Coronary flow reserve : a functional measure of stenosis severity

In 1959 Sones developed selective coronary cineangiography. To date, this technique has remained the only means available for the visualization of the coronary arterial system with such image contrast and resolution, that the presence and severity of coronary stenosis can be determined with sufficient accuracy. Consequently, coronary cineangiography has become the most important tool for clinical decision making, used by the physician caring for patients with coronary artery disease. However, of prime concern has been the relationship between the angiographic severity of the stenosis and the resulting reduction or limitation in coronary blood flow. The concept of coronary flow reserve has been developed as a means to describe the functional capacity of a coronary artery. Several techniques are currently under development to make the assessment of coronary flow reserve possible in awake humans. This thesis describes a radiographic technique to measure coronary flow reserve, that can be applied during routine diagnostic or interventional cardiac catheterization. Several methodological aspects on which no previous data existed, such as the role of pharmacological coronary vasodilation, radiographic data acquisition and digital data processing as well as application of this technique in several clinical conditions have been studied.