The 2018 European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation.

The current manuscript is the second update of the original Practical Guide, published in 2013 [Heidbuchel et al. European Heart Rhythm Association Practical Guide on the use of new oral anticoagulants in patients with non-valvular atrial fibrillation. Europace 2013;15:625-651; Heidbuchel et al. Updated European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist anticoagulants in patients with non-valvular atrial fibrillation. Europace 2015;17:1467-1507]. Non-vitamin K antagonist oral anticoagulants (NOACs) are an alternative for vitamin K antagonists (VKAs) to prevent stroke in patients with atrial fibrillation (AF) and have emerged as the preferred choice, particularly in patients newly started on anticoagulation. Both physicians and patients are becoming more accustomed to the use of these drugs in clinical practice. However, many unresolved questions on how to optimally use these agents in specific clinical situations remain. The European Heart Rhythm Association (EHRA) set out to coordinate a unified way of informing physicians on the use of the different NOACs. A writing group identified 20 topics of concrete clinical scenarios for which practical answers were formulated, based on available evidence. The 20 topics are as follows i.e., (1) Eligibility for NOACs; (2) Practical start-up and follow-up scheme for patients on NOACs; (3) Ensuring adherence to prescribed oral anticoagulant intake; (4) Switching between anticoagulant regimens; (5) Pharmacokinetics and drug-drug interactions of NOACs; (6) NOACs in patients with chronic kidney or advanced liver disease; (7) How to measure the anticoagulant effect of NOACs; (8) NOAC plasma level measurement: rare indications, precautions, and potential pitfalls; (9) How to deal with dosing errors; (10) What to do if there is a (suspected) overdose without bleeding, or a clotting test is indicating a potential risk of bleeding; (11) Management of bleeding under NOAC therapy; (12) Patients undergoing a planned invasive procedure, surgery or ablation; (13) Patients requiring an urgent surgical intervention; (14) Patients with AF and coronary artery disease; (15) Avoiding confusion with NOAC dosing across indications; (16) Cardioversion in a NOAC-treated patient; (17) AF patients presenting with acute stroke while on NOACs; (18) NOACs in special situations; (19) Anticoagulation in AF patients with a malignancy; and (20) Optimizing dose adjustments of VKA. Additional information and downloads of the text and anticoagulation cards in different languages can be found on an EHRA website (www.NOACforAF.eu).

The 2018 European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation: executive summary.

The current manuscript is the Executive Summary of the second update to the original Practical Guide, published in 2013. Non-vitamin K antagonist oral anticoagulants (NOACs) are an alternative for vitamin K antagonists (VKAs) to prevent stroke in patients with atrial fibrillation (AF), and have emerged as the preferred choice, particularly in patients newly started on anticoagulation. Both physicians and patients are becoming more accustomed to the use of these drugs in clinical practice. However, many unresolved questions on how to optimally use these agents in specific clinical situations remain. The European Heart Rhythm Association (EHRA) set out to co-ordinate a unified way of informing physicians on the use of the different NOACs. A writing group identified 20 topics of concrete clinical scenarios for which practical answers were formulated, based on available evidence. The 20 topics are (i) eligibility for NOACs; (ii) practical start-up and follow-up scheme for patients on NOACs; (iii) ensuring adherence to prescribed oral anticoagulant intake; (iv) switching between anticoagulant regimens; (v) pharmacokinetics and drug-drug interactions of NOACs; (vi) NOACs in patients with chronic kidney or advanced liver disease; (vii) how to measure the anticoagulant effect of NOACs; (viii) NOAC plasma level measurement: rare indications, precautions, and potential pitfalls; (ix) how to deal with dosing errors; (x) what to do if there is a (suspected) overdose without bleeding, or a clotting test is indicating a potential risk of bleeding; (xi) management of bleeding under NOAC therapy; (xii) patients undergoing a planned invasive procedure, surgery or ablation; (xiii) patients requiring an urgent surgical intervention; (xiv) patients with AF and coronary artery disease; (xv) avoiding confusion with NOAC dosing across indications; (xvi) cardioversion in a NOAC-treated patient; (xvii) AF patients presenting with acute stroke while on NOACs; (xviii) NOACs in special situations; (xix) anticoagulation in AF patients with a malignancy; and (xx) optimizing dose adjustments of VKA. Additional information and downloads of the text and anticoagulation cards in different languages can be found on an EHRA web site (www.NOACforAF.eu).

[Perioperative anticoagulation with NOAC using the example of rivaroxaban]. / Perioperative Antikoagulation mit NOAK am Beispiel Rivaroxaban.

BACKGROUND: Recent findings require an update of earlier recommendations on the perioperative management of non Vitamin K antagonist oral anticoagulants (NOAC). METHOD: The present position paper summarises the outcomes of an expert panel discussion. RESULTS AND CONCLUSIONS: Based on the pharmacokinetic profile of rivaroxaban, a preoperative interruption of 24-72 hours is recommended depending on the patient's renal function, as well as individual and surgery-related bleeding risks. Similar NOAC-free intervals are recommended for patients with epidural catheters. Elective surgery should be delayed accordingly. A low molecular weight heparin (LMWH) "bridging" (in fact "switching") should be avoided because of an increased bleeding risk. Six to 8 hours after the intervention rivaroxaban can be re-initiated or, in case of more extensive interventions or an increased bleeding risk, after 24-72 hours; if necessary this interval could by bridged with LMWH, e. g. if the thromboembolic risk is considered high. In case of emergency surgery with a rivaroxaban pause of less than 9 hours, one should be prepared for a bleeding management including the use of prothrombin concentrate (PCC). Coagulation tests have no value for predicting perioperative bleeding, in contrast to a standardised bleeding history. As an overall estimate, the PT (Quick) can be determined with a suitable reagent. Currently, rivaroxaban-specific measurements of anti Xa levels are available at few specialised centres only. Moderate to severe haemorrhages can usually be managed by temporary interruption of rivaroxaban in conjunction with local and general haemostatic measures. Life-threatening bleeding events require a specific haemostasis management including the administration of PCC; these events are rare and usually have a favourable prognosis, except for intracranial haemorrhages.

Updated European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist anticoagulants in patients with non-valvular atrial fibrillation.

The current manuscript is an update of the original Practical Guide, published in June 2013[Heidbuchel H, Verhamme P, Alings M, Antz M, Hacke W, Oldgren J, et al. European Heart Rhythm Association Practical Guide on the use of new oral anticoagulants in patients with non-valvular atrial fibrillation. Europace 2013;15:625-51; Heidbuchel H, Verhamme P, Alings M, Antz M, Hacke W, Oldgren J, et al. EHRA practical guide on the use of new oral anticoagulants in patients with non-valvular atrial fibrillation: executive summary. Eur Heart J 2013;34:2094-106]. Non-vitamin K antagonist oral anticoagulants (NOACs) are an alternative for vitamin K antagonists (VKAs) to prevent stroke in patients with non-valvular atrial fibrillation (AF). Both physicians and patients have to learn how to use these drugs effectively and safely in clinical practice. Many unresolved questions on how to optimally use these drugs in specific clinical situations remain. The European Heart Rhythm Association set out to coordinate a unified way of informing physicians on the use of the different NOACs. A writing group defined what needs to be considered as 'non-valvular AF' and listed 15 topics of concrete clinical scenarios for which practical answers were formulated, based on available evidence. The 15 topics are (i) practical start-up and follow-up scheme for patients on NOACs; (ii) how to measure the anticoagulant effect of NOACs; (iii) drug-drug interactions and pharmacokinetics of NOACs; (iv) switching between anticoagulant regimens; (v) ensuring adherence of NOAC intake; (vi) how to deal with dosing errors; (vii) patients with chronic kidney disease; (viii) what to do if there is a (suspected) overdose without bleeding, or a clotting test is indicating a risk of bleeding?; (xi) management of bleeding complications; (x) patients undergoing a planned surgical intervention or ablation; (xi) patients undergoing an urgent surgical intervention; (xii) patients with AF and coronary artery disease; (xiii) cardioversion in a NOAC-treated patient; (xiv) patients presenting with acute stroke while on NOACs; and (xv) NOACs vs. VKAs in AF patients with a malignancy. Additional information and downloads of the text and anticoagulation cards in >16 languages can be found on an European Heart Rhythm Association web site (www.NOACforAF.eu).

EHRA practical guide on the use of new oral anticoagulants in patients with non-valvular atrial fibrillation: executive summary.

New oral anticoagulants (NOACs) are an alternative for vitamin K antagonists (VKAs) to prevent stroke in patients with non-valvular atrial fibrillation (AF). Both physicians and patients will have to learn how to use these drugs effectively and safely in specific clinical situations. This text is an executive summary of a practical guide that the European Heart Rhythm Association (EHRA) has assembled to help physicians in the use of the different NOACs. The full text is being published in EP Europace. Practical answers have been formulated for 15 concrete clinical scenarios: (i) practical start-up and follow-up scheme for patients on NOACs; (ii) how to measure the anticoagulant effect of NOACs; (iii) drug-drug interactions and pharmacokinetics of NOACs; (iv) switching between anticoagulant regimens; (v) ensuring compliance of NOAC intake; (vi) how to deal with dosing errors; (vii) patients with chronic kidney disease; (viii) what to do if there is a (suspected) overdose without bleeding, or a clotting test is indicating a risk of bleeding?; (ix) management of bleeding complications; (x) patients undergoing a planned surgical intervention or ablation; (xi) patients undergoing an urgent surgical intervention; (xii) patients with AF and coronary artery disease; (xiii) cardioversion in a NOAC-treated patient; (xiv) patients presenting with acute stroke while on NOACs; (xv) NOACs vs. VKAs in AF patients with a malignancy. Since new information is becoming available at a rapid pace, an EHRA web site with the latest updated information accompanies the guide (www.NOACforAF.eu). It also contains links to the ESC AF Guidelines, a key message pocket booklet, print-ready files for a proposed universal NOAC anticoagulation card, and feedback possibilities.

European Heart Rhythm Association Practical Guide on the use of new oral anticoagulants in patients with non-valvular atrial fibrillation.

New oral anticoagulants (NOACs) are an alternative for vitamin K antagonists (VKAs) to prevent stroke in patients with non-valvular atrial fibrillation (AF). Both physicians and patients will have to learn how to use these drugs effectively and safely in clinical practice. Many unresolved questions on how to optimally use these drugs in specific clinical situations remain. The European Heart Rhythm Association set out to coordinate a unified way of informing physicians on the use of the different NOACs. A writing group listed 15 topics of concrete clinical scenarios and formulated as practical answers as possible based on available evidence. The 15 topics are: (1) Practical start-up and follow-up scheme for patients on NOACs; (2) How to measure the anticoagulant effect of NOACs; (3) Drug-drug interactions and pharmacokinetics of NOACs; (4) Switching between anticoagulant regimens; (5) Ensuring compliance of NOAC intake; (6) How to deal with dosing errors; (7) Patients with chronic kidney disease; (8) What to do if there is a (suspected) overdose without bleeding, or a clotting test is indicating a risk of bleeding? (9) Management of bleeding complications; (10) Patients undergoing a planned surgical intervention or ablation; (11) Patients undergoing an urgent surgical intervention; (12) Patients with AF and coronary artery disease; (13) Cardioversion in a NOAC-treated patient; (14) Patients presenting with acute stroke while on NOACs; (15) NOACs vs. VKAs in AF patients with a malignancy. Since new information is becoming available at a rapid pace, an EHRA Web site with the latest updated information accompanies this text (www.NOACforAF.eu).

Catheter ablation for ventricular tachycardia after failed endocardial ablation: epicardial substrate or inappropriate endocardial ablation?

BACKGROUND: The substrate of myocardial ventricular tachycardia (VT) may involve the subepicardial myocardium. OBJECTIVE: The purpose of this study was to assess the incidence of epicardial substrates in patients with a previously failed endocardial ablation attempt for VT as well as the safety and effectiveness of epicardial ablation. METHODS: Using an electroanatomic mapping system, endocardial and epicardial maps were acquired. Irrigated radiofrequency current ablations of all inducible VTs were performed. RESULTS: Between 2005 and 2009, 59 patients with or without structural heart disease underwent epicardial VT ablation. Pericardial access failed in 3 (5%) of these patients. Of the remaining 56 patients, an epicardial substrate was found in 41 (73%). Overall, acute success was achieved in 46 (78%) of 59 patients, with complete VT abolition in 27 (46%) and partial abolition in 19 (32%). Successful outcomes were the result of endocardial ablation only in 14 (24%) patients, epicardial ablation in 21 (36%), and endocardial/epicardial in 11 (19%). Ablation failed to prevent reinduction in 8 (13%) patients, and VTs were noninducible prior to ablation in 5 (8%). Two periprocedural deaths occurred, one after right ventricular perforation and one due to electromechanical dissociation. Hepatic bleeding occurred in two patients. Recurrence of any VT occurred in 27 (47%) of 57 surviving patients during median follow-up of 362 days (q1-q3; 180-468 days). Repeat epicardial mapping was not feasible due to adhesions in 3 (25%) of 12 patients. CONCLUSION: In patients with a previously failed endocardial VT ablation, epicardial mapping reveals a VT substrate in nearly three fourths of all patients, and epicardial ablation is required for successful VT abolition in more than half of patients. However, life-threatening complications may occur. Repeat epicardial access was not possible in 25% due to local pericardial adhesions.

Catheter ablation of multiple unstable macroreentrant tachycardia within the right atrium free wall in patients without previous cardiac surgery.

BACKGROUND: Macroreentrant atrial tachycardia (AT) involving the right atrial free wall (RAFW) has been reported in patients without atriotomy. Catheter ablation of these ATs remains challenging due to the multiple morphologies of ATs with unstable reentrant circuits in some patients. The purpose of this study was to clarify the electrophysiological characteristics of these ATs and attempt the novel approach for catheter ablation. METHODS AND RESULTS: Electrophysiological study and catheter ablation were performed in 17 patients (14 men; 71 [quartile 1, 67; quartile 3, 76] years) with reentrant ATs originating from the RAFW using 3D mapping. All patients had no history of cardiac surgery. Clinical ATs with stable cycle length and atrial activation were identified in 11 patients (group A). All ATs were successfully ablated. In the remaining 6 patients, clinical tachycardia continuously changed, with a different cycle length and P-wave morphology and atrial activation sequence during mapping or entrainment study (group B). A complete isolation of the RAFW was attempted in group B. After complete isolation was achieved in 5 of 6 patients, ATs were not induced in these 6 patients. The number of previous failed catheter ablations and induced ATs were higher in group B than in group A. During 31 (19; 37) months of follow-up, AT recurrence developed in 27% patients from group A and 33% from group B. CONCLUSIONS: Multiple and unstable macroreentrant ATs from the RAFW can occur in patients without a history of cardiac surgery. The RAFW isolation has the potential to abolish all ATs.

The 'single big cryoballoon' technique for acute pulmonary vein isolation in patients with paroxysmal atrial fibrillation: a prospective observational single centre study.

AIMS: Cryothermal energy (CTE) ablation via a balloon catheter (Arctic Front, Cryocath) represents a novel technology for pulmonary vein isolation (PVI). However, balloon-based PVI approaches are associated with phrenic nerve palsy (PNP). We investigated whether 'single big cryoballoon'-deployed CTE lesions can (i) achieve acute electrical PVI without left atrium (LA) imaging and (ii) avoid PNP in patients with paroxysmal atrial fibrillation (PAF). METHODS AND RESULTS: After double transseptal punctures, one Lasso catheter and a big 28 mm cryoballoon catheter using a steerable sheath were inserted into the LA. PV angiography and ostial Lasso recordings from all PVs were obtained. Selective PV angiography was used to evaluate balloon to LA-PV junction contact. CTE ablation lasted 300 s, and the PN was paced during freezing at right-sided PVs. Twenty-seven patients (19 males, mean age: 56 +/- 9 years, LA size: 42 +/- 5 mm) with PAF (mean duration: 6.6 +/- 5.7 years) were included. PVI was achieved in 97/99 PVs (98%). Median (Q(1); Q(3)) procedural, balloon, and fluoroscopy times were 220 min (190; 245), 130 min (90; 170), and 50 min (42; 69), respectively. Three transient PNP occurred after distal PV ablations. No PV stenosis occurred. Total median (Q(1); Q(3)) follow-up time was 271 days (147; 356), and 19 of 27 patients (70%) remained in sinus rhythm (3-month blanking period). CONCLUSION: Using the single big cryoballoon technique, almost all PVs (98%) could be electrically isolated without LA imaging and may reduce the incidence of PNP as long as distal ablation inside the septal PVs is avoided.

Substrate mapping vs. tachycardia mapping using CARTO in patients with coronary artery disease and ventricular tachycardia: impact on outcome of catheter ablation.

AIMS: For ablation of ventricular tachycardia (VT) in patients after myocardial infarction, a three-dimensional mapping system is often used. We report on our overall success rate of VT ablation using CARTO in 47 patients, with a subgroup analysis comparing VT mapping with the results of mapping that had to be performed during sinus rhythm or pacing (substrate mapping). METHODS AND RESULTS: A CARTO map was performed and VT ablation attempted using two strategies: Patients in the VT-mapping group had incessant VT (four patients) or inducible stable VT (18 patients) such that the circuit of the clinical VT could be reconstructed using CARTO. During VT, the critical area of slow conduction was identified using diastolic potentials and conventional concealed entrainment pacing. In contrast, patients in the substrate-mapping group had initially inducible VT. However, a complete VT map was not possible because of catheter-induced mechanical block (six patients) or because haemodynamics deteriorated during the ongoing VT (19 patients). Therefore, pathological myocardium was identified by fragmented, late- and/or low-amplitude (<1.5 mV) bipolar potentials during sinus rhythm or pacing, and the ablation site was primarily determined by pace mapping inside or at the border of this pathological myocardium. Acute ablation success in all patients with regard to non-inducibility of the clinical VT or any slower VT was 79% after a single ablation procedure, but increased to 95% after a mean of 1.2 ablation procedures. However, chronic success was 75%, when it was defined as freedom from any ventricular tachyarrhythmia (VT or VF) during a follow-up of 25+/-13 months. In the subgroup analysis, patients in the VT-mapping group were not significantly different from patients in the substrate-mapping group with regard to age (65+/-7 vs. 65+/-9 years), ejection fraction (30+/-7 vs. 30+/-8%), VT cycle length (448+/-81 vs. 429+/-82 ms), number of radiofrequency applications (17+/-9 vs. 14+/-6 applications), use of an irrigated tip catheter (23 vs. 32%), and ablation results. CONCLUSION: When using a CARTO-guided approach for VT ablation in patients with coronary artery disease, the freedom from any ventricular arrhythmia is high (75%), but leaves the patient at a 23% risk of developing fast VT/VF during follow-up. Mapping during sinus rhythm or pacing is as successful as mapping during VT.

Complete pulmonary vein isolation guided by three-dimensional electroanatomical mapping for the treatment of paroxysmal atrial fibrillation in patients with hypertrophic obstructive cardiomyopathy.

AIMS: Evaluation of the clinical outcome of patients with hypertrophic obstructive cardiomyopathy (HOCM) and paroxysmal atrial fibrillation (AF) treated with complete pulmonary vein (PV) isolation guided by three-dimensional (3-D) electroanatomical (EA) mapping. METHODS: Circumferential radiofrequency (RF) ablation and continuous circular lesions (CCLs) around the left and right-sided PVs were performed in 4 highly symptomatic patients (2 males; age 57.5 +/- 8.3 years) with HOCM and anti-arrhythmic drug (AAD) refractory paroxysmal AF. Ablation was guided by 3-D EA mapping combined with conventional circumferential PV mapping. The endpoints of the ablation were defined as: (1) absence of all PV spikes documented with the two Lasso catheters within the ipsilateral PVs; and (2) no recurrence of the PV spikes within all PVs following intravenous administration of adenosine. RESULTS: The ablation endpoints were achieved in all patients. A repeat ablation was performed in one patient due to repetitive atrial tachycardia, 1 month after the initial procedure. During a follow-up of 5.8 +/- 2.7 months, all patients are free of AF recurrence. Short episodes of symptomatic AT were documented after the repeat procedure, and were well controlled with oral amiodarone in the patient. No procedure-related complications were observed. CONCLUSION: The present study demonstrates that complete isolation of ipsilateral PVs guided by 3-D EA mapping is potentially effective for the treatment of highly symptomatic, drug refractory paroxysmal AF in patients with HOCM.

Recovered pulmonary vein conduction as a dominant factor for recurrent atrial tachyarrhythmias after complete circular isolation of the pulmonary veins: lessons from double Lasso technique.

BACKGROUND: Atrial tachyarrhythmias (ATa) can recur after continuous circular lesions (CCLs) around the ipsilateral pulmonary veins (PVs) in patients with atrial fibrillation (AF). This study characterizes the electrophysiological findings in patients with and without ATa after complete PV isolation. METHODS AND RESULTS: Twenty-nine of 100 patients had recurrent ATa after complete PV isolation by use of CCLs during a mean follow-up of approximately 8 months. A repeat procedure was performed in 26 patients with ATa and in 7 volunteers without ATa at 3 to 4 months after CCLs. No recovered PV conduction was demonstrated in the 7 volunteers, whereas recovered PV conduction was found in 21 patients with recurrent ATa (right-sided PVs in 9 patients and left-sided PVs in 16 patients). The interval from the onset of the P wave to the earliest PV spike was 157+/-66 ms in the right-sided PVs and 149+/-45 ms in the left-sided PVs. During the procedure, PV tachycardia activated the atrium and resulted in atrial tachycardia (AT) in 10 patients. All conduction gaps were successfully closed with segmental RF ablation. After PV isolation, macroreentrant AT was induced and ablated in 3 patients. In the 5 patients without PV conduction, focal AT in the left atrial roof in 2 patients and non-PV foci in the left atrium in 1 patient were successfully abolished; in the remaining 2 patients, no ablation was performed because of noninducible arrhythmias. During a mean follow-up of approximately 6 months, 24 patients were free of ATa without antiarrhythmic drugs. CONCLUSIONS: In patients with recurrent ATa after CCLs, recovered PV conduction is a dominant finding in approximately 80% of patients and can be successfully eliminated by segmental RF ablation. Also, mapping and ablation of non-PV arrhythmias can improve clinical success.

Complete isolation of left atrium surrounding the pulmonary veins: new insights from the double-Lasso technique in paroxysmal atrial fibrillation.

BACKGROUND: Paroxysmal atrial fibrillation (PAF) can be eliminated with continuous circular lesions (CCLs) around the pulmonary veins (PVs), but it is unclear whether all PVs are completely isolated. METHODS AND RESULTS: Forty-one patients with symptomatic PAF underwent 3D mapping, and all PV ostia were marked on the 3D map based on venography. Irrigated radiofrequency energy was applied at a distance from the PV ostia guided by 2 Lasso catheters placed within the ipsilateral superior and inferior PVs. The mean radiofrequency duration was 1550+/-511 seconds for left-sided PVs and 1512+/-506 seconds for right-sided PVs. After isolation, automatic activity was observed in the right-sided PVs in 87.8% and in the left-sided PVs in 80.5%. During the procedure, a spontaneous or induced PV tachycardia (PVT) with a cycle length of 189+/-29 ms was observed in 19 patients. During a mean follow-up of 6 months, atrial tachyarrhythmias recurred in 10 patients. Nine patients underwent a repeat procedure. Conduction gaps in the left CCL in 9 patients and in the right CCL in 2 patients were closed during the second procedure. A spontaneous PVT with a cycle length of 212+/-44 ms was demonstrated in 7 of 9 patients, even though no PVT had been observed in 6 of these 7 patients during the first procedure. No AF recurred in 39 patients after PV isolation during follow-up. CONCLUSIONS: Automatic activity and fast tachycardia within the PVs could reflect an arrhythmogenic substrate in patients with PAF, which could be eliminated by isolating all PVs with CCLs guided by 3D mapping and the double-Lasso technique in the majority of patients.

Initial experience with remote catheter ablation using a novel magnetic navigation system: magnetic remote catheter ablation.

BACKGROUND: Catheters are typically stiff and incorporate a pull-wire mechanism to allow tip deflection. While standing at the patient's side, the operator manually navigates the catheter in the heart using fluoroscopic guidance. METHODS AND RESULTS: A total of 42 patients (32 female; mean age, 55+/-15 years) underwent ablation of common-type (slow/fast) or uncommon-type (slow/slow) atrioventricular nodal reentrant tachycardia (AVNRT) with the use of the magnetic navigation system Niobe (Stereotaxis, Inc). It consists of 2 computer-controlled permanent magnets located on opposite sides of the patient, which create a steerable external magnetic field (0.08 T). A small magnet embedded in the catheter tip causes the catheter to align and to be steered by the external magnetic field. A motor drive advances or retracts the catheter, enabling complete remote navigation. Radiofrequency current was applied with the use of a remote-controlled 4-mm, solid-tip, magnetic navigation-enabled catheter (55 degrees C, maximum 40 W, 60 seconds) in all patients. The investigators, who were situated in the control room, performed the ablation using a mean of 7.2+/-4.7 radiofrequency current applications (mean fluoroscopy time, 8.9+/-6.2 minutes; procedure duration, 145+/-43 minutes). Slow pathway ablation was achieved in 15 patients, whereas slow pathway modulation was the end point in the remaining patients. There were no complications. CONCLUSIONS: The Niobe magnetic navigation system is a new platform technology allowing remote-controlled navigation of an ablation catheter. In conjunction with a motor drive unit, this system was used successfully to perform completely remote-controlled mapping and ablation in patients with AVNRT.

Catheter ablation of subepicardial ventricular tachycardia using electroanatomic mapping.

BACKGROUND: In patients with left ventricular tachycardia (VT) and failed endocardial ablation, a subepicardial substrate may be considered. PATIENTS AND METHODS: Seven patients with drug-refractory VT of right bundle branch block morphology were investigated to identify the arrhythmogenic substrate using three-dimensional (3-D) electroanatomic endocardial and epicardial mapping. RESULTS: In three patients with repetitive monomorphic VT, endocardial and epicardial mapping during tachycardia showed a focal pattern with an earliest activation preceding the onset of the QRS complex by 20 and 28 ms in the lateral aspect of the epicardial outflow tract in two patients and by 24 ms near the posterolateral mitral annulus in one patient; in two patients with sustained VT, endocardial mapping during tachycardia displayed a focal pattern with a wide breakthrough, and epicardial mapping showed a macroreentrant VT with an isthmus located in the left anterior wall in one patient and in the left inferolateral wall in the other. In the remaining two patients, endocardial and epicardial mapping were performed during sinus rhythm. An area with fragmented and late potentials as well as low amplitude was only identified in the epicardial left inferolateral wall. During tachycardia, a diastolic potential was only recorded on the epicardium and coincided with the late potential during sinus rhythm in the same area. A focal or linear epicardial irrigated lesion terminated the VT and resulted in noninducibility in all seven patients. During a median follow-up of 16 months, VT recurred in two patients without antiarrhythmic drugs. The recurrent VT was successfully reablated in one patient and treated with oral amiodarone in the other. CONCLUSION: Subepicardial left focal and macroreentrant VT may present as focal origin on endocardial mapping and can only be abolished by radiofrequency (RF) applications in the epicardial space.

An underrecognized subepicardial reentrant ventricular tachycardia attributable to left ventricular aneurysm in patients with normal coronary arteriograms.

BACKGROUND: In patients with apparently normal hearts, ventricular tachycardia (VT) may only involve the subepicardial myocardium. METHODS AND RESULTS: Four patients with exercise-induced fast VT with right bundle branch block morphology were investigated. ECG showed a small q wave in leads II, III, and aVF during sinus rhythm (SR) in all 4 patients. Left ventricular angiography showed small inferolateral aneurysms in all patients. Coronary arteriograms were normal in all 4 patients. Six unstable VTs (cycle length, 200 to 305 ms) and 1 stable VT (cycle length 370 ms) were reproducibly induced in the 4 patients. During SR, endocardial mapping was normal in all 4 patients, and epicardial mapping showed fragmented and late potentials in the left inferolateral wall anatomically consistent with the left ventricle aneurysm. During tachycardia, epicardial mapping showed a macroreentrant VT with focal endocardial activation in the patient with stable VT, whereas in 2 patients with unstable VT, a diastolic potential was only recorded and coincided with the late potential in the same area. Epicardial ablation was performed in 3 patients and successfully abolished those VTs. No VT recurred in 2 patients during follow-up of 2 and 9 months. Clinical VT recurred 6 months after the ablation and was successfully ablated in a repeated epicardial ablation in 1 patient. In the remaining patient without epicardial ablation, an implantable cardiac defibrillator was implanted. There were multiple shocks during a follow-up of 31 months. CONCLUSIONS: In patients with normal coronary arteriograms and left ventricle aneurysm, exercise-induced VT with right bundle branch block morphology may have a subepicardial arrhythmogenic substrate, which may be amenable to epicardial ablation.

Total pulmonary vein occlusion as a consequence of catheter ablation for atrial fibrillation mimicking primary lung disease.

INTRODUCTION: Catheter ablation has recently been used for curative treatment of atrial fibrillation. METHODS AND RESULTS: Three of 239 patients who underwent ablation close to the pulmonary vein (PV) ostia at our institute developed severe hemoptysis, dyspnea, and pneumonia as early as 1 week and as late as 6 months after the ablation. Because the patients were arrhythmia-free, the treating physician initially attributed the symptoms to new-onset pulmonary disease (e.g., bronchopulmonary neoplasm). After absent PV flow was confirmed by transesophageal echocardiography, transseptal contrast injection depicted a totally occluded PV in all three patients. Successful recanalization, even in chronically occluded Pvs, was performed in all patients. During follow-up, Doppler flow measurements by transesophageal echocardiography demonstrated restenosis in all primarily dilated PV, which led to stent implantation. CONCLUSION: PV stenosis/occlusion after catheter ablation of atrial fibrillation occurs in a subset of patients. However, because in-stent restenosis occurred in two patients after 6 to 10 weeks, final interventional strategy for PV stenosis or occlusion remains unclear. To prevent future PV stenosis or occlusion, a decrease in target temperature and energy of radiofrequency current or the use of new energy sources (ultrasound, cryothermia, microwave) seems necessary.

Risk of sudden death after successful accessory atrioventricular pathway ablation in resuscitated patients with Wolff-Parkinson-White syndrome.

INTRODUCTION: Cardiac arrest in patients with Wolff-Parkinson-White (WPW) syndrome can be due to ventricular fibrillation mediated by fast conduction over the accessory pathway during atrial fibrillation. However, if primary ventricular fibrillation is the reason for resuscitation, placement of an implantable cardioverter defibrillator (ICD) would be indicated. The aim of this study was to test the hypothesis that in resuscitated patients with WPW syndrome, recurrences can be prevented by sole ablation of their accessory pathways. METHODS AND RESULTS: We performed a long-term follow-up study of 48 resuscitated patients with WPW syndrome who underwent successful accessory pathway ablation as their sole primary treatment. Cardiac arrest had occurred either spontaneously in 32 patients (group A) or after intravenous administration of antiarrhythmic drugs in 16 patients (group B) and was never associated with an acute myocardial infarction or other concomitant factors. All patients had normal left ventricular function at echocardiography. A total of 56 accessory AV pathways were ablated successfully with radiofrequency current (n = 55) or during surgery (n = 1) and were located at the left free wall (n = 35), right free wall (n = 8), or septal-paraseptal region (n = 13). Follow-up 5.0+/-1.9 years after ablation (range 0.2 to 7.9) was obtained in all 48 patients. All of the patients were alive, and none had a life-threatening arrhythmia or syncope after successful ablation of their accessory pathways. CONCLUSION: In resuscitated patients with WPW syndrome who have normal left ventricular function at echocardiography and no ECG abnormalities suggesting additional electrical disease, ablation of their overt accessory pathways prevented cardiac arrest recurrences; therefore, ICD placement is generally not indicated.