Changes in diastolic stiffness and tone of the left ventricle during angina pectoris.

Reported elevations of left ventricular filling pressures during angina suggest increased myocardial stiffness. Both left ventricular beginningand end-diastolic pressures and volumes were measured in seven patients before, during, and after angina induced by atrial pacing. During nine episodes of angina, mean end-diastolic pressure rose from 12 to 29 mm Hg and ejection fraction fell from 0.47 to 0.37. Logarithms of beginning and end-diastolic pressures were plotted against the corresponding volumes for each angiogram. During angina, there was a marked in-