Thomas Blum

Small or Large Isolation Areas Around the Pulmonary Veins for the Treatment of Atrial Fibrillation? Results From a Prospective Randomized Study

Background— Pulmonary vein (PV) isolation is a promising new treatment for atrial fibrillation (AF). We hypothesized that isolation of large areas around both ipsilateral PVs with verification of conduction block is more effective than the isolation of each individual PV. Methods and Results— A total of 110 patients, 67 with paroxysmal AF and 43 with persistent AF, were randomly assigned to undergo either isolation of each individual PV or isolation of large areas around both ipsilateral PVs. The isolation of each individual PV was an electrophysiologically guided, ostial segmental ablation with a 64-pole basket catheter or a 20-pole circular mapping catheter (group I). Isolation of large areas was performed around the 2 ipsilateral veins with a nonfluoroscopic navigation system and a circular 20-pole mapping catheter for verification of conduction block (group II). In both groups, an irrigated-tip ablation catheter (25 to 35 W) was used to achieve complete isolation. Procedure and ablation times were longer in group II, whereas fluoroscopic time was significantly shorter (P≤0.001). After a follow-up period of 15±4 months, 27 patients in group I (49%) and 37 patients in group II (67%) remained free of symptoms of AF and had no AF or atrial flutter during repetitive Holter monitoring without antiarrhythmic drug treatment after a single procedure (P≤0.05). Conclusions— The rate of success was significantly higher and fluoroscopy times were significantly lower in the group with large isolation areas around both ipsilateral PVs than in those who underwent individual PV isolation.

Incidence of pulmonary vein stenosis 2 years after radiofrequency catheter ablation of refractory atrial fibrillation

AIMS Pulmonary vein ablation offers the potential to cure patients with atrial fibrillation. In this study, we investigated the incidence of pulmonary vein stenosis after radiofrequency catheter ablation of refractory atrial fibrillation by systematic long-term follow-up. METHODS AND RESULTS Forty-seven patients with refractory and highly symptomatic atrial fibrillation underwent radiofrequency catheter ablation of arrhythmogenic triggers inside the pulmonary veins and/or ostial pulmonary vein isolation with conventional mapping and ablation technology. These patients had follow-up examinations at 2 years with transoesophageal doppler-echo and/or angio magnetic resonance imaging for the evaluation of the pulmonary veins. Seventy-seven percent of the patients were free from atrial fibrillation, 51% were without antiarrhythmic drugs, and 26% were on previously ineffective antiarrhythmic drug therapy. However, 13 of the 47 patients showed significant pulmonary vein stenosis or occlusion. Only three of these 13 patients complained of dyspnoea. Distal ablations inside the pulmonary vein were associated with a 5.6-fold higher risk of stenosis than ostial ablations. CONCLUSIONS At 2-year follow-up, the risk of significant pulmonary vein stenosis/occlusion after radiofrequency catheter ablation of refractory atrial fibrillation with conventional mapping and ablation technology was 28%. Distal ablations inside smaller pulmonary veins should be avoided because of the higher risk of stenosis than ablation at the ostium.

Feasibility and Safety of Pulmonary Vein Isolation Using a New Mapping and Navigation System in Patients With Refractory Atrial Fibrillation

Background—Ostial pulmonary vein (PV) isolation by radiofrequency (RF) catheter ablation can cure patients with atrial fibrillation (AF); however, this procedure carries the risk of PV stenosis. The aim of this study was to assess the feasibility of a new mapping and navigation technique using a multipolar basket catheter (BC) for PV isolation in patients with refractory AF and to analyze its safety with regard to PV stenosis at long-term follow-up. Methods and Results—We studied 55 patients (mean age, 53±11 years; 40 male) with drug-refractory AF (paroxysmal, n=37; persistent, n=18). A 64-pole BC was placed transseptally into each of the accessible PVs. By use of a nonfluoroscopic navigation system, the ablation catheter was guided to the BC electrodes at the PV ostium, with earliest activation during sinus rhythm. RF was delivered by use of maximum settings of temperature at 50°C and power at 30 W. The end point of the procedure was the complete elimination of all distal and fragmented ostial PV potentials. Of 165 targeted veins, 163 were successfully isolated with a mean RF duration of 720±301 seconds per vein. At 1-year follow-up, 62% of the patients were in sinus rhythm without antiarrhythmic drugs. Contrast-enhanced magnetic resonance angiography revealed 2 PV stenoses of >25% out of 165 treated vessels. Conclusions—The use of a multipolar BC allowed effective and safe PV isolation by combining 3D mapping and navigation. At 1-year follow-up, 62% of the patients were in sinus rhythm without antiarrhythmic drugs, and the incidence of relevant diameter reduction of the treated PVs was 1.2%.

Effects of circumferential ostial radiofrequency lesions on pulmonary vein activation recorded with a multipolar basket catheter.

Aims: Two different ablation procedures are performed to cure patients of atrial fibrillation (AF): (1) the electrophysiological pulmonary vein (PV) isolation, and (2) the anatomical circumferential ablation of all four PV ostia. The aim of this study was to determine the effects of circumferential radiofrequency lesions around the ostia on PV activation.

Predictors of Atrial Tachyarrhythmias in Subjects with Type 1 ECG Pattern of Brugada Syndrome

Background: Previous studies have demonstrated a high incidence of atrial tachyarrhythmias (ATs) in patients with Brugada syndrome (BS). The present study aimed to investigate whether various 12‐lead electrocardiogram (ECG) and electrophysiological parameters may help to differentiate subjects with a high probability to develop ATs.

Long‐Term Impact of Right Ventricular Pacing on Left Ventricular Systolic Function in Pacemaker Recipients With Preserved Ejection Fraction: Results From a Large Single‐Center Registry

Background There is limited evidence of long‐term impact of right ventricular pacing on left ventricular (LV) systolic function in pacemaker recipients with preserved LV ejection fraction (LVEF). The objective of the study was to evaluate the outcome and echocardiographic course of baseline preserved LVEF in a large cohort of pacemaker recipients with respect to pacing indication and degree of right ventricular pacing. Methods and Results We enrolled 991 patients (73±10 years, 54% male) with baseline normal (>55%) LVEF (n=791) or mildly reduced (41–55%) LVEF (n=200) who had paired echocardiographic data on LV systolic function recorded at implantation and last follow‐up. According to pacing indication, patients were divided into atrioventricular block group A (n=500) and sinus node disease group B (n=491). Main outcome measures were all‐cause mortality and deterioration of LV function ≥2 LVEF categories at last follow‐up. Patients were followed for an average of 44 months. Death from any cause occurred in 166 (17%), and deterioration of LV function ≥2 LVEF categories in 56 (6%) patients. There was no significant difference in outcome between group A and group B either in patients with normal LVEF or in those with mildly reduced LVEF. Mean percentage of right ventricular pacing was not predictive of outcome. Conclusions In a large cohort of pacemaker recipients with predominantly normal LVEF, clinically relevant LV dysfunction develops rather infrequently. No significant difference in all‐cause mortality and development of severe LV dysfunction is observed between patients with atrioventricular block and sinus node disease. Accordingly, de novo biventricular pacing cannot be recommended for patients with preserved LVEF.

Electrocardiographic differentiation of common type atrioventricular nodal reentrant tachycardia from atrioventricular reciprocating tachycardia via a concealed accessory pathway

Objective — The present study aimed to evaluate the diagnostic value of specific ECG markers in the differentiation of common type atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT) via a concealed accessory pathway. Methods — One hundred and ten ECGs with paroxysmal narrow QRS complex, short RP tachycardia were evaluated. Subjects with overt ventricular pre-excitation during sinus rhythm were excluded from the study. The mechanism of arrhythmia was established during the electrophysiological study and confirmed by the efficacy of radiofrequency ablation. Results — Of the 110 patients, 74 displayed common type AVNRT and 36 AVRT. Predictors of AVNRT were the presence of pseudo r’-waves in lead V1 [sensitivity 39.19%; specificity 97.14%; positive predictive value (PPV) 96.67%; negative predictive value (NPV) 43.04%] and pseudo S-waves in inferior leads (sensitivity 28.38%; specificity 94.29%; PPV 91.30%; NPV 38.37%). In the setting of visible P-waves, an RP interval ≤ 90 ms favoured the diagnosis of AVNRT (sensitivity 57.14%; specificity 80.65%). Predictors of AVRT were QRS alternans (sensitivity 50%; specificity 89.19%; PPV 69.23%; NPV 78.57%) as well as ST-segment alterations during tachycardia. The overall sensitivity, specificity, PPV and NPV of ST-segment depression for discriminating AVRT from AVNRT were 97.22%, 58.11%, 53.03%, 97.73%, respectively. Similarly, the sensitivity, specificity, PPV and NPV of ST-segment elevation in lead aVR were 94.44%, 58.11%, 52.31%, and 95.56%, respectively. Multiple logistic regression analysis showed that ST-segment depression [(odds ratio (OR): 12.67, 95% confidence interval (CI): 1.77-90.81, P = 0.011)] and QRS alternans (OR: 9.43, 95% CI: 1.38-64.37, P = 0.022) displayed the highest predictive ability favouring the diagnosis of AVRT. Conclusions — Twelve-lead ECG parameters may help to differentiate the mechanism of supraventricular tachycardia prior to the ablation procedure.

Ostiale Pulmonalvenenisolation bei Patienten mit therapieresistentem Vorhofflimmern mit Hilfe eines multipolaren Basketkatheters und eines neuen Navigationssystems

SummaryBackground Focal discharges from pulmonary veins are the major sources of paroxysmal atrial fibrillation. The aim of this study was to analyze the activation pattern of pulmonary veins with help of a multipolar basket catheter and to disconnect them from the left atrium by radiofrequency catheter ablation. Method We studied 51 patients (mean age 53±11 years, 36 male) with drug refractory atrial fibrillation (paroxysmal n=33, persistent n=18). A 64-pole basket catheter (CONSTELLATION®, EPT diameter=31mm) was placed transseptally into the pulmonary veins to identify the earliest vein activation during sinus rhythm or coronary sinus pacing. The ablation catheter was placed next to the electrodes showing the earliest pulmonary vein activation utilizing a novel navigation system (ASTRONOMER®, EPT). The radiofrequency energy was delivered with a maximum temperature of 50°C and a maximum power of 30Watts. In 22 patients an irrigated tip catheter (BIOSENSE-WEBSTER) was used. Endpoint was the complete elimination of all distal pulmonary vein potentials during sinus rhythm. Results The mean number of procedures per patients were 1.25, mean procedure time 234±78 minutes, mean fluoroscopy time 41±18 minutes. A total of 148 out of 150 mapped veins were successfully isolated at the ostium with a mean RF-duration of 12.0±5.8min/vein. One pericardial tamponade occurred. The carbonization on the splines of the basket catheter – observed in 12 cases with use of a non-irrigated tip catheter – was prevented by use of the irrigated tip catheter. After a mean follow-up of 10±5 months, 29 out of 51 patients (57%) are in sinus rhythm without any antiarrhythmic drug use, 22 of 33 (67%) of the patients with paroxysmal atrial fibrillation. Conclusion The use of a multipolar basket catheter for mapping of the pulmonary veins facilitates the identification of conduction paths from the left atrium into the pulmonary veins. The ASTRONOMER® navigation system allows precise steering of the ablation catheter to areas identified as left atrial to PV conduction pathways and reduces the radiation exposure.ZusammenfassungHintergrund Vorhofflimmern wird überwiegend durch Trigger in den Pulmonalvenen induziert und unterhalten. Studienziel war die 3-dimensionale Analyse der Pulmonalvenenaktivierung mit Hilfe eines multipolaren Basketkatheters und die ostiale elektrische Diskonnektion der Vene vom linken Vorhof durch gezielte fokale Katheterablation. Methoden Bei 51 Patienten (mittleres Alter 53±11 Jahre, 36 Männer) mit therapieresistentem Vorhofflimmern (paroxysmal 33, persistierend 18) wurden alle Pulmonalvenen mit einer Aktivierung im Sinusrhythmus ostial isoliert. Ein 64 poliger Basketkatheter (CONSTELLATION®, EPT) mit einem Durchmesser von 31mm wurde zur Identifikation der elektrischen Leitungswege transseptal in die Pulmonalvene platziert. Diese Leitungswege wurden dann unter Zuhilfenahme eines Navigationssystems (ASTRONOMER®, EPT) mit dem Ablationskatheter angesteuert und abladiert (maximale Temperatur 50°, maximale Leistung 30W). Bei 22 Patienten wurde ein gekühlter Katheter (BIOSENSE-WEBSTER) eingesetzt. Endpunkt der Ablation war die Eliminierung aller distaler Pulmonalvenenpotentiale. Ergebnisse Insgesamt wurden 1,25 Eingriffe pro Patient durchgeführt, die mittlere Untersuchungszeit lag bei 234±78min, die Durchleuchtungszeit bei 41±18min. Von 150 gemappten Pulmonalvenen wurden 148 mit im Mittel 12,0±5,8min HF-Energie erfolgreich isoliert. Als Komplikation trat eine Perikardtamponade auf. Bei der Verwendung von nicht gekühlten Ablationskathetern wurde in 12 Fällen eine Karbonisation auf den „splines” des Basketkatheters beobachtetet. Dies konnte durch die Verwendung eines gekühlten Katheters verhindert werden. 29/51 (57%) Patienten sind nach einem mittleren Follow Up von 10±5 Monaten ohne Antiarrhythmika im Sinusrhythmus, 22/33 (67%) der Patienten mit paroxysmalen Vorhofflimmern. Schlussfolgerungen Ein multipolarer Basketkatheter erleichtert in Kombination mit dem Navigationssystem ASTRONOMER® die Identifikation und die gezielte ostiale Ablation der Leitungswege vom linken Vorhof in die Pulmonalvene.

Response to Letter Regarding Article, “Small or Large Isolation Areas Around the Pulmonary Veins for the Treatment of Atrial Fibrillation? Results From a Prospective Randomized Study”

In their letter regarding our article,1 Drs Kriatselis and Roser suggest that large isolation during circumferential ablation can only be proved using 2 circumferential mapping catheters, 1 in each ipsilateral …

Nicht-medikamentöse Therapie von Herzrhythmusstörungen

Nicht-medikamentose Therapieverfahren haben in den vergangenen 20 Jahren einen zunehmenden Stellenwert bei der Behandlung von Herzrhythmusstorungen erlangt, z.T. haben sie die medikamentose Therapie vollstandig verdrangt. Das gilt z. B. fur die Behandlung symptomatischer Bradykardien mittels Herzschrittmacher. Aber auch im Bereich tachykarder Herzrhythmusstorungen sind sie z.T. nicht nur eine Alternative zur medikamentosen Therapie, sondern durfen schon heute als Therapie I.Wahl gelten. Das gilt insbesondere fur die Katheterablationsbehandlungen supraventrikularerTachykardien, aber auch fur die Implantation automatischer Kardioverter/Defibrillatoren in der Sekundarprophylaxe des plotzlichen Herztodes oder als primar prophylaktische Therapie bei ausgewahlten Hochrisikopatienten.