Cardiac contractility is regulated by changes in intracellular Ca concentration ([Ca2+] i).
Normal function requires that [Ca2+] i be sufficiently high in systole and low in diastole …

Normal cardiac function requires that intracellular Ca2+ concentration be reduced to low
levels in diastole so that the ventricle can relax and refill with blood. Heart failure is often …

Atrial fibrillation (AF) is commonly associated with heart failure. A bidirectional relationship
exists between the two—AF exacerbates heart failure causing a significant increase in heart …

Calcium signaling underlies much of physiology. Almost all the Ca2+ in the cytoplasm is
bound to buffers, with typically only∼ 1% being freely ionized at resting levels in most cells …

The SLC8 gene family encoding Na+/Ca2+ exchangers (NCX) belongs to the CaCA
(Ca2+/Cation Antiporter) superfamily. Three mammalian genes (SLC8A1, SLC8A2, and …

In the heart, Ca2+ influx via CaV1. 2 L-type calcium channels (LTCCs) is a multi-functional
signal that triggers muscle contraction, controls action potential duration, and regulates gene …

Changes of intracellular Ca2+ concentration regulate many aspects of cardiac myocyte
function. About 99% of the cytoplasmic calcium in cardiac myocytes is bound to buffers, and …

In mammalian cardiac myocytes, the plasma membrane includes the surface sarcolemma
but also a network of membrane invaginations called transverse (t-) tubules. These …

Rationale: Transverse tubules (t-tubules) regulate cardiac excitation–contraction coupling
and exhibit interchamber and interspecies differences in expression. In cardiac disease, t …

Rationale: The organization of the transverse-tubular (tt) system and relationship to the
sarcoplasmic reticulum (SR) underpins cardiac excitation–contraction coupling. The …