Interpretation of cardiac pathophysiology from pressure waveform analysis: pericardial compressive hemodynamics, Part III.

Failure of right atrial pressure to normalize after pericardial pressure is relieved suggests persistent effusive-constrictive physiology, myocardial failure, or cardiomyopathy which may have indistinguishable hemodynamic pressure waveforms. Clinical characteristics, ancillary testing, and endomyocardial biopsy may be required to obtain a definite diagnosis in such cases. The hemodynamic waveforms obtained during pericardiocentesis provide insight into the pathophysiologic processes, producing symptoms of dyspnea in this interesting patient group.