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  • 1
    Electronic Resource
    Electronic Resource
    Patterns of spiral tip motion in cardiac tissues (1998)
    Woodbury, NY : American Institute of Physics (AIP)
    Chaos 8 (1998), S. 137-148 
    Details
    ISSN: 1089-7682
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In support of the spiral wave theory of reentry, simulation studies and animal models have been utilized to show various patterns of spiral wave tip motion such as meandering and drifting. However, the demonstration of these or any other patterns in cardiac tissues have been limited. Whether such patterns of spiral tip motion are commonly observed in fibrillating cardiac tissues is unknown, and whether such patterns form the basis of ventricular tachycardia or fibrillation remain debatable. Using a computerized dynamic activation display, 108 episodes of atrial and ventricular tachycardia and fibrillation in isolated and intact canine cardiac tissues, as well as in vitro swine and myopathic human cardiac tissues, were analyzed for patterns of nonstationary, spiral wave tip motion. Among them, 46 episodes were from normal animal myocardium without pharmacological perturbations, 50 samples were from normal animal myocardium, either treated with drugs or had chemical ablation of the subendocardium, and 12 samples were from diseased human hearts. Among the total episodes, 11 of them had obvious nonstationary spiral tip motion with a life span of 〉2 cycles and with consecutive reentrant paths distinct from each other. Four patterns were observed: (1) meandering with an inward petal flower in 2; (2) meandering with outward petals in 5; (3) irregularly concentric in 3 (core moving about a common center); and (4) drift in 1 (linear core movement). The life span of a single nonstationary spiral wave lasted no more than 7 complete cycles with a mean of 4.6±4.3, and a median of 4.5 cycles in our samples. Conclusion: (1) Patently evident nonstationary spiral waves with long life spans were uncommon in our sample of mostly normal cardiac tissues, thus making a single meandering spiral wave an unlikely major mechanism of fibrillation in normal ventricular myocardium. (2) A tendency toward four patterns of nonstationary spiral tip motion was observed. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.166294
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  • 2
    Electronic Resource
    Electronic Resource
    Mesenchymal Stem Cell Injection Induces Cardiac Nerve Sprouting and Increased Tenascin Expression in a Swine Model of Myocardial Infarction (2003)
    350 Main Street , Malden , MA 02148-5018 , USA , and 9600 Garsington Road , Oxford OX4 2DQ , UK . : Blackwell Science Inc
    Journal of cardiovascular electrophysiology 14 (2003), S. 0 
    Details
    ISSN: 1540-8167
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Introduction: Mesenchymal stem cell (MSC) transplantation is a promising technique to improve cardiac function. Whether MSC can increase cardiac nerve density and contribute to the improved cardiac function is unclear. Methods and Results: Anterior wall myocardial infarction was created in 16 swine. One month later, 6 swine were given MSC and fresh bone marrow (BM) into infarcted myocardium (MSC group). Four swine were given fresh BM only (BM group), and 6 swine were given culture media (MI-only group). The swine were sacrificed 95.8 ± 3.5 days after MI. Six normal swine were used as control. Immunocytochemical staining was performed using antibodies against growth-associated protein 43 (GAP43), tyrosine hydroxylase (TH), and three subtypes of tenascin (R, C, and X). Five fields per slide were counted for nerve density. The results show the following. (1) There were more GAP43-positive nerves in the MSC group than in the BM, MI-only, or Control group (P 〈 0.0001). TH staining showed higher nerve densities in the MSC group than in the MI-only (P 〈 0.01) or Control group (P 〈 0.0001) in the atria. (2) There were more sympathetic (TH-positive) nerves in myocardium distant from infarct than in the peri-infarct area (P 〈 0.05). (3) Optical intensity and color analyses showed significantly higher tenascin R and tenascin C expression in the MSC and BM groups than in the MI-only or Control group (P 〈 0.01). Conclusion: MSC injected with BM into swine infarct results in overexpression of cardiac tenascin, increased the magnitude of cardiac nerve sprouting in both atria and ventricles, and increased the magnitude of atrial sympathetic hyperinnervation 2 months after injection. (J Cardiovasc Electrophysiol, Vol. 14, pp. 841-848, August 2003)
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1540-8167.2003.03124.x
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  • 3
    Electronic Resource
    Electronic Resource
    Marshall Bundle and the Valve of Vieussens (2003)
    350 Main Street , Malden , MA 02148-5018 , USA , and 9600 Garsington Road , Oxford OX4 2DQ , UK . : Blackwell Science Inc
    Journal of cardiovascular electrophysiology 14 (2003), S. 0 
    Details
    ISSN: 1540-8167
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1540-8167.2003.03245.x
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