Red cell aggregation in cardiovascular diseases and crucial role of inversion phenomenon.

Perfusion of the heart muscle remains an important area of studies fraught with great difficulties. An analogue of capillary system has been organized by using in vitro flow of blood from the heart patients in a slit-capillary photo-viscometer. The rate of aggregation of red cells and the morphology of aggregates have been observed and quantitated in representative cases. A possible role of the sludge-like aggregates is discussed from the viewpoint of the "inversion phenomenon" which amplifies resistance to flow as a function of rheology (rigidity or deformability) of cell aggregates and single cells. This pattern might be alike that of arterial spasm or can serve as a model for capillary occlusions. A description is given of the new instrument, the slit-capillary photo-viscometer, and stereological parameters obtained in macro- and micro-photography are included. Linear regressions of such parameters against stasis time are highly significant, showing correlation coefficient up to 0.99. These regressions can be compared for slopes and elevations observed in different blood samples, with significance up to 0.001.