Ratiology and a Complementary Class of Metrics for Cardiovascular Investigations

Abstract

Cardiovascular investigations often involve ratio-based metrics or differences:ejection fraction, arterial pressure augmentation index, coronary fractional flowreserve, pulse pressure. Focusing on a single number (ratio or difference)implies that information is lost. The lost companions constitute a well-definedbut thus far unrecognized class, having additive value, a physical dimension,and often a physiological meaning. Physiologists should play a prominent rolein exploring these complementary avenues and also define alternatives.