Browsing by Subject "Heart Atria"

Now showing 1 - 4 of 4
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    Contrast in intracardiac acoustic radiation force impulse images of radiofrequency ablation lesions.
    (Ultrason Imaging, 2014-04) Eyerly, Stephanie A; Bahnson, Tristram D; Koontz, Jason I; Bradway, David P; Dumont, Douglas M; Trahey, Gregg E; Wolf, Patrick D
    We have previously shown that intracardiac acoustic radiation force impulse (ARFI) imaging visualizes tissue stiffness changes caused by radiofrequency ablation (RFA). The objectives of this in vivo study were to (1) quantify measured ARFI-induced displacements in RFA lesion and unablated myocardium and (2) calculate the lesion contrast (C) and contrast-to-noise ratio (CNR) in two-dimensional ARFI and conventional intracardiac echo images. In eight canine subjects, an ARFI imaging-electroanatomical mapping system was used to map right atrial ablation lesion sites and guide the acquisition of ARFI images at these sites before and after ablation. Readers of the ARFI images identified lesion sites with high sensitivity (90.2%) and specificity (94.3%) and the average measured ARFI-induced displacements were higher at unablated sites (11.23 ± 1.71 µm) than at ablated sites (6.06 ± 0.94 µm). The average lesion C (0.29 ± 0.33) and CNR (1.83 ± 1.75) were significantly higher for ARFI images than for spatially registered conventional B-mode images (C = -0.03 ± 0.28, CNR = 0.74 ± 0.68).
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    Intrapulmonary shunt confirmed by intracardiac echocardiography in the diagnosis of hepatopulmonary syndrome.
    (Hepatology, 2013-10) Khabbaza, Joseph E; Krasuski, Richard A; Tonelli, Adriano R
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    STIM1-Ca2+ signaling in coronary sinus cardiomyocytes contributes to interatrial conduction.
    (Cell calcium, 2020-05) Zhang, Hengtao; Bryson, Victoria; Luo, Nancy; Sun, Albert Y; Rosenberg, Paul
    Pacemaker action potentials emerge from the sinoatrial node (SAN) and rapidly propagate through the atria to the AV node via preferential conduction pathways, including one associated with the coronary sinus. However, few distinguishing features of these tracts are known. Identifying specific molecular markers to distinguish among these conduction pathways will have important implications for understanding atrial conduction and atrial arrhythmogenesis. Using a Stim1 reporter mouse, we discovered stromal interaction molecule 1 (STIM1)-expressing coronary sinus cardiomyocytes (CSC)s in a tract from the SAN to the coronary sinus. Our studies here establish that STIM1 is a molecular marker of CSCs and we propose a role for STIM1-CSCs in interatrial conduction. Deletion of Stim1 from the CSCs slowed interatrial conduction and increased susceptibility to atrial arrhythmias. Store-operated Ca2+ currents (Isoc) in response to Ca2+ store depletion were markedly reduced in CSCs and their action potentials showed electrical remodeling. Our studies identify STIM1 as a molecular marker for a coronary sinus interatrial conduction pathway. We propose a role for SOCE in Ca2+ signaling of CSCs and implicate STIM1 in atrial arrhythmogenesis.
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    Treatment-Related Changes in Left Atrial Structure in Atrial Fibrillation: Findings From the CABANA Imaging Substudy.
    (Circulation. Arrhythmia and electrophysiology, 2021-05) Rettmann, Maryam E; Holmes, David R; Monahan, Kristi H; Breen, Jerome F; Bahnson, Tristram D; Mark, Daniel B; Poole, Jeanne E; Ellis, Alicia M; Silverstein, Adam P; Al-Khalidi, Hussein R; Lee, Kerry L; Robb, Richard A; Packer, Douglas L; CABANA Imaging Investigators
    [Figure: see text].