N Szegedi

Radiofrequency ablation of focal atrial tachycardia: Benefit of electroanatomical mapping over conventional mapping

BACKGROUND Catheter ablation is a proven therapy of focal atrial tachycardia. However limited information is available about the additional value of electroanatomical over conventional mapping methods for this specific arrhythmia. METHODS Consecutive catheter ablation procedures of FAT were analyzed in two cardiology centres. Only conventional mapping was used in 30 of the 60 procedures whereas additionally CARTO mapping was performed in another 30 procedures. Acute, six-month success rate, and procedural data were analyzed. RESULTS Localization of ectopic foci is congruent with previously published data. There was no statistically significant difference between procedure time and fluoroscopy time using additionally CARTO mapping, compared to conventional mapping only. Acute success rate was higher in procedures guided by CARTO mapping than in procedures based on conventional mapping (27/30 vs. 18/30, p = 0.0081). During the 6-month follow-up period there was a better outcome (p = 0.045) in case of CARTO guided procedures (success: 11 cases, partial success: 12 cases, failure: 4 cases) compared to conventional mapping (success: 4 cases, partial success: 18 cases, failure: 7 cases). CONCLUSIONS Catheter ablation of focal atrial tachycardias using the CARTO electroanatomical mapping system seems to provide higher acute and 6-month success rate compared to ablation using conventional mapping methods only.

Successful direct thrombin inhibitor treatment of a left atrial appendage thrombus developed under rivaroxaban therapy

Absztrakt A szerzők a 62 eves, rivaroxabannal antikoagulalt ferfi betegnel perzisztens pitvarfibrillacio miatt pulmonalisvena-izolaciot terveztek. A preoperativ transoesophagealis echokardiografia soran bal pitvari fulcsethrombus jelenletet mutattak ki. Thrombophilia iranyaban vegzett vizsgalataik alapjan a beteg heterozigotanak bizonyult metilen-tetrahidrofolat-reduktaz-genmutaciora. Felteteleztek, hogy ebben az esetben a direkt trombininhibitor hatekonyabb antithromboticus hatassal birhat, ezert dabigatranra valtottak. Ket honapnyi direkt trombininhibitor kezeles es folsavpotlas mellett a thrombus feloldodott. A szerzők kiemelik, hogy pitvarfibrillalo betegnel adekvat rivaroxabanterapia mellett is kialakulhat bal pitvari fulcsethrombus. Jelen eset felveti annak a lehetőseget, hogy a metilen-tetrahidrofolat-reduktaz-genmutacio csokkentheti a Xa faktor inhibitorok hatekonysagat. Az esettanulmany alapjan dabigatranra valo csere hatekony lehet a bal pitvari fulcsethrombusok feloldasaban. Orv. Hetil., 2016, ...The authors present the history of a 62-year-old man on continuous rivaroxaban therapy who was scheduled for pulmonary vein isolation due to persistent atrial fibrillation. Preoperative transesophageal echocardiography detected the presence of left atrial appendage thrombus. Thrombophilia tests showed that the patient was heterozygous carrier of the methylene-tetrahydrofolate reductase gene mutation. The authors hypothesized that a direct thrombin inhibitor might exert a more appropriate effect against thrombosis in this case and, therefore, a switch to dabigatran was performed. After two months of anticoagulation with the direct thrombin inhibitor and folic acid supplementation the thrombus resolved. The authors underline that thrombus formation may develop in atrial fibrillation even if the patient is adequately treated with rivaroxaban. This case suggests, that methylene-tetrahydrofolate reductase gene mutation may modulate the efficacy of direct Xa factor inhibitors. According to this case history, dabigatran may be an effective therapeutic option in resolving established thrombus.

Rivaroxabankezelés mellett kialakult bal pitvari fülcsethrombus sikeres kezelése direkt trombininhibitorral

Absztrakt A szerzők a 62 eves, rivaroxabannal antikoagulalt ferfi betegnel perzisztens pitvarfibrillacio miatt pulmonalisvena-izolaciot terveztek. A preoperativ transoesophagealis echokardiografia soran bal pitvari fulcsethrombus jelenletet mutattak ki. Thrombophilia iranyaban vegzett vizsgalataik alapjan a beteg heterozigotanak bizonyult metilen-tetrahidrofolat-reduktaz-genmutaciora. Felteteleztek, hogy ebben az esetben a direkt trombininhibitor hatekonyabb antithromboticus hatassal birhat, ezert dabigatranra valtottak. Ket honapnyi direkt trombininhibitor kezeles es folsavpotlas mellett a thrombus feloldodott. A szerzők kiemelik, hogy pitvarfibrillalo betegnel adekvat rivaroxabanterapia mellett is kialakulhat bal pitvari fulcsethrombus. Jelen eset felveti annak a lehetőseget, hogy a metilen-tetrahidrofolat-reduktaz-genmutacio csokkentheti a Xa faktor inhibitorok hatekonysagat. Az esettanulmany alapjan dabigatranra valo csere hatekony lehet a bal pitvari fulcsethrombusok feloldasaban. Orv. Hetil., 2016, ...The authors present the history of a 62-year-old man on continuous rivaroxaban therapy who was scheduled for pulmonary vein isolation due to persistent atrial fibrillation. Preoperative transesophageal echocardiography detected the presence of left atrial appendage thrombus. Thrombophilia tests showed that the patient was heterozygous carrier of the methylene-tetrahydrofolate reductase gene mutation. The authors hypothesized that a direct thrombin inhibitor might exert a more appropriate effect against thrombosis in this case and, therefore, a switch to dabigatran was performed. After two months of anticoagulation with the direct thrombin inhibitor and folic acid supplementation the thrombus resolved. The authors underline that thrombus formation may develop in atrial fibrillation even if the patient is adequately treated with rivaroxaban. This case suggests, that methylene-tetrahydrofolate reductase gene mutation may modulate the efficacy of direct Xa factor inhibitors. According to this case history, dabigatran may be an effective therapeutic option in resolving established thrombus.

Successful Catheter Ablation of Right Atrial Tachycardia After Bilateral Lung Transplantation.

A 47-year-old woman underwent bilateral lung transplantation for pulmonary fibrosis in June of 2013. The early postoperative period was complicated by continuous atrial arrhythmias that proved unresponsive to antiarrhythmic agents (propafenon and bisoprolol). Therefore, in February 2014, we performed an electrophysiological study after adequate antibiotic and antimycotic prophylaxis. During the procedure, the clinical tachycardia was easily inducible with burst atrial pacing and programmed atrial extrastimuli. Tachycardia cycle length varied between 380 ms and 420 ms, and A-A-V response after ventricular burst pacing suggested atrial tachycardia. Entrainment mapping from the area of early activation failed to demonstrate reentry as the underlying mechanism of the tachycardia, thus ectopic atrial tachycardia was diagnosed. Electroanatomical mapping was performed with ENSITE NavX system (Endocardial Solutions Inc.) during ongoing arrhythmia (Figure ​(Figure1).1). Activation map showed that earliest activation was in the right atrium, corresponding to a scar of the extracorporeal membrane oxigenator (ECMO) cannula during lung transplantation. To avoid paralysis of the diaphragm, we paced the high right atrial region with high energy to demonstrate and mark the location of right phrenic nerve. Subsequently, we performed RF ablation with 3.5 mm irrigated tip catheter (AlCath Flux Blue G eXtra) using 40 W energy and 43°C temperature limit. After the application of one RF ablation at the site of earliest activation (ablation time 46 seconds), the arrhythmia stopped immediately and was no longer inducible even after administration of isoproterenol. The total procedure time was 75 minutes with a fluoroscopy time of 2.3 minutes. No procedural complications occurred. Outpatient visits and 24-hour Holter electrocardiogram monitoring were scheduled every 3 months. The patient was free of symptoms and arrhythmia episodes without any antiarrhythmic medication during the 9-month follow-up period. FIGURE 1 Left side: 12 lead surface electrocardiogram (paper speed 100 mm/sec) and intracardiac electrocardiogram (ablation catheter and coronary sinus catheter) during ongoing arrhythmia. Cycle length is changing from beat to beat. The local activation recorded ... Atrial tachyarrhythmias are frequent after lung transplantation but the incidence of right atrial tachycardia is very low. Most commonly atrial fibrillation is observed in the early postoperative period and left atrial tachycardia occurs later in time.1-4 Right atrial tachycardia might also be associated to the operation, during which an ECMO is implanted with cannulation of the right atrium and aorta. Damaging the anterior part of the high right atrium during this step might be the ground of arrhythmia substrate formation. To the best of our knowledge, our case represents the first successful ablation of right atrial tachycardia after lung transplantation due to scarring of a passagere cannula of ECMO. Ablation of typical right atrial flutter and left atrial tachycardias originating from the donor pulmonary veins has been reported previously.1-4 Atrial ablation in lung transplant recipients is rarely performed, in contrast to heart transplant recipients, where ablation of atrial arrhythmias has repeatedly been reported and arrhythmias are dominantly originating from the right atrium.5

Successful emergency ablation of ventricular tachycardia in the early postoperative period after left ventricular assist device implantation

A case of a 38-year-old male patient is reported. Left ventricular assist device was implanted because of end stage heart failure. In the early postoperative period, electrical storm with rapid ventricular tachycardia (VTs) occurred that was refractory to medical therapy. Emergency VT ablation was performed successfully. VT frequently occurs after LVAD implantation and radiofrequency ablation can be an effective therapeutic option. We report a case of a 38-year-old male patient, who suffered an extensive anterior ST-segment elevation myocardial infarction in 2002 treated with thrombolysis. LAD PCI (2005), amiodarone-induced hyperthyreosis (2007) and primary prophylactic ICD implantation (2008) are the most relevant findings in his past medical history. Since then he required several hospitalizations for worsening heart failure symptoms. In May 2013, he was admitted due to rapid VT causing hemodynamic instability requiring two appropriate ICD shocks. Heart transplantation was considered as an option but it was contraindicated because of high pulmonary vascular resistance refractory to vasodilator therapy. Left ventricular assist device (LVAD, HeartMate II) implantation was performed as ‘‘destination therapy’’. In the early postoperative period (5 days after implantation) electrical storm occurred requiring multiple ICD shocks. Shock therapy of ICD was deactivated and multiple external electric cardioversions were needed despite the intravenous administration of high dose antiarrhythmic drugs (amiodarone, procainamide and beta blocker). Due to drug refractory electrical storm radiofrequency ablation of the incessant VT was decided in the early postoperative period. Procedure was performed under uninterrupted anticoagulation, respecting the high thromboembolic risk of the assist device. We decided to use transaortic retrograde approach only. During the electrophysiological study sustained monomorphic VT was inducible (cycle length: 330 ms, superior axis, right bundle branch block morphology). During ongoing arrhythmia, rapid electroanatomic mapping (CARTO3, Biosense Webster) was performed which found that the site of earliest activation is at the inferoseptal region of the left ventricle, in the intrinsic myocardial scar near to the junction of the inflow cannula. The exit point was also identified at the same site with entrainment mapping. Then 5 radiofrequency ablations were applied (total ablation time 790 s, energy 40 W, temperature 43 C) using 3.5 mm irrigated tip catheter (Thermocool, D curve, Biosense Webster). We would like to highlight that the ablation site was near to the inflow cannula but we kept some distance from the device to avoid damaging of the surgical sutures. The VT stopped immediately and was no longer inducible even with 2 ventricular extrastimuli at 330 ms drive. No complications were observed during or in relation to the ablation procedure (total procedure time: 45 min, fluoroscopy time: 8 min). After the procedure, patient was free of sustained VT episodes during the 12-month follow-up period. VT is frequently observed in patients after LVAD implantation, but very limited data are available regarding VT ablation in the early postoperative period. Until now publications usually dealt with VTs originating near the cannula, but there are scarce data about VTs arising from the intrinsic scar [1–5]. Managing VT in these difficult N. Szegedi G. Szeplaki B. Merkely L. Geller (&) Heart and Vascular Center, Semmelweis University, Varosmajor street 68, Budapest 1122, Hungary e-mail: laszlo.geller@gmail.com