an imaging element characterizes tissue morphology by analyzing perfusion patterns of a contrast media in tissue visualized by the imaging element , to identify infarcted tissue . in a preferred implementation , a catheter tube introduced into a heart region carries the imaging element , as well as a support structure spaced from the imaging element , which contacts endocardial tissue . the imaging element is moved as the imaging element visualizes tissue . a selected electrical event is sensed in surrounding myocardial tissue , which regulates movement of the imaging element . the support element stabilizes the moving imaging element as it visualizes tissue , providing resistance to dislodgment or disorientation despite the presence of dynamic forces .