Balance of blood pressure equivalents as a new quantitative scale for identifying cardiac versus vascular reactor: Comparisons with Gregg, Matyas and James' (2002) hemodynamic profile scale

Abstract:  A quantitative scale for identifying cardiac versus vascular reactor, balance of blood pressure equivalents ( BE ), was newly advocated and compared with a very recently advocated one, hemodynamic profile ( HP ), by Gregg, Matyas and James (2002). BE was defined as " (Δ Q/Q ₀) P ₀'  − ( Δ R/R ₀ )P ₀." Here, P ₀ , Q ₀, and R ₀ were mean blood pressure ( P ), cardiac output ( Q ), and total peripheral resistance ( R ) during baseline, and Δ Q and Δ R were the difference scores of Q and R from baseline to stress, respectively. This was named as BE because the two terms in the formula indicated changes in Q and R in their blood pressure equivalents. Comparisons of the BE and HP scales were carried out, theoretically, in a newly introduced pressor space, on orthogonality with the extent of elevation of P (Δ P ); and then, practically, by using hypothetical data. In summary, it was shown that data points in the neighborhood in the pressor space can be judged as having not so different hemodynamic balance whether the BE or HP scale was used. As a merit, the BE scale seemed helpful to an intuitive understanding of the hemodynamics during stress. As a demerit, it cannot maintain the quasi-orthogonal relationship with Δ P when Q or R changes profoundly in the face of stress.