is closely related as both are due to vascular disease in older males. Both erect penis and heart pumping need good blood supply, in a state of vascular disease
like atherosclerosis these functions are largely affected. Blood vessels taking blood to penis are smaller than heart vessels so usually penile erection is affected before than heart pumping. As heart function is important for survival, so evaluation for heart function is suggested in those older males ( 50 years or above ) who develop erectile dysfunction.