Figure 6.

Random Subcellular Ca²⁺ oscillations during ventricular arrhythmia. Disorganized subcellular Ca²⁺ dynamics is occasionally observed under LQT2 conditions, with multiple Ca²⁺ wavefronts which collide, break and annihilate each other (bottom, 1–5). Ca²⁺ signal tracings (top right) from 3 pixels indicated in high-resolution image (top left, 150×150 μm² image size) illustrate the lack of spatial synchrony. Stable Ca²⁺ baseline is not reached in any cell in the field-of-view, and the signals from different regions of the same cell are poorly correlated. This may reflect an extreme degree of cellular Ca²⁺ overload. See also Movie G.