The Denolin Lecture 1998. Towards measurement of coronary blood flow in patients and its alteration by interventions

Several methods of measuring coronary blood flow in intact conscious man are reviewed, on the basis of personal contributions or the experiences of our teams.

It is important to distinguish between global, regional and transmural blood flow measurements. The advantages and limitations of the following methods are discussed: diffusible inert and radioactive tracers, dye dilution, roentgendensitometry, magnetic resonance imaging and contrast echocardiography. In interventional cardiology it is most important to be able to measure flow through single coronary vessels. Information on coronary artery Doppler velocity during vasodilation and at rest is less useful than the concept of fractional flow reserve. This is based on pressure measurements under maximal vasodilation to ascertain the presence of borderline flow-limiting lesions. This information is necessary in order to decide whether to proceed with angioplasty or not.

The historical design of percutaneous coronary angioplasty and beta-irradiation of coronary restenosis, established under the author's guidance, are put into perspective. The author pays tribute to many excellent colleagues who worked with him at the Zurich and Geneva University Hospitals.