Figure 32-14 Normal arterial blood pressure waveform and its relationship to the electrocardiographic R wave. 1, Systolic upstroke; 2, systolic peak pressure; 3, systolic decline; 4, dicrotic notch; 5, diastolic runoff; 6, end-diastolic pressure. (Redrawn from Mark JB: Atlas of Cardiovascular Monitoring. New York, Churchill Livingstone, 1998, Fig. 8-1.)