We present a case of an 83-year-old female with past medical history of rheumatic fever associated mitral stenosis for which she underwent mitral commissurotomy 25 years prior to presentation. Subsequently, she underwent coronary artery bypass grafting and mitral valve replacement with a bio-prosthetic valve 8 years prior to presentation. Presently, she started experiencing worsening dyspnea and heart failure symptoms. Echocardiography showed mildly reduced left ventricular ejection fraction with severe aortic stenosis and pulmonary hypertension. The bioprosthetic mitral valve was functioning normally. We performed right and left heart catheterization for evaluation. Peak aortic gradient was 50 mm Hg with a mean gradient of 39 mm Hg. Aortic valve area was calculated to be 0.31 cm(2). However, simultaneous measurement of left ventricular and wedge pressures showed a significant gradient of 11 mm Hg across the mitral valve with a calculated mitral valve area of 0.4 cm(2). Because of discordant information between echocardiographic and hemodynamic data, we proceeded with trans-septal puncture to directly measure left atrial pressures. Simultaneous left atrial and left ventricular pressure measurement demonstrated a mean gradient of 4 mm Hg across the mitral valve with an area calculated at 1.9 cm(2). We review the tracings in detail and discuss the pitfalls of using pulmonary capillary wedge pressure as a surrogate for left atrial pressure.