Atrial fibrosis progression in patients with no history of atrial fibrillation.

BACKGROUND: Unexpected high levels of atrial fibrosis are found in individuals with no history of atrial fibrillation (AF). The temporal behavior of atrial fibrosis in this population is still unknown. We sought to investigate the progression and predictors of atrial fibrosis in non-AF individuals. METHODS: Non-AF individuals at baseline who underwent late gadolinium enhancement magnetic resonance imaging (LGE-MRI) for assessment of left atrial (LA) fibrosis at least twice were retrospectively included in this study. The incidence of AF was assessed using review of medical records. RESULTS: In 42 non-AF patients (15 females, 65.9 ± 8.6 years old), all patients had a detectable level of LA fibrosis at baseline, ranging from 4.5% to 28.8%, with a mean of 12.9 ± 5.9%. LA fibrosis in the second LGE-MRI was significantly higher in all patients compared to the first measurement (mean value of 12.9 ± 5.9% vs. 17.34 ± 6.8%; p < .05). Congestive heart failure was a significant clinical predictor of atrial fibrosis progression. The seven patients (16.6%) who developed new-onset AF during follow-up showed a significantly higher degree of LA fibrosis on their second MRI, compared to individuals who stayed in sinus rhythm (20.5 ± 6.9% vs. 16.7 ± 6.7%, p < .05). CONCLUSION: Atrial fibrotic remodeling is a dynamic process that is progressively increasing in non-AF patients, accentuated by congestive heart failure. The higher extent of LA remodeling observed in patients who developed AF could highlight either the fact that AF is an expression of a highly dynamic left atrial substrate, or that remodeling processes are accelerated by AF.

Characteristics of early recurrences detected by continuous cardiac monitoring influencing the long-term outcome after atrial fibrillation ablation.

AIMS: Early recurrences (ER) of atrial arrhythmias are common after catheter ablation of atrial fibrillation (AF). The significance of these ER is controversial. Based on data of continuous cardiac monitoring, we sought to investigate the characteristics of ER and their impact on late recurrences (LR) during follow-up. METHODS: One hundred twenty-six patients with paroxysmal (49%) or persistent (51%) AF underwent an AF ablation with subsequent implantation of implantable loop recorder. Follow up was 12 months using remote monitoring. All atrial arrhythmia (AF or atrial tachycardia-AT-) episodes >30 seconds. within the 3-month blanking period were considered and the AF burden evaluated every 3 months. RESULTS: Within the 3-months blanking period, 72 patients (57%) experienced an AF/AT recurrence. Survival free from any arrhythmia recurrence during follow-up was 40% in patients with ER vs 69% in those without ER. AF burden during the blanking period and timing of ER correlated significantly with LR at 12 months (area under curve = 0.74, P < .0001 and .831, P < .0001). An AF burden ≥0.5% and ER after 74 days predicted LR (sensitivity 60%, specificity 84.4%; sensitivity 75.6%, specificity 90.3%). In cox regression analysis, AF burden ≥0.5% and ER after 74 days were independently associated with LR. CONCLUSION: Continuous cardiac monitoring after AF ablation provides important information regarding early recurrence episodes and their prognostic impact. A cut-off of 74 days for the blanking period seems to better differentiate patients with a good or a poor long-term outcome. An AF burden ≥0.5% during the 3 months postablation is predictive for late arrhythmia recurrences.

Reduction of atrial fibrillation burden by pulmonary vein isolation leads to a decrease of CD11b expression on inflammatory cells.

Aims: It is hypothesized that inflammation could promote structural and electrical remodelling processes in atrial fibrillation (AF). Atrial infiltration of monocytes and granulocytes has been shown to be dependent on CD11b expression. The aim of this study was to investigate whether treatment of AF by pulmonary vein isolation (PVI) may lead to reduced inflammation, as indicated by a decrease of CD11b expression on monocytes and granulocytes. Methods and results: Flow-cytometric quantification analysis and determination of systemic inflammatory markers of peripheral blood were performed in 75 patients undergoing PVI 1 day before and 6 months after PVI. The extent of activation of monocytes and granulocytes was measured by quantifying the cell adhesion molecule CD11b. The mean expression of CD11b on monocytes (20.9 ± 2.5 vs. 10.2 ± 1.4; P < 0.001) and granulocytes (13.9 ± 1.6 vs. 6.8 ± 0.5; P < 0.001), as well as the relative count of CD11b-positive monocytes (P < 0.05) and CD11b-positive granulocytes (P < 0.01) were significantly reduced when comparing the identical patients before and 6 months after PVI. Systemic inflammatory parameters showed only a declining tendency after 6 months. Patients with unsuccessful PVI and ongoing AF on the day of follow-up showed no decrease in CD11b expression. Conclusions: A significant reduction of CD11b expression on monocytes and granulocytes, as a sign of reduced cellular inflammation, was achieved by treatment of AF using PVI. These data strongly support that AF is not only a consequence of but also a cause for inflammatory processes, which, in turn, may contribute to atrial remodelling.

Association of platelet activation markers with recurrence of atrial fibrillation after pulmonary vein isolation.

Atrial fibrillation (AF) is known to cause platelet activation. AF and its degree of thrombogenesis could be associated with monocyte-platelet aggregates (MPAs). We investigated on whether the content of MPAs or other platelet activation markers is associated with the recurrence of AF after pulmonary vein isolation (PVI). A total of 73 patients with symptomatic AF underwent PVI. After 6 months, all patients were evaluated for episodes of AF recurrence. At the same time, flow-cytometric quantification analyses were performed to determine the content of MPAs. Further platelet activation parameters were detected by using either cytometric bead arrays or quantitative immunological determination. Patients with recurrent AF (n = 20) compared to individuals without AF relapse (n = 53) were associated with an increased content of MPAs (43 ± 3% vs. 33 ± 2%, p = 0.004), as well as an increased CD41 expression on monocytes (191 ± 20 vs. 113 ± 6, p = 0.001). The level of the soluble platelet activation markers such as D-dimer, sCD40L, and sP-selectin did not differ between these groups. The content of MPAs correlated weakly with the level of sCD40L (r = 0.26, p = 0.03), but not with sP-selectin and D-dimer, whereas sP-selectin and sCD40L correlated with each other (r = 0.38, p = 0.001). Only the cellular marker of platelet activation, the content of MPAs, was increased in patients with recurrent AF after PVI. In contrast, soluble markers remained unaltered. These data indicate a distinct mechanism and level of platelet activation in AF. The clinical relevance of MPAs in identifying AF recurrence or in guiding the therapy with anticoagulants remains to be elucidated.

Fluoroscopy integrated 3D mapping significantly reduces radiation exposure during ablation for a wide spectrum of cardiac arrhythmias.

AIMS: Despite the use of established 3D-mapping systems, invasive electrophysiological studies and catheter ablation require high radiation exposure of patients and medical staff. This study investigated whether electroanatomic catheter tracking in prerecorded X-ray images on top of an existing 3D-mapping system has any impact on radiation exposure. METHODS AND RESULTS: Two hundred and ninety-five consecutive patients were either ablated with the guidance of the traditional CARTO-3 system (c3) or with help of the CARTO-UNIVU system (cU): [typical atrial flutter (AFL) n = 58, drug refractory atrial fibrillation (AF) n = 81, ectopic atrial tachycardia (EAT) n = 37, accessory pathways (APs) n = 22, symptomatic, idiopathic premature ventricular complexes (PVCs) n = 56, ventricular tachycardias (VTs) n = 41]. The CARTO-UNIVU allowed a reduction in radiation exposure: fluoroscopy time: AFL c3: 8.6 ± 0.8 min vs. cU: 2.9 ± 0.3 min, P < 0.001; AF c3: 16.0 ± 1.3 min vs. cU: 6.4 ± 0.9 min, P < 0.001; EAT c3: 23.4 ± 3.1 min vs. cU: 9.7 ± 1.7 min, P < 0.001; AP c3: 7.1 ± 1.2 min vs. cU: 6.0 ± 1.5 min, P = 0.59; PVCs c3: 17.6 ± 2.3 min vs. cU: 15.2 ± 2.8 min, P = 0.52; VT c3: 31.4 ± 3.4 min vs. cU: 17.5 ± 2.4 min, P = 0.003. Corresponding to the fluoroscopy time the fluoroscopy dose was also reduced significantly. These advantages were not at the cost of increased procedure times, periprocedural complications, or decreased acute ablation success rates. CONCLUSION: In a wide spectrum of cardiac arrhythmias, and especially in AF and VT ablation, fluoroscopy integrated 3D mapping contributed to a dramatic reduction in radiation exposure without prolonging procedure times and compromising patient's safety. That effect, however, could not be maintained in patients with APs and PVCs.

Target temperature management of 33 degrees C exerts beneficial haemodynamic effects after out-of-hospital cardiac arrest.

BACKGROUND: Accumulating evidence indicates that target temperature management (TTM) is beneficial in patients resuscitated after cardiac arrest since it appears to improve neurological outcome. However, the optimal cooling method (surface vs. intravascular) has not yet been specified. Substantial heart disease is present in most of these patients and therefore haemodynamic effects of cooling need to be considered very carefully. We analysed the haemodynamic response to TTM in patients treated with surface versus intravascular cooling following out-of-hospital cardiac arrest. METHODS AND RESULTS: In this observational study 63 consecutive subjects presenting to the hospital after successful resuscitation following of out-of-hospital cardiac arrest received an intravascular (40 patients) or external cooling device (23 patients) to induce TTM. While with intravascular cooling the target temperature of 33 degrees C was reached after 159 minutes, the minimum temperature achieved with surface cooling was about 35 degrees C after 437 minutes. Haemodynamic parameters were recorded in a 4-hour rhythm for the first 12 hours after induction of hypothermia. Generally, TTM of 33 degrees C resulted in a higher systemic vascular resistance index (749 vs. 467 dyn*sec/cms/m2; P= 0.04) but also in a marked reduction of heart rate (67.70 vs. 100.00 bpm; P < 0.001), a higher mixed venous oxygen saturation (76 vs. 68%; P = 0.016), and a higher stroke volume index (45 vs. 33 mI/m2; P = 0.036). TTM additionally resulted in a higher cardiac power index (0.55 vs. 0.46 Watt/m2; P = 0.024). CONCLUSION: TTM of 33 degrees C compared to 35 degrees C exerts beneficial haemodynamic effects and might be viewed as an adjunct inotropic therapy avoiding the undesired side effects of vasoactive substances.

Sex-specific outcomes and left atrial remodeling following catheter ablation of persistent atrial fibrillation: results from the DECAAF II trial.

BACKGROUND: Catheter ablation is recognized as an effective treatment for atrial fibrillation (AF). Despite its effectiveness, significant sex-specific differences have been observed, which influence the outcomes of the procedure. This study explores these differences in a cohort of patients with persistent AF. We aim to assess sex differences in baseline characteristics, symptoms, quality of life, imaging findings, and response to catheter ablation in patients with persistent AF. METHODS: This post hoc analysis of the DECAAF II trial evaluated 815 patients (161 females, 646 males). Between July 2016 and January 2020, participants were enrolled and randomly assigned to receive either personalized ablation targeting left atrial (LA) fibrosis using DE-MRI in conjunction with pulmonary vein isolation (PVI) or PVI alone. In this analysis, we aimed to compare female and male patients in the full cohort in terms of demographics, risk factors, medications, and outcomes such as AF recurrence, AF burden, LA volume reduction assessed by LGE-MRI before and 3 months after ablation, quality of life assessed by the SF-36 score, and safety outcomes. Statistical methods included t-tests, chi-square, and multivariable Cox regression. RESULTS: Females were generally older with more comorbidities and experienced higher rates of arrhythmia recurrence post-ablation (53.3% vs. 40.2%, p < 0.01). Females also showed a higher AF burden (21% vs. 16%, p < 0.01) and a smaller reduction in left atrial volume indexed to body surface area post-ablation compared to male patients (8.36 (9.94) vs 11.35 (13.12), p-value 0.019). Quality of life scores were significantly worse in females both pre- and post-ablation (54 vs. 66 pre-ablation; 69 vs. 81 post-ablation, both p < 0.01), despite similar improvements across sexes. Safety outcomes and procedural parameters were similar between male and female patients. CONCLUSION: The study highlights significant differences in the outcomes of catheter ablation of persistent AF between sexes, with female patients showing worse quality of life, higher recurrence of AF and AF burden after ablation, and worse LA remodeling.

Dexrazoxane prevents the development of the impaired cardiac phenotype in caveolin-1-disrupted mice.

: Caveolin-1-deficient (cav1) mice display a severely diseased cardiac phenotype with systolic and diastolic heart failure. Accumulating evidence supports a causative role of uncoupled endothelial nitric oxide synthase in the development of these abnormalities. Interestingly, a similar molecular mechanism was proposed for anthracycline-induced cardiomyopathy. Currently, dexrazoxane is approved for the prevention of anthracycline-induced cardiomyopathy. Given the molecular similarities between the anthracycline-induced cardiomyopathy and the cardiomyopathy in cav1 mice, we questioned whether dexrazoxane may also prevent the evolution of the cardiac pathologies in cav1 mice. We evaluated dexrazoxane treatment for 6 weeks in cav1 mice and wild-type controls. This study provides the first evidence for a reduced reactive oxygen species formation in the vessels of dexrazoxane-treated cav1 mice. This reduced oxidative stress resulted in a markedly reduced rate of apoptosis, which finally was translated into a significantly improved heart function in dexrazoxane-treated cav1 mice. These hemodynamic improvements were accompanied by significantly lowered proatrial natriuretic peptide levels. Notably, these protective properties of dexrazoxane were not evident in wild-type animals. Taken together, these novel findings indicate that dexrazoxane significantly reduces vascular reactive oxygen species formation cav1. Because this is paralleled by an improved cardiac performance in cav1 mice, our data suggest dexrazoxane as a novel therapeutic strategy in this specific cardiomyopathy.

[Should we treat asymptomatic premature ventricular contractions?] / Asymptomatische ventrikuläre Extrasystolen behandeln?

Premature ventricular contractions (PVC) are a common arrhythmia. Therapy is indicated in case of frequent symptomatic PVC or deterioration of left ventricular function. Asymptomatic patients should be evaluated critically for possible PVC-associated symptoms. Catheter ablation of PVCs in patients with normal left ventricular ejection fraction (LVEF) is safe and effective. PVC-induced cardiomyopathy should be considered in unexplained LVEF dysfunction with a PVC burden of at least 10%. If ECG and echocardiography do not clearly rule out structural heart disease (SHD) or the clinical presentation raises suspicion of SHD, cardiac magnetic resonance imaging should be performed. If SHD has been excluded, the guidelines recommend catheter ablation as primary therapy in frequent monomorphic PVC, regardless of symptoms. To prevent PVC-induced cardiomyopathy, ablation can also be considered in asymptomatic patients with a PVC burden > 20%. Also, in patients with known SHD frequent PVC can aggravate LV dysfunction and catheter ablation should be considered.

Feasibility and Efficacy of Transcatheter Tricuspid Valve Repair in Patients with Cardiac Implanted Electrical Devices and Trans-Tricuspid Leads.

BACKGROUND: Transcatheter tricuspid valve repair using the edge-to-edge-technique (TEER) has emerged as an alternative therapy in patients with severe tricuspid regurgitation (TR) and high surgical risk. This study aimed to evaluate the feasibility and efficacy of tricuspid valve TEER in patients with cardiac implanted electric devices (CIEDs). METHODS: All patients who underwent tricuspid valve TEER at our center were retrospectively included. Patients were classified according to the presence of CIEDs. Procedure success was defined as implantation of at least one clip and the reduction of TR of at least one grade. Procedure success and intrahospital outcome were compared between the two groups. RESULTS: One-hundred and six consecutive patients underwent tricuspid TEER (age 80.1 ± 6.4 years, male = 42; 39.6%). Among them, 25 patients (23.6%, age 80.6 ± 7.3 years, male = 14; 56%) had CIEDs. Patients with CIEDs had a significantly lower left ventricular ejection fraction (LV-EF) compared to those without CIEDs (47.2 ± 15% vs. 56.2 ± 8.2%, p = 0.004, respectively). Moreover, arterial hypertension was more common in patients with CIEDs (96% vs. 79%, p = 0.048). The success of the procedure did not differ between the non-CIED vs. CIED group (93.8% vs. 92%, p = 0.748). Furthermore, the number and position of implanted clips, the duration of the procedure, the post-procedural pressure gradient across the tricuspid valve, and post-procedural TR severity were comparable between both groups. CONCLUSION: Tricuspid valve TEER is feasible and efficient in patients with CIEDs. The success of the procedure, as well as the intrahospital outcome were comparable between patients with and without CIEDs.

Optimal Ablation Settings Predicting Durable Scar Detected Using LGE-MRI after Modified Left Atrial Anterior Line Ablation.

(1) Background: The modified anterior line (MAL) has been described as an alternative to the mitral isthmus line. Despite better ablation results, achieving a bidirectional line block can be challenging. We aimed to investigate the ablation parameters that determine a persistent scar on late-gadolinium enhancement magnet resonance imaging (LGE-MRI) as a surrogate parameter for successful ablation 3 months after MAL ablation. (2) Methods: Twenty-four consecutive patients who underwent a MAL ablation have been included. The indication for MAL was perimitral flutter (n = 5) or substrate ablation in the diffuse anterior left atrial (LA) low-voltage area in persistent atrial fibrillation (AF) (n = 19). The MAL was divided into three segments: segment 1 (S1) from mitral annulus to height of lower region of left atrial appendage (LAA) antrum; segment 2 (S2) height of lower region of LAA antrum to end of upper LAA antrum; segment 3 (S3) from end of upper LAA antrum to left superior pulmonary vein. Ablation was performed using a contact force irrigated catheter with a power of 40 Watt and guided by automated lesion tagging and the Ablation Index (AI). The AI target was left to the operator's choice. An inter-lesion distance of ≤6 mm was recommended. The bidirectional block was systematically evaluated using stimulation maneuvers at the end of procedure. All patients underwent LGE-MRI imaging at 3 months, regardless of symptoms, to identify myocardial lesions (scars). (3) Results: Bidirectional MAL block was achieved in all patients. LGE-MRI imaging revealed scarring in 45 of 72 (63%) segments. In all three segments of MAL, ablation time and AI were significantly higher in scarred areas compared with non-scar areas. The mean AI value to detect a durable scar was 514.2 in S1, 486.7 in S2 and 485.9 in S3. The mean ablation time to detect a scar was 20.4 s in S1, 22.1 s in S2 and 20.2 s in S3. Mean contact force and impedance drop were not significantly different between scar and non-scar areas. (4) Conclusions: Targeting optimal AI values is crucial to determine persistent left atrial scars on an LGE-MRI scan 3 months after ablation. AI guided linear left atrial ablation seems to be effective in producing durable lesions.

Simple periprocedural precautions to reduce Doppler microembolic signals during AF ablation.

BACKGROUND: Doppler microembolic signals (MES) occur during atrial fibrillation ablation despite of permanent flushed transseptal sheaths, frequent controls of periprocedural coagulation status and the use of irrigated ablation catheters PURPOSE: To investigate the number and type of MES depending on the procedure time, prespecified procedure steps, the activated clotting time (ACT) during the ablation procedure and the catheter contact force. METHODS: In a prospective trial, 53 consecutive atrial fibrillation patients underwent pulmonary vein isolation by super-irrigated "point-by-point" ablation. All patients underwent a periinterventional, continuous transcranial Doppler examination (TCD) of the bilateral middle cerebral arteries during the complete ablation procedure. RESULTS: An average of 686±226 microembolic signals were detected by permanent transcranial Doppler. Thereby, 569±208 signals were differentiated as gaseous and 117±31 as solid MES. The number of MES with regard to defined procedure steps were as follows: gaseous: [transseptal puncture, 26 ± 28; sheath flushing, 24±12; catheter change, 21±11; angiography, 101±28; mapping, 9±9; ablation, 439±192; protamine administration, 0±0]; solid: [transseptal puncture, 8±8; sheath flushing, 9±5; catheter replacement, 6±6; angiography, not measurable; mapping, 2±5; ablation, 41±22; protamine administration, 0±0]. Significantly less MES occurred with shorter procedure time, higher ACT and the use of tissue contact force monitoring. CONCLUSION: The current study demonstrates that during atrial fibrillation ablation using irrigated, "point-by-point" RF ablation, masses of microembolic signals are detected in transcranial ultrasound especially in the period of RF current application. The number of MES depends on the total procedure time and the reached ACT during ablation. The use of contact force monitoring might reduce MES during RF ablation.

Comparison of uninterrupted direct oral anticoagulation with vitamin-K antagonists during AF-ablation in the clinical routine. A single center register.

BACKGROUND: Uninterrupted direct oral anticoagulation (DOAC) in AF-ablation is recommended, proven by randomized trials. The outcome and the periinterventional differences between DOACs and VKA in the real world clinical practice are discussed controversial. HYPOTHESIS: To investigate efficiency and safety of uninterrupted DOAC therapy compared to VKA during AF-Ablation in real world setting with a focus on periinterventional heparin dosage.

[Catheter ablation of supraventricular tachycardia]. / Katheterablation bei supraventrikulären Tachykardien.

Supraventricular tachycardias (SVT) are common, with atrioventricular nodal reentry tachycardias (AVNRT) being the most common paroxysmal supraventricular tachycardia. The pathophysiological understanding and the catheter ablation of SVTs have developed steadily in recent years. For example, dividing AVNRT into "typical" and "atypical" depending on the HA-, VA-interval and AH/HA ratio is recommended. Because of higher rates of recurrences after cryoablation, radiofrequency ablation has prevailed in AVNRT. The current ESC guidelines for SVTs recommend the ablation of accessory pathways in asymptomatic high-risk patients and it is now a Class I recommendation. There is no recommendation for the access in left-sided accessory pathways. However, a transseptal compared to transaortic approach seems more promising in acute success. The use of a three-dimensional (3D) mapping system leads to a reduction of the fluoroscopy times and procedure duration. Ablation of focal atrial tachycardia remains challenging despite the use of 3D electroanatomical mapping systems. However, new technologies such as high-density (HD) multipoint mapping systems can be helpful. HD mapping systems also allow a better understanding of left and right atrial macroreentry tachycardia after previous ablation or cardiac surgery and in primary nature. However, in all technological advances, a proficient understanding of the basic techniques in electrophysiology, such as entrainment mapping, is mandatory.

Predictive Factors and Safety of Noninvasive Mechanical Ventilation in Combination With Propofol Deep Sedation in Left Atrial Ablation Procedures.

Catheter ablation is nowadays the core treatment of atrial fibrillation (AF). Propofol infusion sedation is an accepted safety strategy; however, respiratory depression with respiratory variations is frequent. Noninvasive mechanical ventilation (NIV) added to deep sedation could improve procedural safety and success. We sought to assess the predictive factors and safety of NIV in combination to propofol deep sedation in left atrial ablation procedures. Procedural data from 252 consecutive patients who underwent left atrial ablation (166 [66%] persistent, 86 [34%] for paroxysmal AF) were analyzed. Sedation with 1% propofol was used in all procedures and controlled by electrophysiologists. Arterial blood gas analysis was performed regularly during the procedure. NIV was indicated for respiratory depression with pH <7.25 and pCO2 >50 mm Hg or agitated patient with the need for more profound sedation. No patient needed endotracheal intubation, and no procedure was abandoned due to adverse effects of sedation. NIV was used in 25 patients (10%). Predictive factors for the use of NIV were high-dose propofol sedation (p = 0.010), persistent AF (p = 0.029), prolonged procedure time (p = 0.006), increased body mass index (p = 0.008) and presence of obstructive sleep apnea (OSA; p <0.001). In a Cox regression analysis, OSA was an independent factor for NIV use (p = 0.016). In conclusion, propofol deep sedation for patients who underwent left atrial ablation is safe. Adding NIV in high-risk patients (i.e., OSA, high body mass index, and lengthy procedure duration) provides better respiratory homeostasis and could impact long-term procedure results.

Acute and long-term outcome of focal atrial tachycardia ablation in the real world: results of the german ablation registry.

INTRODUCTION: Catheter ablation of focal atrial tachycardia (FAT) can be a challenging procedure and results have been rarely described. The purpose of this study was to determine the characteristics and results of FAT ablation in the large cohort of the German Ablation Registry. METHODS: The German Ablation Registry is a nationwide prospective multicenter database including 12566 patients who underwent an ablation procedure between 2007 and 2010. Among them 431 (3.4%) underwent an FAT ablation and 413 patients with documented locations were analyzed. Patients were divided into three groups according to the FAT location: biatrial (BiA, n = 31, 7.5%), left atrial (LA, n = 110, 26.5%), and right atrial (RA, n = 272, 66%). RESULTS: Acute success rate was 84% (68 vs. 85 vs. 85% in biA, LA, and RA, respectively, p = 0.038). 4.8% of patients had an early recurrence during hospitalization, most in biatrial location (p < 0.001). No major acute complication occurred. At 12 months, 81% were asymptomatic or improved. The incidence of major adverse cardiovascular and cerebrovascular events (MACCE) was 3.7%. Arrhythmia freedom without antiarrhythmic drugs was 58% and was lower in biA (34 vs. 56% in LA vs. 62% in RA, p = 0.019). Early recurrence during hospitalization was an outstanding predictive factor for recurrence during follow-up. CONCLUSION: In this large patient population, FAT ablation had a relatively high acute success rate with a low complication rate. During follow-up, the recurrence rate was high, particularly in biatrial location. This was frequently predicted by an early recurrence during hospitalization.

Conventional mapping and ablation of focal ventricular tachycardias in the healthy heart.

Ventricular tachycardias (VT) in the healthy heart, also known as idiopathic VTs, often have a focal origin. Triggered activity due to delayed after-depolarization is the most likely mechanism of focal VTs. Localization of the site of origin of focal VTs is based on activation mapping with or without combination with pace mapping. The characteristic anatomic site of origin of idiopathic VTs is the right and left outflow tract. Other sites include the tricuspid and mitral annulus, the papillary muscles, and Purkinje fibers. Catheter ablation is indicated for monomorphic symptomatic VT and can be an alternative to antiarrhythmic drugs. Success rates are high, but mapping and ablation can be challenging. We review the main electrophysiological findings and the important clues for ablation of focal VTs. Specific considerations for each location are considered.

Total atrial conduction time to predict occult atrial fibrillation after cryptogenic stroke.

BACKGROUND: Insertable cardiac monitor (ICM) increases the detection rate of occult atrial fibrillation (AF) after cryptogenic stroke. The aim of this study was to evaluate the prognostic significance of total atrial conduction time (TACT) assessed by tissue Doppler imaging (PA-TDI interval) to predict AF presence in patients with cryptogenic stroke. METHODS: Ninety patients (57.7 ± 12.3 years, 48 % women) after acute cryptogenic stroke and ICM implantation were prospective recruited at four centers for continuous rhythm monitoring. In all patients, TACT was measured by PA-TDI interval via echocardiography. Patients were followed up (331 ± 186 days) for detection of AF (defined by episode lasting ≥30 s). RESULTS: AF was detected in 16 patients (18 %) during follow-up (331 ± 186 days). The median period to AF detection was 30 days (q1-q3; 16-62 days). Patients who exhibited occult AF were characterized by significantly longer PA-TDI intervals (154.7 ± 12.6 vs. 133.9 ± 9.5 ms, p < 0.0001). The cut-off value of PA-TDI interval at 145 ms demonstrated sensitivity and specificity for AF detection of 93.8 and 90.5 %, respectively. In multivariate analysis, CHA2DS2-VASc score (HR 1.96 per 1 point, p < 0.01) and longer PA-TDI interval (HR 4.05 per 10 ms, p < 0.0001) were independent predictors of occult AF. CONCLUSION: Our data suggest that measurement of TACT could help to predict future AF detection in patients with cryptogenic stroke. The clinical importance of prolonged rhythm monitoring or indication of direct anticoagulation therapy after cryptogenic stroke based on TACT should be further investigated.

Monocyte-platelet aggregates and CD11b expression as markers for thrombogenicity in atrial fibrillation.

BACKGROUND: A strong interdependence is known between atrial fibrillation (AF), inflammation and thrombogenesis. Monocyte-platelet aggregates (MPAs) are sensitive markers of platelets and monocyte activation. It is not known whether MPAs are associated with thrombogenicity in AF. Therefore, we examined differences in the content of MPAs and CD11b expression in patients with AF in dependence of the presence of atrial thrombus formation. METHODS: 107 patients with symptomatic AF underwent transesophageal echocardiography (TEE) before planned cardioversion or pulmonary vein isolation. Flow-cytometric quantification analysis was done on the day of performed TEE to determine the content of MPAs and the expression of CD11b on monocytes and granulocytes. RESULTS: Compared to patients without thrombus (n = 80) those with an echocardiographic proven left atrium (LA) thrombus (n = 27) showed an increased extent of the risk factors age, diabetes and heart failure. The content of MPAs (147 ± 12 vs. 311 ± 29 cells/µl, p < 0.001) as well as the CD11b expression on monocytes (p < 0.05) and granulocytes (p < 0.05) were strongly associated with the existence of a LA thrombus. The content of MPAs and the CD11b expression remained independent predictors for LA thrombus after adjustment in logistic regression analysis and negatively correlated with left atrial appendage flow velocity. MPAs above 170 cells/µl (OR 34.2, p = 0.01) had a sensitivity of 96 % and a specificity of 73 % for predicting LA-thrombus. CONCLUSIONS: The content of MPAs and the CD11b expression on monocytes and granulocytes are increased in AF-patients with proven thrombus formation. They seem to be appropriate biomarkers for stratification of thromboembolic risk in patients with AF.