Spatial heterogeneity of calcium transient alternans during the early phase of myocardial ischemia in the blood-perfused rabbit heart

被引:99
作者
Qian, YW
Clusin, WT
Lin, SF
Han, J
Sung, RJ
机构
[1] Stanford Univ, Sch Med, Div Cardiovasc, Stanford, CA 94305 USA
[2] Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA
关键词
calcium; myocardium; ischemia; fluorescence; arrhythmias;
D O I
10.1161/hc4201.097136
中图分类号
R5 [内科学];
学科分类号
1002 ; 100201 ;
摘要
Background-Optical mapping of cytosolic calcium transients in intact mammalian hearts is now possible using long-wavelength [Ca2+](i) indicators. We propose that beat-to-beat [Ca2+](i) transient alternans during ischemia may lead to spatial and temporal heterogeneity of calcium-activated membrane currents. Methods and Results-To test this hypothesis, isolated rabbit hearts were loaded with the fluorescent [Ca2+](i) indicator, rhod-2 AM, and imaged at 300 frames/sec during blood-perfused ischemic trials. High-quality [Ca2+](i) transients were recorded in each of 8 hearts. [Ca2+](i) transient alternans was never present in control records but occurred in each of the hearts during ischemia, with onset after 2 to 4 minutes. Alternans was confined to circumscribed regions of the heart surface 5 to 15 mm across. Multiple regions of alternans were found in most hearts, and regions that were out of phase with one another were found in 6 hearts. Quantitative maps of alternans were constructed by calculating an alternans ratio. This ratio behaved as a continuous variable that reached a maximum value in the center of the regions with alternans. Conclusions-These results demonstrate marked spatial heterogeneity of the [Ca2+](i) transient during the early phase of ischemia, which could produce electrical instability and arrhythmias in large mammalian hearts.
引用
收藏
页码:2082 / 2087
页数:6
相关论文
共 16 条
  • [11] INACTIVATION OF CALCIUM CHANNELS IN MAMMALIAN HEART-CELLS - JOINT DEPENDENCE ON MEMBRANE-POTENTIAL AND INTRACELLULAR CALCIUM
    LEE, KS
    MARBAN, E
    TSIEN, RW
    [J]. JOURNAL OF PHYSIOLOGY-LONDON, 1985, 364 (JUL): : 395 - 411
  • [12] Panoramic optical imaging of electrical propagation in isolated heart
    Lin, SF
    Wikswo, JP
    [J]. JOURNAL OF BIOMEDICAL OPTICS, 1999, 4 (02) : 200 - 207
  • [13] MITANI A, 1994, J NEUROCHEM, V62, P626
  • [14] Ca2+ waves during triggered propagated contractions in intact trabeculae
    Miura, M
    Boyden, PA
    ter Keurs, HEDJ
    [J]. AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY, 1998, 274 (01): : H266 - H276
  • [15] EFFECTS OF ISCHEMIA AND HYPERCARBIC ACIDOSIS ON MYOCYTE CALCIUM TRANSIENTS, CONTRACTION, AND PHI IN PERFUSED RABBIT HEARTS
    MOHABIR, R
    LEE, HC
    KURZ, RW
    CLUSIN, WT
    [J]. CIRCULATION RESEARCH, 1991, 69 (06) : 1525 - 1537
  • [16] Wu Yiming, 1997, American Journal of Physiology, V273, pH2161