Search results for " atrium"
showing 10 items of 35 documents
Determination of Synchronization of Electrical Activity in the Heart by Shannon Entropy Measure
2005
In this paper we propose a new index of synchronization for the study of heart’s electrical activity during atrial fibrillation (AF). The index relies on the measure of the time delays between correspondent activations in two atrial electrograms and on the characterization of their dispersion by a measure of Shannon Entropy. The algorithm was validated on simulated signals mimicking different degree of synchronization. Results showed the index was able to discriminate among different levels of organization, provided that it works on series of at least 50 activations (time resolution of almost 10 sec during AF). Moreover, we applied the algorithm to real bipolar electrograms, obtained from a…
A giant left atrium in a patient with Barlow syndrome, abnormal chordae tendineae, and perforation of the anterior mitral leaflet
2019
Quantification of synchronization during atrial fibrillation by Shannon entropy: Validation in patients and computer model of atrial arrhythmias
2005
Atrial fibrillation (AF), a cardiac arrhythmia classically described as completely desynchronized, is now known to show a certain amount of synchronized electrical activity. In the present work a new method for quantifying the level of synchronization of the electrical activity recorded in pairs of atrial sites during atrial fibrillation is presented. A synchronization index (Sy) was defined by quantifying the degree of complexity of the distribution of the time delays between sites by Shannon entropy estimation. The capability of Sy to discriminate different AF types in patients was assessed on a database of 60 pairs of endocardial recordings from a multipolar basket catheter. The analysis…
Wave similarity mapping shows the spatiotemporal distribution of fibrillatory wave complexity in the human right atrium during paroxysmal and chronic…
2005
Introduction: The complexity of waveforms during atrial fibrillation may reflect critical activation patterns for the arrhythmia perpetuation. In this study, we introduce a novel concept of map, based on the analysis of the wave morphology, which gives a direct evidence in the human right atrium on the spatiotemporal distribution of fibrillatory wave complexity in paroxysmal (PAF) and chronic (CAF) atrial fibrillation. Methods and Results: Electrograms were recorded from a 64-electrode catheter in the right atrium of 15 patients during PAF (n = 8) and CAF (n = 7). Wave similarity maps were constructed by calculating the degree of morphological similarity of activation waves (S) at each atri…
Separation of left atrium from right pulmonary artery: a new echocardiographic sign of pericardial effusion.
1981
We report a new echocardiographic sign of pericardial effusion in patients with pericardial effusion examined by the suprasternal approach. In normal individuals the right pulmonary artery is closely connected with the superior wall of the left atrium. A separation of these structures is only to be noticed during atrial contraction. In 12 of 17 patients with a pericardial effusion observed a separation of the left atrium from the right pulmonary artery ranging from 3 to 20 mm throughout the cardial cycle. We suggest that this echo-free zone represents fluid in the transverse pericardial sinus which is located between the two structures. In five patients with a small pericardial effusion (le…
Right atrium compression by a renal cyst: a tomographic diagnosis.
2011
The Ipsilateral Interhemispheric Transprecuneal Approach to the Atrium: Technical Considerations and Clinical Outcome on a Series of 7 Patients
2022
Surgical removal of tumors of the atrium is challenging due to their deep location, vascularization, and to their complex three-dimensional relationships with the highly functional white matter fibers of the region. To assess the feasibility and the effectiveness of the ipsilateral interhemispheric transprecuneus approach (IITA) for tumors involving the atrium and the posterior third of the temporal horn, a retrospective chart review of all patients who had undergone a surgical treatment for intraventricular tumors between January 2008 and January 2017 was performed, and the step-by-step approach is described. Ten patients affected by lesions of the atrium of the lateral ventricle underwent…
Comparison of Nonclassic and Classic Phenotype of Hypertrophic Cardiomyopathy Focused on Prognostic Cardiac Magnetic Resonance Parameters: A Single-C…
2022
Patients with nonclassic phenotypes (NCP)—more advanced stages of hypertrophic cardiomyopathy (HCM)—constitute an intriguing and heterogeneous group that is difficult to diagnose, risk-stratify, and treat, and often neglected in research projects. We aimed to compare cardiac magnetic resonance (CMR) parameters in NCP versus classic phenotypes (CP) of HCM with special emphasis given to the parameters of established and potential prognostic importance, including numerous variables not used in everyday clinical practice. The CMR studies of 88 patients performed from 2011 to 2019 were postprocessed according to the study protocol to obtain standard and non-standard parameters. In NCP, the late …
Safety and efficacy of left atrial appendage occlusion with the ACP or Watchman device guided by intracardiac echocardiography from the left atrium
2021
Abstract Background There is a paucity of randomized data regarding the safety and efficacy of the use of intracardiac echocardiography (ICE) from the left atrium (LA) to guide left atrial appendage occlusion (LAAO) procedures under local anesthesia using either of the available devices. Hypothesis The aim of this study was to compare the efficacy and safety of ICE from the LA with transesophageal echocardiography (TEE) for guidance during transcatheter LAAO procedures. Methods Single‐center, cohort study of patients undergoing LAAO with the Amplatzer Cardiac Plug or Watchman device. Procedures were guided by ICE from the LA with local anesthesia (n = 175) or TEE under general anesthesia (n…