Project description:Transient ischemic attacks (TIAs) typically present with easily recognizable neurological focal deficits. Symptoms such as paroxysmal involuntary movements are not usually considered to be a manifestation of TIA. We report a case with video documentation of TIA due to permanent atrial flutter presenting as acute left hemichorea. To our knowledge, such a case has not yet been reported. The present case constitutes a crucial diagnostic challenge in neurological practice in order to prevent a high risk of subsequent ischemic stroke.
Project description:Clinical electrophysiology has made the traditional classification of rapid atrial rhythms into flutter and tachycardia of little clinical use. Electrophysiological studies have defined multiple mechanisms of tachycardia, both re-entrant and focal, with varying ECG morphologies and rates, authenticated by the results of catheter ablation of the focal triggers or critical isthmuses of re-entry circuits. In patients without a history of heart disease, cardiac surgery or catheter ablation, typical flutter ECG remains predictive of a right atrial re-entry circuit dependent on the inferior vena cava-tricuspid isthmus that can be very effectively treated by ablation, although late incidence of atrial fibrillation remains a problem. Secondary prevention, based on the treatment of associated atrial fibrillation risk factors, is emerging as a therapeutic option. In patients subjected to cardiac surgery or catheter ablation for the treatment of atrial fibrillation or showing atypical ECG patterns, macro-re-entrant and focal tachycardia mechanisms can be very complex and electrophysiological studies are necessary to guide ablation treatment in poorly tolerated cases.
Project description:Atrial flutter (AFL) is a common atrial arrhythmia typically characterized by electrical activity propagating around specific anatomical regions. It is usually treated with catheter ablation. However, the identification of rotational activities is not straightforward, and requires an intense effort during the first phase of the electrophysiological (EP) study, i.e., the mapping phase, in which an anatomical 3D model is built and electrograms (EGMs) are recorded. In this study, we modeled the electrical propagation pattern of AFL (measured during mapping) using network theory (NT), a well-known field of research from the computer science domain. The main advantage of NT is the large number of available algorithms that can efficiently analyze the network. Using directed network mapping, we employed a cycle-finding algorithm to detect all cycles in the network, resembling the main propagation pattern of AFL. The method was tested on two subjects in sinus rhythm, six in an experimental model of in-silico simulations, and 10 subjects diagnosed with AFL who underwent a catheter ablation. The algorithm correctly detected the electrical propagation of both sinus rhythm cases and in-silico simulations. Regarding the AFL cases, arrhythmia mechanisms were either totally or partially identified in most of the cases (8 out of 10), i.e., cycles around the mitral valve, tricuspid valve and figure-of-eight reentries. The other two cases presented a poor mapping quality or a major complexity related to previous ablations, large areas of fibrotic tissue, etc. Directed network mapping represents an innovative tool that showed promising results in identifying AFL mechanisms in an automatic fashion. Further investigations are needed to assess the reliability of the method in different clinical scenarios.
Project description:We report a case of a 70-year-old woman who presented for a cavotricuspid isthmus atrial flutter ablation that was aborted prematurely. On subsequent imaging, she was discovered to have a right atrial diverticulum, which was present on prior imaging but not reported, likely due to unfamiliarity with the entity. (Level of Difficulty: Intermediate.).
Project description:BackgroundStandard therapy of atypical atrial flutter (AFL) aims at deploying ablation lines between two non-conducting anatomical structures, thereby creating a line of block within the re-entry circuit. We have developed an ablation strategy, where we incorporate voltage information as a surrogate for atrial fibrosis from the electro-anatomical map (EAM) during AFL ablation procedures to create individualized, substrate-based ablation lines along the area of most pronounced low-voltage within the reentry-circuit.ObjectiveThe aim of this study was to evaluate acute procedural success and long-term outcome of a substrate-based ablation (SBA) strategy in comparison to a standard anatomically based ablation (ABA) strategy for the ablation of atypical AFL.MethodsPatients that underwent ablation for AFL at our institution were included. SBA procedures were compared to ABA procedures. Endpoints were acute termination of AFL and recurrence of the index AFL or any other AFL during follow-up.ResultsWe included 47 patients, 24 individuals (51.1%) in the SBA group and 23 patients (48.9%) in the ABA group. Most patients had signs of atrial cardiomyopathy, namely enlarged left atrial diameter (LAD) and extended amount of left atrial low-voltage areas (LVA). Termination of AFL occurred in 27 of 29 (93.1%) AFL in the SBA group and in 28 of 31 (90.3%) AFL in the ABA group (p = 0.99). Freedom from recurrence of any atypical AFL after 2.5 years was 21.5% in the ABA group compared to 48.8% in the SBA group (p = 0.047).ConclusionSubstrate-based ablation is as effective as an anatomically-based ablation in the acute termination of AFL but yields better rhythm outcome with less recurrence of AFL in patients with atrial cardiomyopathy.
Project description:Atrial flutter (AFL) is a common form of arrhythmia recurrence after atrial fibrillation (AF) ablation. We aimed to define (1) the incidence of AFL and (2) the clinical factors associated with cavo-tricuspid isthmus dependent (typical) and atypical AFL, after AF ablation. The retrospective cohort consisted of 1,029 patients that underwent initial radiofrequency AF ablation from May 2005 to December 2013 at a single academic center. Patients with missing follow-up data, history of AFL ablation, and those with undocumented AFL were excluded. Atrial volumes were measured using three-dimensional cardiac computed tomography or magnetic resonance imaging. A total of 607 patients were included in the final cohort (age 59.2 ± 10.6 years, 76.0% men, 58.7% paroxysmal AF). During a median follow-up of 845 days (interquartile range 389 to 1,597 days), 122 (20.1%) patients developed AFL. Of these, 17 had typical AFL, 98 had atypical AFL, and 7 patients had both circuits. In the multivariable Cox regression analysis, only right atrial volume index (hazard ratio [HR] 1.25 per 10 ml/m2, confidence interval [CI] 95% 1.10 to 1.42) was associated with incident typical AFL; whereas persistent AF (HR 1.59, CI 95% 1.06 to 2.40), linear lesions (HR 1.58, CI 95% 1.02 to 2.46) and left atrial volume index (HR 1.17 per 10 ml/m2, CI 95% 1.07 to 1.27) were associated with incident atypical AFL. In conclusion, noninvasive measures of right and left atrial remodeling are strongly associated with incident AFL after AF ablation. Strategies to prevent incident AFL using these measures after index ablation warrant further investigation.