Abstract: Angiotensin II receptor antagonists are useful for decreasing QT dispersion or inhibiting the progression of QT prolongation in patients. Also disclosed is a method for monitoring the reduction in die risk of experiencing an adverse cardiac event, such as sudden cardiac death, myocardial infarction or arrhythmias, using QT dispersion in patients treated with a therapeutically effective amount of an angiotensin II antagonist.

Abstract: A method for inhibiting smooth muscle cell proliferation in an injured blood vessel includes the steps of administering a photoactivatable psoralen to a patient in an amount to achieve local arterial tissue levels of psoralen suitable for light-dependent inhibition of smooth muscle cell growth, and delivering radiation in the visible wavelength range to the injured region of the blood vessel at a level sufficient for photoactivation of the psoralen. The psoralen is preferably 8-methoxypsoralen and can be delivered systemically or locally. The method of the invention can be used for preventing restenosis in a blood vessel following transluminal angioplasty. Both the psoralen and the visible light can be delivered with a laser balloon catheter having a porous balloon. The method of the invention may also be used for inhibiting proliferation of other undesired cell types in a patient's body.

Abstract: A method for inhibiting smooth muscle cell proliferation in an injured blood vessel includes the steps of administering a photoactivatable psoralen to a patient in an amount to achieve local arterial tissue levels of psoralen suitable for light-dependent inhibition of smooth muscle cell growth, and delivering radiation in the visible wavelength range to the injured region of the blood vessel at a level sufficient for photoactivation of the psoralen. The psoralen is preferably 8-methoxypsoralen and can be delivered systemically or locally. The method of the invention can be used for preventing restenosis in a blood vessel following transluminal angioplasty. Both the psoralen and the visible light can be delivered with a laser balloon catheter having a porous balloon. The method of the invention may also be used for inhibiting proliferation of other undesired cell types in a patient's body.

Abstract: Methods are provided for laser induced fluorescence intensity feedback and control during laser angioplasty. In a first aspect of the invention, a catheter including an eccentric guidewire lumen and at least one optical fiber is positioned relative to an obstruction in a blood vessel by rotating the catheter and monitoring the fluorescence intensity. When the fluorescence intensity has a maximum value, the optical fiber is aligned with the obstruction. In another aspect of the invention, fluorescence intensity feedback is used to determine when a laser ablation device has crossed an occlusion. An abrupt drop in fluorescence intensity indicates that the ablation device has crossed the occlusion. In a further aspect of the invention, fluorescence intensity feedback is used to determine the effectiveness of fluid flushing in a blood vessel.

Abstract: A method of detecting pre-malignant lesions in the gastrointestinal tract comprises positioning an opitcal fiber in a patient's gastrointestinal tract and transmitting ultraviolet laser light through said optical fiber means to cause the tissue of the gastrointestinal tract illuminated by the laser to fluoresce in the near visible band of frequencies. The fluorescence spectrum is returned through the optical fiber to a spectrum analyzing means which analyzes the spectrum in the wavelength range of 350 to 700 nm to determine whether the tissue caused to fluoresce is pre-malignant. Tissue so diagnosed may be ablated by a high power laser using the same fiberoptic system.

Abstract: A process and apparatus for ablating atherosclerotic or tumorous tissues is disclosed. Optical fibers direct low power light energy at a section of tissue to be ablated to cause the section to fluoresce. The fluorescence pattern is analyzed to determine whether the fluorescence frequency spectrum is representative of normal or abnormal tissue. A source of high power ultraviolet laser energy directed through an optical fiber at the section of tissue is fired only when the fluorometric analysis indicates that it is directed at abnormal tissue.