Photomedicine is beginning to have a broad impact in the diagnosis and treatment of cardiovascular diseases. Laser angioplasty is now an FDA treatment for removal of atherosclerotic lesions within the cardiovascular system. Improved understanding of the secondary photoacoustic effects of excimer laser angioplasty has led to a marked improvement in efficiency with reduced vascular injury. The concept of selective photothermolysis, based on short pulsed lasers and preferential absorption by hemoglobin, is now being used in clinic trials for the removal of thrombi in coronary arteries causing myocardial infarction, thrombi occluding coronary bypass grafts. Laser thrombolysis is also being investigated for the potential treatment of stroke. A broad range of pharmacologic agents activated by light, thus far being used for photodynamic therapy of cancer, are being investigated for prevention of atherosclerosis following vascular surgery or angioplasty.
Transmyocardial laser revascularization involves the use of CO2 or holmium lasers to create holes in the myoardium to reduce anginal syndromes recacitrant to conventional therapy and is now being investigated in large world-wide clinical trials. Unfortunately, the understanding of photobiology underlying this potential therapy is far behind the investigative effort in clinical trials. Voltage sensitive dyes are being used to investigate the etiology and pathophysiology of malignant dysrhythmia. A real time study of action potentials as they progress through the myocardium in and around ischemic or other pathologic zones is for the first time being elucidated using basic concepts in photobiology. Reconstruction of arterial walls is being investigated using dye targeted laser fusion of biomaterial to repair damaged arteries. Practical use photobiological concepts and technology is proving to have an important impact in a broad spectrum of cardiovascular treatments and diagnostics.
Gregory KW, Novel Cardiovascular Applications in Photobiology and Photomedicine. Photobiology and Photomedicine 63:1045,1996