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Background: Radiofrequency (RF) catheter ablation is one of the most common strategies for the current management of cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL). The interindividual anatomic variability can influence the duration and outcome of ablation procedure., Objective: The purpose of this study was to establish complication rates in patients undergoing RF catheter ablation for CTI-dependent AFL, assess the role of CTI morphology in procedural success, and determine the anatomic variability of CTI ex vivo., Methods: RF catheter ablation for CTI-dependent AFL was performed in 337 consecutive patients. Angiographically determined CTI morphology was classified as either simple or complex due to pouchlike recesses. Macroscopic and histologic examination of the CTI was performed in 104 heart specimens from consecutive autopsies., Results: Complex CTI anatomy was present in 10.9% of AFL patients. RF application time to achieve bidirectional isthmus block was longer in patients showing pouchlike recesses than in those without (10.7 vs 8.3 min; P= .025). Acute procedure failure or major complications occurred in 3 cases, all with complex CTI anatomy. A pouchlike recess of the CTI was present in 9.6% of autopsy hearts. Histomorphometric analysis of the CTI atrial wall demonstrated that the central level was the thinnest in the 3 sectors and the paraseptal level was the thickest., Conclusion: Although RF catheter ablation is a safe and effective procedure for AFL treatment, CTI anatomic complexity can affect ablation parameters and outcome. Standard definition of CTI morphologic variants is recommended. Preprocedural assessment of CTI anatomy might lead to personalized ablation preventing potential difficulties and complications., (Copyright © 2019 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Device follow-up is mandatory in the care of patients with a pacemaker. However, in most cases, device checks appear to be mere technical, time-consuming procedures. The aim of this research is to evaluate whether remote follow-up can replace in-clinic device checks by assessing clinical outcomes for pacemaker patients followed only via remote follow-up., Methods and Results: Consecutive pacemaker patients followed with remote monitoring were prospectively included by 6 Italian cardiology centers in an observational investigation. The workflow for remote monitoring included an initial assessment by nursing staff and, when necessary, by a responsible physician for medical decisions. No in-person visits were scheduled after the start of remote monitoring. One-thousand and two-hundred and fifty one patients (30% female, 75±11years old) were followed for a median observation period of 15months. Out of 4965 remote transmissions, 1882 (38%) had at least one clinically relevant event to be investigated further, but, only after 137 transmissions (2.8%), the patients were contacted for an in-clinic visit or hospitalization. Sixty-nine patients died and 124 were hospitalized for various reasons. Atrial fibrillation episodes were the most common clinical events discovered by remote transmissions, occurring in 1339 (26%) transmissions and 471 (38%) patients., Conclusions: Our experience shows that remote monitoring in a pacemaker population can safely replace in-clinic follow-up, avoiding unnecessary in-hospital device follow-up., (Copyright © 2016. Published by Elsevier Ireland Ltd.)

Aims: Implantable cardioverter defibrillators improve survival of patients at risk for ventricular arrhythmias, but inappropriate shocks occur in up to 30% of patients and have been associated with worse quality of life and prognosis. In heart failure patients with cardiac resynchronization therapy defibrillators (CRT-Ds), we evaluated whether a new generation of detection and discrimination algorithms reduces inappropriate shocks., Methods and Results: We analysed 1983 Medtronic CRT-D patients (80% male, 67 ± 10 years), 1368 with standard devices (Control CRT-D) and 615 with new generation devices (New CRT-D). Expert electrophysiologists reviewed and classified the electrograms of all device-detected ventricular tachycardia/fibrillation episodes. Total follow-up was 3751 patients-years. Incidence of inappropriate shocks at 1 year was 2.8% [95% confidence interval (CI) = 2.0-3.5] in Control CRT-D and 0.9% (CI = 0.4-2.2) in New CRT-D (hazard ratio = 0.37, CI = 0.21-0.66, P < 0.001). In New CRT-D, inappropriate shocks were reduced by 77% [incidence rate ratio (IRR) = 0.23, CI = 0.16-0.35, P < 0.001] and inappropriate anti-tachycardia pacing by 81% (IRR = 0.19, CI = 0.11-0.335, P < 0.001). Annual rate per 100 patient-years for appropriate VF detections was 3.0 (CI = 2.1-4.2) in New CRT-D and 3.2 (CI = 2.1-5.0) in Control CRT-D (P = 0.68), for syncope was 0.4 (CI = 0.2-0.9) in New CRT-D and 0.7 (CI = 0.5-1.0) in Control CRT-D (P = 0.266), and for death was 1.0 (CI = 0.6-1.6) in New CRT-D and 3.5 (CI = 3.0-4.1) in Control CRT-D (P < 0.001)., Conclusion: Detection and discrimination algorithms used in new generation CRT-D significantly reduced inappropriate shocks when compared with standard CRT-D. This result, with no compromise on VF sensitivity or risk of syncope, has important implications for patients' quality of life and prognosis., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.)

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.

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., (©2014 Wiley Periodicals, Inc.)

Hyperkalaemia is an electrolyte disturbance that can have effects on myocardial conduction causing electrocardiographic changes. Several factors may predispose to and promote potassium serum level increase leading to typical electrocardiographic abnormalities. We describe the case of a patient who presented with hyperkalaemia and an electrocardiographic aspect consistent with a sine-wave pattern.

Objectives: To evaluate the prevalence of severe right atrial conduction delay in patients with sinus node dysfunction (SND) and atrial fibrillation (AF) and the effects of pacing in the right atrial appendage (RAA) and in the inter-atrial septum (IAS)., Methods: Forty-two patients (15 male, 72 +/- 7 years) underwent electrophysiologic study to measure the difference between the conduction time from RAA to coronary sinus ostium during stimulation at 600 ms and after extrastimulus (DeltaCTos). Patients were classified as group A if DeltaCTos > 60 ms and group B if < 60 ms. Each Group was randomized to RAA/IAS pacing and algorithms ON/OFF., Results: Fifteen patients (36%, group A) had DeltaCTos = 76 +/- 11 ms and 27 patients (64%, group B) had DeltaCTos = 36 +/- 20 ms. Twenty-two patients were paced at the RAA and 20 at the IAS. During the study, no AF recurrences were reported in 11 of 42 (26%) patients, independently of RAA or IAS pacing. Patients from group A and RAA pacing had 0.79 +/- 0.81 episodes of AF/day during DDD, which increased to 1.52 +/- 1.41 episodes of AF/day during DDDR + Alg (P = 0.046). Those with IAS pacing had 0.5 +/- 0.24 episodes of AF/day during DDD, which decreased to 0.06 +/- 0.08 episodes of AF/day during DDDR + Alg (P = 0.06). In group B, no differences were reported between pacing sites and pacing modes., Conclusions: Severe right atrial conduction delay is present in one-third of patients with SND and AF: continuous pacing at the IAS is superior to RAA for AF recurrences. In patients without severe conduction delay, no differences between pacing site or mode were observed.

Background: Ostial radiofrequency catheter ablation (RFCA) of pulmonary veins (PVs) is a promising invasive approach for the non-pharmacologic treatment of atrial fibrillation, but PV stenosis has been reported as a possible complication of this intervention. The aim of this study was to assess PV anatomy and stenosis (i.e. number and progression) by means of transesophageal echocardiography (TEE) during the follow-up of patients undergoing RFCA., Methods: Twenty-three consecutive patients with refractory and highly symptomatic atrial fibrillation underwent ostial radiofrequency isolation of arrhythmogenic triggers/foci, localized into the PVs, by an electroanatomic approach (CARTO system) or circular mapping with a multipolar catheter (LASSO) placed under radioscopic guidance. All patients were investigated using TEE and magnetic resonance angiography before radiofrequency application to evaluate PV anatomy. TEE examination was repeated after 2 months of follow-up and, in the presence of a stenosis, 1 year later., Results: TEE allowed to identify 100% of the left and right superior PVs, 96% of right inferior PVs, and 74% of the left inferior PVs. Anatomic variants were detected at TEE in 33% of patients against 37% at magnetic resonance angiography (95% of concordance). After ostial RFCA, TEE disclosed a significant reduction in the mean diameters of the left superior PV (14.1 +/- 3.2 vs 12.0 +/- 2.7 mm, p < 0.01), left inferior PV (11.2 +/- 2.3 vs 9.8 +/- 2.2 mm, p = 0.05) and right superior PV (14.2 +/- 2.6 vs 12.9 +/- 2.7 mm, p < 0.05), and an increase in the mean peak velocities of the left superior PV (69.8 +/- 14.8 vs 91 +/- 42.4 cm/s, p < 0.05) and left inferior PV (59.2 +/- 18.1 vs 79.3 +/- 40.5 cm/s, p < 0.05). From a total of 88 PVs treated, 7 (7.9%) showed a higher significant stenosis in patients treated using the LASSO than the CARTO system (31.3 vs 2.8% respectively, p < 0.01). After 1-year follow-up there was no progression of PV stenosis., Conclusions: TEE was successful to evaluate PV anatomy and stenosis of patients undergoing ostial RFCA for atrial fibrillation. This complication is not rare and seems to be strictly related to the method of ablation, in particular when circular mapping and disconnection of triggers/foci was carried out by only a circular multipolar catheter without an electroanatomic approach.

A 71-year-old male patient with end-stage heart failure, atrial fibrillation, congestive and low output symptoms, underwent biventricular pacing and atrioventricular junction ablation while anuric and hypotensive. Following atrioventricular junction ablation blood pressure increased by 20 mmHg during biventricular but not during right ventricular apical pacing. A rapid clinical improvement was observed and the patient was discharged from the hospital in NYHA functional class III.