Myocardial cell membrane electrochemical gradient

The myocardial cell membrane electrochemical gradient is the potential energy stored in the form of concentration and electrical differences of ions—primarily sodium (Na+), potassium (K+), and calcium (Ca2+)—across the sarcolemma (StatPearls, "Physiology, Cardiac Action Potential"). This gradient is established and maintained by the active transport of ions via the Na+/K+-ATPase pump and the selective permeability of various ion channels (CVPhysiology, "Membrane Potential"). It serves as the fundamental biophysical driver for the cardiac action potential, which is essential for the rhythmic contraction and relaxation of the heart (NIH, "Ion Channels in the Heart"). In pathological conditions such as myocardial ischemia or heart failure, the gradient can be disrupted due to ATP depletion or channel dysfunction, leading to life-threatening arrhythmias (PubMed, PMID: 15607383). While the gradient itself is a physiological state rather than a single molecular target, it is the primary parameter modulated by antiarrhythmic drugs and cardiac glycosides. These drugs act on the underlying ion channels and transporters to restore electrical stability and prevent abnormal impulse generation (StatPearls, "Antiarrhythmic Medications"). Consequently, maintaining this gradient is a central goal in the management of cardiovascular diseases.

Other names

Resting membrane potentialTransmembrane electrochemical potentialCardiac membrane potential

Drugs modulate the electrochemical gradient by inhibiting or activating specific ion channels (sodium, potassium, calcium) or active transporters (Na+/K+-ATPase) to alter the rate of depolarization, repolarization, or the resting potential (StatPearls, 2023).