Left atrial total emptying fraction measured by cardiovascular magnetic resonance imaging predicts low-voltage areas detected during electroanatomical mapping.

AIMS: Low-voltage areas (LVAs) found during left atrial (LA) electroanatomical mapping are increasingly targeted by radiofrequency catheter ablation (RFCA) on top of pulmonary vein isolation to improve arrhythmia-free survival in patients with atrial fibrillation (AF). However, pre-procedural prediction of LVAs remains challenging. The purpose of the present study was to describe the association between parameters of LA function and dimensions, respectively, derived from pre-procedural cardiovascular magnetic resonance (CMR) imaging, and the presence of LVAs on LA voltage mapping. METHODS AND RESULTS: Patients who underwent first-time RFCA for paroxysmal or persistent AF and who were in stable sinus rhythm during pre-procedural CMR imaging were included in this study. Cardiovascular magnetic resonance-derived parameters of LA function and dimensions were calculated. Low-voltage areas were defined as areas with bipolar voltage amplitudes of ≤0.5 mV on electroanatomical mapping. In total, 259 consecutive patients were included in this analysis. Low-voltage areas were found in 25 of 259 patients (9.7%). Compared with those without LVAs, patients with LVAs were significantly older, were more likely to be female, had a higher CHA2DS2-VASc score, had larger LA volumes, and had a lower LA total emptying fraction (TEF). In multivariate analysis, only LA TEF [odds ratio (OR) 0.885, 95% confidence interval (CI) 0.846-0.926, P < 0.001] and the CHA2DS2-VASc score (OR 1.507, 95% CI 1.115-2.038, P = 0.008) remained independently associated with the presence of LVAs. CONCLUSION: Left atrial TEF and the CHA2DS2-VASc score were independently associated with the presence of LVAs found during LA electroanatomical mapping. These findings may help to improve pre-procedural prediction of pro-arrhythmogenic LVAs and to improve peri-procedural patient management.

Patient perspectives on same-day discharge following catheter ablation for atrial fibrillation: results from a patient survey as part of the monocentric FAST AFA trial.

AIMS: Same-day discharge (SDD) following catheter ablation (CA) of atrial fibrillation (AF) was already introduced in selected facilities in Europe, but a widespread implementation has not yet succeeded. Data on patients' perspectives are lacking. Therefore, we conducted a survey to address patients' beliefs towards SDD and identify variables that are associated with their evaluation. METHODS AND RESULTS: As part of the prospective, monocentric FAST AFA trial, patients aged ≥20 years undergoing left atrial CA for AF were asked to participate in the survey consisting of a study-specific questionnaire, the AF knowledge scale, and pre-defined patient-reported outcome measures. The study cohort was stratified based on SDD willingness, and a logistic regression analysis was used to identify predictors for patients' valuation. Between 26 July 2021 and 01 July 2022, 256 of 376 screened patients consented to study participation of whom 248 (mean age 61.8 years, 33.9% female) completed the SDD survey. Of them, 50.0% were willing to have SDD concepts integrated into their clinical course with increased patient comfort (27.5%), shorter waiting times (14.6%), and a cost-efficient treatment (14.0%) being imaginable benefits. In contrast, expressed concerns included uncertainties with occurring complaints (50.6%), the insufficient recognition (47.8%), and treatment (48.9%) of complications. European Heart Rhythm Association class at baseline and inpatient treatments within the preceding year were predictors for SDD willingness whereas comorbidity burden or AF knowledge were not. CONCLUSION: We provide a detailed survey expressing patients' beliefs towards SDD following left atrial CA. Our findings may facilitate adequate patient selection to improve the future implementation of SDD programs in suitable cohorts.

A randomized trial of non-fasting vs. fasting for cardiac implantable electronic device procedures (Fast-CIED Study).

AIMS: Data on safety and efficacy of a non-fasting strategy in minimal invasive cardiac procedures are lacking. We assessed a non-fasting strategy compared with a fasting strategy regarding patient's well-being and safety in elective cardiac implantable electronic device (CIED) procedures. METHODS AND RESULTS: In this randomized, single-blinded clinical trial, 201 patients (non-fasting = 100, fasting = 101) with a mean age of 72.0 ± 11.6 years (66.7% male) were assigned to a non-fasting strategy (solids/fluids allowed up to 1 h) or a fasting strategy (at least 6 h no solids and 2 h no fluids) before the procedure and analysed on an intention-to-treat basis. The co-primary outcomes were patients' well-being scores (based on numeric rating scale, 0-10) and incidence of intra-procedural food-related adverse events, including vomiting, perioperative pulmonary aspiration, and emergency intubation. Renal, haematological, and metabolic blood parameters and 30-day follow-up data were gathered. The summed pre-procedural patients' well-being score was significantly lower in the non-fasting group [non-fasting: 13.1 ± 9.6 vs. fasting: 16.5 ± 11.4, 95% confidence interval (CI) of mean difference (MD) -6.35 to -0.46, P = 0.029], which was mainly driven by significantly lower scores for hunger and tiredness in the non-fasting group (non-fasting vs. fasting; hunger: 0.9 ± 1.9 vs. 3.1 ± 3.2, 95% CI of MD -2.86 to -1.42, P < 0.001; tiredness: 1.6 ± 2.3 vs. 2.6 ± 2.7, 95% CI of MD -1.68 to -0.29, P = 0.023). No intra-procedural food-related adverse events were observed. Relevant blood parameters and 30-day follow-up did not show significant differences. CONCLUSION: These results showed that a non-fasting strategy is beneficial to a fasting one regarding patient's well-being and comparable in terms of safety for CIED procedures (NCT04389697).

Clinical utility of cardiovascular magnetic resonance imaging in patients with implantable cardioverter defibrillators presenting with electrical instability or worsening heart failure symptoms.

BACKGROUND: Data on the usefulness of cardiovascular magnetic resonance (CMR) imaging for clinical decision making in patients with an implanted cardioverter defibrillator (ICD) are scarce. The present study determined the impact of CMR imaging on diagnostic stratification and treatment decisions in ICD patients presenting with electrical instability or progressive heart failure symptoms. METHODS: 212 consecutive ICD patients underwent 1.5 T CMR combining diagnostic imaging modules tailored to the individual clinical indication (ventricular function assessment, myocardial tissue characterization, adenosine stress-perfusion, 3D-contrast-enhanced angiography); four CMR examinations (4/212, 2%) were excluded due to non-diagnostic CMR image quality. The resultant change in diagnosis or clinical management was determined in the overall population and compared between ICD patients for primary (115/208, 55%) or secondary prevention (93/208, 45%). Referral indication consisted of documented ventricular tachycardia, inadequate device therapy or progressive heart failure symptoms. RESULTS: Overall, CMR imaging data changed diagnosis in 40% (83/208) with a significant difference between primary versus secondary prevention ICD patients (37/115, 32% versus 46/93, 49%, respectively; p = 0.01). The information gain from CMR led to an overall change in treatment in 21% (43/208) with a similar distribution in primary versus secondary prevention ICD patients (25/115,22% versus 18/93,19%, p = 0.67). The effect on treatment change was highest in patients initially scheduled for ventricular tachycardia ablation procedure (18/141, 13%) with revision of the treatment plan to medical therapy or coronary revascularization. CONCLUSIONS: CMR imaging in ICD patients presenting with electrical instability or worsening heart failure symptoms provided diagnostic or management-changing information in a considerable proportion (40% and 21%, respectively).

Oesophageal Probe Evaluation in Radiofrequency Ablation of Atrial Fibrillation (OPERA): results from a prospective randomized trial.

AIMS: The aim of the study was to determine the incidence of oesophageal lesions after radiofrequency ablation (RFA) of atrial fibrillation (AF) with or without the use of oesophageal temperature probes. METHODS AND RESULTS: Two hundred patients were prospectively randomized into two groups: the OPERA+ group underwent RFA using oesophageal probes (SensiTherm™); the OPERA- group received RFA using fixed energy levels of 25 W at the posterior wall without an oesophageal probe. All patients underwent post-interventional endoscopy and Holter-electrocardiogram after 6 months. (Clinical.Trials.gov: NCT03246594). One hundred patients were randomized in OPERA+ and 100 patients in OPERA-. The drop-out rate was 10%. In total, 18/180 (10%) patients developed endoscopically diagnosed oesophageal lesions (EDEL). There was no difference between the groups with 10/90 (11%) EDEL in OPERA+ vs. 8/90 (9%) in OPERA- (P = 0.62). Despite the higher power delivered at the posterior wall in OPERA+ [28 ± 4 vs. 25 ± 2 W (P = 0.001)], the average EDEL size was equal [5.7 ± 2.6 vs. 4.5 ± 1.7 mm (P = 0.38)]. The peak temperature did not correlate with EDEL size. During follow-up, no patient died. Only one patient in OPERA- required a specific therapy for treatment of the lesion. Cumulative AF recurrence after 6 (3-13) months was 28/87 (32%) vs. 34/88 (39%), P = 0.541. CONCLUSION: This first randomized study demonstrates that intraoesophageal temperature monitoring using the SensiTherm™ probe does not affect the probability of developing EDEL. The peak temperature measured by the thermoprobe seems not to correlate with the incidence of EDEL. Empiric energy reduction at the posterior wall did not affect the efficacy of the procedure.

Global multielectrode contact-mapping plus ablation with a single catheter in patients with atrial fibrillation: Global AF study.

INTRODUCTION: The critical question for technological advancement of catheter ablation of atrial fibrillation (AF) is whether a creative new concept can combine and even improve the options of single-tip catheters with the simplicity of the use of balloon catheters. Herein are described the results from the first clinical study of a new multielectrode contact-mapping plus ablation array (Globe) offering such a complete solution. METHODS AND RESULTS: The multielectrode Globe array consists of 16 flat ribs with 122 gold-plated electrodes. Each electrode can record electrograms, ablate, pace, and can measure tissue contact and temperature. Single-shot pulmonary vein isolation (PVI) is possible with temperature-guided ablation of up to 24 electrodes simultaneously with automatic, individual power control of every electrode. Sixty patients with symptomatic AF underwent PVI using the Globe. In all sixty patients, acute PVI was achieved in 232 of 234 attempted PVs (99.1%). In 34 patients treated with "single-hot-shot" ablation, PVI was achieved in 136 of 136 PVs (100%). Single-procedure 12-month freedom from AF off antiarrhythmic drugs in the "single-hot-shot" group was 75.5% and freedom from AF/atrial tachycardia 72.3%. In two patients, pericardial tamponade was observed, one after a transseptal puncture, and one during array insertion with an over-advanced sheath. There were no other device-related serious adverse events, including stroke, PV stenosis, esophageal perforation, or phrenic nerve palsy. CONCLUSIONS: In this first clinical series, the Globe catheter was found to be an easy-to-use system for single-shot PVI. The continuously updated multielectrode voltage and activation mapping data indicate future options for mapping and ablation beyond PVI.

Cardiovascular magnetic resonance imaging in patients with cardiac implantable electronic devices: best practice and real-world experience.

AIMS: Cardiovascular magnetic resonance (CMR) imaging has long been a contraindication for patients with a cardiac implantable electronic device (CIED). Recent studies support the feasibility and safety for non-thoracic magnetic resonance imaging, but data for CMR are sparse. The aim of the current study was to determine the safety in patients with magnetic resonance (MR)-conditional or non-MR-conditional CIED and to develop a best practice approach. METHODS AND RESULTS: All patients with a CIED undergoing CMR imaging (1.5 T) between April 2014 and April 2017 were included in the study. Devices were programmed according to the standardized protocol directly before and after the CMR examination. Follow-up interrogation was performed 6 months after CMR examination. Results were compared with a large, reference cohort of CIED patients not undergoing any MR examination. A total of 200 consecutive patients with a CIED (non-MR-conditional, n = 103) were included in the study. Directly after CMR imaging, one device failure (0.5%, battery status = end of service) was noted necessitating premature generator replacement. In three patients (2%) of pacemaker/implantable cardioverter-defibrillator (ICD) carriers a sustained ventricular tachycardia (VT) occurred during CMR imaging. Ten ICD showed a decrease in battery capacity immediately after CMR. Overall, the reference cohort showed comparable changes of CIED function during follow-up. CONCLUSION: With adherence to a standardized protocol and established exclusion criteria CMR imaging could safely be performed in patients with a CIED. The potential risks of device malfunction necessitate the presence of a device trained individual during the entire CMR examination. If there is a history of VT storm the attendance of an experienced cardiologist, should be mandatory.

Characteristics of the ablation lesions in cardiac magnetic resonance imaging after radiofrequency ablation of ventricular arrhythmias in relation to the procedural success.

BACKGROUND: In human patients, studies about the cardiac magnetic resonance (CMR) appearance of the acute radiofrequency (RF) lesions in relation to the procedural outcomes after catheter ablation (CA) of ventricular arrhythmias (VA) are scarce. We aimed to investigate the RF lesions characteristics in relation to the procedural success. METHODS: Patients referred for ablation of VA received CMR (1.5 T) using gadolinium contrast before and after ablation. CA in left ventricle was performed using a 3.5-mm irrigated catheter. The volume and transmurality of the RF-induced lesions were measured in early gadolinium-enhanced postablation CMRs. Acute failure was defined as persistently inducible VA at the end of the CA. RESULTS: Twenty-five patients (60.7 ±â€¯9.8 years, 19 with sustained ventricular tachycardia) were studied. All RF lesions had nonenhanced core. The volume of the nonenhanced lesions showed positive correlation with the maximal RF power (r = 0.598, P = .002) and the impedance drop (r = 0.416, P = .038). Patients with transmural (≥75%) lesions had significantly larger impedance drop as compared to those with nontransmural lesions (<75%): 20.3 ±â€¯9.4 versus 13.5 ±â€¯4.3, P = .037. In the failures, the lesions volume was nonsignificantly larger: 3.86 ±â€¯3.3% versus 2.6 ±â€¯1.7%, P = .197; however, it was considerably deeper: 86 ±â€¯13% versus 62 ±â€¯26%, P = .03. CONCLUSIONS: CMR after VA ablation showed nonenhanced lesions resembling the no-reflow phenomenon in myocardial infarction. Although the size and the depth of the RF injury correlated with the ablation energy and impedance drop, they were not associated with acute ablation success.

Association of left ventricular late gadolinium enhancement with left atrial low voltage areas in patients with atrial fibrillation.

Aims: Presence of late gadolinium enhancement (LGE) is related to adverse cardiovascular outcome. Many patients suffering from atrial fibrillation (AF) undergo cardiovascular magnetic resonance (CMR) imaging prior to ablation. Since quantification of atrial fibrosis still lacks reproducibility, we sought to investigate risk factors for the presence of left ventricular (LV)-LGE and a possible correlation between ventricular fibrosis as defined by positive LGE and pathological atrial voltage maps evaluated by 3D mapping systems. Methods and results: Between May 2015 and January 2017, 241 patients with AF (73% persistent AF, 71% male, mean age 62.8 ± 10.1 years, Redo procedure in 24%, AF history 4.5 ± 5.2 years) underwent CMR including LV LGE prior to pulmonary vein (PV) isolation at Heart Center Leipzig. Depending on CMR results, two groups were separated: 'LV-LGE negative' (Group A, n = 197, 82%) and 'LV-LGE positive' (Group B, n = 44, 18%). To identify low voltage areas (LVA), a 3D electro-anatomic map was created during PV isolation. Multivariate analysis revealed male gender [odds ratio (OR) 7.6, 95% confidence interval (95% CI) 2.4-23.9, P = 0.001] and an increased CHA2DS2VASc Score (OR 1.6, 95% CI 1.2-2.2, P = 0.004) as significantly associated with LV-LGE. Impaired left ventricular ejection fraction, LV dilatation, larger LA size and, enlarged septum diameter occurred significantly more often in the 'LGE positive' group. Low voltage areas were detected in 83 patients overall (34%): Group A: n = 64/197 (33%), Group B: n = 19/44 (43%) (P = 0.177). Conclusion: Male gender and high CHA2DS2VASc Score are significantly associated with presence of LV-LGE, but LV-LGE is not associated with left atrial LVA.

Artefact-free late gadolinium enhancement imaging in patients with implanted cardiac devices using a modified broadband sequence: current strategies and results from a real-world patient cohort.

Aims: Cardiac magnetic resonance (CMR) imaging in patients with implanted cardiac devices is often limited by device-related imaging artefacts. Limitations can potentially be overcome by employing a broadband late gadolinium enhancement (LGE)-CMR imaging technique. The purpose of this study was to investigate the relationship between implanted cardiac devices and the optimal frequency offset on broadband LGE-CMR imaging to increase the artefact-free visibility of myocardial segments. Methods and results: A phantom study was performed to characterize magnetic field disturbances related to 15 different cardiac devices. This was complemented by B0 and B1+ imaging of three different device types in four healthy volunteers. Findings were validated in 28 patients with an indication for arrhythmogenic substrate characterization before catheter ablation. In the phantom study, the placement of a PM, implantable cardioverter-defibrillator (ICD) or CRT-D generator led to a significant impairment of the radiofrequency field. B0 mapping in phantom and volunteers showed the highest off-resonance maximum with CRT-D systems with the maximum off-resonance significantly decreasing for ICD or PM systems, respectively. In all patients, with conventional LGE imaging 73.1% (61.5-92.3%) of LV segments were free of device-related artefacts, while with the broadband LGE technique, a significant increase of artefact-free segments was achieved [96.4% (85.7-100%); P = 0.00008]. Conclusion: Using a modified broadband sequence for LGE imaging significantly increased the number of artefact-free myocardial segments thereby leading to improved diagnostic value of the CMR exam. Since the occurrence and extent of hyperintensity artefacts are closely related to the individual device, more studies are warranted to evaluate if the results can be extrapolated to other devices and manufacturers.

Supraventricular arrhythmias in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy associate with long-term outcome after catheter ablation of ventricular tachycardias.

Aims: This study aimed to assess the impact of supraventricular tachycardia (SVT) on long-term results of radiofrequency catheter ablation therapy of ventricular tachycardia (VT) in a large cohort of patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). Methods and results: Supraventricular tachycardia occurrence has been studied in patients from our ARVD/C registry (70 patients, 48 male, age 53.2 ± 14.0, 45 patients (64.3%) with previous VT ablation). SVT were diagnosed in 26 of 70 patients (37.1%). Atrial fibrillation (AF) was the most frequent atrial arrhythmia, diagnosed in 17 patients (24.3%). In univariate analysis advanced age, clinical symptoms of heart failure, enlarged right atrium, diagnosis of significant tricuspid regurgitation (TR), and inappropriate implantable cardioverters-defibrillators therapy were associated with SVT. In binary logistic regression analysis only heart failure: hazard ratio (HR) 10.89, 95% confidence interval (95% CI) 1.08-109.96 (P = 0.043) and significant TR: HR 4.79, 95% CI 1.35-16.33 (P = 0.015) remained associated with SVT. In patients with previous VT ablation Cox multiple regression survival analysis revealed older age (≥53 years): HR 4.63, 95% CI 1.51-14.24 (P = 0.008) and SVT: HR 3.01, 95% CI 1.15-7.89 (P = 0.025) as predictors for VT recurrence during the follow-up. Conclusion: SVT and older age are associated with the recurrence of VT after catheter ablation in patients with ARVD/C.

In vivo validation of a novel algorithm for automatic premature ventricular contractions recognition.

INTRODUCTION: Template-matching algorithms are routinely used in the catheter ablation of patients with premature ventricular contractions (PVCs). However, systematic analysis of the accuracy and spatial resolution of such systems is lacking. Therefore, the aim of this evaluation was to perform a systematic in vivo validation of performance of a novel automated template-matching algorithm. METHODS AND RESULTS: In a porcine model, paced beats simulating PVCs from different origins were investigated. The ability to discriminate between sinus rhythm and PVCs was tested by simulating PVCs using sequential pacing from different cardiac chambers. The accuracy of the algorithm in correctly classifying PVCs was reviewed by an independent investigator. In addition, the spatial resolution of pace matching was evaluated by assessing the QRS morphology discrimination at a distance of 0, 2, 4, and 6 mm of a simulated PVCs focus. The specificity of the algorithm for recognizing simulated PVCs was 99.6% and the sensitivity was 85.3%. There was a significant difference in the discrimination metric discrimination metric (with 0% being a perfect match and 100% being no correlation) between PVC origin (median 0%, interquartile range (IQR) 0-2%) versus at 2 mm (5%, IQR 2-7%), 4 mm (16%, IQR 11-21%), and 6 mm (24%, IQR 19-28%, P < 0.001 for all). The c-statistic for discrimination between PVC origin and a distance ≥ 2 mm was 0.93. CONCLUSIONS: Automated template matching had high specificity and sensitivity, with good spatial discrimination and a pace-mapping resolution in range of 2 mm. Clinical application of this algorithm may assist in the interventional treatment of patients with PVCs.

ECG morphology of premature ventricular contractions predicts the presence of myocardial fibrotic substrate on cardiac magnetic resonance imaging in patients undergoing ablation.

BACKGROUND: The most likely origin of premature ventricular contractions (PVCs) may be deduced from surface electrocardiogram (ECG) analysis while planning an electrophysiological study (EPS). Apart from purely benign forms of increased ventricular ectopy, myocardial substrate (e.g., regional fibrosis) may be present in certain cases, which will significantly impact the ablation approach. Cardiac magnetic resonance (CMR) imaging can reliably identify fibrotic target lesions and, hence, may assist in adequate patient selection and procedural planning. METHODS AND RESULTS: We analyzed 101 patients (59% males, mean age 57.15 ± 15.5 years, mean PVC count 19,801 ± 14,021 per 24 hours) referred for ablation of PVCs. The CMR (1.5T, Philips Ingenia, Best, The Netherlands) protocol included cine and three-dimensional-delayed enhancement imaging using standard cardiac geometries. On surface, ECG right bundle branch block (RBBB) morphology was present in 43% of patients. Twenty-one patients showed the fibrotic substrate on CMR. On univariate analysis, both RBBB morphology (P < 0.001) and presence of multiple PVC morphologies (≥2) significantly predicted the presence of fibrotic substrate (P = 0.01), which various baseline characteristics including left ventricular ejection fraction (45.7 ± 12.6% vs. 50.6 ± 11.0%, P = 0.08) failed to do. CMR-identified fibrosis was associated with the site of origin of the clinical PVCs during EPS and was successfully treated by radiofrequency ablation in 93% (PVC reduction >95%). CONCLUSION: In patients with RBBB morphology and/or multiple PVC patterns, CMR imaging before ablation may be helpful due to the increased prevalence of fibrotic lesions with regard to patient stratification and periprocedural management.

Magnetic resonance imaging guided transatrial electrophysiological studies in swine using active catheter tracking - experience with 14 cases.

OBJECTIVES: To evaluate the feasibility of performing comprehensive Cardiac Magnetic resonance (CMR) guided electrophysiological (EP) interventions in a porcine model encompassing left atrial access. METHODS: After introduction of two femoral sheaths 14 swine (41 ± 3.6 kg) were transferred to a 1.5 T MR scanner. A three-dimensional whole-heart sequence was acquired followed by segmentation and the visualization of all heart chambers using an image-guidance platform. Two MR conditional catheters were inserted. The interventional protocol consisted of intubation of the coronary sinus, activation mapping, transseptal left atrial access (n = 4), generation of ablation lesions and eventually ablation of the atrioventricular (AV) node. For visualization of the catheter tip active tracking was used. Catheter positions were confirmed by passive real-time imaging. RESULTS: Total procedure time was 169 ± 51 minutes. The protocol could be completed in 12 swine. Two swine died from AV-ablation induced ventricular fibrillation. Catheters could be visualized and navigated under active tracking almost exclusively. The position of the catheter tips as visualized by active tracking could reliably be confirmed with passive catheter imaging. CONCLUSIONS: Comprehensive CMR-guided EP interventions including left atrial access are feasible in swine using active catheter tracking. KEY POINTS: • Comprehensive CMR-guided electrophysiological interventions including LA access were conducted in swine. • Active catheter-tracking allows efficient catheter navigation also in a transseptal approach. • More MR-conditional tools are needed to facilitate left atrial interventions in humans.

Implanted defibrillators in trouble: initial device misclassification leads to correct diagnosis-a case series.

AIMS: Supraventricular tachycardia, mistakenly diagnosed as ventricular tachycardia, may lead to inappropriate ICD therapy. Inappropriate ICD therapy associates with increased morbidity and mortality. A reduction of inappropriate therapy is therefore desired. METHODS AND RESULTS: We present three different cases that beautifully illustrate the diagnostic possibilities of stored electrograms. Initial differential diagnoses in all three patients included ventricular tachycardia, focal atrial tachycardia, atrio-ventricular re-entry tachycardia, and atrio-ventricular nodal re-entry tachycardia. The first case was diagnosed as atrio-ventricular nodal re-entry tachycardia. In the second case, atrio-ventricular re-entry tachycardia was revealed. Ectopic atrial tachycardia was the reason for inappropriate therapy in the third patient. CONCLUSION: Thorough analysis of stored electrograms yielded correct diagnosis in all cases, which subsequently was confirmed by electrophysiological study.

Initial Experience With Ultra High-Density Mapping of Human Right Atria.

INTRODUCTION: Recently, an automatic, high-resolution mapping system has been presented to accurately and quickly identify right atrial geometry and activation patterns in animals, but human data are lacking. This study aims to assess the clinical feasibility and accuracy of high-density electroanatomical mapping of various RA arrhythmias. METHODS AND RESULTS: Electroanatomical maps of the RA (35 partial and 24 complete) were created in 23 patients using a novel mini-basket catheter with 64 electrodes and automatic electrogram annotation. Median acquisition time was 6:43 minutes (0:39-23:05 minutes) with shorter times for partial (4.03 ± 4.13 minutes) than for complete maps (9.41 ± 4.92 minutes). During mapping 3,236 (710-16,306) data points were automatically annotated without manual correction. Maps obtained during sinus rhythm created geometry consistent with CT imaging and demonstrated activation originating at the middle to superior crista terminalis, while maps during CS pacing showed right atrial activation beginning at the infero-septal region. Activation patterns were consistent with cavotricuspid isthmus-dependent atrial flutter (n = 4), complex reentry tachycardia (n = 1), or ectopic atrial tachycardia (n = 2). His bundle and fractionated potentials in the slow pathway region were automatically detected in all patients. Ablation of the cavotricuspid isthmus (n = 9), the atrio-ventricular node (n = 2), atrial ectopy (n = 2), and the slow pathway (n = 3) was successfully and safely performed. CONCLUSIONS: RA mapping with this automatic high-density mapping system is fast, feasible, and safe. It is possible to reproducibly identify propagation of atrial activation during sinus rhythm, various tachycardias, and also complex reentrant arrhythmias.

Pulmonary vein dilatation in a case of total pulmonary vein occlusion: Contemporary approach using a combination of 3D-mapping system and image integration.

Pulmonary vein stenosis (PVS) is a known complication of PV isolation procedures for atrial fibrillation. In this report a case of recurring PV occlusion after repeated percutaneous procedures has been described. Focus is on a novel interventional technique employing a three-dimensional mapping system which enables targeting total occlusion of PVs and on the use of a drug eluting balloon. A focused review of the current literature regarding ongoing limitations of PV stenosis treatment has been provided. © 2015 Wiley Periodicals, Inc.

Real-time magnetic resonance-guided ablation of typical right atrial flutter using a combination of active catheter tracking and passive catheter visualization in man: initial results from a consecutive patient series.

AIMS: Recently cardiac magnetic resonance (CMR) imaging has been found feasible for the visualization of the underlying substrate for cardiac arrhythmias as well as for the visualization of cardiac catheters for diagnostic and ablation procedures. Real-time CMR-guided cavotricuspid isthmus ablation was performed in a series of six patients using a combination of active catheter tracking and catheter visualization using real-time MR imaging. METHODS AND RESULTS: Cardiac magnetic resonance utilizing a 1.5 T system was performed in patients under deep propofol sedation. A three-dimensional-whole-heart sequence with navigator technique and a fast automated segmentation algorithm was used for online segmentation of all cardiac chambers, which were thereafter displayed on a dedicated image guidance platform. In three out of six patients complete isthmus block could be achieved in the MR scanner, two of these patients did not need any additional fluoroscopy. In the first patient technical issues called for a completion of the procedure in a conventional laboratory, in another two patients the isthmus was partially blocked by magnetic resonance imaging (MRI)-guided ablation. The mean procedural time for the MR procedure was 109 ± 58 min. The intubation of the CS was performed within a mean time of 2.75 ± 2.21 min. Total fluoroscopy time for completion of the isthmus block ranged from 0 to 7.5 min. CONCLUSION: The combination of active catheter tracking and passive real-time visualization in CMR-guided electrophysiologic (EP) studies using advanced interventional hardware and software was safe and enabled efficient navigation, mapping, and ablation. These cases demonstrate significant progress in the development of MR-guided EP procedures.

Renal denervation for treatment of cardiac arrhythmias: state of the art and future directions.

It has now been more than a quarter of a century since modulation of the sympathetic nervous system was proposed for the treatment of cardiac arrhythmias of different origins. But it has also been some time since some of the early surgical attempts have been abandoned. With the development of ablation techniques, however, new approaches and targets have been recently introduced that have revolutionized our way of thinking about sympathetic modulation. Renal nerve ablation technology is now being successfully used for the treatment of resistant hypertension, but the indication spectrum might broaden and new therapeutic options might arise in the near future. This review focuses on the possible impact of renal sympathetic system modulation on cardiac arrhythmias, the current evidence supporting this approach, and the ongoing trials of this method in electrophysiological laboratories. We will discuss the potential roles that sympathetic modulation may play in the future.

Insights from preclinical ultra high-density electroanatomical sinus node mapping.

AIMS: Although sinus node modification by catheter ablation is an established therapy for the treatment of inappropriate sinus tachycardia, there is incomplete understanding of sinus node anatomy and function but also limited electroanatomical mapping data. Recently, an automatic, ultra high-resolution mapping system has been presented to accurately and quickly identify right atrial (RA) geometry and activation patterns but detailed assessment of sinus node activation has not been performed which was one aim of this study. Preclinical experiences are compared with previous sinus node mapping studies in animals and humans, and potential clinical implications for catheter ablation are discussed. METHODS AND RESULTS: In anaesthetized and ventilated 14 pigs, 30 endocardial and 2 eipcardial RA maps were generated using the Rhythmia™ mapping system without complications and earliest activation sites (EAS) and sinus break-out (SBO) were determined. At baseline, EAS and SBO were located anterior to the middle (n = 6) or lower third (n = 8) of the crista terminalis exhibiting a unicentric activation pattern in all cases. Conduction pathways were directed anterior, posterior, superior, or inferior with substantial inter-individual variation in direction, pathway distance, and conduction time. Orciprenaline, propranolol, or amiodarone shifted endocardial activation with considerable variation between animals with inconsistent patterns. Multicentric activation was found in one case after orciprenaline infusion. Sequential endocardial and epicardial high-density mapping of the RA was performed in two animals and showed a high congruence of the sinus node activation in the endo- and the epicardial map. CONCLUSION: Ultra high-density mapping allows fast, simple, and very detailed assessment of sinus node activation. Future studies are clearly needed to evaluate novel mapping and ablation strategies for an improved understanding of sinus node disease and better outcomes.