disclosed is a “ tracker system ” that includes implanted electrical leads which are part of an implanted cardiotracker plus external equipment that includes external alarm means and a physician &# 39 ; s programmer . the tracker system is designed to monitor the degradation of a patient &# 39 ; s cardiovascular condition from one or more causes . these causes include the rejection of a transplanted heart and / or the progression of a stenosis in a coronary artery . as one or more stenoses in a coronary artery become progressively more narrow thereby causing reduced blood flow to the heart muscle coronary circulation , the tracker system can alert the patient by either or both internal and / or external alarm means to take the appropriate medical action . the physician &# 39 ; s programmer can be used to display histograms of key heart signal parameters that are indicative of the patient &# 39 ; s cardiovascular condition .