Extent of agreement between two methods for estimating acute directional changes of cardiac stroke index.

Cardiovascular physiologists frequently infer directional changes in cardiac stroke volume and cardiac output from changes in aortic pulse pressure and atrial pressure. Errors are probably not infrequent. The Hamilton and Remington pressure pulse contour method can also indicate directional fluctuations in cardiac stroke volume. Comparison of the results of the two methods of analysis in situations where cardiac stroke index was changed acutely revealed good correspondence of indicated changes under conditions of simple alterations in venous return, but poor correspondence under more complex conditions such as after injections of pressor amines.