Figure 32-39 Severe mitral regurgitation. A tall systolic v wave (v) is inscribed in the pulmonary artery wedge pressure (PAWP) trace and also distorts the pulmonary artery pressure (PAP) trace, thus giving it a bifid appearance. The electrocardiogram (ECG) is abnormal because of ventricular pacing. Left ventricular end-diastolic pressure is estimated best by measuring PAWP at the time of the electrocardiographic R wave, before onset of the regurgitant v wave. Note that mean PAWP exceeds left ventricular end-diastolic pressure in this condition. (Redrawn from Mark JB: Atlas of Cardiovascular Monitoring. New York, Churchill Livingstone, 1998, Fig. 17-11.)