primary nursing: each patient was assigned to an expert nurse for management and to a responsible physician for medical decisions. In-person visits were scheduled once a year. Seventy-five Italian sites enrolled 1650 patients [27% pacemakers, 27% single-chamber implantable cardioverter defibrillators (ICDs), 22% dual-chamber ICDs, 24% ICDs with cardiac resynchronization therapy]. Population resembled the expected characteristics of CIED patients. During a 20 ± 13 month follow-up, 2471 independently adjudicated events were collected in 838 patients (51%): 2033 (82%) were detected during HM sessions; 438 (18%) during in-person visits. Sixty were classified as false-positive, with generalized estimating equation-adjusted sensitivity and positive predictive value of 84.3% [confidence interval (CI), 82.5-86.0%] and 97.4% (CI, 96.5-98.2%), respectively. Overall, 95% of asymptomatic and 73% of actionable events were detected during HM sessions. Median reaction time was 3 days [interquartile range (IQR), 1-14 days]. Generalized estimating equation-adjusted incremental utility, calculated according to four properties of major clinical interest, was in favour of the HM sessions: +0.56 (CI, 0.53-0.58%), P < 0.0001. Resource consumption: 3364 HM sessions performed (76% by nurses), median committed monthly manpower of 55.5 (IQR, 22.0-107.0) min × health personnel/100 patients. CONCLUSION: Home Monitoring was highly effective in detecting and managing clinical events in CIED patients in daily practice with remarkably low manpower and resource consumption.

Catheter ablation of atrioventricular nodal reentrant tachycardia in patients with a prolonged PR interval at sinus rhythm.

Radiofrequency transcatheter ablation is an effective and safe treatment for atrioventricular node reentry tachycardia. Slow pathway ablation is considered the ablative technique of choice, but when atrioventricular nodal reentrant tachycardia is associated with a prolonged PR interval at sinus rhythm, a higher risk of delayed atrioventricular (AV) block has been reported. Studies on the subject are few, enrolling low numbers of patients with variable selection criteria and producing different results. Hence, optimal ablation strategy remains controversial. The aim of this study is to review the available knowledge on the topic. Experience from our centers is also briefly reported.

Management of alert messages in the remote monitoring of implantable cardioverter defibrillators and pacemakers: an Italian single-region study.

AIMS: The remote monitoring of pacemakers and implantable cardioverter defibrillators (ICDs) promotes accurate supervision of the patient and device. Alert settings appear to be a crucial parameter of its efficacy. The purpose of our study was to evaluate various settings for alerts and alert message management in patients with pacemakers and ICDs. METHODS AND RESULTS: We prospectively evaluated 282 patients (181 males, 101 females, mean age 72 ± 11 years) who were referred to nine electrophysiological centres in the Veneto region of Italy for a pacemaker (76 patients) or ICD (206 patients) implant in which remote monitoring was activated (Biotronik Home Monitoring®, Biotronik, Berlin, Germany). During a mean follow-up of 382 ± 261 days, we received 106,039 transmissions. In the pacemaker group, the alerts that were most frequently activated were those concerning battery exhaustion, surveying impedances, sensing and threshold measurements, as well as missing transmissions. In the ICD/ICD-cardiac resynchronization therapy group, the alerts nearly always activated were those concerning a detection setoff, battery exhaustion, critical values of impedance, or ineffective maximum energy shock. In both groups, the alarms for heart rate monitoring and supraventricular arrhythmia were activated in fewer cases at higher variability among centres. CONCLUSIONS: Our study demonstrates that more attention is paid to critical technical data than to patients' clinical profiles, probably to limit an excessive flow of data into the centre. Accurate alert settings, personalized to the patients' features, are essential for easier and more effective management of patients who are followed remotely.

Evidence of reverse mismatch with positron emission tomography imaging in a patient with reversible myocardial dysfunction.

We describe the case of a patient who came to our attention because of a reversible depression of myocardial contractility, probably due to myocarditis. A positron emission tomography study showed, in correspondence to the malfunctioning segments, a decreased F18-2-fluoro-2-deoxyglucose (F18-FDG) uptake in the presence of a normal perfusion as assessed by means of N13-labeled ammonia uptake. This phenomenon, called "reverse mismatch", shows that viability is not always dependent on FDG uptake and that it could be associated with the recovery of myocardial contractility. Some interpretations of the association between a reversible dysfunction and a reduced myocardial glucose metabolism are presented. The central role of nitric oxide and of cyclic guanosine monophosphate is hypothesized to explain both the mechanical and metabolic abnormalities.