TECHNIQUES IN THE ANGIOGRAPHIC ANALYSIS OF CORONARY FLOW - PAST, PRESENT, AND FUTURE

The current method of analyzing coronary flow data is the TIMI flow gr ade method. This method is convenient and easy to apply, but there are limitations to this categorical method of analyzing coronary artery f low. We have developed a new method of analyzing analyzing coronary bl ood flow called the ''TIMI frame count.'' Using the TIMI frame countin g method, we have shown that the flow in the coronary arteries is in f act distributed as a continuous variable and that there are nondiscret e categories of slow and fast flow. This article discusses the statist ical basis for the development of this new, simple, and continuous ind ex of coronary Pow and provides a ''how-to manual'' describing the pra ctical implementation of the new TIMI frame count method. We also desc ribe simple new techniques for measuring the distance to the landmark used for TIMI frame counting. Knowing the distance and the time from t he TIMI frame count, velocity can easily be calculated. Tables are pro vided that can be used for these calculations on-line in the cardiac c atheterization laboratory. If the diameter is known, flow can also be calculated from these tables. We also describe new applications of mar ker wires to measure distance and velocity.