Daniel Steven

Pulmonary Vein Isolation Versus Defragmentation: The CHASE-AF Clinical Trial.

BACKGROUNDnLong-term success rates using ablation for persistent atrial fibrillation (AF) are disappointing and usually do not exceed 60%.nnnOBJECTIVESnThis study sought to compare arrhythmia-free survival between pulmonary vein isolation (PVI) and a stepwise approach (full defrag) consisting of PVI, ablation of complex fractionated electrograms, and additional linear ablation lines in the setting of atrial tachycardias (AT) in patients with persistent AF after PVI.nnnMETHODSnFrom November 2010 to February 2013, 205 patients (151 men; 61.7 ± 10.2 years of age) underwent de novo ablation for persistent AF. Subsequently, patients were prospectively randomized to either PVI alone (n = 78) or full defrag (n = 75), with 52 patients not randomized due to AF termination with the original PVI. The primary endpoint was recurrence of any AT after a blanking period of 3 months.nnnRESULTSnDuring the entire study, 241 ablations were performed (mean: 1.59 in the PVI-alone group, 1.55 in the full-defrag group). With the stepwise approach, termination of AF occurred in 45 (60%) patients. However, arrhythmia-free survival did not differ whether patients underwent single or multiple procedures (p = 0.468). Procedure duration, fluoroscopy time, and radiofrequency duration were significantly longer in the full-defrag group (all p < 0.001).nnnCONCLUSIONSnA stepwise approach aimed at AF termination does not seem to provide additional benefit over PVI alone in patients with persistent AF, but it is associated with significantly longer procedural and fluoroscopic duration as well as radiofrequency application time. (The Randomized Catheter Ablation of Persist End Atrial Fibrillation Study [CHASE-AF]; NCT01580124).

Idiopathic ventricular outflow tract arrhythmias from the great cardiac vein: challenges and risks of catheter ablation.

INTRODUCTIONnCatheter ablation for idiopathic ventricular arrhythmia is well established but epicardial origin, proximity to coronary arteries, and limited accessibility may complicate ablation from the venous system in particular from the great cardiac vein (GCV).nnnMETHODSnBetween April 2009 and October 2010 14 patients (56 ± 15 years; 9 male) out of a total group of 117 patients with idiopathic outflow tract tachycardias were included undergoing ablation for idiopathic VT or premature ventricular contractions (PVC) originating from GCV. All patients in whom the PVC arose from the GCV were subject to the study. In these patients angiography of the left coronary system was performed with the ablation catheter at the site of earliest activation.nnnRESULTSnSuccessful ablation was performed in 6/14 (43%) and long-term success was achieved in 5/14 (36%) patients. In 4/14 patients (28.6%) ablation was not performed. In another 4 patients (26.7%), ablation did not abolish the PVC/VT. In the majority, the anatomical proximity to the left coronary system prohibited effective RF application. In 3 patients RF application resulted in a coronary spasm with complete regression as revealed in repeat coronary angiography.nnnCONCLUSIONnA relevant proportion idiopathic VT/PVC can safely be ablated from the GCV without significant permanent coronary artery stenosis after RF application. Our data furthermore demonstrate that damage to the coronary artery system is likely to be transient.

[Catheter ablation for atrial fibrillation: clinically established or still an experimental method?].

ZusammenfassungSeit der Entdeckung, dass die fokale Triggerung aus den Pulmonalvenen (PV) die entscheidende Rolle bei der Entstehung der paroxysmalen Form des Vorhofflimmerns (PAF) spielt, hat die Katheterablation dieser Arrhythmie eine rasche Verbreitung erfahren. Die Elimination der PV-Leitungseigenschaft ist dabei heute das allgemein akzeptierte primäre Ziel bei PAF und führt in 60–85% der Fälle nach der ersten Prozedur zur Freiheit von Vorhofflimmern (AF). Bei Wiederholung der Katheterablation liegen die Erfolgsraten bei > 80%. Gestützt durch die aktuellen Leitlinien ist dies bei symptomatischen und medikamentös therapierefraktären Patienten (nach Versuch mit einem Antiarrhythmikum) ein gezielt einsetzbares und in erfahrenen Zentren etabliertes Verfahren. Bei chronisch persistierendem Vorhofflimmern (CAF) hat es in den letzten 2 Jahren einen enormen Fortschritt durch die Einführung einer neuen, schrittweisen Strategie gegeben. Hierbei werden die herkömmlichen Ansätze (Pulmonalvenenisolation [PVI], Defragmentierung und ggf. lineare Läsionen) kombiniert und mit dem Ziel der Terminierung des AF durch die Ablation angewendet. Dabei ist die erste Prozedur auch oft nur der erste Schritt auf dem Weg zum Sinusrhythmus bei allerdings sehr guter Prognose nach Terminierung des Vorhofflimmerns (> 80% Sinusrhythmus). Über die Hälfte der Patienten bedarf mehr als nur einer Prozedur, welche dann oft die Behandlung konsekutiv auftretender atrialer Tachyarrhythmien zum Ziel hat. Aufgrund der limitierten Nachbeobachtungszeit sowie des zeitlichen Aufwands, der mangelnden Übertragbarkeit und der möglichen Komplikationen ist die Katheterablation bei CAF derzeit noch nicht klinisch „etabliert“ und insbesondere beim Vorliegen einer Herzinsuffizienz als experimentell zu bezeichnen. Gerade deshalb ist es wichtig, in zukünftigen Untersuchungen Prädiktoren zu identifizieren, welche ein Fehlschlagen der Prozedur bei CAF vorhersagen (Größe des linken Vorhofs, Dauer des AF, atriale Zykluslänge) und somit helfen, die Patientenauswahl zu verbessern. Für PAF gilt es, die unbefriedigenden Ergebnisse bezüglich der hohen Rezidivrate nach der ersten Prozedur zu optimieren. Hier könnte die Anwendung neuer Strategien (z.B. Testung der PV-Leitung durch Adenosin) und Technologien (z.B. robotische Navigation) hilfreich sein.AbstractInterventional treatment for atrial fibrillation (AF) has been introduced as a therapeutic option soon after the pulmonary veins (PV) have been discovered as the dominant sources of paroxysmal atrial fibrillation (PAF). Elimination of PV conduction is the initial goal during catheter ablation in this setting. The success rate after the initial procedure varies between 60% and 85%, with > 80% after subsequent interventions. Supported by the current guidelines, interventional treatment of AF is indicated in case of symptomatic arrhythmias refractory to antiarrhythmic treatment. The introduction of the combined, stepwise approach has been another important breakthrough with regard to the treatment of chronic persistent atrial fibrillation (CAF). This strategy includes the combination of all conventional ablation strategies (pulmonary vein isolation [PVI], defragmentation, linear ablation) with the goal of AF termination by radiofrequency current. The first procedure for CAF treatment is quite frequently also only the first step toward stable sinus rhythm with a favorable outcome after AF termination (> 80% sinus rhythm). In more than half of the patients predominantly atrial arrhythmias other than AF have to be targeted in a second procedure. This approach is currently under clinical investigation and so far not “clinically established” due to the fact that it is a quite time-consuming and challenging procedure even in experienced centers. Future studies may help to identify predictors for procedure failure (e.g., left atrial size, AF duration, atrial cycle length) in order to improve patient selection. Additionally, it has to be underscored, that in PAF the relatively high recurrence rate after the first procedure still is the subject of further investigations. This aspect might be improved by the introduction of novel strategies (i.e., testing of concealed PV conduction after ablation with adenosine) or technologies (i.e., robotic navigation) for PAF ablation.Interventional treatment for atrial fibrillation (AF) has been introduced as a therapeutic option soon after the pulmonary veins (PV) have been discovered as the dominant sources of paroxysmal atrial fibrillation (PAF). Elimination of PV conduction is the initial goal during catheter ablation in this setting. The success rate after the initial procedure varies between 60% and 85%, with > 80% after subsequent interventions. Supported by the current guidelines, interventional treatment of AF is indicated in case of symptomatic arrhythmias refractory to antiarrhythmic treatment. The introduction of the combined, stepwise approach has been another important breakthrough with regard to the treatment of chronic persistent atrial fibrillation (CAF). This strategy includes the combination of all conventional ablation strategies (pulmonary vein isolation [PVI], defragmentation, linear ablation) with the goal of AF termination by radiofrequency current. The first procedure for CAF treatment is quite frequently also only the first step toward stable sinus rhythm with a favorable outcome after AF termination (> 80% sinus rhythm). In more than half of the patients predominantly atrial arrhythmias other than AF have to be targeted in a second procedure. This approach is currently under clinical investigation and so far not clinically established due to the fact that it is a quite time-consuming and challenging procedure even in experienced centers. Future studies may help to identify predictors for procedure failure (e.g., left atrial size, AF duration, atrial cycle length) in order to improve patient selection. Additionally, it has to be underscored, that in PAF the relatively high recurrence rate after the first procedure still is the subject of further investigations. This aspect might be improved by the introduction of novel strategies (i.e., testing of concealed PV conduction after ablation with adenosine) or technologies (i.e., robotic navigation) for PAF ablation.Interventional treatment for atrial fibrillation has been introduced as a therapeutic option since the pulmonary veins (PV) have been discovered as the dominant sources of paroxysmal atrial fibrillation (PAF). Elimination of PV conduction is the initial goal during catheter ablation in this setting. The success rate after the initial procedure varies between 60 and 85 %, with more than 80 % after subsequent interventions. Supported by the current guidelines, interventional treatment of AF is indicated in case of symptomatic arrhythmias refractory to antiarrhythmic treatment. The introduction of the combined, stepwise approach has been another important breakthrough with regard to the treatment of chronic persistent atrial fibrillation (CAF). This strategy includes the combination of all conventional ablation strategies (PV isolation, ablation of complex fractionated atrial electrograms, linear ablation) with the goal of AF termination. The first procedure for CAF treatment is quite frequently also only the first step towards stable sinus rhythm with a favourable outcome after AF termination (> 80 % sinus rhythm). In more than half of the patients predominantly other atrial arrhythmias than AF have to be targeted in a second procedure. This approach is currently under clinical investigation and so far not clinically established due to the fact that it is a quite time consuming and challenging procedure even in experienced centres. Future studies may help to identify predictors for procedure failure (e.g. LA size, AF duration, atrial cycle length, spectral analysis) in order to improve patient selection. Additionally, it has to be underscored, that in paroxysmal atrial fibrillation the relatively high recurrence rate after the first procedure still is the subject of further investigations. This aspect might be improved by the introduction of novel strategies (i.e. testing of concealed PV conduction after ablation with adenosine) or new technologies (i.e. robotic navigation) for PAF ablation.

Necessity of epicardial ablation for ventricular tachycardia after sequential endocardial approach

BACKGROUNDnCatheter ablation (CA) of ventricular tachycardia (VT) is an important treatment option in patients with structural heart disease (SHD) and implantable cardioverter defibrillator (ICD). A subset of patients requires epicardial CA for VT.nnnOBJECTIVEnThe purpose of the study was to assess the significance of epicardial CA in these patients after a systematic sequential endocardial approach.nnnMETHODSnBetween January 2009 and October 2012 CA for VT was analyzed. A sequential CA approach guided by earliest ventricular activation, pacemap, entrainment and stimulus to QRS-interval analysis was used. Acute CA success was assessed by programmed ventricular stimulation. ICD interrogation and 24h-Holter ECG were used to evaluate long-term success.nnnRESULTSnOne hundred sixty VT ablation procedures in 126 consecutive patients (114 men; age 65±12years) were performed. Endocardial CA succeeded in 250 (94%) out of 265 treated VT. For 15 (6%) VT an additional epicardial CA was performed and succeeded in 9 of these 15 VT. Long-term FU (25±18.2month) showed freedom of VT in 104 pts (82%) after 1.2±0.5 procedures, 11 (9%) suffered from repeated ICD shocks and 11 (9%) died due to worsening of heart failure.nnnCONCLUSIONSnDespite a heterogenic substrate for VT in SHD, endocardial CA alone results in high acute success rates. In this study additional epicardial CA following a sequential endocardial mapping and CA approach was performed in 6% of VT. Thus, due to possible complications epicardial CA should only be considered if endocardial CA fails.

Interventional management of recurrent paroxysmal atrial fibrillation despite isolated pulmonary veins: impact of an ablation strategy targeting inducible atrial tachyarrhythmias

AIMSnPulmonary vein isolation (PVI) is an effective treatment option for paroxysmal atrial fibrillation (PAF). Reconnection of pulmonary veins (PVs) is the predominant cause for recurrence of PAF. However, treatment of patients with recurrence of PAF despite isolated PV in the absence of extra-PV foci remains challenging.nnnMETHODS AND RESULTSnOf 265 patients undergoing repeat catheter ablation (CA) for recurrence of PAF 21 (8%) patients (14 men, age 58 ± 14 years) showed no reconnection of PV. Therefore, inducibility of sustained atrial arrhythmias was tested. If sustained atrial fibrillation (AF) or sustained atrial tachycardia (AT) was induced, patients underwent CA. During follow-up (FU), Holter- and Tele-electrocardiogram were performed. In 19 (91%) of 21 patients, sustained atrial arrhythmias [16 (84%) AF; 3 (15%) patients AT] were induced. One patient showed PAF. Eighteen patients underwent CA aiming for termination of induced arrhythmia. In 14 (77%) patients, termination into sinus rhythm was achieved. Despite extensive CA, three (16%) patients were externally cardioverted. No periprocedural complications occurred. During 21.2 ± 6.8-month FU, 10 (53%) patients were free of any arrhythmia. Paroxysmal atrial fibrillation recurred in 4 (21%) and AT in 5 (26%) patients. One patient showed persistent AF. Repeat CA was scheduled and successfully performed for these patients.nnnCONCLUSIONnIn patients with recurrence of PAF despite isolated PV, termination of induced atrial arrhythmias can be achieved in most patients by defragmentation and AT ablation. Moreover, this ablation strategy results in favourable mid-term outcome results.

Interventionelle Therapie von paroxysmalem Vorhofflimmern

Atrial fibrillation is one of the most common arrhythmias and effects probably more than 35xa0million people worldwide. The incidence in patients older than 70 years of age is as high as 10%. One can expect that according to our demographic development this entity will be increasingly important within the next years and decades. Along with the well know and established but at the same time limited opportunities of pharmacological treatment option of this arrhythmia, catheter ablation has evolved as a safe and effective treatment option. Electrical isolation of the pulmonary vein remains the standard of care and results in success rates as high as 80% using modern ablation strategies. Optimization of procedural and ablation techniques has lead to this high success rates. Different energy sources are available, such as radiofrequency, cryoenergy and laser are widely used today to treat patients with symptomatic atrial fibrillation. PV isolation using a so called single-shot ablation approach has shown to be effective with a reduced requirement of periprocedural resources and therefore resulting in wider application of this treatment not only in specialized electrophysiological centers. The rapid development in this field leads to the question which approach can be used as the most likely to result in the highest success and least complication rates. This question will be addressed in the following manuscript.ZusammenfassungVorhofflimmern (VHF) betrifft annährend 35xa0Mio. Menschen weltweit und ist mit schwerwiegenden Folgeschäden assoziiert. Neben den bekannten und gleichermaßen limitierten medikamentösen Behandlungsoptionen hat sich die Katheterablation als sichere und effektive interventionelle Therapieoption insbesondere bei paroxysmalem VHF etabliert. Die Pulmonalvenen (PV) sind als Ursprungsort von paroxysmalem VHF gut verstanden. Durch deren elektrische Isolation können heute unter Berücksichtigung möglicher Folgeprozeduren hohe Erfolgsraten von etwa 80% erzielt werden; eine Optimierung der Prozedur- und Verfahrenstechniken und die Anlage einer weit im linken Vorhof geführten Ablationslinie haben dazu beigetragen. Verschiedene Techniken stehen für die elektrische Isolation der PV zur Verfügung. Hierzu gehören die Ablation mittels Hochfrequenzstrom, die Verwendung von Kälte (Kryoenergie) und die Applikation von gebündeltem Licht (Laser), um die Isolation der PV zur erreichen. Bei den Ballonkathetern ist die Ablation mittels Kryoenergie derzeit das am weitesten verbreitete Verfahren. In Bezug auf die Hochfrequenzablation haben sich in den letzten Jahren moderne Kathetertechniken und zusätzliche technische Verfahren etabliert, um möglichst hohe Erfolgsraten bei möglichst geringen Komplikationen zu erreichen. Dieser Artikel soll einen Überblick über die rasante Entwicklung in diesem Bereich und einen Hinweis geben, welche technischen Verfahren heute Verwendung finden und welche Kombination die vielversprechendste für eine dauerhaft erfolgreiche Isolation der PV zur Behandlung des paroxysmalen VHF ist.AbstractAtrial fibrillation is one of the most common arrhythmias and effects probably more than 35xa0million people worldwide. The incidence in patients older than 70 years of age is as high as 10%. One can expect that according to our demographic development this entity will be increasingly important within the next years and decades. Along with the well know and established but at the same time limited opportunities of pharmacological treatment option of this arrhythmia, catheter ablation has evolved as a safe and effective treatment option. Electrical isolation of the pulmonary vein remains the standard of care and results in success rates as high as 80% using modern ablation strategies. Optimization of procedural and ablation techniques has lead to this high success rates. Different energy sources are available, such as radiofrequency, cryoenergy and laser are widely used today to treat patients with symptomatic atrial fibrillation. PV isolation using a so called “single-shot” ablation approach has shown to be effective with a reduced requirement of periprocedural resources and therefore resulting in wider application of this treatment not only in specialized electrophysiological centers. The rapid development in this field leads to the question which approach can be used as the most likely to result in the highest success and least complication rates. This question will be addressed in the following manuscript.

External electrical cardioversion of persistent atrial fibrillation in a patient with a Micra™ Transcatheter Pacing System

We report a case of a 85-year old woman with a preexisting Transcatheter Pacing System (TPS) (Micra™ VR, Fa. Medtronic, Inc., Minneapolis, MN, USA) undergoing several external electrical cardioversions (CV) for symptomatic persistent atrial fibrillation (persAF). Due to bradycardia in the setting of atrial fibrillation a right apical TPS implantation was performed earlier. Four weeks prior to presentation at our facility an unsuccessful CV with a maximum biphasic energy level of 360J was performed, after which amiodarone was initiated. At the time of presentation three shocks with 100u202fJ, 200u202fJ and 360u202fJ were delivered without sustained restoration of a stable sinus rhythm. Patches were in an anterior-posterior position. No complications and no significant changes in device parameters in comparison to the pre-acquired values were observed. To our knowledge, this is the first case report of an external CV in a patient with a TPS. External CV in patients with a preexisting TPS seems to be safe and feasible.

Development of nonfibrotic left ventricular hypertrophy in an ANG II-induced chronic ovine hypertension model.

Hypertension is a major risk factor for many cardiovascular diseases and leads to subsequent concomitant pathologies such as left ventricular hypertrophy (LVH). Translational approaches using large animals get more important as they allow the use of standard clinical procedures in an experimental setting. Therefore, the aim of this study was to establish a minimally invasive ovine hypertension model using chronic angiotensin II (ANG II) treatment and to characterize its effects on cardiac remodeling after 8 weeks. Sheep were implanted with osmotic minipumps filled with either vehicle control (n = 7) or ANG II (n = 9) for 8 weeks. Mean arterial blood pressure in the ANG II‐treated group increased from 87.4 ± 5.3 to 111.8 ± 6.9 mmHg (P = 0.00013). Cardiovascular magnetic resonance imaging showed an increase in left ventricular mass from 112 ± 12.6 g to 131 ± 18.7 g after 7 weeks (P = 0.0017). This was confirmed by postmortem measurement of left ventricular wall thickness which was higher in ANG II‐treated animals compared to the control group (18 ± 4 mm vs. 13 ± 2 mm, respectively, P = 0.002). However, ANG II‐treated sheep did not reveal any signs of fibrosis or inflammatory infiltrates as defined by picrosirius red and H&E staining on myocardial full thickness paraffin sections of both atria and ventricles. Measurements of plasma high‐sensitivity C‐reactive protein and urinary 8‐iso‐prostaglandin F2α were inconspicuous in all animals. Furthermore, multielectrode surface mapping of the heart did not show any differences in epicardial conduction velocity and heterogeneity. These data demonstrate that chronic ANG II treatment using osmotic minipumps presents a reliable, minimally invasive approach to establish hypertension and nonfibrotic LVH in sheep.

First epicardial mapping of the left ventricle using the Advisor ™ HD Grid catheter

We report, to our knowledge, the first epicardial mapping of ventricular tachycardia (VT) originating from the left ventricle (LV) using the AdvisorTM HD Grid mapping catheter (Fa. Abbott, St. Paul, MN, USA). A 60-year-old male patient presented with recurrence of electrical storm in the setting of dilative cardiomyopathy. Interrogation of the pre-existing implantable biventricular cardioverter defibrillator (Viva Quad XT CRT-D, Fa. Medtronic, USA) revealed numerous symptomatic VTs with cycle length of 560 and 580 ms. Because of previous partially successful endoand epicardial ablation, a primarily endoand epicardial access was obtained using a retrograde aortic and subxiphoidial epicardial access. For mapping of potential slow conduction areas and LAVAs (local abnormal ventricular activities), a novel high-resolution multipolar catheter (AdvisorTM HD Grid mapping catheter (Fa. Abbott, St. Paul, MN, USA)) in conjunction with a 3D mapping system (EnsiteVelocityTM, Fa. Abbott, St. Paul, MN, USA) was used. After endoand epicardial ablation, no recurrence of sustained VTepisodes during the procedure and after 3-month follow-up occurred. Epicardial mapping with the AdvisorTM HD Grid catheter was safe and feasible in this LV VT ablation procedure. Figure 1(a) presents the 12-channel ECG of the first clinical VT (cycle length 580 ms; positive in II, III, and aVF; and transition in V2). Figure 1(b) shows the 12-channel ECG from the epicardial VT with a very wide QRS complex (cycle length 560 ms; positive in II, III, and aVF; and a positive concordance). Figure 1(c) demonstrates local abnormal ventricular activities (VT 2) using the high-resolution multipolar catheter (red circles). The catheter composed of a shaft containing two electrodes and four splines, each containing four electrodes. CSmarks the signals of a diagnostic catheter in the coronary vein sinus Figure 2 presents the endo(a) and epicardial (b) maps of the left ventricle performed with the AdvisorTMHDGrid mapping catheter (HD) (Fa. Abbott, St. Paul, USA) in conjunction with a 3D mapping system (Ensite VelocityTM, Fa. Abbott, St. Paul, MN, USA). In Fig. 2(c), a combination of the endoand epicardial map (right lateral) is demonstrated. The red dots indicate the location of the ablation.

Correction to: first epicardial mapping of the left ventricle using the advisor ™ HD grid catheter

Figure 1 as originally published was incorrect—on the published fig. 1C there is no RVA catheter and the wrong figure caption was used. Figurexa01 has been corrected along with the figure caption.