Ca2+ signaling in the working heart

The video sequence is taken from a heart beating spontaneously in an anesthetized, ventilated mouse. The left atrium is seen at top and the left ventricle is at lower right. The sequence was obtained at 128 Hz with an Andor iXon camera attached to a Leica MSFLIII microscope.

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High speed imaging of cardiac activation

High speed Ca2+ imaging in the isolated, perfused heart. A single spontaneous cardiac activation cycle is shown highlighting atrial and ventricular wave conduction and the atrioventricular delay. The images were obtained at 1 kHz with a Micam Ultima camera coupled to a macrolens pair.

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The atrioventricular canal creates the atrioventricular delay

Activation of the embryonic day 10.5 heart. The superfused heart beats spontaneously and is imaged from the dorsal surface at 67 Hz. Note the slowed conduction through the atrioventricular canal and the direct movement of the activation wave from common atrium to common ventricle. Images obtained with an Andor iXon camera attached to a Leica MSFLIII microscope.

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Functional maturation of the A-V node

Activation of the embryonic day 13.5 day heart. Imaging conditions are as in Video 3. Note termination of the activation wave at atrioventricular border and emergence of the activation wave at the ventricle apex, indicating the functional maturation of the A-V node and the loss of the atrioventricular canal conduction pathway.