The concept of diastolic heart failure has generated a fair amount of controversy, with some authorities questioning whether specific evidence of diastolic dysfunction has been found in patients diagnosed with this condition. Zile and colleagues described findings from diagnostic studies performed on a series of patients diagnosed with diastolic heart failure.
The study authors enrolled 47 patients scheduled for diagnostic cardiac catheterizations who had heart failure and normal left ventricular ejection fractions. These patients were compared with 10 control patients who had no evidence of heart failure but underwent catheterization for the evaluation of chest pain and were found to have normal coronary arteries and systolic function. During cardiac catheterization, a micromanometer was inserted into the left ventricle to measure precisely left ventricular pressures during diastole. Echocardiography was performed on all patients, measuring left ventricular volumes at the beginning and end of diastole. Analysis of pressure and volume values during diastole was used to determine active relaxation and passive stiffness of the left ventricular wall, which are key indicators of diastolic function.
All 47 patients with diastolic heart failure had evidence of abnormal active relaxation, with the minimum diastolic pressure in the left ventricle occurring before the time of complete wall relaxation. All 10 control patients reached minimum diastolic pressure after complete relaxation had occurred. Left ventricular passive stiffness was calculated from measures of pressure and volume at the end of diastole. Increased end-diastolic pressure and decreased end-diastolic volume, which are evidence of abnormally increased passive stiffness, were noted in patients with diastolic heart failure.
The authors conclude that patients diagnosed with diastolic heart failure have consistently demonstrable abnormalities of diastolic function. They argue that “diastolic heart failure” is an appropriate clinical term to describe heart failure in patients with normal ejection fractions and elevated diastolic pressures.