Does prolonged mechanical unloading reduce myofilament sensitivity to calcium and sarcoplasmic reticulum calcium uptake leading to contractile dysfunction?
Prolonged myocardial unloading causes depressed contractility due to reduced SR Ca(2+) uptake and myofilament sensitivity to Ca(2+). These effects may be relevant with regard to myocardial performance after prolonged LVAD support.
Our results propose a new mechanism which could contribute to HAM/TSP pathogenesis.