A method of visualizing and treating the heart by providing a balloon end contact scope with a main lumen, an essentially transparent contact viewing portion, and integral laser delivery means or other equipment channel suitable for viewing the heart; precisely positioning the contact viewing portion in contact with a portion of the heart adjacent the position to be viewed; and visualizing the heart. The scope may have a gripping surface particularly suitable for percutaneous use. For MIS use, the scope tents the pericardial sac. The method can be used to place a guide wire or tether to the heart to locate a fluoroscopic or other visualization means or to perform additional visualization, fluoroscopic marking or other interventional procedures. The method also comprises the step of delivering laser energy to a portion of the heart to effect transmyocardial revascularization. The method can be performed either by surgically or minimally invasively introducing a balloon end viewing scope into the chest cavity of a patient and through the pericardial sac of the heart to a position between the pericardial sac and the epicardial surface of the heart or by introducing a balloon end viewing scope into the vasculature of a patient, for example at a point on the femoral artery, and into an internal chamber of the heart.