Screening tools for the detection of clinically silent cardiac sarcoidosis.

BACKGROUND: clinically silent cardiac sarcoidosis (CS) may be associated with adverse outcomes, hence the rationale for screening patients with extracardiac sarcoidosis. The optimal screening strategy has not been clearly defined. METHODS: patients with extra-cardiac sarcoidosis were prospectively included and underwent screening consisting of symptom history, electrocardiography (ECG), transthoracic echocardiogram, Holter, and signal-averaged ECG (SAECG). Cardiac magnetic resonance (CMR) was performed in all patients. Clinically silent CS was defined as CMR demonstrating late gadolinium enhancement (LGE) in a pattern compatible with CS according to a majority of independent and blinded CMR experts. Significant cardiac involvement was defined as the presence of LGE ≥6% and/or a positive fluorodeoxyglucose-positron emission tomography. RESULTS: among the 129 patients included, clinically silent CS was diagnosed in 29/129 (22.5%), and 19/129 patients (14.7%) were classified as CS with significant cardiac involvement. There was a strong association between hypertension and CS (p < 0.05). Individual screening tools provided low diagnostic yield; however, combination of tests performed better, for example, a normal Holter and a normal SAECG had negative predictive values of 91.7%. We found consistently better diagnostic accuracy for the detection of CS with significant cardiac involvement. CONCLUSION: clinically silent CS and CS with significant cardiac involvement were found in 22.5% and 14.7% of patients with extra-cardiac sarcoidosis. The association with hypertension raises the possibility that some cases of hypertensive cardiomyopathy may be mistaken for CS. Screening with readily available tools, for example Holter and SAECG, may help identifying patients without CS where additional CMR is not needed.

En mann i 60-årene med dyspné og systolisk bilyd etter hjerteinfarkt.

Background: Ventricular septal rupture (VSR) following acute myocardial infarction is rare in the modern revascularisation era. Nevertheless, clinical awareness is paramount, as presentation may vary. Case presentation: A middle-aged male with no history of cardiovascular disease developed progressive heart failure symptoms while travelling abroad. Initial workup revealed a prominent systolic murmur, but findings were inconsistent with acute coronary syndrome. Transthoracic echocardiogram showed a small hypokinetic area in the basal septum, preserved left ventricular function and no significant valvulopathy. Despite the absence of chest pain, an invasive angiography revealed occlusion of a septal branch emerging from the left anterior descending artery, otherwise patent coronary arteries. Despite administration of diuretics, the patient remained symptomatic and presented two months later to his primary care provider with a persisting systolic murmur. He was subsequently referred to the outpatient cardiology clinic where echocardiography revealed a large VSR involving the basal anteroseptum of the left ventricle with a significant left-to-right shunt. After accurate radiological and haemodynamic assessment of the defect, he successfully underwent elective surgical repair. Interpretation: Although traditionally associated with large transmural myocardial infarctions, VSR may arise also from minor, subclinical events. A new-onset murmur is a valuable hint for the alert clinician.

Diagnostics, treatment and outcomes of cardiac sarcoidosis in a Norwegian cohort.

BACKGROUND: Evidence-based guidelines for cardiac sarcoidosis (CS) regarding use of second- and third-line agents, treatment duration, surveillance and prognostic factors are lacking. OBJECTIVE: To analyze the clinical presentation, diagnostics, treatment, monitoring and clinical outcomes in a Norwegian cohort. METHODS: Using discharge diagnoses between 2017 through 2020 from a large tertiary center, we identified 52 patients with CS. We performed a systematic chart review following a pre-specified checklist. The primary outcome of major cardiovascular events (MACE) was defined as a composite of cardiovascular hospitalization, defibrillator therapy, cardiac transplantation, or death. RESULTS: 18-fluorodeoxyglucose positron emission tomography (FDG-PET) showed pathological tracer uptake in 35/36 (97%) of immunosuppression-naïve patients. Immunosuppressive treatment was administered to 49/52 patients (94%) for a median of 43 (IQR 34) months; 69% were treated with second-line (methotrexate, azathioprine, mycophenolate mofetil) and 25% with third-line (rituximab, infliximab) agents, respectively. Rituximab reduced inflammation as assessed by interval FDG-PET imaging and was overall well tolerated. Median duration to first MACE was 6 (IQR 10) months and 17/23 patients (74%) experienced a MACE within 12 months from CS diagnosis. No mortality was recorded and 20% achieved full remission. Age below the median of 53 years at time of diagnosis was associated with an increased risk of a MACE. CONCLUSION: Long-term immunosuppression including a liberal use of non-steroidal agents, appeared essential in treating CS. Although the burden of cardiovascular events was substantial, the survival was excellent in this contemporary cohort. Prospective randomized studies are urgently needed to define the best therapy for these patients.

Incidence of Atrial Fibrillation as the Initial Manifestation of Cardiac Sarcoidosis: Insights From a Catheter Ablation Registry.

Background: Cardiac sarcoidosis (CS) is a rare form of arrhythmogenic cardiomyopathy; a delayed diagnosis can lead to significant consequences. Patients with clinically manifest CS often have minimal extracardiac involvement and thus frequently present initially to cardiology. Indeed, certain specific arrhythmic scenarios should trigger investigations for undiagnosed CS. Atrial fibrillation (AF) has been described as one of the presenting features of CS; however, the incidence of this presentation is not known. Methods: At our institution, cardiac computerized tomography is routinely performed prior to catheter ablation for AF. Noncardiac incidental findings are described by radiologists and are followed-up by interval investigations. We systematically reviewed noncardiac reports from 1574 consecutive patients in our prospective AF ablation registry. Specifically, we used text-scraping techniques to search on the following keywords: "adenopathy" and "sarcoidosis." Detailed chart review of identified cases was then performed to evaluate results of interval investigations and assess long-term outcomes. Results: Twenty of 1574 patients (1.3%) had noncardiac reports containing "adenopathy" and/or "sarcoidosis." After interval imaging and a follow-up period averaging 60 ± 35 months, only 2 patients of 1574 (0.13%) were diagnosed with CS. Four of 20 (20%) had a previous history of extracardiac sarcoidosis, and another 1 of 20 (5%) was subsequently diagnosed with extracardiac sarcoidosis. However, none of these 5 patients had evidence of cardiac involvement. Conclusions: CS is a rare finding among patients undergoing a first-time AF ablation. Our findings suggest that AF is an uncommon initial presentation of CS. Thus, investigations for CS in patients with AF are not warranted routinely, unless additional suggestive clinical features are present.

Contexte: La sarcoïdose cardiaque (SC) est une forme rare de cardiomyopathie arythmogène; un retard dans le diagnostic peut entraîner d'importantes conséquences. Les patients qui présentent une SC cliniquement manifeste ont souvent une atteinte extracardiaque minime, et consultent donc souvent d'abord en cardiologie. En effet, certains scénarios arythmiques précis devraient déclencher la recherche de signes d'une SC non diagnostiquée. La fibrillation auriculaire (FA) a été décrite comme un signe indicateur de SC; on ne connaît toutefois pas l'incidence de ce signe. Méthodologie: Dans notre établissement, la tomodensitométrie cardiaque est souvent réalisée avant une ablation par cathéter de la FA. Les découvertes non cardiaques fortuites sont décrites par les radiologues, puis font l'objet d'un suivi par des examens d'imagerie réalisés à intervalles déterminés. Nous avons systématiquement évalué les éléments non cardiaques signalés chez 1 574 patients consécutifs dans notre registre prospectif sur l'ablation de la FA. Nous avons utilisé des techniques de dépouillement du texte pour trouver les mots-clés suivants : « adenopathy ¼ (adénopathie) et « sarcoidosis ¼ (sarcoïdose). Un examen du dossier médical complet des cas retenus a été réalisé pour évaluer les résultats des examens de suivi et évaluer les résultats à long terme. Résultats: Parmi les 1 574 patients, 20 (1,3 %) présentaient des notes non cardiaques contenant les termes « adenopahy ¼ (adénopathie) ou « sarcoidosis ¼ (sarcoïdose). Après l'examen d'imagerie et une période de suivi d'une durée moyenne de 60 ±35 mois, seuls deux patients (0,13 %) ont reçu un diagnostic de SC. Quatre des 20 patients visés (20 %) présentaient des antécédents de sarcoïdose extracardiaque, et un patient sur 20 (5 %) a reçu un diagnostic de sarcoïdose extracardiaque à la suite de l'intervention. Toutefois, aucun de ces cinq patients ne montrait de signes d'atteinte cardiaque. Conclusions: La SC est une occurrence rare chez les patients qui subissent une première ablation de la FA. Nos constats indiquent que la FA est une présentation initiale peu commune de la SC. Aussi, la recherche de la SC chez les patients atteints de FA n'est pas justifiée dans une procédure de routine, à moins que d'autres caractéristiques cliniques pointant vers cette affection ne soient présentes.

An International Survey of Current Clinical Practice in the Treatment of Cardiac Sarcoidosis.

Cardiac sarcoidosis (CS) is a potentially serious form of infiltrative cardiomyopathy. Despite scarce evidence, immunosuppressive treatment is generally recommended, but local routines may vary significantly. We sought to survey the clinical practices in the treatment of CS, with the aim that the results may suggest future research priorities. We conducted a web-based survey focused on treatment-naive patients with CS. We subclassified CS according to the presence/absence of overt cardiac presentation (clinically manifest/silent) and to the presence/absence of active inflammation (metabolically active/inactive by fluorodeoxyglucose positron emission tomography). The survey was developed jointly by the authors and administered to expert clinicians (n = 79) involved in CS treatment. An agreement threshold was set at 70%. A total of 62 of 79 respondents (78.5%) from 12 countries completed the survey. The agreement threshold was reached for: (1) always treating clinically manifest, metabolically active CS, 57 of 62 (91.9%), (2) never treating clinically silent, metabolically inactive CS, 44 of 62 (71.0%), (3) not requiring histopathologic confirmation of sarcoidosis before treatment initiation, (49 of 62, 79.0%), (4) using fluorodeoxyglucose positron emission tomography for assessing treatment indication (44 of 62, 71.0%) and treatment response (44 of 62, 71.0%), and (5) using prednisone as a first-line agent (100%), although respondents were divided on monotherapy (69.4%) or combination with methotrexate 25.8%. The approach to particular scenarios, tapering, and duration of treatment showed the greatest variation in response. In conclusion, in this survey of clinical practice, important aspects of CS treatment reached the agreement threshold, whereas others showed a great degree of clinical equipoise.

Diagnosis and Treatment of Cardiac Sarcoidosis.

About 5% of sarcoidosis patients develop clinically manifest cardiac features. Cardiac sarcoidosis (CS) typically presents with conduction abnormalities, ventricular arrhythmias and heart failure. Its diagnosis is challenging and requires a substantial degree of clinical suspicion as well as expertise in advanced cardiac imaging. Adverse events, particularly malignant arrhythmias and development of heart failure, are common among CS patients. A timely diagnosis is paramount to ameliorating outcomes for these patients. Despite weak evidence, immunosuppression (primarily with corticosteroids) is generally recommended in the presence of active inflammation in the myocardium. The burden of malignant arrhythmias remains important regardless of treatment, thus leading to the recommended use of an implantable cardioverter defibrillator in most patients with clinically manifest CS.

Relationship between ablation index and myocardial biomarkers after radiofrequency catheter ablation for atrial fibrillation.

BACKGROUND: Further in-vivo evidence is needed to support the usefulness of ablation index (AI) in guiding atrial fibrillation (AF) ablation. We aimed at evaluating the relationship between AI and other lesion indicators and the release of myocardial-specific biomarkers following radiofrequency AF ablation. METHODS: Forty-six patients underwent a first-time radiofrequency AF ablation and were prospectively enrolled in this study. Pulmonary vein isolation was performed by six experienced electrophysiologists with a point-by-point approach, guided by strict Visitag criteria and consistent AI target values. Myocardial-specific biomarkers troponin T and creatine kinase myocardial band were measured after 6 (TnT6 and CKMB6) and 20 h (TnT20 and CKMB20) following sheath removal. Ablation duration, impedance drop (ID), force-time integral (FTI) and AI were registered automatically and analyzed offline. RESULTS: TnT release was 985 ± 495 ng/L and 1038 ± 461 ng/L (p = ns) while CKMB release was 7.3 ± 2.7 µg/L and 6.5 ± 2.1 µg/L (p < 0.001) at 6 and 20 h respectively. Ablation duration, ID, FTI and AI were all significantly correlated with the release of myocardial-specific biomarkers both at 6 and 20 h. Ablation index showed the highest degree of correlation with TnT6, TnT20, CKMB6 and CKMB20 (Pearson's R 0.69, 0.69, 0.61, 0.64 respectively, p < 0.001). Multiple regression analysis demonstrated that AI had the strongest association with TnT6, TnT20, CKMB6 and CKMB20 (ß 0.43, ß 0.71, ß 0.44 and ß 0.43 respectively). CONCLUSION: Ablation index appears as the strongest lesion indicator as measured by the release of myocardial-specific biomarkers following radiofrequency catheter ablation for AF.

The impacts of contact force, power and application time on ablation effect indicated by serial measurements of impedance drop in both conventional and high-power short-duration ablation settings of atrial fibrillation.

BACKGROUND: This study aimed to clarify the interrelationship and additive effects of contact force (CF), power and application time in both conventional and high-power short-duration (HPSD) settings. METHODS: Among 38 patients with paroxysmal atrial fibrillation who underwent first-time pulmonary vein isolation, 787 ablation points were collected at the beginning of the procedure at separate sites. Energy was applied for 60 s under power outputs of 25, 30 or 35 W (conventional group), or 10 s when using 50 W (HPSD group). An impedance drop (ID) of 10 Ω was regarded as a marker of adequate lesion formation. RESULTS: ID ≥ 10 Ω could not be achieved with CF < 5 g under any power setting. With CF ≥ 5 g, ID could be enhanced by increasing power output or prolonging ablation time. ID for 30 and 35 W was greater than for 25 W (p < 0.05). Ablation with 35 W resulted in greater ID than with 30 W only when CF of 10-20 g was applied for 20-40 s (p < 0.05). Under the same power output, ID increased with CF level at different time points. The higher the CF, the shorter the time needed to reach ID of 10 Ω and maximal ID. ID correlated well with ablation index under each power, except for lower ID values at 25 W. ID with 50 W for 10 s was equivalent to that with 25 W for 40 s, but lower than that with 30 W for 40 s or 35 W for 30 s. CONCLUSIONS: CF of at least 5 g is required for adequate ablation effect. With CF ≥ 5g, CF, power output, and ablation time can compensate for each other. Time to reach maximal ablation effect can be shortened by increasing CF or power. The effect of HPSD ablation with 50 W for 10 s is equivalent to conventional ablation with 25 W for 40 s and 30-35 W for 20-30 s in terms of ID.

Incidence and clinical predictors of subsequent atrial fibrillation requiring additional ablation after cavotricuspid isthmus ablation for typical atrial flutter.

OBJECTIVES: We sought to investigate the incidence of atrial fibrillation after catheter ablation for typical atrial flutter and to determine the predictors for symptomatic atrial fibrillation that required a further additional dedicated ablation procedure. DESIGN: 127 patients underwent elective cavotricuspid isthmus ablation with the indication of symptomatic, typical atrial flutter. The occurrence of atrial flutter, atrial fibrillation, cerebrovascular events and the need for additional ablation procedures for symptomatic atrial fibrillation was assessed during long-term follow-up. RESULTS: The majority of patients (70%) manifested atrial fibrillation during a follow-up period of 68 ± 24 months, and a significant proportion (42%) underwent one or multiple atrial fibrillation ablation procedures after an average of 26 months from the index procedure. Recurrence of typical atrial flutter was rare. Ten patients (8%) suffered cerebrovascular events. Earlier documentation of atrial fibrillation (OR 3.53), previous use of flecainide (OR 3.33) and left atrial diameter (OR 2.96) independently predicted occurrence of atrial fibrillation during the follow-up. A combination of pre- and intra-procedural documentation of atrial fibrillation (OR 3.81) and previous use of flecainide (OR 2.43) independently predicted additional atrial fibrillation ablation. DISCUSSION: Atrial fibrillation occurred in the majority of patients after ablation for typical atrial flutter and 42% of them required an additional dedicated ablation procedure. Pre- and intraprocedural documentation of atrial fibrillation together with previous use of flecainide independently predicted atrial fibrillation occurrence and a need for additional ablation. Anticoagulation treatment should be continued in high-risk patients in spite of clinical disappearance of atrial flutter.

Effect of flecainide on the extension and localization of complex fractionated electrogram during atrial fibrillation.

AIMS: Complex fractionated electrogram (CFE) ablation in addition to pulmonary vein isolation is an accepted strategy for the treatment of non-paroxysmal atrial fibrillation (AF). We sought to determine the effect of flecainide on the distribution and extension of CFE areas. METHODS: Twenty-three non-paroxysmal AF patients were enrolled in this prospective study. A first CFE map was obtained under baseline conditions by sampling 5 s of continuous recording from the distal electrodes of the ablation catheter. Intravenous flecainide (1 mg/kg) was administered over 10 min and followed by 30-min observation time. A second CFE map was obtained with the same modalities. CFE-mean values, CFE areas, and atrial electrogram amplitude were retrieved from the electro-anatomical mapping system (Ensite NavX). RESULTS: After flecainide administration, CFE-mean values increased (111.5 ± 55.3 vs. 132.3 ± 65.0 ms, p < 0.001) with a decrease of CFE area (32.9%) in all patients. Atrial electrogram amplitude decreased significantly (0.30 ± 0.31 vs. 0.25 ± 0.20 mV, p < 0.001). We observed 80.9% preservation of CFE areas. A CFE mean of 78 ms was the best cutoff for predicting stable CFE areas. CONCLUSIONS: Flecainide reduces the extension of CFE areas while preserving their spatial localization. A CFE-mean value <80 ms may be crucial to define and locate stable CFE areas.

Ablation effect indicated by impedance fall is correlated with contact force level during ablation for atrial fibrillation.

INTRODUCTION: Previous studies have validated the use of impedance fall as a measure of the effects of ablation. We investigated whether catheter-to-tissue contact force correlated with impedance fall during atrial fibrillation ablation. METHODS AND RESULTS: A total of 394 ablation points from 35 patients who underwent atrial fibrillation ablation were selected and analyzed in terms of the presence of stable catheter contact in non-ablated areas in the left atrium. A fixed power output (30 W) was applied for 60 seconds. Contact force, impedance fall, and force-direction angle were retrieved and exported for off-line analysis. Qualified points were divided into 5 groups according to the level of contact force (1-5 g, 6-10 g, 11-15 g, 16-20 g, and >20 g). An acute impedance fall was observed in the first 10 seconds followed by a plateau in group I and by a further fall in the other groups. Group V showed a rise in impedance during the last 20 seconds of ablation. Levels of impedance fall at each time point were significantly different among all the groups (P<0.001) except between groups III and IV. There was a significant correlation between contact force and maximum impedance fall (rho = 0.54, P<0.01). Lesions with a force-direction angle of 0-30° had significantly lower contact force and maximum impedance fall than those with angles of 30-60° and 60-135° (P<0.01). CONCLUSIONS: Under stable catheter conditions, contact force correlates with impedance fall during 60 seconds of ablation. Contact force exceeding 5 g produces greater impedance fall, which probably indicates adequate lesion formation. A contact force greater than 20 g may lead to late tissue overheating.

Long-term outcomes of adjunctive complex fractionated electrogram ablation to pulmonary vein isolation as treatment for non-paroxysmal atrial fibrillation.

PURPOSE: The adjunctive ablation of areas of complex fractionated electrogram (CFE) to pulmonary vein isolation (PVI) is an emerging strategy for patients with non-paroxysmal atrial fibrillation (AF). We studied the long-term outcomes of this approach. METHODS: Sixty-six patients (mean age 58 ± 9, 86.4 % male) with non-paroxysmal AF underwent ablation procedures consisting of PVI plus extensive CFE ablation. Post-ablation atrial tachycardia (AT) was also targeted if presented. All patients were followed up regularly on an ambulatory basis by means of ECG and Holter recordings. RESULTS: After a mean follow-up period of 40 ± 14 months and 1.7 ± 0.7 procedures, 38 patients (57.6 %) were free of arrhythmias, 15 (22.7 %) displayed clinical improvement and 13 (19.7 %) suffered recurrences of persistent AF/AT. Females displayed poorer long-term outcomes than males (arrhythmia-free 22.2 vs. 63.2 %, p < 0.05). Multivariate analysis demonstrated that long duration of uninterrupted AF prior to the procedure was an additional predictor of long-term failure (odds ratio 1.49, p < 0.01). ROC analysis (area under curve 0.80; p < 0.001) estimated 3.5 years as the optimal cut-off point for predicting long-term failure (sensitivity 85 %, specificity 74 %). The cumulative data showed a significantly higher percentage of arrhythmia-free patients when the duration of AF had been ≤ 2 years (69.7 %) and ≤ 4 years (68.9 %) than when it was > 4 years (33.3 %; p < 0.01). CONCLUSIONS: PVI + CFE ablation in non-paroxysmal AF appears to provide a reasonable proportion of arrhythmia-free patients during long-term follow-up. Poorer long-term results can be expected among female patients and those with an uninterrupted AF duration of > 4 years.

N-terminal pro-B-type natriuretic peptide level at long-term follow-up after atrial fibrillation ablation: a marker of reverse atrial remodelling and successful ablation.

AIMS: We investigated the relationship between arrhythmia burden, left atrial volume (LAV) and N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) at baseline and after long-term follow-up of atrial fibrillation (AF) ablation. METHODS: We studied 38 patients (23 paroxysmal, 6 women, mean age 56 ± 11) scheduled for AF ablation. LAV was calculated on the basis of computed tomography images at baseline and long-term follow-up, and arrhythmia burden was graded from self-reported frequency and duration of AF episodes. RESULTS: After a mean period of 22 ± 5 months, 28/38 patients (11/15 persistent) were free from AF recurrence. At baseline there were no differences in mean LAV (125 vs. 130 cm(3), p = 0.7) or median NT-pro-BNP (33.5 vs. 29.5 pmol/L, p = 0.9) between patients whose ablation had been successful or otherwise. At long-term follow-up, there was a marked decrease in LAV (105 vs. 134 cm(3), p < 0.05) and level of NT-pro-BNP (7 vs. 17.5 pmol/L, p < 0.05) in the successful ablation patients. NT-pro-BNP correlated with LAV both at baseline (r = 0.71, p < 0.001) and at follow-up (r = 0.57, p < 0.001). Arrhythmia burden correlated with both NT-pro-BNP (r = 0.47, p < 0.01) and LAV (r = 0.52, p < 0.01). A decrease in NT-pro-BNP at follow-up of >25% of baseline value had a specificity of 0.89 and a sensitivity of 0.6 (receiver operator characteristics, accuracy 0.82) for ablation success. CONCLUSIONS: NT-pro-BNP correlates with LAV and arrhythmia burden in AF patients and both NT-pro-BNP and LAV decrease significantly after successful ablation. A decrease in NT-pro-BNP of >25% from the baseline value could be useful as a marker of ablation success.

Ventricular arrhythmias originating from the aortomitral continuity: an uncommon variant of left ventricular outflow tract tachycardia.

AIMS: Ventricular arrhythmias arising from the fibrous rings have been demonstrated, but knowledge about the aortomitral continuity (AMC) as a source of the arrhytmias is still limited. The objective is to describe the characteristics of ventricular arrhythmias originating from the AMC in patients without structural heart disease. METHODS AND RESULTS: Ten patients with ventricular tachycardia (VT) and/or premature ventricular contractions, who had been successfully treated by catheter ablation at the AMC beneath the aortic valve, were enrolled. Clinical data and electrocardiographic characteristics were analysed. Three of the 10 patients had previously registered episodes of supraventricular tachycardia and had undergone catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT). In four patients with anterior AMC location, early R/S wave transition was found in the precordial leads, with equal R and S amplitudes in V2, rS in V1, and R in V3. In six patients whose VT arose from the middle part of the AMC, we demonstrated a special ('rebound') transition pattern, with which equal R and S amplitudes occurred in V2, and high R waves in V1 and V3. In the anterior AMC location, the S/R ratios in leads V1 and V2 were >1 and statistically significantly higher than those located in the middle (V1: 1.59 vs. 0.23, P< 0.001; V2: 1.52 vs. 0.41, P< 0.01). CONCLUSIONS: We report a series of ventricular arrhythmias arising from the AMC with different R/S wave transition patterns in the precordial leads on the electrocardiogram. There may be a relationship between ventricular arrhythmias from AMC and AVNRT.

Remote magnetic versus manual catheters: evaluation of ablation effect in atrial fibrillation by myocardial marker levels.

BACKGROUND: A remote magnetic navigation (MN) system is available for radiofrequency ablation of atrial fibrillation (AF), challenging the conventional manual ablation technique. The myocardial markers were measured to compare the effects of the two types of MN catheters with those of a manual-irrigated catheter in AF ablation. METHODS: AF patients underwent an ablation procedure using either a conventional manual-irrigated catheter (CIR, n = 65) or an MN system utilizing either an irrigated (RMI, n = 23) or non-irrigated catheter (RMN, n = 26). Levels of troponin T (TnT) and the cardiac isoform of creatin kinase (CKMB) were measured before and after ablation. RESULTS: Mean procedure times and total ablation times were longer employing the remote magnetic system. In all groups, there were pronounced increases in markers of myocardial injury after ablation, demonstrating a significant correlation between total ablation time and post-ablation levels of TnT and CKMB (CIR r = 0.61 and 0.53, p < 0.001; RMI r = 0.74 and 0.73, p < 0.001; and RMN r = 0.51 and 0.59, p < 0.01). Time-corrected release of TnT was significantly higher in the CIR group than in the other groups. Of the patients, 59.6% were free from AF at follow-up (12.2 ± 5.4 months) and there were no differences in success rate between the three groups. CONCLUSIONS: Remote magnetic catheters may create more discrete and predictable ablation lesions measured by myocardial enzymes and may require longer total ablation time to reach the procedural endpoints. Remote magnetic non-irrigated catheters do not appear to be inferior to magnetic irrigated catheters in terms of myocardial enzyme release and clinical outcome.