Figure 32-19 Beat-to-beat variability in arterial pressure waveform morphologies. A, Pulsus alternans. B, Pulsus paradoxus. The marked decline in systolic arterial pressure and pulse pressure during spontaneous inspiration (arrows) is characteristic of this condition. (Redrawn from Mark JB: Atlas of Cardiovascular Monitoring. New York, Churchill Livingstone, 1998, Fig. 18-10.)