Implantation of an implantable cardioverter defibrillator (ICD) is standard care for primary prevention of sudden cardiac death. However, ICD-related complications are increasing as the population of ICD recipients grows. ICD-related complications in a national DO-IT Registry cohort of 1442 primary prevention ICD patients were assessed in terms of additional use of hospital care resources and costs. During a median follow-up of 28.7 months (IQR 25.2–33.7) one or more complications occurred in 13.5

INTRODUCTION:Approximately 18% of patients with atrial fibrillation (AF) undergo a repeat ablation within 12 months after their index ablation. Despite the high prevalence, comparative studies on nonpulmonary vein (PV) target strategies in repeat AF ablation are scarce. Here, we describe 12 months efficacy of non-PV and PV target ablations as a repeat ablation strategy.METHODS:A multicentre retrospective, descriptive study was conducted with data of 280 patients who underwent repeat AF ablation. The ablation strategy for repeat ablation was at the operators' discretion. Non-PV target ablation (n = 140) included PV reisolation, posterior wall isolation, mitral line, roofline, and/or complex fractionated atrial electrogram ablation. PV target ablation (n = 140), included reisolation and/or wide atrium circumferential ablation. Patients' demographics and rhythm outcomes during 12 months follow-up were analyzed.RESULTS:At 12 months, more atrial tachyarrhythmias were observed in the non-PV target group (48.6%) compared to the PV target group (29.3%, p = .001). Similarly, a significantly higher AF and atrial tachycardia (AT) recurrence rate was observed after non-PV target ablation compared to PV target ablation (36.4% vs. 22.1% and 22.9% vs. 10.7%). After adjustment, a significantly higher risk of AT recurrence remained in the non-PV target group. Both groups significantly de-escalated antiarrhythmic drug use; de-escalation was more profound after PV target ablation. Patients with isolated PVs during non-PV target ablation had a significantly higher risk for AF recurrence than those with reconnected PVs.CONCLUSION:Compared to PV target ablation, non-PV target repeat ablation did not improve outcomes after 12 months and was independently associated with an increased risk for AT recurrences.

Background Clinical outcome of pulmonary vein isolation (PVI) has been predominantly focused on the reoccurrence of atrial fibrillation (AF) and the maintenance of sinus rhythm. However, there has been a limited intermediate follow-up on health-related quality-of-life (HRQoL) of patients. Given the relatively high recurrence rate of persistent AF after PVI treatment, it is important to follow up with clinical outcomes on symptom improvement as well as health-related quality-of-life. This study was designed to investigate the recurrence rate of atrial tachyarrhythmia (ATa), AF-related symptoms and HRQoL after PVI in patients with persistent AF who were treated with the second generation cryoballoon. Methods Total 148 patients participated in the study who were treated by PVI between 2013 and 2017 for persistent AF. All patients visited the out-patient clinic 2–5 years after PVI. During this visit all patients filled-out an AF Effect on Quality-of-life (AFEQT) questionnaire and a seven-day Holter was applied. All rhythm recordings acquired post ablation were collected and analysed, and the modified European Heart Rhythm Association score (mEHRA) scores were calculated before and after the ablation. Results The average age of patients was 63±9 year old and 44 (27.9%) were female. Mean CHA 2 DS 2 VASc score was 1.9±1.4, and moderate and severe left atrial (LA) dilation was present in 53 (36.1%) and 15 (10.2%) patients, respectively. After a follow-up of 3.7±1.0 years, 81 (54.7%) patients had an ATa recurrence and 35 (23.6%) patients underwent a repeat LA ablation. However, the mEHRA score significantly improved in 80.4% of the patients ( p <0.001), with the median overall AFEQT score of 88.9 [70.4–97.2]. Conclusions There is a considerable ATa recurrence rate after PVI of persistent AF at intermediate-term follow-up. However, our data indicate that PVI significantly improved AF-related symptoms and resulted in a high HRQoL for 2–5 years in patients with persistent AF.

Background One third of primary prevention implantable cardioverter‐defibrillator patients receive appropriate therapy, but all remain at risk of defibrillator complications. Information on these complications in contemporary cohorts is limited. This study assessed complications and their risk factors after defibrillator implantation in a Dutch nationwide prospective registry cohort and forecasts the potential reduction in complications under distinct scenarios of updated indication criteria. Methods and Results Complications in a prospective multicenter registry cohort of 1442 primary implantable cardioverter‐defibrillator implant patients were classified as major or minor. The potential for reducing complications was derived from a newly developed prediction model of appropriate therapy to identify patients with a low probability of benefitting from the implantable cardioverter‐defibrillator. During a follow‐up of 2.2 years (interquartile range, 2.0–2.6 years), 228 complications occurred in 195 patients (13.6%), with 113 patients (7.8%) experiencing at least one major complication. Most common ones were lead related (n=93) and infection (n=18). Minor complications occurred in 6.8% of patients, with lead‐related (n=47) and pocket‐related (n=40) complications as the most prevailing ones. A surgical reintervention or additional hospitalization was required in 53% or 61% of complications, respectively. Complications were strongly associated with device type. Application of stricter implant indication results in a comparable proportional reduction of (major) complications. Conclusions One in 13 patients experiences at least one major implantable cardioverter‐defibrillator–related complication, and many patients undergo a surgical reintervention. Complications are related to defibrillator implantations, and these should be discussed with the patient. Stricter implant indication criteria and careful selection of device type implanted may have significant clinical and financial benefits.

Aims The European REMOTE-CIED study is the first randomized trial primarily designed to evaluate the effect of remote patient monitoring (RPM) on patient-reported outcomes in the first 2 years after implantation of an implantable cardioverter-defibrillator (ICD). Methods and results The sample consisted of 595 European heart failure patients implanted with an ICD compatible with the Boston Scientific LATITUDE (R) RPM system. Patients were randomized to RPM plus a yearly in-clinic ICD check-up vs. 3-6-month in-clinic check-ups alone. At five points during the 2-year follow-up, patients completed questionnaires including the Kansas City Cardiomyopathy Questionnaire and Florida Patient Acceptance Survey (FPAS) to assess their heart failure-specific health status and ICD acceptance, respectively. Information on clinical status was obtained from patients' medical records. Linear regression models were used to compare scores between groups over time. Intention-to-treat and per-protocol analyses showed no significant group differences in patients' health status and ICD acceptance (subscale) scores (all Ps > 0.05). Exploratory subgroup analyses indicated a temporary improvement in device acceptance (FPAS total score) at 6-month follow-up for secondary prophylactic in-clinic patients only (P< 0.001). No other significant subgroup differences were observed. Conclusion Large clinical trials have indicated that RPM can safely and effectively replace most in-clinic check-ups of ICD patients. The REMOTE-CIED trial results show that patient-reported health status and ICD acceptance do not differ between patients on RPM and patients receiving in-clinic check-ups alone in the first 2 years after ICD implantation.

Background Eight-mm ablation catheters are widely used in cavotricuspid isthmus ablation (CTI) for treatment of right sided atrial flutter. However a high success rate, these large ablation tips comes with adisadvantage of lower resolution of fractionated signals. Purpose The aim of this study was to evaluate the additional diagnostic value of the electrograms recordedfrom mini electrodes (MEs) in an 8-mm ablation catheter tip during CTI. Methods CTI-ablation procedures were compared retrospectively in two groups, namely, group A: the Abbott Safire 8-mm tip with a 3D mapping system (n =37) and group B: the Boston Scientific MiFi IntellaTip XP 8-mm tip without a 3D mapping system (n=13). We analyzedacute procedural success, ablation characteristics and recurrence rate at one-year follow-up. Electrograms from MEs were analyzedright before the onset of the critical ablation application that resulted in acute CTI-block. We determined whether these ME electrograms had additional diagnostic value in addition to of the 8-mm tip derivedelectrogram. Results At the onset of the critical ablation application, the MEs had an important additional value in 3 out of 13 cases as local signals were sensed on the MEs that were not recorded by the 8-mm tip electrode. In 2cases the ME did not show local electrogramsalthough the ablationwas still effective. Acute procedural and long-term success wereobserved in all patients. No differences were found in time to bidirectional block, procedure time or fluoroscopic exposure. Conclusion Our data show that signals recorded from the MEs had additional diagnostic value, but only in asmall percentage of the patients. We did not observe, although omitting 3D-mapping in the ME group, any differencebetween groups with regard to procedural or ablation characteristicsduring CTI-ablation.

Background Implantable cardioverter-defibrillators (ICDs) are widely used for the prevention of sudden cardiac death. At present, both clinical benefit and cost-effectiveness of ICD therapy in primary prevention patients are topics of discussion, as only a minority of these patients will eventually receive appropriate ICD therapy. Methods/design The DO-IT Registry is a nationwide prospective cohort with a target enrolment of 1,500 primary prevention ICD patients with reduced left ventricular function in a setting of structural heart disease. The primary outcome measures are death and appropriate ICD therapy for ventricular tachyarrhythmias. Secondary outcome measures are inappropriate ICD therapy, death of any cause, hospitalisation for ICD related complications and for cardiovascular reasons. As of December 2016, data on demographic, clinical, and ICD characteristics of 1,468 patients have been collected. Follow-up will continue up to 24 months after inclusion of the last patient. During follow-up, clinical and ICD data are collected based on the normal follow-up of these patients, assuming ICD interrogations take place every six months and clinical follow-up is once a year. At baseline, the mean age was 66 (standard deviation [SD] 10) years and 27% were women. Conclusion The DO-IT Registry represents a real-world nationwide cohort of patients receiving ICDs for primary prevention of sudden cardiac death with reduced left ventricular function in a setting of structural heart disease. The registry investigates the efficacy of the current practice and aims to develop prediction rules to identify subgroups who will not (sufficiently) benefit from ICD implantation and to provide results regarding costs and budget impact of targeted supply of primary preventions ICDs.

Background: Remote ischemic preconditioning (remote IPC) induced by short non-deleterious ischemic episodes prior to an index ischemic event is known to protect the heart from lethal myocardial ischemia-reperfusion (I/R) injury.Although demonstrated to be effective across almost all species, the underlying signaling pathways and specifically a role for nitric oxide (NO) remain poorly understood.We and others recently showed that brief episodes of limb I/R via blood pressure cuff in-/deflations increases endothelial NO synthase (eNOS) activity with a subsequent formation of NO, nitroso species (RNO) and nitrite.Nitrite, in turn, has been shown to protect the myocardium from lethal ischemia-reperfusion when activated by the heme globin myoglobin (Mb).We therefore hypothesized that remote IPC initiates the release of NO species in an eNOS-dependent manner, and that Mb is required to reduce this endogenously formed species to NO to protect the myocardium.Methods and Results: This study was conducted using a mouse model of remote IPC followed by open-chest I/R via reversible ligation of the left coronary artery in vivo.Four cycles of remote IPC consisting of 5 minutes of hindlimb ischemia followed by 5 minutes of reperfusion, checked by laser Doppler perfusion imaging, caused a release of NO, RNO and nitrite into the circulation.Remote IPC furthermore stimulated a post-translational modification of mitochondrial complex I by S-nitrosation and a subsequent decrease in reactive oxygen species in the reperfused myocardium.This finally caused a reduction in myocardial infarct size per area at risk from 36±2% to 17±1% in wild-types (n=5,p<0.0001).Targeted disruption of endothelial nitric oxide synthase in eNOS-/-mice impaired the release of NO species during remote IPC and completely abolished the beneficial effects on myocardial necrosis (control vs. remote IPC: 45±3% vs. 41±3%, p=n.s.).Finally, in Mb-deficient mice (Mb-/-) remote IPC caused an increase in NO species, but was without effects on infarct size (control vs. remote IPC: 31±1% vs. 35±2% p=n.s.).All values are means±SEM. Conclusion:A concerted action between vascular and myocardial signaling pathways is involved in the NO triggered protection from remote ischemic preconditioning.While eNOS is essentially required for the formation of circulation NO species as triggering mechanisms, Mb in the heart is required for the activation of nitrite to nitric oxide leading to protection of the myocardium at risk.

BACKGROUND:Coronary artery fistulas (CAFs) are infrequent anomalies, coincidentally detected during coronary angiography (CAG).AIM:To elucidate the currently used diagnostic imaging modalities and applied therapeutic approaches.MATERIALS AND METHODS:Five Dutch patients were found to have CAFs. A total of 170 reviewed subjects were subdivided into two comparable groups of 85 each, treated with either percutaneous 'therapeutic' embolisation (PTE group) or surgical ligation (SL group).RESULTS:In our series, the fistulas were visualised with several diagnostic imaging tests using echocardiography, multidetector computed tomography, and CAG. Four fistulas were unilateral and one was bilateral; five originated from the left and one originated from the right coronary artery. Among the reviewed subjects, high success rates were found in both treatment groups (SL: 97% and PTE: 93%). Associated congenital or acquired cardiovascular disorders were frequently present in the SL group (23%). Bilateral fistulas were present in 11% of the SL group versus 1% of the PTE group. The fistula was ligated surgically in one and abolished percutaneously in another. Medical treatment including metoprolol was conducted in two, and watchful waiting follow-up was performed in one.CONCLUSIONS:Several diagnostic imaging techniques are available for assessment of the anatomical and functional characteristics of CAFs.

A 62-year-old patient presented with dizzy spells after her dual chamber pacemaker (Medtronic Enrhythm P1501DR), implanted for complete AV block, had been reprogrammed to deliver antitachycardia therapy (ATP) for paroxysmal atrial tachycardia. Her symptoms were caused by inhibition of ventricular backup pacing during ATP, leading to ventricular asystoles. Inhibition was the result of premature ventricular beats occurring prior to ATP: when ventricular backup pacing is left in the default setting, this pacemaker withholds backup pacing if any of the four preceding events is a sensed event. This case illustrates the possibly hazardous effects of default pacemaker settings, especially in pacemaker-dependent patients. (Neth Heart J 2010;18:323-6.).

Radiofrequency (RF) ablation has proven to be highly effective in the treatment of tachyarrhythmias in Koch's triangle. Despite this successful approach, several disadvantages can be expected, such as patient discomfort, coagulum formation on the electrode, intralesional haemorrhage, endocardial disrup- tion leading to thrombus formation, steam popping or perfor- ation, some degree of tissue disruption with irreversible damage, and ragged edges, making it potentially arrhythmo- genic. More importantly, there is an increased risk for right bundle branch block or inadvertent complete heart block. Therefore, alternative energy sources have been developed, of which cryo ablation seems to be very promising. This energy source has the ability to reversibly demonstrate loss of function with cooling to less negative temperatures (cryo mapping) so that prospective ablation sites can be investi- gated, before a definitive and irreversible lesion is created.1 This should lead to less applications and abolish the risk of per- manent conduction disturbances. Progressive ice formation at the catheter tip causes adherence to the adjacent tissue, making ablation safe to perform during unstable catheter posi- tion or even during tachycardia, without the risk of dislodge- ment of the catheter at termination of the arrhythmia. The more precise delivery of therapy due to cryo mapping and the creation of smaller lesions both in area and volume, together with the formation of a homogenous fibrosis with a proven preservation of the extracellular matrix and a well demarcated border, makes it potentially less thrombo- genic and proarrhythmic. In atrioventricular nodal reentrant tachycardia (AVNRT), it is the only method to target the slow pathway on EP basis, as during cryo mapping programmed atrial stimulation can be performed to determine if the AH jump has disappeared and/or AVNRT is no longer inducible without carrying the risk of dislodgement of the catheter.2 Of course, extensive clinical investigation is needed to evaluate these theoretical advantages. In this context, four articles have recently been published in this journal concerning cryo ablation in patients with AVNRT.3-6.

AIMS:To rely solely on clinical symptoms of recurrent palpitations to evaluate the success of interventional procedures can be misleading. This study was designed to assess the efficacy of event recording in evaluating long-term success in patients treated for atrioventricular nodal reentrant tachycardia (AVNRT) or right posteroseptally located accessory pathways (RPS) either by radiofrequency (RF) or by cryoablation (CA).METHODS AND RESULTS:Sixty-three patients with AVNRT and eight with RPS were randomized. Patients were encouraged to activate an event recorder in the case of recurrent palpitations for the first 3 months. One year after the procedure, patients were asked specific arrhythmia related questions. Thirty-six patients underwent RF and 35 CA. Acute success was finally achieved in 34 (94%) patients in the RF and 33 (94%) in the CA groups. Assessment of long-term success demonstrated a similar proportion of palpitations in the RF and CA groups: 11 (31%) vs. 17 (49%). Only 12 patients activated the event recorder, four patients in RF, including one patient with chest pain, and eight in the CA group. Analysis of recordings revealed recurrent AVNRT or circus movement tachycardia in four patients (one RF and three CA), atrial fibrillation in one RF patient, and sinus tachycardia in six (one RF and five with CA). In addition, a complete 12 lead ECG of a recurrent arrhythmia was made in three RF and two CA patients (in-hospital or after the event recording). A total of seven patients underwent a second procedure (four RF and three CA). Without the event recorder, seven patients would have been misclassified as having recurrent arrhythmia.CONCLUSION:Event recording enhances the sensitivity of detecting arrhythmia recurrences in evaluating therapy efficacy and should be considered in every interventional follow-up study. Analysis of recordings showed that CA is as effective as RF in the treatment of AVNRT and RPS at long-term follow-up.

Today, radiofrequency (RF) catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT) is accompanied by a high success, a low recurrence, and a low complication rate. Despite the fact that over the years this technique has been refined, several shortcomings still remain. In this overview, the most important pitfalls in the treatment of AVNRT with RF energy are discussed. Cryothermy has the ability to overcome some of them. Both ice mapping and cryoadherence are important characteristics of this energy source to study prospective ablation sites before a definitive and irreversible lesion is created. Theoretically, this could lead to less applications with less tissue damage and abolish the risk for permanent conduction disturbances. The early experience with this technique will be described. Until now, it still has to be proven that in a large cohort of patients, cryothermy is at least as effective, and safer than RF.

textabstractKoch’s triangle is an intruiging area. On the atrial aspect, the triangular area itself is delineated by the tendon of Todaro, which inserts in the atrial aspect of the central fibrous body to mark the apex of Koch´s triangle. The ventricular border is formed by the septal leaflet of the tricuspid valve. The base of the triangle is marked by the inferior right atrium around the orifice of the coronary sinus (cavo-tricuspid isthmus), along with the musculature extending to the hinge of the septal leaflet of the tricuspid valve, i.e. septal isthmus. The anatomy and electrophysiological chararteristics of this region provide a substrate for different arrhythmias to develop. Chapter 1 is devoted to address to all these different aspects. In the first part an overview is given of the known embryology of the atrioventricular conduction axis and its direct environment, as well as the anatomy and electrophysiological characteristics of this region. Until now a lot of questions on its anatomy and physiology still exist, despite intensive research. As already mentioned, different arrhythmias can develop, which can be cured with transvenous radiofrequency (RF) catheter ablation, although some pitfalls still remain present.

Background: Radiofrequency (1717) catheter ablation is highly effective with a low complication rate. However, lesions created by RF energy are irreversible, inhomogeneous, and therefore potentially proarrhythmic.Objectives: The aim of this study was to examine the magnitude and importance of long-term proarrhythmic effects of RF energy. Methods andResults: Between 1991 and 1995, 120 patients underwent RF ablation for atrioventricular nodal reentrant tachycardia (AVNRT). Patient data were collected by contacting patients and/or filling out a questionnaire, and medical files were screened for recurrent, documented arrhythmias, pharmacological treatment, and repeated EP study. Referring cardiologists were asked about recurrences of tachyarrhythmias. Fourteen patients (11%) were lost to follow-up. During a mean follow-up of 10 years, six patients died. Recurrences of AVNRT were not any more observed after 3 years after ablation. A total of 29 patients (24%) suffered from new arrhythmias, 6 from type 1 atria] flutter, 6 from atrial tachycardia, 9 from atrial fibrillation, and finally 16 from symptomatic premature atria] contractions (PACs), needing medical treatment or a combination of these arrhythmias. Nine patients underwent pacemaker implantation, 4 after developing procedural atrioventricular (AV) conduction disturbances, 2 after His ablation for permanent atria] fibrillation, 1 patient for sick sinus syndrome, and another 2 patients after developing late AV block, respectively, 7 and 9 years after ablation.Conclusion: During long-term follow-up after RF ablation for AVNRT, no AVNRT recurrences were observed, but 29 patients (24%) suffered from new arrhythmias or late AV block. This potential proarrhythmic effect of RF energy promotes the application of alternative energy sources for ablative therapies for cardiac arrhythmias.

Background Myocardial contrast echocardiography (MCE) allows visualization of radiofrequency (RF) ablation lesions in the left ventricle in an animal model. Aim: To test whether MCE allows visualization of RF and cryo ablation lesions in the human right atrium using three-dimensional echocardiography. Methods 18 patients underwent catheter ablation of a supraventricular tachycardia and were included in this prospective single-blind study. Twelve patients were ablated inside Koch's triangle and 6, who served as controls, outside this area. Three-dimensional echocardiography of Koch's triangle was performed before and after the ablation procedure in all patients, using respiration and ECG gated pullback of a 9 MHz ICE transducer, with and without continuous intravenous echocontrast infusion (SonoVue, Bracco). Two independent observers analyzed the data off-line. Results MCE identified ablation lesions as a low contrast area within the normal atrial myocardial tissue. Craters on the endocardial surface were seen in 10 (83%) patients after ablation. Lesions were identified in 11 out of 12 patients (92%). None of the control patients were recognized as having been ablated. The confidence score of the independent echo reviewer tended to be higher when the number of applications increased. Conclusions 1. MCE allows direct visualization of ablation lesions in the human atrial myocardium. 2. Both RF and cryo energy lesions can be identified using MCE.