Impaired relaxation and elevated intracellular Ca2+ in contracting myocardium of hypertensive heart disease and HFpEF
Contributor: Steven Stroud
Relaxing can be hard in hypertensive heart disease (HHD). Specifically, for the stiff ventricle destined for HFpEF. Is it a problem with relaxation of myocytes, or is it due to stiffening from fibrosis?
Entry of Ca2+ into the myocyte begins a flood of stored Ca2+, stimulating contraction. The cell can relax only when this Ca2+ is taken away from the contractile apparatus. Along with SERCA and phospholamban, the sarcolemmal Na+/Ca2+ exchanger (NCX) handles this important duty.