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Funding Acknowledgements Type of funding sources: None. Introduction Clinical presentation of cardiac sarcoidosis is a chamaeleon. Detection of granuloma in the histopathology proofs the diagnosis of sarcoidosis, however myocardial biopsy is associated with a high sampling error. However, a prompt immune suppressive therapy would influence the patient’s prognosis significantly. Analyzing our cohort of epicardial (and endocardial) VT ablation respectively we intend to identify additional markers supporting the diagnosis sarcoidosis. Method In the last 4 years 130 patients (mean age 49 y, 63 % male ) were hospitalized for epicardial (and endocardial) VT ablation. 19 patients had the diagnosis sarcoidosis or were newly diagnosed. Mean follow up time was 4,3 a. ECG criteria, primary manifestation, histological findings, therapy, history of VT ablation, distribution of scar in MRI and anatomical mapping, PET CT findings, presence of atrial tachycardias, valve disease and comorbidities were documented. Results 6 of 15 (40 %) patients showed right bundle block , 6 of 19 (31 %) had AV nodal disease, 4 patients primarily presented with AV-block III, 14 patients (73 %) primarily presented themselves with ventricular arrhythmias (3 with cardiac arrest), in 93 % patients biopsy revealed elevated CD 68 macrophages and CD 3 T- lymphocytes, 6 of 16 were positive for granuloma (37,5 %). All patients were treated with steroids, 13 patients with a combination of immune suppressive therapy. All were treated with VT ablation, mean 2 ablations per patient. 6 of 6 (100 %) patients showed positive PET CT. Analyzing the scar distribution the most common locations in the 17 segment model were segment 2,3,4 and 5 and septal RV. (septal substrate in 66 %). There was a high correlation between the scar findings in the MRI and the anatomical mapping. No patient died during follow up, 1 patient had high urgent transplant after withdrawal of the steroids. Statistical analysis (Kendall-Tau-b) found a significant correlation between presence of CD3 Lymphocytes, fibrosis, VT as primary manifestation, the presence of ICD, positive PET-CT and septal substrate. Conclusion Patients presenting with ventricular arrhythmias combined with a positive PET CT, elevated CD3 T lymphocytes and CD68 macrophages in the biopsy and septal substrate are suspective of sarcoidosis and immune suppressive therapy should be considered. Further data are warranted to proof that observation and to differentiate from other cardiac diseases.

Funding Acknowledgements Type of funding sources: None. Introduction Catheter ablation of VTs and intramyocardial substrate (IS) remains a challenge that may require alternative mapping and ablation strategies such as bipolar ablation (BA) to achieve VT non inducibility. However, the long-term success of these alternative strategies is still uncertain. Purpose The aim of this study was to report the midterm center experience success of BA RF ablation of VT in patients with documented intramyocardial scar in cardiac imaging. Methods 19 patients with documented intramyocardial substrate on cardiac imaging (cardiac MRI or cardio CT with delayed enhancement) and VT recurrences after at least one conventional catheter ablation were retrospectively included. The intraprocedural success (i.e. VT non inducibility at the end of procedure) respectively midterm success (i.e VT recurrence after 6 months from BA) were investigated. The ablation was performed using a special RF generator which permits bipolar RF ablation between 2 irrigated catheters. Results A total number of 19 patients were included (100 % men, mean age 66,7 ± 9,16 y/o). The mean LVEF was 39,5 ± 5,7. The distribution of underlying structural heart disease was as follow: 21 % ischemic cardiomyopathy (4 out of 19 patients), 52 % dilative cardiomyopathy (10 out of 19 patients) respectively 26 % other etiologies (5 out of 19 patients). A mean number of 2 ± 1 conventional VT ablation were previously performed. In almost all patients (94 %, 18 out of 19 patients) the clinical VT was induced before the BA (mean CL 342 ± 91ms). The BA was performed predominantly septal (84%, 16 out of 19 patients). In 3 patients an endo/epicardial BA was performed. No VT was inducible any more at the end of procedure in 15 patients (79 %). At a mean follow up of 1 ± 0,5 years no recurrence of clinical VT was noted but non-clinical VT recurrence was seen in 9 patients (47 %) exclusively in patients with septal substrate. Conclusion BA represents a good alternative strategy for CA in patients with IS and failed conventional VT ablation with good acute success but high VT recurrence rate in patients with septal IS.

Eine junge Patientin prasentiert sich mit Palpitationen. Bei der Abklarung fallen im Langzeit-EKG gehaufte ventrikulare Extrasystolen (VES) auf, echokardiographisch eine hochgradige Mitralklappeninsuffizienz mit Mitralklappenprolaps. Es wurde daher eine Mitralklappenoperation geplant, nach weiterem diagnostischen Work-up der Patientin wurde jedoch eine andere Therapie durchgefuhrt, die sich retrospektiv als hocheffizient darstellt.

Funding Acknowledgements Type of funding sources: None. Background Data about VT ablation in patients with electrical storm (ES) is limited. This study sought to compare the prognostic outcome of patients undergoing VT ablation after electrical storm with and without a septal substrate on mortality, VT recurrence rates, rehospitalization rates and major adverse cardiac events (MACE). Methods In this large single-centre study patients presenting with ES and undergoing VT ablation were included from June 2018 to April 2021. Patients with septal substrate were compared to patients without septal substrate. The primary prognostic outcome was cardiovascular mortality, secondary endpoints were VT recurrence rates, rehospitalization rates and MACE all after a median follow-up of 22 months. Results A total of 108 patients underwent a first VT ablation due to electrical storm and were included (65 ± 13 years; 86% male; 45% ischemic cardiomyopathy). Cardiovascular risk factors were equally distributed among both groups (all p>0.05). Major complications occurred in 11% of all patients with increased postinterventional third degree AV blocks among patients with septal substrate (9% vs 0%; p=0.062). Noninducibility of the clinical VT was achieved in 98% of all patients without a septal substrate and in 91% of all patients with a septal substrate (p=0.136). Noninducibility of any VT was achieved in 88% without a septal substrate and in 66% with a septal substrate (p=0.011). However, in non-invasive programmed stimulation before hospital discharge VT inducibility did not differ among both groups (p>0.05). After 1 year and a median of 22 months follow-up, patients with septal substrate died significantly more often due to cardiovascular causes (25% vs. 7%; log-rank p=0.021). In univariate analysis cardiovascular mortality for ES patients with septal substrate was 3.9 fold higher (HR 3.979; CI 95% 1.124 – 14.092; p=0.032). Independent predictors of adverse outcome in multivariable regression analysis were presence of septal substrate (HR 4.836; p=0.026) and increased numbers of VTs inducible during VT ablation (HR 1.635; p=0.007). VT recurrence during follow-up was 59% and equally distributed among both groups (log rank p=0.911). Rehospitalization rates (log rank p=0.532) and rates of MACE (log rank p=0.463) were equal. Conclusions Presence of a septal substrate is associated with adverse long-term cardiovascular mortality in patients admitted for VT ablation after electrical storm. Despite decreased ablation success in these patients VT recurrence rates were not increased during follow-up.

Funding Acknowledgements Type of funding sources: None. Background Data about VT ablation in patients with electrical storm (ES) is limited. This study sought to compare the prognostic outcome of patients with ES to those with ventricular tachyarrhythmias but without ES undergoing VT ablation on mortality, VT recurrence rates, rehospitalization rates and major adverse cardiac events (MACE). Methods In this large single-centre study patients presenting with ES and undergoing VT ablation from June 2018 to April 2021 were compared to patients undergoing VT ablation due to ventricular tachyarrhythmias but without ES. The primary prognostic outcome was cardiovascular mortality, secondary endpoints were VT recurrence rates, rehospitalization rates and MACE all after a median follow-up of 22 months. Results A total of 311 patients underwent a first VT ablation due to ventricular tachyarrhythmias and were included (63 ± 14 years; 86% male). Of them 108 presented with ES. In the ES cohort dilated cardiomyopathy as underlying heart disease was significantly increased (p=0.008), whereas all other cardiomyopathies were equally distributed. Major complications were equal among both groups (p>0.05). Ablation of the clinical VT was achieved in 95% of all patients without ES and in 94% of all patients with ES (p>0.05). Noninducibility of any VT was achieved in 91% without ES and in 76% with ES (p=0.001). This was also reflected in higher VT induction rates in non-invasive programmed stimulation before hospital discharge among ES patients (40% vs. 19%; p=0.031). After a median of 22 months of follow-up, patients with ES revealed slightly increased cardiovascular mortality rates (17% vs. 9%; log-rank p=0.061; HR 1.902; CI 95% 0.961 – 3.765; p=0.061). Furthermore, ES patients suffered from increased VT recurrence rates (59% vs. 40%; log rank p=0.006), rehospitalization rates (73% vs. 49%; log rank p=0.001) and MACE (71% vs. 45%; log rank p=0.001). ES patients displayed a 1.7-fold increased risk for VT recurrence (HR 1.701; CI 95% 1.160 – 2.493; p=0.006), a 1.9-fold increase for rehospitalization (HR 1.885; CI 95% 1.366 – 2.600; p=0.001) and a 1.9-fold increase for occurrence of MACE (HR 1.935; CI 95% 1.398 – 2.679; p=0.001). Presence of ES was the only independent predictors of VT recurrence and occurrence of MACE, whereas ES and decreased LVEF were independent predictors of rehospitalization. Conclusions VT ablation in patients with ES is challenging and these patients reveal highest risk for recurrent VTs, rehospitalization and MACE. These patients need close follow-ups and optimal guideline-directed therapy.

Ventrikulare Extrasystolen (VES) stellen in den meisten Fallen eine benigne Art von Herzrhythmusstorungen dar, die am haufigsten aus dem rechts- oder linksventrikularen Ausflusstrakt stammen und die zufalligerweise im Elektrokardiogramm (EKG) dokumentiert werden. Dennoch spielen die Anamnese, die Vorgeschichte des Patienten bzw. eine kardiale Bildgebung eine entscheidende Rolle in der Differenzierung zwischen benignen vs. malignen (d. h. assoziiert einer vorliegenden strukturellen Herzerkrankung) VES. Die Lokalisierung des myokardialen Ursprungs der VES basiert im Wesentlichen auf der Analyse des QRS-Komplexes im 12 Kanal-EKG. Die Entscheidung zur Therapie von VES ist primar bedingt durch die Symptomatik des Patienten, die VES-Last im 24-h-Langzeit-EKG in Kombination mit der systolischen Funktion des linken/rechten Ventrikels bzw. der vorliegenden strukturellen Herzerkrankung. Die medikamentose Therapie kann erwogen werden, in der Regel ist die Katheterablation aber effektiver und fur den Patienten bei geringem Risiko angenehmer und effizienter.

Eukaryotic cells possess a dynamic network of membranes that vary in lipid composition. To perform numerous biological functions, cells modulate their shape and the lateral organization of proteins associated with membranes. The modulation is generally facilitated by physical cues that recruit proteins to specific regions of the membrane. Analyzing these cues is difficult due to the complexity of the membrane conformations that exist in cells. Here, we examine how different types of membrane proteins respond to changes in curvature and to lipid phases found in the plasma membrane. By using giant plasma membrane vesicles derived from transfected cells, the proteins were positioned in the correct orientation and the analysis was performed in plasma membranes with a biological composition. Nanoscale membrane curvatures were generated by extracting nanotubes from these vesicles with an optical trap. The viral membrane protein neuraminidase was not sensitive to curvature, but it did exhibit strong partitioning (coefficient of K = 0.16) disordered membrane regions. In contrast, the membrane repair protein annexin 5 showed a preference for nanotubes with a density up to 10-15 times higher than that on the more flat vesicle membrane. The investigation of nanoscale effects in isolated plasma membranes provides a quantitative platform for studying peripheral and integral membrane proteins in their natural environment.

Vorhofflimmern ist assoziiert mit einem erhohten Risiko fur Schlaganfall oder periphere Embolien. Das Herzohr des linken Atriums (LAA) gilt als der favorisierte Ort der Thrombogenese, da hier die Flussgeschwindigkeit des Blutes in Abhangigkeit von vielen Faktoren reduziert und somit die Thrombogenitat erhoht ist. Die Therapie mit oralen Antikoagulanzien (OAK) hat sich als Standardtherapie zur Verhinderung von thromboembolischen Ereignissen etabliert. Bei wiederholt auftretenden Blutungen unter OAK oder bei erhohtem Blutungsrisiko besteht eine zumindest relative Kontraindikation. Als Alternative kommt hier die mechanische und funktionelle Elimination des LAA (LAA-Okklusion, LAAO) ins Spiel. Technische Moglichkeiten beinhalten den endokardialen Herzohrverschluss, die epikardiale LAA-Ligatur oder den operativen Herzohrverschluss. Die meisten Studienergebnisse existieren fur den endokardialen Herzohrverschluss, der einer OAK-Therapie mit Vitamin-K-Antagonisten bezuglich Mortalitat und embolischen Ereignissen nicht unterlegen ist.

Introduction To evaluate short-term efficacy and incidence of ablation-induced endoscopically detected esophageal injury in patients undergoing high-power, short-duration (HPSD) pulmonary vein isolation using a novel irrigated radiofrequency ablation catheter and ablation generator setup. Methods and results Atrial fibrillation (AF) patients, who underwent AF ablation using an irrigated radiofrequency ablation catheter specifically designed for a HPSD ablation approach (50 W, with a target Ablation Index of 350 at posterior wall), received postablation esophageal endoscopy after ablation. In total 45 consecutive patients (67 ± 10 years; 58% male; 42% paroxysmal AF) undergoing AF ablation using a specialized ablation catheter (QDOT) were included in the study. Thirty-one of 45 patients (69%) underwent a first-time pulmonary vein isolation (Group 1, 67 ± 11 years; 55% male; 48% paroxysmal AF). Fourteen patients (31%) underwent a redo AF procedure (Group 2, 66 ± 8 years; 64% male; 29% paroxysmal AF). Patients undergoing first-time pulmonary vein isolation were included in the final analysis. In these patients an endoscopically detected esophageal lesion (EDEL) was detected in 5 of 31 (16%) patients (erosion n = 2, ulcer n = 3). Mean contact force at posterior wall ablation sites was significantly lower in patients with postprocedural EDEL compared with patients without EDEL (11.9 ± 0.8 g vs. 15.6 ± 4.7 g). Conclusion PVI using a specialized high-power ablation catheter in conjunction with a HPSD ablation approach results in a 16% incidence of EDEL in first AF ablation candidates. Future studies evaluating high-power short duration ablation strategies should include esophageal endoscopy to estimate the risk of clinically relevant esophageal complications.

Acute management of patients with ventricular arrhythmia (VA) is aimed at immediate VA termination if the patient is hemodynamically instable and early termination after initial diagnostic work-up if tolerated. Prolonged episodes of VA may lead to hemodynamic and metabolic decompensation and early resumption of normal ventricular activation is warranted. Termination is best performed by electrical cardioversion, anti-tachycardia pacing (if available, in cases with an implanted defibrillator [ICD]) or defibrillation. Antiarrhythmic drug treatment may lead to rhythm stabilization in cases of VA recurrence. Scrutinizing the electrocardiogram (ECG) of VA is extremely helpful to differentiate potential mechanisms, underlying cardiac pathologies and identify treatment options, as well as a differential diagnosis if a ventricular origin is unclear. In general, structural VA should be differentiated from idiopathic and non-structural (idiopathic) VA. On the other hand, based on ECG morphology VA should be classified into monomorphic versus polymorphic ventricular tacyhcardia (VT)/ventricular fibrillation (VF). Polymorphic VT/VF may be related to reversible causes as well as genetically determined arrhythmia syndromes and a specialized treatment pathway may be chosen: (1) VA termination, (2) evaluation and treatment of potential VA causes, (3) acute (medical treatment) and chronic (interventional treatment using catheter ablation) prevention of recurrence and (4) treatment of underlying heart disease, if identified, are crucial pillars of VA management. These patients can be managed in dedicated VT units and by multispecialty teams integrating all potential aspects of rhythm stabilization and treating underlying cardiac abnormalities. Heart failure management in patients with reduced left ventricular function may be crucial for the long-term prognosis.

Ventricular tachycardias (VT) in patients with structural heart diseases have predominantly a scar-associated reentry mechanism so that substrate-based ablation approaches also have to be used in nearly all procedures. In many VT cases-especially in nonischemic cardiomyopathy (NICM) and arrhythmogenic right ventricular cardiomyopathy-a critical epicardial substrate can be identified as an essential component of the reentry circuit so that for the ablation-based modification of the substrate in these cases an epicardial approach is necessary. In cases of redo-VT ablation procedures in ischemic cardiomyopathy (after a previously endocardial ablation), an epicardial approach should also be considered. There are also cases in whom no endocardial substrate can be identified and an isolated epicardial substrate can be identified. Worldwide epicardial VT ablations are usually performed after gaining epicardial access using subxyphoidal puncture. The results of recent studies show a higher efficiency with stabilization of cardiac rhythm and reduction of recurrent VT episodes (about 70% event-free survival at the 2‑year follow-up) after endo-plus epicardial substrate modification. In electrical storm cases, an early epicardial VT ablation approach also appears to be relevant, especially in NICM. Epicardial instrumentation and ablation represents a complex procedure which should only be performed in experienced centers with cardiac surgery back-up. In these experienced centers, the complications rate is less than 5%.

Aims To correlate oesophageal magnetic resonance imaging (MRI) abnormalities with ablation-induced oesophageal injury detected in endoscopy. Methods and results Ablation-naïve patients with atrial fibrillation (AF), who underwent ablation using a contact force sensing irrigated radiofrequency ablation catheter, received a cardiac MRI on the day of ablation, and post-ablation oesophageal endoscopy (OE) 1 day after ablation. Two MRI expert readers recorded presence of abnormal oesophageal tissue signal intensities, defined as increased oesophageal signal in T2-fat-saturated (T2fs), short-tau inversion-recovery (STIR), or late gadolinium enhancement (LGE) sequences. Oesophageal endoscopy was performed by experienced operators. Finally, we correlated the presence of any affection with endoscopically detected oesophageal thermal lesions (EDEL). Among 50 consecutive patients (age 67 ± 7 years, 60% male), who received post-ablation MRI and OE, complete MRI data were available in 44 of 50 (88%) patients. In OE, 7 of 50 (14%) presented with EDEL (Category 1 lesion: erosion n = 3, Category 2 lesion: ulcer n = 4). Among those with EDEL, 6 of 7 (86%) patients presented with increased signal intensities in all three MRI sequences, while only 2 of 37 (5%) showed hyperintensities in all three MRI sequences and negative endoscopy. Correspondingly, sensitivity, specificity, positive predictive value, and negative predictive value (NPV) for MRI (increased signal in T2fs, STIR, and LGE) were 86%, 95%, 75%, and 97%, respectively. Conclusion Increased signal intensity in T2fs, STIR, and LGE represents independent markers of EDEL. In particular, the combination of all three has the highest diagnostic value. Hence, MRI may represent an accurate, non-invasive method to exclude acute oesophageal injury after AF ablation (NPV: 97%).

Ventrikulare Tachykardien treten als Komplikation des Spontanverlaufs einer strukturellen Herzerkrankung – haufig aufgrund einer Narbenprogression – auf und stellen weltweit die fuhrende Ursache des plotzlichen Herztods dar. Patienten mit strukturellen Herzerkrankungen und anhaltenden VTs weisen eine erhohte Mortalitatsrate und eine verminderte Lebenserwartung im Vergleich zu Patienten ohne dokumentierte VTs auf. Daher wird in den aktuellen europaischen Leitlinien eine fruhzeitige Ablation insbesondere bei Patienten mit ischamischer Kardiomyopathie (ICM) und vermehrten, therapiebedurftigen VTs empfohlen (Klasse I, Level B). Eine fruhzeitige, invasive Strategie – z. T. auch gleich nach der ersten Therapie durch implantierte Defibrillatoren – wird empfohlen (Klasse II, Level B). Infolge der Komplexitat der myokardialen Vernarbung, meistens in den letzten Krankheitsstadien der strukturellen Herzerkrankung, weisen diese Patienten haufig eine ausgedehnte epikardiale Beteiligung auf. Daher ist die VT-Ablation nur mit einem endokardialen Zugang mit niedrigen Erfolgschancen assoziiert. Es existieren bestimmte Herzerkrankungen, bei welchen sich Vernarbungen primar epikardial entwickeln (arrhythmogene rechtsventrikulare Kardiomyopathie, Chagas-Krankheit und ca. 80 % der NIDCM). Daher erscheint die Verwendung eines kombinierten endo-/epikardialen Zugangs oder sogar nur eines isolierten epikardialen Zugangs zur VT-Ablation in diesen Fallen haufig sinnvoll. Diese Prozeduren werden an erfahrenen, spezialisierten Ablationszentren mit groser Routine durchgefuhrt. Neue Studien weisen eine hohere Erfolgsrate der VT-Ablation auf, wenn eine zusatzliche epikardiale Ablation durchgefuhrt wird.

Ventricular tachycardia (VT) is a leading cause of cardiovascular death and remains the main cause of sudden cardiac death. Implanted cardiac defibrillators (ICD) improve survival but the recurrent ICD therapies, mostly ICD shocks, are associated with an increased mortality and deleterious psychological effects. In this regard and based on the results of multicenter studies, the current European guidelines recommend early referral for catheter ablation. The ablation strategy (isolated endocardial approach or combined epi-/endocardial) depends mostly on the underlying myocardial disease. Thus, almost all patients with right ventricular dysplasia and Chagas disease, the majority of those with dilative cardiomyopathy, and some patients with ischemic cardiomyopathy (mostly posterior wall infarction or large transmural anterior wall infarction) have an epicardial scar as the underlying substrate for recurrent VT episodes. Thus, in this group of patients, isolated endocardial VT ablation may be associated with an increased VT recurrence and therefore an epicardial approach is also needed. Cardiac imaging (cardio-CT/MRI with late enhancement[MRI LE]) can reliably identify the distribution and characteristics of the myocardial scar and may be helpful in planning the ablation strategy. When performed in highly specialized centers, epicardial catheter ablation of VT leads to a significant reduction of recurrent VT episodes compared to the endocardial VT ablation alone and with lower complication rates.

Ventricular tachycardias (VT) in patients with structural heart diseases have predominantly a scar-associated reentry mechanism so that substrate-based ablation approaches also have to be used in nearly all procedures. In many VT cases-especially in nonischemic cardiomyopathy (NICM) and arrhythmogenic right ventricular cardiomyopathy-a critical epicardial substrate can be identified as an essential component of the reentry circuit so that for the ablation-based modification of the substrate in these cases an epicardial approach is necessary. In cases of redo-VT ablation procedures in ischemic cardiomyopathy (after a previously endocardial ablation), an epicardial approach should also be considered. There are also cases in whom no endocardial substrate can be identified and an isolated epicardial substrate can be identified. Worldwide epicardial VT ablations are usually performed after gaining epicardial access using subxyphoidal puncture. The results of recent studies show a higher efficiency with stabilization of cardiac rhythm and reduction of recurrent VT episodes (about 70% event-free survival at the 2‑year follow-up) after endo-plus epicardial substrate modification. In electrical storm cases, an early epicardial VT ablation approach also appears to be relevant, especially in NICM. Epicardial instrumentation and ablation represents a complex procedure which should only be performed in experienced centers with cardiac surgery back-up. In these experienced centers, the complications rate is less than 5%.

Targeting repetitive sources identified during atrial fibrillation (focal impulse and rotor modulation, FIRM) has been used as an ablation strategy using specific mapping tools. Aim of this study was to evaluate FIRM mapped rotors with a new multipolar mapping algorithm. Patients with persistent atrial fibrillation undergoing FIRM ablation were included. Mapping of left atrial rotors was performed with a 64-pole basket catheter in conjunction with a specialized phase mapping algorithm. Subsequently, raw signals were analyzed by a novel mapping system (CARTOFINDER™). Comparison of FIRM identified sources with areas of repetitive activation analyzed by CARTOFINDER™ was performed. Nine patients were included (5 redo procedures; male n = 6; 66.5 ± 8.6 years) and 28 left atrial rotors were compared with the findings of the novel mapping system. CARTOFINDER™ identified repetitive activation patterns in 6 mapping sequences at remote sites (2 rotational patterns, 4 linear activation patterns). In this comparative preliminary study, two different mapping technologies to detect repetitive atrial activation during ongoing AF were used. Whereas rotational activation was documented using FIRM mapping no corresponding repetitive activation patterns near sites of FIRM-mapped rotor cores were identified using the novel mapping technology even though using the same electrogram characteristics and mapping basket position.

Aims Aim of this study was to evaluate the impact of a recently introduced contact force ablation catheter with modified irrigation technology compared with a conventionally irrigated ablation catheter on the incidence of endoscopically detected oesophageal lesions (EDEL). Methods and results Patients with symptomatic, drug-refractory paroxysmal or persistent atrial fibrillation (AF) who underwent left atrial radiofrequency (RF) catheter ablation were prospectively enrolled. Patients were ablated using a single-tip RF contact force ablation catheter with conventional irrigation (Group 1; n = 50) or with a recently introduced intensified ‘surround flow’ irrigation technology (Group 2; n = 50). Assessment of EDEL was performed by oesophagogastroduodenoscopy in all patients after ablation. A total of 100 patients (mean age 63.6 ± 12.1 years; men 58%) with paroxysmal ( n = 41; 41%) or persistent AF were included. Groups 1 and 2 patients were comparable in regard to baseline characteristics and procedural parameters, especially ablation time at posterior left atrial wall. Overall, 13 patients (13%) developed EDEL after AF ablation (8 oesophageal ulcerations, 5 erythema). The incidence of EDEL including oesophageal ulcerations was higher in Group 2 compared with Group 1 patients without statistical significance (18 vs. 8%, P = 0.23). One pericardial tamponade and one access site bleeding occurred in Group 2. No further adverse events were reported in both groups. Conclusion According to these preliminary results, the use of an improved ablation catheter irrigation technology (surround flow) in conjunction with contact force measurement was associated with a higher but not statistically significant probability of oesophageal thermal lesions. Further studies including larger patient cohorts are needed.

The Southern Energy Efficiency Center (SEEC) builds collaborative partnerships with: state and local governments and their program support offices, the building delivery industry (designers, contractors, realtors and commissioning agents), product manufacturers and their supply chains, utilities and their program implementers, consumers and other stakeholders in order to forge a strong regional network of building energy efficiency allies. Through a project Steering Committee composed of the state energy offices and building industry stakeholders, the SEEC works to establish consensus-based goals, priorities and strategies at the regional, state and local levels that will materially advance the deployment of high-performance “beyond code” buildings. In its first Phase, SEEC will provide limited technical and policy support assistance, training, certification and education to a wide spectrum of the building construction, codes and standards, and the consumer marketplace.

Estrogens produced within breast tumors may play a pivotal role in growth stimulation of the breast cancer cells. However, it is elusive whether the epithelial breast cancer cells themselves synthesize estrogens, or whether the surrounding tumor stromal cells synthesize and supply the cancer cells with estrogen. The aromatase enzyme catalyzes the estrogen production, aromatizing circulating androgens into estrogens. The aim of this study was to investigate aromatase expression and function in a model system of human breast cancer, using the estrogen responsive human MCF-7 breast cancer cell line. Cells were cultured in a low estrogen milieu and treated with estrogens, aromatizable androgens or non-aromatizable androgens. Cell proliferation, expression of estrogen-regulated proteins and aromatase activity were investigated. The MCF-7 cell line was observed to express sufficient aromatase enzyme activity in order to aromatize the androgen testosterone, resulting in a significant cell growth stimulation. The testosterone-mediated growth effect was completely inhibited by the aromatase inhibitors letrozole and 4-hydroxy-androstenedione. Expression studies of estrogen-regulated proteins confirmed that testosterone was aromatized to estrogen in the MCF-7 cells. Thus, the results indicate that epithelial breast cancer cells possess the ability to aromatize circulating androgens to estrogens.

Automatic analysis of the frequency content of the fibrillatory baseline on the standard surface ECG during atrial fibrillation (AF) accurately reflects the average frequency of atrial fibrillatory activity. Atrial fibrillatory frequency (f) was determined from surface ECG recordings. After filtering averaged QRST complexes were subtracted in one-minute ECG segments. The resulting signal was subjected to Fourier transformation and the dominant f was determined in the 3 to 12 Hz frequency range. Assessment of f in 30 patients with persistent AF (18 male, 12 female, mean age 60/spl plusmn/11 years) showed a decrease at night (6.8/spl plusmn/0.7 Hz at 10 AM; 6.7/spl plusmn/0.7 Hz at 4 PM; 6.6/spl plusmn/0.7 Hz at 10 PM and 6.4/spl plusmn/0.7 Hz at 4 AM, p=.028). In 12 patients (12 male, mean age 55/spl plusmn/9 years) oral amiodarone (n=5), sotalol (n=5) or flecainide (n=2) reduced mean f from 7.0/spl plusmn/0.5 Hz to 6.3/spl plusmn/0.6 Hz (p=.003) without AF termination. Atrial fibrillatory frequency determined from ECG recordings shows a circadian pattern with a lower frequency at night. This test may be used to monitor directly the atrial response to antiarrhythmic medication.

This study was conducted (1) to examine the relationship between left atrial appendage (LAA) flow velocity and pulmonary venous flow (PVF) variables during nonrheumatic atrial fibrillation (AF), and (2) to determine whether a reduction in LAA flow is reflected by the fibrillatory wave amplitude on the surface ECG.Although LAA Doppler echocardiographic signals provide information regarding the velocity and direction of flow only for a localized narrow sample, systolic PVF represents in part the global left atrial function, mainly relaxation. Controversy exists about whether the amplitude of fibrillatory waves recorded on the surface ECG correlates with LAA flow velocity during AF.Thirty-three patients (20 men, 13 women; mean [+/- SD] age, 61 +/- 11 years) with nonrheumatic AF undergoing transthoracic and transesophageal echocardiography were studied. A correlation between LAA flow velocity and systolic PVF variables (peak systolic velocity, R: = 0.450, p = 0.009; velocity-time integral of systolic flow, R = 0.491, p = 0.004; systolic fraction of PVF, R: = 0.627, p0.0001) was observed. Patients with a low LAA flow profile (25 cm/s) had a reduced systolic PVF. Longer AF duration and the occurrence of moderate mitral regurgitation were related to reduced LAA flow. AF was subdivided into coarse (peak-to-peak fibrillatory amplitudeor = 1 mm) or fine (1 mm) in standard ECG lead V1. There was no association between the coarseness of AF and the LAA flow profile.In patients with nonrheumatic AF, a reduction in LAA flow velocity correlates with a reduction in systolic PVF. These hemodynamic changes are not reflected by the ECG fibrillatory wave amplitude.