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Objectives Information on normative reference values for cardiac structures is critical for the accurate application of echocardiography for guiding clinical decision-making. Many studies using transthoracic echocardiography (TTE) have shown that Indians have smaller diameters of various cardiac structures. There are no normative studies for transesophageal echocardiography (TEE). The authors observed dimensions of various cardiac structures in healthy Indian patients under general anesthesia using TEE and compared them with existing guidelines from non-Indian data. Design The Indian Normative TEE Measurements study was a multicenter, prospective observational study conducted in India. Setting Operating rooms for noncardiac surgeries in tertiary care–level hospitals. Participants Adult patients undergoing noncardiac surgery who were free from any cardiac, respiratory, and renal diseases and had no contraindications for TEE. Interventions After inducing general anesthesia and achieving stable hemodynamic conditions, a comprehensive TEE examination was performed and various measurements were made. Measurements and Main Results For each of the 83 patients undergoing noncardiac surgery, 39 various measurements for left ventricle, right ventricle, both atria, and all valves were made. This included diameters and functional parameters. They were analyzed in a vendor-neutral software off-line. The absolute values of many of the measurements were higher in men, but when indexed to body surface area (BSA) they were similar in both sexes. The values were lower than most of the Western data but matched previous Indian studies using TTE. Conclusions The authors present normative values of various echocardiographic parameters using TEE. Because of its variations, it is recommended to use India-specific data to make decisions in Indian patients. It may be prudent to use BSA-indexed values during decision-making.

Background Cardioneuroablation (CNA) targets the intrinsic cardiac autonomic nervous system ganglionated plexi located in the peri-atrial epicardial fat. There is increasing interest in CNA as a treatment of vasovagal syncope (VVS), despite no randomized clinical trial (RCT) data. Objective The purpose of this study was to poll the opinion on CNA) for VVS. Methods A REDCap (Research Electronic Data Capture) survey was administered to international physicians treating patients with VVS on their opinion about patient selection criteria, ablation approach, RCT design, and most appropriate end points for CNA procedures. Results The survey was completed by 118 physicians; 86% were cardiac electrophysiologists. The majority of respondents (79%) would consider referring a patient with refractory VVS for CNA, and 27% have performed CNA for VVS themselves. Most felt patient selection should require a head-up tilt test with a cardioinhibitory response (67%) and suggest a minimum age of 18 years with a median of 3 (interquartile range 2–5) episodes in the past year. There were differences in patient selection between physicians who have performed CNA themselves and those who have not. The majority felt that the ablation strategy should include both atria (70%) with an anatomical approach in combination with autonomic stimulation (85%). Performing a sham procedure in the control arm was supported by 56% of respondents, providing equipoise in RCT design. The preferred primary outcome was freedom from syncope within 1 year of follow-up. Conclusion There is widespread support for well-designed RCTs to confirm the hypothesized clinical benefit of CNA, provide data to guide the risk-benefit equations during patient selection, and appropriately estimate the placebo effect.

Objectives This study was to test the hypotheses that: 1) when using phase analysis, repetitive Wannabe re-entry produces a phase singularity point (i.e., a rotor); and 2) the location of the stable rotor is close to the focal source. Background Recent contact mapping studies in patients with persistent atrial fibrillation (AF) demonstrated that phase analysis produced a different mechanistic result than classical activation sequence analysis. Our studies in patients with persistent AF showed that focal sources sometimes produced repetitive Wannabe re-entry, that is, incomplete re-entry. Methods During open heart surgery, we recorded activation from both atria simultaneously using 510 to 512 electrodes in 12 patients with persistent AF. We performed activation sequence mapping and phase analyses on 4 s of mapped data. For each detected stable rotor (>2 full rotations [720°] recurring at the same site), the corresponding activation patterns were examined from the activation sequence maps. Results During AF, phase singularity points (rotors) were identified in both atria in all patients. However, stable phase singularity points were only present in 6 of 12 patients. The range of stable phase singularity points per patient was 0 to 6 (total 14). Stable phase singularity points were produced due to repetitive Wannabe re-entry generated from a focal source or by passive activation. A conduction block sometimes created a stable phase singularity point (n = 2). The average distance between a focal source and a stable rotor was 0.9 ± 0.3 cm. Conclusions Repetitive Wannabe re-entry generated stable rotors adjacent to a focal source. No true re-entry occurred.

Objectives: The goal of this study is to investigate the impact of various underlying heart diseases (UHDs) and prior atrial fibrillation (AF) episodes on conduction heterogeneity. Background: It is unknown whether intra-atrial conduction during sinus rhythm differs between various UHD or is influenced by AF episodes. Methods: Epicardial sinus rhythm mapping of the right atrium, Bachmann's bundle (BB), left atrium and pulmonary vein area was performed in 447 participants (median age: 67 [interquartile range (IQR): 59 to 73] years) with or without AF undergoing cardiac surgery for ischemic heart disease, (ischemic and) valvular heart disease, or congenital heart disease. Conduction times (CTs) were defined as Δ local activation time between 2 adjacent electrodes and used to assess frequency (CTs ≥ 4 ms) and magnitude of conduction disorders (in increments of 10 ms). Results: When comparing the 3 types of UHD, there were no differences in frequencies and magnitude of CTs at all locations (p ≥ 0.017 and p ≥ 0.005, respectively). Prior AF episodes were associated with conduction slowing throughout both atria (14.9% [IQR: 11.8 to 17.0] vs. 12.8% [IQR: 10.9 to 14.6]; p < 0.001). At BB, CTs with magnitudes ≥30 ms were more common in patients with AF (n = 56.2% vs. n = 36.0%; p < 0.004). Conclusions: UHD has no impact on the frequency and severity of conduction disorders. AF episodes are associated with more conduction disorders throughout both atria and with more severe conduction disorders at BB. The next step will be to determine the relevance of these conduction disorders for AF development and maintenance.

This study sought to define the extent and spatial distribution of endocardial-epicardial dissociation (EED) in a swine model.The mechanisms underlying persistent atrial fibrillation (AF) remain unclear.Sixteen swine underwent simultaneous endocardial and epicardial mapping using 32-electrode grid catheters. This included 6 swine with rapid atrial pacing-induced atrial remodeling. Three right atrial (RA) and 3 left atrial (LA) regions were mapped during sinus rhythm, atrial pacing, acute or persistent AF, and AF in the presence of pericardial acetylcholine. Unipolar electrogram recordings over 10-s epochs underwent offline phase analysis using customized software. Regional activation patterns on paired surfaces and the instantaneous phase at each matched electrode location were analyzed. EED was defined as paired electrodes out of phase by ≥20 ms.The mean distance between matched endocardial-epicardial electrode pairs was 4.4 ± 1.8 mm. During episodes of AF, rotational activations with ≥3 full rotations were not seen. EED was seen during 34.4 ± 16.4% of mapped time periods: LARA, persistentacute AF in the LA, and acetylcholine-inducedacute AF in both atria (p 0.05 for each). Most marked EED in persistent AF was in the LA appendage (47.2 ± 3.7%) and the LA posterior wall (50.3 ± 4.7%).Marked EED was seen in a swine model of AF, particularly during persistent AF. There was significantly more EED in the LA than the RA and, particularly, in the LA PW and LAA. Mapping approaches limited to the endocardium may not sufficiently characterize the complexity of AF.

Background Postoperative atrial fibrillation (POAF) is common after cardiac surgery and is associated with an inferior outcome. The high cure rate compared with non-POAF raises questions regarding the electrophysiologic mechanism. Despite being common, until now the electrophysiologic mechanism of POAF was never assessed. Methods Ten patients (5 men; mean age, 75 ± 5 years) with POAF underwent noninvasive 3-dimensional beat-by-beat mapping and were compared with 10 patients (6 men; mean age, 70 ± 10 years) with preoperative persistent AF (PEAF) undergoing open heart procedures. Three-dimensional mappings were compared by the nature and location of focal and rotor activity using the validated Bordeaux classification. Results Rotor activity was present in both atria of all patients; 299 rotors (mean, 30 ± 12) were mapped in the POAF group and 289 (mean, 29 ± 22) in the PEAF group. The most common region for macro reentry in both groups was the pulmonary vein area. Left atrium and left atrial appendage activity accounted for 59% (177/299 POAF group) and 62% (180/289 PEAF group) of all drivers. Rotor activity in the right atrium was documented in all patients. Focal activity was captured in only 2 patients in the POAF group and in 6 patients in the PEAF group. Conclusions The mechanism of POAF is comparable with that of PEAF. Rotor activity was similar in both groups, but focal activity was numerically less common in the POAF group, which may be related to differences in atrial tissue remodeling. In POAF, transient substrate changes seem to facilitate the development of AF. A better understanding of atrial tissue changes by mapping and tissue analysis should lead to better preventive approaches.

Late thrombus formation is a rare complication associated with patent foramen ovale (PFO) closure devices. We report the case of an incidental discovery of large thrombi in both atria 9 months after percutaneous PFO occlusion that required cardiac surgery for thrombi removal. (Level of Difficulty: Beginner.), Graphical abstract, Late thrombus formation is a rare complication associated with patent foramen ovale (PFO) closure devices. We report the case of an incidental…

Introduction The aim of this study was to investigate electrophysiological findings in patients with arrhythmia recurrence undergoing a repeat ablation procedure using ultra-high-density (UHDx) mapping following an index procedure using either contact-force (CF)-guided radiofrequency current (RFC) pulmonary vein isolation (PVI) or second-generation cryoballoon (CB) PVI for treatment of atrial fibrillation (AF). Methods and results Fifty consecutive patients with recurrence of AF and/or atrial tachycardia (AT) following index CF-RFC PVI (n = 21) or CB PVI (n = 29) were included. A 64-pole mini-basket mapping catheter in combination with an UHDx-mapping system-guided ablation was used. RFC was applied using a catheter tip with three incorporated mini-electrodes. PV reconnection rates were higher after CF-RFC PVI (CF-RFC: 2.5 ± 1.3 PVs vs CB: 1.4 ± 0.9 PVs; P = .0025) and left PVs were more frequently reconnected (CF-RFC: 64% PVs vs CB: 35% PVs; P = .0077). Fractionated signals along the antral index ablation line (FS) were found in 30% of CB-PVI patients (CF-RFC: 9.5% vs CB:30%; P = .098) targeted for ablation. In five cases, FS were a critical part of maintaining consecutive AT. The main AT mechanism found during reablation (n = 45 ATs) was macroreentry (80% [36/45], CF-RFC: 78.9% vs CB: 80.8%; P = 1.0) with a variety of circuits throughout both atria. Conclusion UHDx mapping is sensitive in detecting conduction gaps along the index ablation line. Left PVs are more frequently reconnected after initial CF-RFC PVI. FS are a common finding after CB PVI and can maintain certain forms of ATs. ATs after index PVI are mostly macroreentries with a broad spectrum of entities.

We performed a systematic review of the literature on assessment of right atrial (RA) and left atrial (LA) deformation by myocardial strain imaging in patients with repaired tetralogy of Fallot. Ten studies with a total of 536 adolescent and adult patients were included, of which 5 evaluated RA deformation, 2 studied LA deformation and 3 assessed deformation of both atria. Seven studies used speckle tracking echocardiography, 2 employed tissue Doppler imaging and 1 applied cardiac magnetic resonance feature tracking. Main findings were (i) reduced regional and/or global RA and LA strain and strain rate consistent with reduced conduit, reservoir and contractile function of the two atria in patients; (ii) associations between RA and LA deformation indices suggestive of atrial-atrial interaction; and (iii) relationships between RA deformation and indices of right ventricular systolic and diastolic function. The lack of data on prognostic value of atrial strain is an important knowledge gap.

Traditional observation analysis techniques are widely used by researchers to analyze public spaces, in terms of visibility, and movement patterns. This method enables the researcher to have realistic results, however it depends mainly on the researcher’s views. The main aim of the research is to reach a more reliable method for evaluating and analyzing connectivity by integrating traditional observation techniques with a more accurate analysis technique, like Depthmap software analysis. The study highlights the importance of applying this technique along with observation method to assist and validate the results. The research was conducted by applying the two analysis techniques on two atria, inside “City Stars Mall” shopping center, located in Cairo city. Both atria are similar, however, the first atrium has a larger scale, while the second has a smaller scale. Results show that Depthmap analysis technique is better in smaller scaled atrium spaces, while observation is more realistic in larger scaled spaces. Each technique has its advantages over the other. However, the paper proves that in order to reach a clear and accurate analysis, both techniques must be applied together for accurate and reliable results. Keywords: Atrium, Observation, Depthmap, Connectivity, Visibility, Accessibility

Introduction. Growing evidence suggests that fibrotic changes can be observed in atrial fibrillation (AF) in both atria. Quantification of the scar burden during electroanatomical mapping might have important therapeutic and prognostic consequences. However, as the current invasive treatment of AF is focused on the left atrium (LA), the role of the right atrium (RA) is less well understood. We aimed to characterize the clinical determinates of the RA low-voltage burden and its relation to the LA scaring. Methods. We have included 36 patients who underwent catheter ablation for AF in a prospective observational study. In addition to LA mapping and ablation, high-density RA bipolar voltage maps (HD-EAM) were also reconstructed. The extent of the diseased RA tissue (≤0.5 mV) was quantified using the voltage histogram analysis tool (CARTO®3, Biosense Webster). Results. The percentage of RA diseased tissue burden was significantly higher in patients with a CHA2DS2-VASc score ≥ 2 p=0.0305, higher indexed LA volume on the CTA scan and on the HD‐EAM (p=0.0223 and p=0.0064, respectively), or higher indexed RA volume on the HD‐EAM p=0.0026. High RA diseased tissue burden predicted the presence of high LA diseased tissue burden (OR = 7.1, CI (95%): 1.3–38.9, p=0.0145), and there was a significant correlation of the same (r = 0.6461, p<0.0001). Conclusions. Determining the extent of the right atrial low-voltage burden might give useful clinical information. According to our results, the diseased tissue burden correlates well between the two atria: the right atrium mirrors the left atrium.

The hearts of three dogs, clinically diagnosed as having persistent atrial standstill syndrome (PAS), were studied post mortem. The most significant gross findings in the hearts of all three dogs were dilatation and marked reduction in the thickness of both atrial walls. Histopathologically, all three had widespread progressive loss of the atrial myocardium with replacement by fatty or fibrofatty tissue, consistent with atrial myopathy. The lesion mainly affected the upper half of both atria and was more severe in the epimyocardium and midmyocardium than in the endomyocardium. On the basis of these observations, it is proposed that the atrial myopathy commences in the upper regions of both atria and progresses downwards, as has been demonstrated electrophysiologically in PAS in humans, and extends from the epicardium towards the endocardium.

We report a case of a recurrence of 5 cardiac myxomas in both atria with atypical anatomical features difficult to image. Although a multimodality imaging was performed, three-dimensional echocardiography (3DE) was the only technique able to correctly identify all the recurrences and the anatomical characteristics of the myxomas. MRI detected the blood supply of the mass but even after careful review was able to identify only 4 of the 5 lesions. Even though it was already reported the usefulness of 3DE to better delineate the site of attachment of cardiac tumors, it was never reported its sensibility in the setting of multiple myxomas; this case highlights the ability of the 3DE in this challenging scenario and its potential for being considered the key adjunctive modality for the anatomy when advanced surgical plan is required.

Primary malignant neoplasms of the heart are rare. Cardiac rhabdomyosarcoma is the second most common primary sarcoma. We report a rare case of a 49-year-old woman with a huge biatrial cardiac rhabdomyosarcoma treated by performing surgical resection followed by salvage chemotherapy for local recurrence. Cardiac sarcoma that occupy both atria are extremely rare. Although the prognosis of cardiac rhabdomyosarcoma is dismal, surgical resection should be recommended as a first line therapy to clarify the diagnosis and to relieve symptoms associated with the tumor.

Introduction A univentricular (UV) heart is found when both atria drain mainly into one ventricle; while if either ventricle cannot sustain the systemic or the pulmonary circulation, a functionally UV heart emerges. UV heart is the source of hot debates and discussions for decades that stem from controversies in terminologies, analysis, and management. Objective To study the morphological pattern of univentricular hearts. Design Cohort, descriptive study. Setting Review 13-year data from the file system of a high-volume, tertiary, teaching cardiac centre and study the patients having pathologies meeting the definition of UV heart. Results 461 patients have UV hearts; constituting 1.4% of all patients with a congenital heart disease (CHD) visiting the centre of the study. Functionally UV heart in the form of biventricular atrioventricular (AV) connection plus one ventriculoarterial (VA) connection was seen in 179 cases (38%) with aortic atresia being the most common (N = 98; 55%). On the other hand, UV AV connection was seen in 282 cases (62%). Under this category, 203 cases (72%) show an absent AV connection and 79 hearts (28%) with double-inlet anatomy. Conclusion UV heart is a rare complex CHD with lots of scientific debates. It is hoped that this long-term study will be the basis and a reference to paediatric cardiologists, echocardiographers, and other interested professionals.

The molecular pathomechanisms underlying atrial thrombogenesis are multifactorial and still require detailed investigations. Transgenic mice with cardiomyocyte-directed expression of the transcriptional repressor CREM-IbΔC-X (CREM-TG) represent an experimental model of atrial fibrillation (AF) that shows a gradual, age-dependent progression from atrial ectopy to persistent AF. Importantly, this model develops biatrial thrombi. The molecular characteristics related to the thrombogenesis in CREM-TG mice have not been studied, yet.The inflammatory and prothrombotic state was evaluated at the transcriptional (qRT-PCR) and protein level in the left (LA) and right atria (RA) from CREM-TG mice at the age of 20weeks and compared to wild-type controls. Moreover, histological analyses of atrial thrombi were performed.The endocardial dysfunction was mirrored by diminished levels of eNOS-mRNA in both atria (RA: 0.79±0.04, LA: 0.72±0.06; each P0.05). Moreover, the PAI-1/t-PA mRNA ratio was significantly increased in both atria (RA: 3.6±0.6; P0.01, LA: 4.0±1.0; P0.05) indicating a high risk of thrombus formation. However, the inflammatory phenotype was more pronounced in the RA and was reflected by a significant increase in the mRNA levels encoding adhesion molecules ICAM-1 (2.1±0.2; P0.01), VCAM-1 (2.3±0.5; P0.05), and selectin P (3.6±0.5: P0.05).CREM-TG mice represent a valuable model for studying atrial thrombogenesis and assessing therapeutic approaches preventing embolic events in the systemic and pulmonary circulation.

Primary cardiac lymphoma (PCL) is a very rare kind of primary heart tumor, belonging to non-Hodgkin's lymphoma whose major pathological type is diffuse large B-cell lymphoma. The common symptoms include heart failure, pericardial effusion, and malignant arrhythmias. Early diagnosis and treatment of PCL are of great importance due to its merely 7-month median survival period. Here, we report a 48-year-old male patient in whom both atria were involved and had to undergo palliative surgery because of severe clinical symptoms.

It is unknown to what extent atrial fibrillation (AF) episodes affect intra-atrial conduction velocity (CV) and whether regional differences in local CV heterogeneities exist during sinus rhythm. This case-control study aims to compare CV assessed throughout both atria between patients with and without AF. Patients (n = 34) underwent intra-operative epicardial mapping of the right atrium (RA), Bachmann’s bundle (BB), left atrium (LA) and pulmonary vein area (PVA). CV vectors were constructed to calculate median CV in addition to total activation times (TAT) and unipolar voltages. Biatrial median CV did not differ between patients with and without AF (90 ± 8 cm/s vs. 92 ± 6 cm/s, p = 0.56), only BB showed a CV reduction in the AF group (79 ± 12 cm/s vs. 88 ± 11 cm/s, p = 0.02). In patients without AF, there was no predilection site for the lowest CV (P5) (RA: 12%, BB: 29%, LA: 29%, PVA: 29%). In patients with AF, lowest CV was most often measured at BB (53%) and ranged between 15 to 22 cm/s (median: 20 cm/s). Lowest CVs were also measured at the LA (18%) and PVA (29%), but not at the RA. AF was associated with a prolonged TAT (p = 0.03) and decreased voltages (P5) at BB (p = 0.02). BB was a predilection site for slowing of conduction in patients with AF. Prolonged TAT and decreased voltages were also found at this site. The next step will be to determine the relevance of a reduced CV at BB in relation to AF development and maintenance.

Introduction The right atrium (RA) is readily accessible; however, it is unclear whether changes in the RA are representative of the LA. We performed detailed bi-atrial electroanatomic mapping to determine the electrophysiological relationship between the atria. Methods and results Consecutive patients with persistent AF underwent bi-atrial electroanatomical mapping with a contact force catheter acquiring points with a CF > 10 g prior to ablation. Points were analyzed for tissue voltage, complex electrograms, low voltage (

Objective The aim of this study was to assess atrial changes across pregnancy and postpartum using cardiac magnetic resonance imaging (cMRI) to measure atrial end-diastolic volume (EDV). Study Design This was a 2-year prospective observational study of healthy nulliparous women. Each underwent serial cMRI in both maternal left lateral and supine positions at five epochs: 12 to 16 weeks, 26 to 30 weeks, 32 to 36 weeks, within 48 hours after delivery, and 12 weeks postpartum. EDV was calculated and compared with 12-week postpartum values. Results A total of 24 women completed the study. One woman developed preeclampsia, and her data were excluded. Mean age was 27 ± 2.8 years, and mean body mass index was 25.4 ± 3.8 kg/m2. Left atrial EDV increased by 12 weeks (p = 0.045) and remained significantly elevated through 32 to 36 (p Conclusion We documented a significant increase in EDV for both atria during pregnancy. Volume changes were greater in the lateral compared with the supine position, with the most dramatic changes in left atrium at 32 to 36 weeks.

Objective To investigate reference levels for central venous pressure or pulmonary artery occlusion pressure monitoring in a lateral position. Design Retrospective observational study. Setting A tertiary university hospital. Participants A total of 204 adults who underwent chest computed tomography scan in the 90° lateral position from November 2006 to February 2015. Interventions None. Measurements and Main Results Distances from the mid-sternum to the uppermost and lowermost blood levels of both atria were measured. Ratios of the distance from the bottom of the thorax to the uppermost and the lowermost blood levels of both atria to the largest diameter of the thorax were calculated. There were significant differences between the distances from the mid-sternum to the uppermost and the lowermost blood levels of the right atrium and those of the left atrium in the right and left lateral positions, respectively. There were significant differences in the uppermost (3.3±0.1 cm; 95% confidence interval [CI] 3.1-3.5) and the lowermost (4.4±0.1 cm; 95% CI 4.2-4.7) blood levels of the right atrium between the right and left lateral positions. Although the uppermost (1.5±0.1 cm; 95% CI 1.3-1.8) and the lowermost (0.4±0.1 cm; 95% CI 0.2-0.6) blood levels of the left atrium between the right and left lateral positions showed differences, their extent was smaller than the right atrium. The uppermost and the lowermost blood levels of the right atrium lay lower than those of the left atrium in the 90° right lateral position. In contrast, in the 90° left lateral position, the uppermost and the lowermost blood levels of the right atrium lay higher than those of the left atrium. Conclusions When monitoring the central venous pressure and pulmonary artery occlusion pressure with patients in the lateral position, changes in the blood level of both atria should be considered when releveling the reference transducer.

The peculiarities of transverse tubule (T-tubule) morphology and distribution in the atrium-and how they contribute to excitation-contraction coupling-are just beginning to be understood.The objectives of this study were to determine T-tubule density in the intact, live right and left atria in a large animal and to determine intraregional differences in T-tubule organization within each atrium.Using confocal microscopy, T-tubules were imaged in both atria in intact, Langendorf-perfused normal dog hearts loaded with di-4-ANEPPS. T-tubules were imaged in large populations of myocytes from the endocardial surface of each atrium. Computerized data analysis was performed using a new MatLab (Mathworks, Natick, MA) routine, AutoTT.There was a large percentage of myocytes that had no T-tubules in both atria with a higher percentage in the right atrium (25.1%) than in the left atrium (12.5%) (P.02). The density of transverse and longitudinal T-tubule elements was low in cells that did contain T-tubules, but there were no significant differences in density between the left atrial appendage, the pulmonary vein-posterior left atrium, the right atrial appendage, and the right atrial free wall. In contrast, there were significant differences in sarcomere spacing and cell width between different regions of the atria.There is a sparse T-tubule network in atrial myocytes throughout both dog atria, with significant numbers of myocytes in both atria-the right atrium more so than the left atrium-having no T-tubules at all. These regional differences in T-tubule distribution, along with differences in cell width and sarcomere spacing, may have implications for the emergence of substrate for atrial fibrillation.

The association of the tetralogy of Fallot (TOF) with a complete atrioventricular septal defect (CAVSD) is a well-recognized congenital heart malformation occurring in 5–10% of hearts with CAVSD and in 1.7% of patients with TOF (1). The complex exhibits features of CAVSD and TOF, specifically a nonrestrictive inlet-type ventricular septal defect (VSD) with anterior extension, an ostium primum, a common unpartitioned atrioventricular valve, anterosuperior deviation of the infundibular septum, and right ventricular outflow tract obstruction (RVOTO) (1). CAVSD associated with TOF (CAVSD-TOF) affects the septa of both atria and ventricles and both ventricular inlets and outlets. Initial experiences of surgical correction for this lesion were associated with high mortality (2-4), however recent reports have demonstrated acceptable outcome (5-14). Controversy still exists about the surgical approach, this related to the number of patches employed for CAVSD correction, the use of a right ventriculotomy, cleft closure and RVOT reconstruction, employment of a transannular patch, previous palliative procedures etc (15,16). The timing of complete repair and the utility of a preliminary shunt have not been well defined in the literature yet.

Introduction Thiram, a fungicides, is widely used on seeds and as foliar agent on turf, vegetables and fruit. It is also used in the rubber industry as a vulcanization accelerator. When absorbed through the respiratory system, it is rapidly metabolised to dimethylthiocarbamate and carbon disulphide, causing noxious effects. A brief review is presented of the literature, centering on the interesting case of a 45-year-old woman admitted to the hospital suffering from acute respiratory failure. Results Computer tomography in angiographic option (angio-CT) showed an extensive, irregular area of ground glass in both upper lobes and apical segments of the lower lobes of the lungs. A significant enlargement of both atria was also described. There was no improvement after cardiac treatment and patient was transferred to the pulmonary department where she was succesfully treated with systemic glucocortycosteroids. The patient remains under the supervision of the pulmonary out-patient department.

Background Mucormycosis is an invasive fungal infection (IFI) most commonly seen in immunocompromised patients. Diabetic ketoacidosis, haematopoietic transplantation, iron overload states, and deferoxamine therapy are considered to be some of the classical risk factors. While cutaneous and rhino-sinusoidal forms may be seen in immunocompetent (IC) individuals, cardiac and mediastinal involvement is rare. In this report, we describe a young patient without predisposing factors who presented as mediastinal mucormycosis with extensive cardiac involvement. Case summary A 19-year-old male presented with complaints of dry cough and dyspnoea on exertion over the last 4 months. Echocardiography showed diffuse infiltration of both atria along with multiple pedunculated freely mobile masses. A computed tomography chest was done to further delineate the true extent of the disease and revealed diffuse infiltration of the mediastinum, bilateral atria and interatrial septum, pulmonary veins, and superior vena cava. A fine needle aspiration cytology from a mediastinal mass revealed broad aseptate fungal hyphae with right angled branching consistent with Mucor. Extensive evaluation could not find any predisposing factors. The patient was started on Amphotericin B and surgical debridement was contemplated. However, owing to the diffuse infiltration around the heart and mediastinal vasculature, debridement could not be performed and the patient eventually succumbed to the illness. Discussion Mediastinal mucormycosis though rare in IC patients, is a rapidly progressive condition with a high fatality. A high index of suspicion needs to be maintained in individuals presenting with infiltrative disorders of the mediastinum for early diagnosis and prompt treatment.

Introduction: The study of the effects of different types of physical exercise on cardiovascular physiology is increasing in the literature. The many mechanisms of hemodynamic control include the atrial release of natriuretic peptides. Although extensive evidence demonstrates their acute effects and the increase in their plasma concentration, it is not known whether both atria respond in a similar way to both types of natriuretic peptide in response to different types of exercise. Objective: To compare the acute responses of different exercise types in the atrial (ANP) and brain (BNP) natriuretic peptides of both atrial cardiomyocytes of Wistar rats. Methods: Animals were divided into control (CG), aerobic (AG), resistance (RG) and combined (ARG). The RG performed six climbs, with a load equivalent to 60% of body weight. The AG ran on a treadmill at a speed of 12m/min for 60 minutes. The ARG exercise consisted of three consecutive ladder climbs, followed by 30 minutes of running. Results: First, the right atrium released more ANP and BNP during all types of exercise; second, the resistance exercise released the most ANP and BNP in both atria; third, in the right atrium, aerobic and combined workouts released more small and medium ANP granules while resistance exercise released larger BNP granules; and fourth, in the left atrium, aerobic exercise released more ANP granules while resistance and combined exercise released larger ANP and BNP granules. Conclusion: All types of exercise induce partial release of natriuretic peptide granules, with greater response to resistance exercise. Furthermore, a particular and different response could be seen in both types of atria in the release of ANP and BNP. Level of evidence II; Therapeutic studies - Investigation of treatment results.

Primary cardiac lymphoma (PCL) is one of the rarest tumors of the heart. The most common type is diffuse, large B-cell lymphoma. Most often, the right atrium and the right ventricle are involved, and if not diagnosed and treated in time, it can be fatal. In this case, a female patient underwent an urgent operation for a large, infiltrative, right atrial mass. Extensive resection of the lateral walls of both atria and the interatrial septum as well as reconstruction were performed successfully. The pathological evaluation suggested PCL. The aim of this case is to raise awareness of this disease and to highlight clinical and surgical approaches.

The goal of pulmonary vein ablation for atrial fibrillation (AF) is returning to normal sinus rhythm; nevertheless it success is limited in part by uncertainly in the mechanisms that sustain AF. 43 AF patients were submitted to an ablation procedure and monitored after ablation. Dominant frequency from intra-atrial recordings obtained before the intervention were analysed in order to predict AF recurrence. The novelty of this study is that dominant frequency was calculated from reconstructed signal by singular spectrum analysis (SSA) application. Patients that maintained sinus rhythm and patients with recurrence in AF showed differences in left atrium dominant frequencies, with higher values in the recurrent AF group than in group without recurrence in the arrhythmia (p=0.02). Moreover, differences between both atria were found in the non-recurrent group, with 5.76 ± 1.31 Hz in the left atrium vs. 6.25±1.23 Hz in the right atrium (p=0.03). These findings show the potential of SSA as a preprocessing method and results are congruent with previous studies.

Myxoma is the most common type of benign cardiac tumor in adults. Myxoma can occur anywhere in the heart. The left atrium is the most frequent site of origin, specifically located on the left atrium side of the fossa oval in the atrial septum, followed by the right atrium, the right ventricle and left ventricle. But biatrial myxoma is extremely rare. Thoracoscopic resection of myxoma has become more common, but there are few reports on thoracoscopic surgery for biatrial myxoma. We present a case of a 72-year-old woman with biatrial myxoma, who presented with intermittent dyspnea for one week. Echocardiography revealed a medium echo in both the left and right atrium and was connected via the atrial septum. Computed tomography revealed a hypointense mass in both atria. Thoracoscopic resection successfully removed the tumors, and histological examination confirmed the diagnosis. Also, the patient was discharged six days after surgery. There was no evidence of tumor recurrence during the one-year follow-up period. Biatrial myxoma is rare. Surgical resection is the primary method for myxoma. Compared with the traditional medium thoracotomy, thoracoscopic surgery for myxoma has the following advantages: less trauma, keeping the integrity of the sternum, less bleeding, faster postoperative recovery, etc. Total thoracoscopic surgery for biatrial myxomas is effective and safe.

Current guidelines recommend that the atria be measured in 2D echocardiographic (2DE) apical views using the method-of-disks (MOD) or area-length (AL) technique as an alternative, although no definitive data exists that these are interchangeable. However, standard apical views maximize the long-axis of the left ventricle, rather than the dimensions of the atria, resulting in atrial foreshortening. We hypothesized that the increase in normal values of atrial volumes in the recent guidelines update was driven by data obtained using either the AL technique or dedicated atrial-focused views, which maximize the longitudinal dimension of the atria and thus provide larger volumes than the MOD measurements in standard apical views. We prospectively studied 30 patients (Philips iE33) to compare 2DE measurements of left and right atrial volumes (LAV, RAV) using the MOD and AL techniques in standard and atrial-focused views, against 3D echocardiography (3DE) derived volumes (QLab) as a reference. Compared to standard views, atrial-focused views provided significantly larger MOD volumes for both atria, which were in better agreement with 3DE, as reflected by higher correlation coefficients (LAV: r = 0.95 vs. 0.89; RAV: r = 0.89 vs. 0.84), smaller biases (LAV: -1 ml vs. 7 ml; RAV: 3 ml vs. 7 ml) and tighter limits of agreement. This was also the case for the AL measurements, which were minimally larger than the MOD values (NS) for both atria. In conclusion, atrial-focused views are a more accurate alternative to standard apical views, which provides larger volumes. This finding can explain the increase in the normal values in the recent guidelines update, which was mostly driven by the use of atrial-focused views, rather than by the differences between MOD and AL techniques. This understanding is essential in order to correctly integrate the revised normal values into clinical practice.

Purpose We used two-dimensional echocardiographic speckle-tracking to investigate whether left and right atrial (LA and RA) phasic function in pediatric heart transplantation (HT) patients is altered and explored the relationship to HT-related clinical variables. Methods Eighty-six subjects (36 HT and 50 normal children) were prospectively enrolled in two centers. Clinical data included age at HT, bypass time, ischemia time, donor age, and incidence of rejection. Atrial deformation indices including strain and strain rates (SRs) were measured using two-dimensional echocardiographic speckle-tracking. Components of phasic atrial function—reservoir (er, SRr), conduit (ecd, SRcd), and booster (ect, SRct) were calculated. Comparisons with controls were made using t test or Kruskal-Wallis test, and correlations to clinical variables were explored. Results The mean age and body surface area of HT subjects were 10.2 ± 6.2 years and 1.2 ± 0.6 m2, respectively. The mean heart rates were higher in HT (96 ± 18 vs 88 ± 21 in controls). There were reductions in RA and LA reservoir (er, SRr), conduit (ecd, SRcd), and booster (ect, SRct) function in HT compared with controls. There was no relationship of LA and RA deformation indices with mean age at HT, bypass time, or ischemia time. The LA ecd correlated weakly with donor age (r = –0.49, P = .04) and RA SRr, and SRcd showed association with duration of HT (P Conclusions Atrial strain determination is feasible in pediatric HT recipients and demonstrates disruption of reservoir, conduit, and booster function of both atria in this population; we speculate this may be a consequence of ventricular diastolic dysfunction.

We present a rare case of small cell carcinoma presenting as a massive biatrial mass with obstructive physiology at a high risk of hemodynamic collapse. A 31 year-old male presented with 6 weeks of shortness of breath. He was found to have a 15 centimeter neoplasm occupying both atria, obliterating

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and is associated with an increased risk of stroke. Indeed, silent AF is frequently identified in unexplained ischemic stroke. 18F-FDG-PET/CT is a powerful tool for assessing myocardial metabolic shift and inflammation, both potentially at stake in AF. This case–control study investigated whether AF could promote FDG uptake in atria after physiological myocardial glucose uptake suppression, and the potential relationship between FDG atrial uptake and prevalence of stroke. We retrospectively enrolled 128 patients (64 consecutive patients with AF and 64 without AF as the control group, matched for age and sex) who underwent 18F-FDG-PET/CT after a high-fat low-carbohydrate diet. We analyzed visual and quantitative FDG uptake parameters of the right and left atria (RA/LA) and the right and left appendages (RAA/LAA), and selected clinical features including history of stroke. Diffuse right atrial uptake was present in a third of patients with AF and only two patients in the control group. FDG uptake intensity of both atria was significantly associated with the underlying heart rhythm. The occurrence of stroke was strongly associated with detectable atrial uptake in multivariate analysis, with an odds ratio superior to that of other known risk factors. This study shows a significant correlation between FDG atrial uptake and AF. While inconsistent, this pattern seems to be associated with an increased prevalence of cardioembolic stroke.

AF is a heterogeneous rhythm disorder that is related to a wide spectrum of etiologies and has broad clinical presentations. Mechanisms underlying AF are complex and remain incompletely understood despite extensive research. They associate interactions between triggers, substrate and modulators including ionic and anatomic remodeling, genetic predisposition and neuro-humoral contributors. The pulmonary veins play a key role in the pathogenesis of AF and their isolation is associated to high rates of AF freedom in patients with paroxysmal AF. However, ablation of persistent AF remains less effective, mainly limited by the difficulty to identify the sources sustaining AF. Many theories were advanced to explain the perpetuation of this form of AF, ranging from a single localized focal and reentrant source to diffuse bi-atrial multiple wavelets. Translating these mechanisms to the clinical practice remains challenging and limited by the spatio-temporal resolution of the mapping techniques. AF is driven by focal or reentrant activities that are initially clustered in a relatively limited atrial surface then disseminate everywhere in both atria. Evidence for structural remodeling, mainly represented by atrial fibrosis suggests that reentrant activities using anatomical substrate are the key mechanism sustaining AF. These reentries can be endocardial, epicardial, and intramural which makes them less accessible for mapping and for ablation. Subsequently, early interventions before irreversible remodeling are of major importance. Circumferential pulmonary vein isolation remains the cornerstone of the treatment of AF, regardless of the AF form and of the AF duration. No ablation strategy consistently demonstrated superiority to pulmonary vein isolation in preventing long term recurrences of atrial arrhythmias. Further research that allows accurate identification of the mechanisms underlying AF and efficient ablation should improve the results of PsAF ablation.

We have shown that a dipeptidyl peptidase 4 (DPP-4) inhibitor suppresses atrial remodeling in a canine atrial fibrillation (AF) model. Glucagon-like peptide-1 (GLP-1) is increased by DPP-4 inhibitors. However, it is not clear whether GLP-1 is involved in the suppression of atrial remodeling. In this study, we evaluated the effect of liraglutide (a GLP-1 analog) on atrial electrophysiological changes using the same canine AF model. We established a canine AF model using continuous 3-week rapid atrial stimulation in seven beagle dogs divided into two groups: a liraglutide group with four dogs (3-week atrial pacing with liraglutide (150 µg/kg/day) administration) and a pacing control group with three dogs (3-week pacing without any medicine). We evaluated the atrial effective refractory period (AERP), conduction velocity (CV), and AF inducibility every week during the protocol using implanted epicardial wires against the surfaces of both atria. In the pacing control group, the AERP was gradually shortened and the CV was decreased along the time course. In the liraglutide group, the AERP was similarly shortened as in the pacing control group (94 ± 4% versus 85 ± 2%, respectively; p = 0.5926), but the CV became significantly higher than that in the pacing control group after 2 and 3 weeks (95 ± 4 versus 83 ± 5%, respectively; p = 0.0339). The AF inducibility was gradually increased in the pacing control group, but it was suppressed in the liraglutide group (5 ± 9% versus 73 ± 5%; p = 0.0262). Liraglutide suppressed electrophysiological changes such as AF inducibility and CV decrease in our canine AF model.

Atrial tachycardia (AT) after orthotopic heart transplantation (OHT) can be complex, occurring in the recipient as well as in the donor atria. Catheter ablation of these multiple ATs is challenging because of the complexity of atrial scar substrates. This case report demonstrates the merit of using a novel multipolar high-density mini-basket mapping catheter for fast, high-resolution mapping of 3 different ATs occurring in both atria of the orthotopic transplant heart.

We characterized the f-waves in atrial fibrillation (AF) in the surface ECG by quantifying the amplitude, irregularity, and dominant rate of the f-waves in leads II, aVL, and V1, and investigated whether those parameters of the f-waves could discriminate long-standing persistent AF (LPeAF) from non-LPeAF. A total of 224 AF patients were enrolled: 112 with PAF (87 males), 48 with PeAF (38 males), and 64 with LPeAF (47 males). The f-waves in surface ECG leads V1, aVL, and II, which reflect well electrical activity in the right atrium (RA), the left atrium (LA), and both atria, respectively, were analyzed. The f-waves for LPeAF had lower amplitudes in II and aVL, increased irregularity and a higher dominant rate in II and V1 compared to PAF and PeAF (all p 1 (≧390/min) (p 1) independently discriminated LPeAF from the other AF types. The f-waves combined with both a low amplitude in lead II and high dominant rate in lead V1 were significantly associated with LPeAF (OR 6.27, p

Background: The mechanisms that initiate and sustain persistent atrial fibrillation are not well characterized. Ablation results remain significantly worse than in paroxysmal atrial fibrillation in which the mechanism is better understood and subsequent targeted therapy has been developed. The aim of this study was to characterize and quantify patterns of activation during atrial fibrillation using contact mapping. Methods: Patients with persistent atrial fibrillation (n=14; mean age, 61±8 years; ejection fraction, 59±10%) underwent simultaneous biatrial contact mapping with 64 electrode catheters. The atrial electrograms were transformed into phase, and subsequent spatiotemporal mapping was performed to identify phase singularities (PSs). RESULTS: PSs were located in both atria, but we observed more PSs in the left atrium compared with the right atrium (779±302, 552±235; P =0.015). Although some PSs of duration sufficient to complete >1 rotation were detected, the maximum PS duration was only 1150 ms, and the vast majority (97%) of PSs persisted for too short a period to complete a full rotation. Although in selected patients there was evidence of PS local clustering, overall, PSs were distributed globally throughout both chambers with no clear anatomic predisposition. In a subset of patients (n=7), analysis was repeated using an alternative established atrial PS mapping technique, which confirmed our initial findings. Conclusions: No sustained rotors or localized drivers were detected, and instead, the mechanism of arrhythmia maintenance was consistent with the multiple wavelet hypothesis, with passive activation of short-lived rotational activity. Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01765075.

Cardiac myxomas are frequently located in the left or right atria, with multiple locations being rare. We report a 59-year-old healthy female with 5 months of cough and exertional dyspnea. A transthoracic echocardiography (TTE) exhibits a 9 × 5 cm nonpedunculated tumor arising from the interatrial septum (IAS) and inhabiting both atria, but was unable to depict the relation with the IAS. Transesophageal echocardiography exposes a single tumor crossing the IAS through an ostium secundum atrial septal defect (ASD) causing right heart functional impairment. Uneventful cardiac surgery allowed complete resection of the lesion and ASD closure. Pathology reported a myxoma.

The initial surgical attempts to treat atrial fibrillation (AF) were isolation procedures designed to confine the arrhythmia to a specific area of the heart for relief of symptoms. The first surgical attempt to ablate AF was unsuccessful but was quickly followed by the Maze-I procedure on September 25, 1987. Because of several adverse sequelae of the Maze-I procedure, it was sequentially modified to the Maze-II and then Maze-III procedures. The Maze-IV procedure was introduced some 10 years later; these are the only 4 procedures that adhere to the concept of a maze pattern of lesions to ablate AF and leave both atria capable of being activated during normal sinus rhythm. The term maze procedure has become generic for virtually any operation designed to treat AF, but procedures that do not adhere to the concept of creating lesions of conduction block in the pattern of a maze are not maze procedures. These include, among others, the Wolf Mini-Maze, the Left-Sided Maze, and the 5-Box Maze, none of which are truly based on the maze-pattern concept. The cardinal feature of maze procedures that is necessary for both effectiveness and comparability to classical maze procedures includes lines of conduction block that preclude macro-reentry anywhere in either atrium while leaving both atria capable of activation by a sinus-generated impulse. Components essential to achieving this include appropriate lesions in both atria, the absence of gaps that allow electrical activity to bypass an intended line of block, and the absence of alternate pathways by which impulses can reach the intended maze exit.

The effects of cryoballoon (CB) ablation in non-pulmonary vein sites have not clearly elucidated. Herein we present a new definition method which helps to predict autonomic modification effect of CB application using atrial electrogram (EGM) characteristics and vagal responses (VRs). A 54-year-old man underwent pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation. Both atria were mapped with the aid of electroanatomical mapping system prior to ablation procedure. The atrial EGMs were divided into 3 groups according to duration, amplitude, and number of deflections. The sites demonstrating fractionated pattern on 2.5 centimeters outside of pulmonary vein ostia were tagged on the mapping to predict the relationship between VR and EGM characteristics during CB application. CB application in the PV demonstrating intensive fractionated EGMs caused a significant VR. We concluded that our case may be starting point to understand mechanism of PVI induced VR during CB application. © 2018 CardioFront LLC. All rights reserved.

Ventricular filling may occur directly from the venous circulation during early diastole or via atrial contraction in late diastole. The contribution of atrial contraction to ventricular filling is typically small in mammals (10-40%), but has been suggested to predominate in reptiles. We investigated the importance of atrial contraction in filling of the ventricle in American alligators (Alligator mississippiensis) by bypassing both atria (with the use of ligatures to prevent atrial filling) and measuring the resultant effects on cardiac output in anesthetized animals. Atrial ligation had no significant effects on total systemic blood flow before or after adrenaline injection. Unexpectedly, pulmonary flow was increased following atrial ligation prior to adrenaline treatment, but was unaffected after it. These findings suggest that the atria are non-essential (i.e. redundant) for ventricular filling in alligators, at least under anesthesia, but may serve as important volume reservoirs.

[EN] Atrial fibrillation (AF) is already the most commonly occurring arrhythmia. Catheter pulmonary vein ablation has emerged as a treatment that is able to make the arrhythmia disappear; nevertheless, recurrence to arrhythmia is very frequent. In this study, it is proposed to perform an analysis of the electrical signals recorded from bipolar catheters at three locations, pulmonary veins and the right and left atria, before to and during the ablation procedure. Principal Component Analysis (PCA) was applied to reduce data dimension and Granger causality and divergence techniques were applied to analyse connectivity along the atria, in three main regions: pulmonary veins, left atrium (LA) and right atrium (RA). The results showed that, before the procedure, patients with recurrence in the arrhythmia had greater connectivity between atrial areas. Moreover, during the ablation procedure, in patients with recurrence in the arrhythmial both atria were more connected than in patients that maintained sinus rhythms. These results can be helpful for procedures designing to end AF., This work has been supported by the Spanish Government, under the grant DPI2015-70821-R received from the research program Retos de la Sociedad' by the Ministry of Economics and Competitiveness.

Introduction. Cardiac masses may be of neoplastic or non-neoplastic nature. The most common benign primary cardiac tumour is myxoma, and the most common malignant tumour is sarcoma. Metastatic tumours are more prevalent than primary cardiac tumours. Surgical excision of the cardiac mass is the treatment of choice. The aim of this study was to evaluate the prevalence of specific types of cardiac masses and their effect on outcomes in surgically treated patients with cardiac masses. Material and methods. We studied all patients treated at the Department of Cardiac Surgery, Świetokrzyskie Cardiology Centre in Kielce, with the echocardiographic diagnosis of a cardiac mass who were operated in 2008–2014. Results. Our study group included 19 patients aged 25 to 80 years (mean age 60.8 years). Based on histologic evaluation of the resected mass, myxoma was diagnosed in 13 patients (68.4%), thrombus in 4 patients (21.1%), lipoma in one patient (5.3%), and metastatic right adrenal tumour in one patient (5.3%). The mass was most commonly located in the left atrium (n = 13, 68.4%), followed by the left ventricle and right atrium (n = 2 each, 10.5%), and the right ventricle and both atria (n = 1 each, 5.3%). Three patients (16%) died in the early postoperative period, and all 16 patients who were discharged from the Department of Cardiac Surgery were alive at long-term follow-up (mean 2.5 years). Conclusions. Surgical excision is the treatment of choice in patients with cardiac masses, except for those in whom the tumour is a manifestation of an advanced neoplastic disease. Long-term outcomes in patients operated due to a cardiac mass are favourable.

Background Atrial function is an important contributor of ventricular function and has a prognostic role in various cardiovascular diseases. We tested the hypothesis that right and left atrial (RA & LA) function may not be equal despite their accommodating identical cardiac output. Methods Two-dimensional (2D) speckle tracking echocardiography was acquired from the apical four-chamber view in 100 normal subjects. Both RA/LA subendocardial borders were traced to obtain atrial volumes, strain (e) and strain rate (SR). Reservoir, conduit, and booster pump functions were evaluated. Consequently, eNeg (corresponding to pump function) and ePos (corresponding to conduit function) were gauged. The SR parameters (SRLateNeg, SRPos, and SREarlyNeg), corresponding respectively to atrial systole, inception of ventricular systole, and inception of ventricular diastole, were measured. Results Mean age was 39 ± 15 years with 50 men (50%). Volumetric indices revealed that reservoir (Filling Volume = 35.1 ± 10.4 mL for LA vs. 27.47 ± 11.93 mL for RA, expansion index = 52.18 ± 16.89% for LA vs. 45.03 ± 16.49% for RA and diastolic emptying index = 52.85 ± 16.85 for LA vs. 45.62 ± 16.5 for RA, P

Aims Targeting of complex fractionated electrograms (CFEs) in the atria is not yet beneficial in treating drug-refractory atrial fibrillation (AF). In order to gain insight into potential anatomical hotspots of fractionated electrograms, a structured literature search was performed. Methods and results PubMed was searched for studies describing fractionation during human atrial electrophysiological measurements (n = 565), of which 36 articles described the pre-ablation distribution of fractionated electrograms for the left atrium and/or right atrium in at least four regions. Fractionation was commonly found in high proportions within all regions of both atria, without clear preference for specific regions. Furthermore, no differences in the fractionation distribution between paroxysmal AF and persistent AF patients were observed. Conclusion Whereas atrial inhomogeneous conduction is widely believed to play a key role in AF initiation and perpetuation, different electrophysiological causes for fractionation and the influence of measurement properties complicate identification of the arrhythmogenic substrate. Thereby, simply targeting all CFEs would be short-sighted. Further research is warranted on how to distinguish 'physiologic CFEs' from 'pathologic CFEs', with only the latter reflecting potential targets for ablative therapy of AF.

Imaging has accelerated mechanistic understanding and its translation to therapy more in the management of heart rhythm disorders arguably than in any other field. State-of-the-art imaging modalities provide hitherto unavailable patient-specific information on geometrical structure, tissue properties, and function of both atria and ventricles. By enabling direct and subject-specific visualization of structure and function before and after clinical and experimental interventions, imaging has made cardiac anatomy a central pillar of modern electrophysiology.

Introduction Atrial fibrillation (AF) often converts to and from atrial tachycardia (AT), but it is undefined if these rhythms are mechanistically related in such patients. We tested the hypothesis that critical sites for AT may be related to regional AF sources in patients with both rhythms, by mapping their locations and response to ablation on transitions to and from AF. Methods From 219 patients undergoing spatial mapping of AF prior to ablation at 3 centers, we enrolled 26 patients in whom AF converted to AT by ablation (n=19) or spontaneously (n=7; left atrial size 42±6cm, 38% persistent AF). Both atria were mapped in both rhythms by 64-electrode baskets, traditional activation maps and entrainment. Results Each patient had a single mapped AT (17 reentrant, 9 focal) and 3.7±1.7 AF sources. The mapped AT spatially overlapped one AF source in 88% (23/26) of patients, in left (15/23) or right (8/23) atria. AF transitioned to AT by 3 mechanisms: (a) ablation anchoring AF rotor to AT (n=13); (b) residual, unablated AF source producing AT (n=6); (c) spontaneous slowing of AF rotor leaving reentrant AT at this site without any ablation (n=7). Electrogram analysis revealed a lower peak-to-peak voltage at overlapping sites (0.36±0.2mV vs 0.49±0.2mV p=0.03). Conclusions Mechanisms responsible for AT and AF may arise in overlapping atrial regions. This mechanistic inter-relationship may reflect structural and/or functional properties in either atrium. Future work should delineate how acceleration of an organized AT may produce AF, and whether such regions can be targeted a priori to prevent AT recurrence post AF ablation.

Background Paroxysmal atrial tachyarrhythmias frequently occur in beta-thalassemia major (beta-TM) patients. The aim of the current study was to evaluate the atrial electromechanical delay (AEMD) in a large beta-TM population with normal cardiac function and its relationship to atrial fibrillation (AF) onset.Methods Eighty beta-TM patients ( 44 men, 36 women), with a mean age of 36.2 +/- 11.1 years, and 80 healthy subjects used as controls, matched for age and gender, were studied for the occurrence of AF during a 5-year follow-up, through 30-day external loop recorder (ELR) monitoring performed every 6 months. Intra-AEMD and inter-AEMD of both atria were measured through tissue Doppler echocardiography. P-wave dispersion (PD) was carefully measured using 12-lead electrocardiogram ( ECG).Results Compared to the healthy control group, the beta-TM patients showed a statistically significant increase in inter-AEMD, intra-left AEMD, maximum P-wave duration, and PD. Dividing the beta-TM group into two subgroups (patients with or without AF), the inter-AEMD, intra-left AEMD, maximum P-wave duration, and PD were significantly higher in the subgroup with AF compared to the subgroup without AF. There were significant good correlations of intra-left AEMD and inter-AEMD with PD. A cut-off value of 40.1 ms for intra-left AEMD had a sensitivity of 76.2% and a specificity of 97.5% in identifying beta-TM patients with AF risk. A cut-off value of 44.8 ms for inter-AEMD had a sensitivity of 81.2% and a specificity of 98.7% in identifying this category of patients.Conclusions Our results showed that the echocardiographic atrial electromechanical delay indices (intra-left and inter-AEMD) and the PD were significantly increased in beta-TM subjects with normal cardiac function. PD and AEMD represent non-invasive, inexpensive, useful, and simple parameters to assess the AF risk in beta-TM patients.

Multiple strategies have previously been described for atrial region (i.e. atrial bodies and aortic tract) segmentation. Although these techniques have proven their accuracy, inadequate results in the mid atrial walls are common, restricting their application for specific cardiac interventions. In this work, we introduce a novel competitive strategy to perform atrial region segmentation with correct delineation of the thin mid walls, and integrated it into the B-spline Explicit Active Surfaces framework. A double stage segmentation process is used, which starts with a fast contour growing followed by a refinement stage with local descriptors. Independent functions are used to define each region, being afterward combined to compete for the optimal boundary. The competition locally constrains the surface evolution, prevents overlaps and allows refinement to the walls. Three different scenarios were used to demonstrate the advantages of the proposed approach, through the evaluation of its segmentation accuracy, and its performance for heterogeneous mid walls. Both computed tomography and magnetic resonance imaging datasets were used, presenting results similar to the state-of-the-art methods for both atria and aorta. The competitive strategy showed its superior performance with statistically significant differences against the traditional free-evolution approach in cases with bad image quality or missed atrial/aortic walls. Moreover, only the competitive approach was able to accurately segment the atrial/aortic wall. Overall, the proposed strategy showed to be suitable for atrial region segmentation with a correct segmentation of the mid thin walls, demonstrating its added value with respect to the traditional techniques., The authors acknowledge Fundacao para a Ciencia e a Tecnologia (FCT), in Portugal, and the European Social Found, European Union, for funding support through the "Programa Operacional Capital Humano" (POCH) in the scope of the PhD grants SFRH/BD/95438/2013 (P. Morais) and SFRH/BD/93443/2013 (S. Queiros).Authors gratefully acknowledge the funding of projects NORTE-01-0145-FEDER-000013 and NORTE-01-0145-FEDER-000022, co-financed by "Programa Operacional Regional do Norte" (NORTE2020), through "Fundo Europeu de Desenvolvimento Regional" (FEDER)., info:eu-repo/semantics/publishedVersion