Early Rhythm-Control Therapy in Patients with Atrial Fibrillation.

BACKGROUND: Despite improvements in the management of atrial fibrillation, patients with this condition remain at increased risk for cardiovascular complications. It is unclear whether early rhythm-control therapy can reduce this risk. METHODS: In this international, investigator-initiated, parallel-group, open, blinded-outcome-assessment trial, we randomly assigned patients who had early atrial fibrillation (diagnosed ≤1 year before enrollment) and cardiovascular conditions to receive either early rhythm control or usual care. Early rhythm control included treatment with antiarrhythmic drugs or atrial fibrillation ablation after randomization. Usual care limited rhythm control to the management of atrial fibrillation-related symptoms. The first primary outcome was a composite of death from cardiovascular causes, stroke, or hospitalization with worsening of heart failure or acute coronary syndrome; the second primary outcome was the number of nights spent in the hospital per year. The primary safety outcome was a composite of death, stroke, or serious adverse events related to rhythm-control therapy. Secondary outcomes, including symptoms and left ventricular function, were also evaluated. RESULTS: In 135 centers, 2789 patients with early atrial fibrillation (median time since diagnosis, 36 days) underwent randomization. The trial was stopped for efficacy at the third interim analysis after a median of 5.1 years of follow-up per patient. A first-primary-outcome event occurred in 249 of the patients assigned to early rhythm control (3.9 per 100 person-years) and in 316 patients assigned to usual care (5.0 per 100 person-years) (hazard ratio, 0.79; 96% confidence interval, 0.66 to 0.94; P = 0.005). The mean (±SD) number of nights spent in the hospital did not differ significantly between the groups (5.8±21.9 and 5.1±15.5 days per year, respectively; P = 0.23). The percentage of patients with a primary safety outcome event did not differ significantly between the groups; serious adverse events related to rhythm-control therapy occurred in 4.9% of the patients assigned to early rhythm control and 1.4% of the patients assigned to usual care. Symptoms and left ventricular function at 2 years did not differ significantly between the groups. CONCLUSIONS: Early rhythm-control therapy was associated with a lower risk of adverse cardiovascular outcomes than usual care among patients with early atrial fibrillation and cardiovascular conditions. (Funded by the German Ministry of Education and Research and others; EAST-AFNET 4 ISRCTN number, ISRCTN04708680; ClinicalTrials.gov number, NCT01288352; EudraCT number, 2010-021258-20.).

Systematic, early rhythm control strategy for atrial fibrillation in patients with or without symptoms: the EAST-AFNET 4 trial.

AIMS: Clinical practice guidelines restrict rhythm control therapy to patients with symptomatic atrial fibrillation (AF). The EAST-AFNET 4 trial demonstrated that early, systematic rhythm control improves clinical outcomes compared to symptom-directed rhythm control. METHODS AND RESULTS: This prespecified EAST-AFNET 4 analysis compared the effect of early rhythm control therapy in asymptomatic patients (EHRA score I) to symptomatic patients. Primary outcome was a composite of death from cardiovascular causes, stroke, or hospitalization with worsening of heart failure or acute coronary syndrome, analyzed in a time-to-event analysis. At baseline, 801/2633 (30.4%) patients were asymptomatic [mean age 71.3 years, 37.5% women, mean CHA2DS2-VASc score 3.4, 169/801 (21.1%) heart failure]. Asymptomatic patients randomized to early rhythm control (395/801) received similar rhythm control therapies compared to symptomatic patients [e.g. AF ablation at 24 months: 75/395 (19.0%) in asymptomatic; 176/910 (19.3%) symptomatic patients, P = 0.672]. Anticoagulation and treatment of concomitant cardiovascular conditions was not different between symptomatic and asymptomatic patients. The primary outcome occurred in 79/395 asymptomatic patients randomized to early rhythm control and in 97/406 patients randomized to usual care (hazard ratio 0.76, 95% confidence interval [0.6; 1.03]), almost identical to symptomatic patients. At 24 months follow-up, change in symptom status was not different between randomized groups (P = 0.19). CONCLUSION: The clinical benefit of early, systematic rhythm control was not different between asymptomatic and symptomatic patients in EAST-AFNET 4. These results call for a shared decision discussing the benefits of rhythm control therapy in all patients with recently diagnosed AF and concomitant cardiovascular conditions (EAST-AFNET 4; ISRCTN04708680; NCT01288352; EudraCT2010-021258-20).

Anticoagulation, therapy of concomitant conditions, and early rhythm control therapy: a detailed analysis of treatment patterns in the EAST - AFNET 4 trial.

AIMS: Treatment patterns were compared between randomized groups in EAST-AFNET 4 to assess whether differences in anticoagulation, therapy of concomitant diseases, or intensity of care can explain the clinical benefit achieved with early rhythm control in EAST-AFNET 4. METHODS AND RESULTS: Cardiovascular treatment patterns and number of visits were compared between randomized groups in EAST-AFNET 4. Oral anticoagulation was used in >90% of patients during follow-up without differences between randomized groups. There were no differences in treatment of concomitant conditions between groups. The type of rhythm control varied by country and centre. Over time, antiarrhythmic drugs were given to 1171/1395 (84%) patients in early therapy, and to 202/1394 (14%) in usual care. Atrial fibrillation (AF) ablation was performed in 340/1395 (24%) patients randomized to early therapy, and in 168/1394 (12%) patients randomized to usual care. 97% of rhythm control therapies were within class I and class III recommendations of AF guidelines. Patients randomized to early therapy transmitted 297 166 telemetric electrocardiograms (ECGs) to a core lab. In total, 97 978 abnormal ECGs were sent to study sites. The resulting difference between study visits was low (0.06 visits/patient/year), with slightly more visits in early therapy (usual care 0.39 visits/patient/year; early rhythm control 0.45 visits/patient/year, P < 0.001), mainly due to visits for symptomatic AF recurrences or recurrent AF on telemetric ECGs. CONCLUSION: The clinical benefit of early, systematic rhythm control therapy was achieved using variable treatment patterns of antiarrhythmic drugs and AF ablation, applied within guideline recommendations.

Catheter Ablation of Ventricular Tachycardia in Patients With MitraClip Device: Preliminary Findings.

INTRODUCTION: Patients with mitral regurgitation are increasingly treated by percutaneous implantation of a MitraClip device (Abbott Park, IL, USA). We investigate the feasibility and safety of the transmitral catheter route for catheter ablation of ventricular tachycardia (VT) in these patients. METHODS: The mitral valve with the MitraClip in situ was crossed under transesophageal 3-dimensional echocardiographic and fluoroscopic guidance using a steerable sheath for ablation of the left ventricle. RESULTS: Five patients (all males, median age 74.0 ± 16.0 years) who had previously a MitraClip implanted were referred for catheter ablation of VT. The left ventricular ejection fraction was 29.0% ± 24.0%. One patient had both an atrial septal defect and a left atrial appendage occluder device in addition to a MitraClip. The duration between MitraClip implantation and ablation was 1019.0 ± 783.0 days. After transseptal puncture, ablation catheter was successfully steered through the mitral valve with the use of fluoroscopy. A complete high-density map of the substrate in sinus rhythm could be obtained in all patients using multipolar mapping catheters. In 1 patient, mapping was carried out using a mini-basket catheter. Procedural endpoints, noninducibility of all VTs, and abolition of all late potentials were achieved in all patients. Procedure time was 255.0 ± 52.5 minute, fluoroscopy time was 23.0 ± 7.3, and the radiation dose was 61.0 ± 37.5 Gycm2 . No mitral insufficiency or worsening of regurgitation was documented after the procedure. CONCLUSIONS: This is the first report demonstrating the feasibility and safety of VT ablation in patients with a MitraClip device using the anterograde transmitral catheter route.

Intrathoracic pressure swings induced by simulated obstructive sleep apnoea promote arrhythmias in paroxysmal atrial fibrillation.

AIMS: There is preliminary evidence for a link between obstructive sleep apnoea (OSA) and arrhythmias such as paroxysmal atrial fibrillation (PAF) and sudden cardiac death but underlying mechanisms remain largely unknown. METHODS AND RESULTS: In this interventional crossover study, we evaluated whether intrathoracic pressure changes, induced by simulated OSA, trigger premature cardiac beats, and alter measures of ventricular repolarization [QTc and Tpeak-to-Tend (TpTec) intervals] in patients with PAF. 12-Lead-electrocardiograms were recorded continuously in 44 patients, while simulating obstructive apnoea (Mueller manoeuvre, MM), obstructive hypopnoea (inspiration through a threshold load, ITH), end-expiratory central apnoea (AP), and during normal breathing (NB) in randomized order. The prevalence of OSA in these 44 patients was assessed by a sleep study. Atrial premature beats (APBs) occurred more frequently during MM (55% of patients) and ITH (32%), but not during AP (14%), compared with NB (9%) (P < 0.001, P = 0.006 and P = 0.688, respectively). Mueller manoeuvre led to a significant prolongation of QTc and TpTec intervals (+17.3 ms, P < 0.001 and +4.3 ms, P = 0.005). Inspiration through a threshold load significantly increased QTc (+9.6 ms, P < 0.001) but not TpTec. End-expiratory central apnoea did not alter QTc and TpTec intervals. According to the sleep study, 56% of patients had OSA (apnoea hypopnoea index ≥5). CONCLUSION: Simulated OSA induces APBs which may be important in patients with PAF, because the majority of episodes of PAF has been shown to be triggered by APBs. Simulated OSA leads to a significant prolongation of ventricular repolarization.

Electrocardiographic features of disease progression in arrhythmogenic right ventricular cardiomyopathy/dysplasia.

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is considered a progressive cardiomyopathy. However, data on the clinical features of disease progression are limited. The aim of this study was to assess 12-lead surface electrocardiographic (ECG) changes during long-term follow-up, and to compare these findings with echocardiographic data in our large cohort of patients with ARVC/D. METHODS: Baseline and follow-up ECGs of 111 patients from three tertiary care centers in Switzerland were systematically analyzed with digital calipers by two blinded observers, and correlated with findings from transthoracic echocardiography. RESULTS: The median follow-up was 4 years (IQR 1.9-9.2 years). ECG progression was significant for epsilon waves (baseline 14% vs. follow-up 31%, p = 0.01) and QRS duration (111 ms vs. 114 ms, p = 0.04). Six patients with repolarization abnormalities according to the 2010 Task Force Criteria at baseline did not display these criteria at follow-up, whereas in all patients with epsilon waves at baseline these depolarization abnormalities also remained at follow-up. T wave inversions in inferior leads were common (36% of patients at baseline), and were significantly associated with major repolarization abnormalities (p = 0.02), extensive echocardiographic right ventricular involvement (p = 0.04), T wave inversions in lateral precordial leads (p = 0.05), and definite ARVC/D (p = 0.05). CONCLUSIONS: Our data supports the concept that ARVC/D is generally progressive, which can be detected by 12-lead surface ECG. Repolarization abnormalities may disappear during the course of the disease. Furthermore, the presence of T wave inversions in inferior leads is common in ARVC/D.

Catheter ablation of atrial fibrillation: an update.

Catheter ablation of atrial fibrillation (AF) is now an important therapeutic modality for patients with AF. There is considerable evidence available from several prospective randomized trials demonstrating that catheter ablation of AF is superior to antiarrhythmic drug therapy in controlling AF and that AF ablation improves quality of life substantially. This is especially true for patients with paroxysmal AF without other severe comorbidities. Catheter ablation is indicated for treatment of patients with symptomatic AF in whom one or more attempts at class 1 or 3 antiarrhythmic drug therapy have failed. Although current guidelines state that is appropriate to perform catheter ablation as a first-line therapy in selected patients, in our clinical practice this is rare. This reflects a number of important realities concerning the field of AF ablation. Catheter ablation of AF is a challenging and complex procedure, which is not free of the risk of potentially life-threatening complications, such as an atrio-oesophageal fistula, stroke, and cardiac tamponade. Although these major complications are rare and their rate is falling, they must be considered by both patients and physicians. The progress made and the new developments on the horizon in the field of AF catheter ablation are remarkable. When radiofrequency catheter ablation was first introduced in the late 1980s, few would have predicted that catheter ablation of AF would emerge as the most commonly performed ablation procedure in most major hospitals.

Clinical role of atrial arrhythmias in patients with arrhythmogenic right ventricular dysplasia.

BACKGROUND: The clinical role of atrial fibrillation/atrial flutter (AF-AFl) and variables predicting these arrhythmias are not well defined in patients with arrhythmogenic right ventricular dysplasia (ARVD). We hypothesized that transthoracic echocardiography (TTE) and 12-lead electrocardiography (ECG) would be helpful in predicting AF-AFl in these patients. METHODS AND RESULTS: ECGs and TTEs of 90 patients diagnosed with definite or borderline ARVD (2010 Task Force Criteria) were analyzed. Data were compared in (1) patients with AF-AFl and (2) all other patients. A total of 18 (20%) patients experienced AF-AFl during a median follow-up of 5.8 years (interquartile range 2.0-10.4). Kaplan-Meier analysis revealed reduced times to AF-AFl among patients with echocardiographic RV fractional area change <27% (P<0.001), left atrial diameter ≥24.4 mm/m(2)(parasternal long-axis, P=0.001), and right atrial short-axis diameter ≥22.1 mm/m(2)(apical 4-chamber view, P=0.05). From all ECG variables, P mitrale conferred the highest hazard ratio (3.37, 95% confidence interval 0.92-12.36, P=0.067). Five patients with AF-AFl experienced inappropriate implantable cardioverter-defibrillator (ICD) shocks compared with 4 without AF-AFl (36% vs. 9%, P=0.03). AF-AFl was more prevalent in heart-transplant patients and those who died of cardiac causes (56% vs. 16%, P=0.014). CONCLUSIONS: AF-AFl is associated with inappropriate ICD shocks, heart transplantation, and cardiac death in patients with ARVD. Evidence of reduced RV function and atrial dilation helps to identify the ARVD patients at increased risk for AF-AFl.

Real World Data from Catheter Ablation of Ventricular Tachycardias and Premature Ventricular Complexes in a Tertiary Care Center.

Background: Catheter ablation in patients with ventricular arrhythmias (VA), such as ventricular tachycardias (VT) or frequent premature ventricular complexes (PVC), is increasingly considered an effective and safe therapy when performed in experienced centers. This study sought to determine acute success rates and complication rates of ablation procedures for patients with VA in a Swiss tertiary care center. Methods: All patients who underwent ablation therapy for VT and PVC at the University Heart Center in Zurich, Switzerland, between March 2012 and April 2017 were included in this analysis. Results: A total of 120 patients underwent catheter ablation for VT and PVC (69 and 51, respectively). Seventy percent of patients were male, and the mean age was 55.3 years. The most common indication for ablation was high PVC burden (47.5%), followed by paroxysmal VT (38.3%), ICD shocks (23.3%), incessant VT (12.5%), electrical storm (7.5%), and syncope (3.3%). Acute success rates for VT and PVC ablations were 94.2% and 92.2%, respectively. Rates for complications (including major and minor) for VT and PVC were 10.1% and 7.8%, respectively. Complications occurred only in patients with structural heart disease; no complications were noted in structurally normal hearts. Conclusions: Our results suggest that catheter ablation for VT and PVC has high acute success rates with a reasonable risk for complications in the setting of tertiary care centers, comparable to those reported in other studies.

[The "Mickey Mouse Heart"]. / Das «Mickey-Mouse-Herz¼.

The "Mickey Mouse Heart" Abstract. The "Mickey Mouse Heart" describes patients with a combination of HFpEF, massive biatrial dilatation and dilatation of the mitral- and tricuspid annulus, atrial fibrillation and severe mitral- and tricuspid regurgitation. Most frequently elderly patients with HFpEF are affected by this syndrome. The underlying molecular mechanisms or risk factors for the typical biatrial dilatation are unknown. The guideline-directed heart failure therapy as well as the evaluation of early rhythm control for atrial fibrillation and the treatment of mitral- and tricuspid regurgitation are recommended.

Complex cardiac anatomy and catheter access: the role of imaging in patients referred for catheter ablation.

A 66-year-old man with Kartagener's syndrome, situs inversus totalis, and recurrent supraventricular tachycardia and a 49-year-old man with atrial fibrillation and drug-refractory rapid ventricular rate response were referred for catheter ablation. In the first case, the mirrored anatomy of the right atrium was reconstructed using three-dimensional electroanatomical mapping, which guided successful ablation of a typical atrioventricular nodal reentrant tachycardia. In the second case, computerized tomography showed the presence of left atrial isomerism with interruption of the inferior vena cava and azygous continuation into the superior vena cava, guiding advancement of the ablation catheter for access into the positionally right atrial ablation site. These cases illustrate the role of imaging in patients with unusual anatomy of the cardiac chambers and major blood vessels guiding optimal catheter access for catheter ablation.

Rationale and current perspective for early rhythm control therapy in atrial fibrillation.

Atrial fibrillation (AF) is the most common sustained arrhythmia and an important source for mortality and morbidity on a population level. Despite the clear association between AF and death, stroke, and other cardiovascular events, there is no evidence that rhythm control treatment improves outcome in AF patients. The poor outcome of rhythm control relates to the severity of the atrial substrate for AF not only due to the underlying atrial remodelling process but also due to the poor efficacy and adverse events of the currently available ion-channel antiarrhythmic drugs and ablation techniques. Data suggest, however, an association between sinus rhythm maintenance and improved survival. Hypothetically, sinus rhythm may also lead to a lower risk of stroke and heart failure. The presence of AF, thus, seems one of the modifiable factors associated with death and cardiovascular morbidity in AF patients. Patients with a short history of AF and the underlying heart disease have not been studied before. It is fair to assume that abolishment of AF in these patients is more successful and possibly also safer, which could translate into a prognostic benefit of early rhythm control therapy. Several trials are now investigating whether aggressive early rhythm control therapy can reduce cardiovascular morbidity and mortality and increase maintenance of sinus rhythm. In the present paper we describe the background of these studies and provide some information on their design.

Feasibility and safety of outpatient radiofrequency catheter ablation procedures for atrial fibrillation.

INTRODUCTION: Percutaneous catheter ablation for atrial fibrillation (AF) is a procedure performed typically in an inpatient setting. The feasibility and safety of catheter ablation in patients with paroxysmal and persistent AF were evaluated on an outpatient basis. METHODS: 230 AF ablation procedures were performed in 206 patients (74% male; mean age 56+/-9 years). Patients were admitted to the hospital outpatient facility in the morning for the AF ablation procedure on the same day. The ablation strategy consisted of wide area circumferential lines around both ipsilateral pulmonary veins. After monitoring in the outpatient service, patients were discharged on the same day, if they were clinically stable. RESULTS: Mean procedure time was 201+/-31 min. Major complications occurred in seven patients (3%). One patient (0.4%) suffered a minor stroke and six patients had pericardial tamponade requiring percutaneous drainage. Patients could be discharged on the same day following 205 (89%) procedures. Among the 148 patients whose clinical outcome was assessed at 6 months, 127 (86%) had a reduction of the total symptomatic AF episodes, compared to pre-ablation, with a complete lack of symptoms in 101 patients (68%). CONCLUSION: Catheter ablation of AF on the day of admission is feasible and safe with a low risk of complications. The vast majority of the patients can be discharged on the same day.

Feasibility of zero or near zero fluoroscopy during catheter ablation procedures.

BACKGROUND: Awareness of risks associated with radiation exposure to patients and medical staff has significantly increased. It has been reported before that the use of advanced three-dimensional electroanatomical mapping (EAM) system significantly reduces fluoroscopy time, however this study aimed for zero or near zero fluoroscopy ablation to assess its feasibility and safety in ablation of atrial fibrillation (AF) and other tachyarrhythmias in a "real world" experience of a single tertiary care center. METHODS: This was a single-center study where ablation procedures were attempted without fluoroscopy in 34 consecutive patients with different tachyarrhythmias under the support of EAM system. When transseptal puncture (TSP) was needed, it was attempted under the guidance of intracardiac echocardiography (ICE). RESULTS: Among 34 patients consecutively enrolled in this study, 28 (82.4%) patients were referred for radiofrequency ablation (RFA) of AF, 3 (8.8%) patients for ablation of right ventricular outflow tract (RVOT) ventricular extrasystole (VES), 1 (2.9%) patient for ablation of atrioventricular nodal reentry tachycardia (AVNRT), 2 (5.9%) patients for typical atrial flutter ablation. In 21 (62%) patients the en- tire procedure was carried out without the use of fluoroscopy. Among 28 AF patients, 15 (54%) patients underwent ablation without the use of fluoroscopy and among these 15 patients, 10 (67%) patients required TSP under ICE guidance while 5 (33%) patients the catheters were introduced to left atrium through a patent foramen ovale. In 13 AF patients, fluoroscopy was only required for double TSP. The total procedure time of AF ablation was 130 ± 50 min. All patients referred for atrial flutter, AVNRT, and VES of the RVOT ablation did not require any fluoroscopy. CONCLUSIONS: This study demonstrates the feasibility of zero or near zero fluoroscopy procedure including TSP with the support of EAM and ICE guidance in a "real world" experience of a single tertiary care center. When fluoroscopy was required, it was limited to TSP hence keeping the radiation dose very low.

Atrial Fibrillation: A New Indicator for Advanced Colorectal Neoplasia in Screening Colonoscopy.

BACKGROUND: Colorectal cancer (CRC) is a common and potentially preventable malignancy. Evidence has emerged that coronary artery disease patients are at increased risk for developing CRC by shared risk factors. Here we investigated an association between CRC and atrial fibrillation (AF), a surrogate marker of cardiovascular risk, in the setting of routine screening colonoscopy. METHODS: We investigated 1949 asymptomatic participants (median age 61 [54-67] years, 49% females) undergoing screening colonoscopy within the SAKKOPI registry (Salzburg Colon Cancer Prevention Initiative). Forty-six participants with AF (2.4%) were identified, and colonoscopy findings were compared to non-AF participants. Propensity Score Matching (PSM) was used to create 1:1 and 3:1 age- and gender-matched couples. RESULTS: Abnormal findings on screening colonoscopy (any form of adenoma or carcinoma) were more common in AF participants with an odds ratios (OR) of 2.4 [1.3-4.3] in the unmatched analysis, and 2.6 [1.1-6.3] and 2.0 [1.1-4.0] in the 1:1 and 3:1 matched groups, respectively. Correspondingly, the odds of finding advanced adenomas or carcinomas was elevated about three-fold across the different matched and unmatched analyses (OR 3.3 [1.1-10.8] for 3:1 matched participants). At the same time, the prevalence and number of colonic lesions were significantly higher in AF participants (63.0% vs. 33.4% for 3:1 matched participants, p < 0.001). Non-CRC related findings on colonoscopy, like diverticulosis, were non-different between groups. CONCLUSION: Participants with AF had a higher burden of advanced premalignant adenomas and CRC in routine colonoscopy screening. Our data suggest that practitioners should monitor the CRC screening status, especially in AF patients.

Clinical Characteristics of Patients with a Right Ventricular Thrombus in Arrhythmogenic Right Ventricular Cardiomyopathy.

BACKGROUND: Thrombus formation within the left ventricle (LV) is a well-known clinical entity and is often associated with underlying myocardial disease, whereas right ventricular (RV) thrombi are rarely observed. This study aimed to investigate the clinical characteristics of patients with arrhythmogenic RV cardiomyopathy (ARVC) who developed an RV thrombus. METHODS AND RESULTS: This study included patients with an RV thrombus from the ARVC databases of the University Heart Center in Zurich, Switzerland, and the Fuwai Hospital in Beijing, China. In total, there were 13 ARVC patients who had an RV thrombus detected. The mean age was 33 ± 15 (range: 11-51) years. Eight patients (62%) were male. The mean Task Force score was 6 ± 1. Nine of these patients (69%) had an RV thrombus only whereas four patients had biventricular thrombi. All 13 ARVC patients had a severely impaired RV function (RV fractional area change 16 ± 9% and RV ejection fraction 15 ± 4%); LV ejection fraction (LVEF) was 40 ± 15%. ARVC patients with an additional LV thrombus had a lower LVEF than the others (24 ± 11 vs. 47 ± 11, p = 0.02). Under therapeutic anticoagulation, complete thrombus resolution was observed in 9/13 patients (69%). CONCLUSION: RV thrombus formation is a potential complication of ARVC with impaired RV function. In patients with biventricular involvement, thrombi may also occur within the LV. Anticoagulation is generally effective to dissolve RV thrombi. This study highlights the need for awareness during cardiac imaging to detect this rare complication of ARVC.

Cardiac injury after percutaneous catheter ablation for atrial fibrillation.

AIMS: Small elevations in troponin T levels have been shown with limited radiofrequency (RF) ablation procedures for supraventricular tachycardia, usually to levels below the threshold for ischaemia or infarction. Left atrial catheter ablation for atrial fibrillation (AF) requires far more RF energy, therefore could be expected to have greater elevation in troponin T. We determined troponin T levels before and after ablation in these patients to evaluate the amount of rise with this ablation. METHODS: All patients undergoing pulmonary vein isolation (PVI) from May 2004 to October 2004 had troponin T levels measured 4 h following completion of the procedure. The first 30 patients also had a troponin T level measured 1 h prior to PVI to establish a baseline reference. RESULTS: Sixty patients were studied, with 81.7% males and a mean age of 54.6 +/- 9.9 years. No patient had underlying structural heart disease. The baseline troponin T level was normal (<0.01 microg/L) in all 30 patients. Post-procedure troponin T levels were elevated in all 60 patients compared with baseline (P < 0.05), with a mean level of 0.85 microg/L and a range of 0.26-1.57 microg/L after an average RF ablation time of 56 +/- 15 min. All levels were above the reference range for diagnosis of acute myocardial infarction (>0.15 microg/L). Troponin T level was not related to the number of RF lesions, RF time, procedure time, or associated external cardioversion. CONCLUSIONS: Troponin T elevations occurred in all patients undergoing PVI, to levels at least 20 times the normal concentration, into the range for diagnosis of acute myocardial infarction. Therefore, troponin T would not be specific for ischaemia in the setting of chest pain post-catheter ablation for AF.