Patent ID: 8617150

Claim:
A method comprising: advancing, into a heart chamber of a subject, an ultrasound tool that includes at least one ultrasound transducer; providing a reflective region at an extramyocardial site of the subject; and activating the ultrasound transducer to ablate myocardial tissue by applying ultrasound energy to the myocardial tissue such that at least a portion of the transmitted energy is reflected by the reflective region onto the myocardial tissue of the subject, wherein the extramyocardial site is within a pericardial region of the subject that consists of one or more regions selected from the group consisting of: a region between a pericardium of a heart of the subject and a myocardium of the heart, a region between a visceral pericardium of the heart and a parietal pericardium of the heart, and a region outside the pericardium and in contact therewith, and wherein providing the reflective region comprises providing the reflective region within the pericardial region.