Detrol and lightheaded

My mother has a prolapsed mitral valve and occassional heart palpatations. She is usually not bothered with this. After taking a weeks sample dose of Detrol LA, she began to feel lightheaded, dizziness, buzzing in her head, and severe heart palpatations and shortness of breath. She called the ambulance and was taken to the emergency room and examined. After bloodwork and an EKG showed no physical problems she was released. She has since stopped the Detrol LA and the symptoms have subsided.