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 beginning- and 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 increase in beginning as well as end-diastolic stiffness of the ventricle. These changes, which were reversible with resolution of angina, may be due to sustained contraction or failure of relaxation of a portion of the left ventricular myocardium during angina pectoris.