Calcium Signalling During Acute Myocardial Ischemia: New insights From Optical Mapping Techniques

摘要

Summary. Acute myocardial ischemia leads to an increase in the systolic and diastolic levels of the intracellular calcium transient during the first few minutes. This overall increase is associated with beat-to-beat fluctations in the peak and trough levels of the transients-calcium transient alternans. New advances in fluorescence imaging techniques have allowed the spatial distribution of calcium transient alternans to be studied during ischemia, and to be correlated with similar imaging of the cardiac action potential. These studies provide further evidence that alternans phenomena are responsible for the genesis of ventricular fibrillation during acute ischemia, and suggest specific molecular mechanisms that could be involved.