Objective: To test the hypothesis that, when measured in the long axis, left ventricular systolic function is abnormal in patients with diastolic heart failure. Design: A case-control study. Setting: University teaching hospital (tertiary referral centre). Patients: 68 patients with heart failure, 29 with a left ventricular ejection fraction (LVEF) of > 0.45 and diastolic dysfunction (diastolic heart failure), 39 with an LVEF of < 0.45 (systolic heart failure), and 105 normal subjects, including 33 age matched controls. Methods: LVEF was measured by cross sectional Simpson's method, and mitral annular amplitudes and velocities by M mode and tissue Doppler echocardiography, respectively, along with mitral Doppler inflow velocities. Results were compared between the three groups. Main outcome measures: Peak systolic mitral annular velocity and amplitude between the different groups. Results: The mitral annular peak mean velocity and amplitude in systole were lower in the patients with diastolic heart failure (mean (SEM), 4.8 (0.2) cm/s) than in the age matched normal controls (6.1 (0.14) cm/s), but higher than those with systolic heart failure (2.8 (0.13) cm/s) (all p < 0.001). Similar changes were seen the mitral annular amplitude during systole. Peak early diastolic velocity and amplitude were also significantly reduced in the group with diastolic heart failure. Left ventricular hypertrophy was evident in over 95% patients in both diastolic and systolic heart failure groups, with a comparable left ventricular mass index. Conclusions: In patients with diastolic heart failure and evidence of left ventricular hypertrophy, there is systolic left ventricular impairment as measured by myocardial Doppler imaging of the longitudinal axis. Thus subtle abnormalities of systolic function are present in patients with heart failure and a normal left ventricular ejection fraction, and there appears to be a continuum of systolic function between those with truly normal, mildly impaired (labelled diastolic heart failure), and obviously abnormal left ventricular systolic function. Isolated diastolic dysfunction is uncommon.H eart failure with a normal left ventricular ejection fraction is usually called "diastolic heart failure" if there are no other obvious causes. In some parts of the world, so called diastolic heart failure may be more common than systolic heart failure in patients presenting with heart failure symptoms. 1 The distinction between the two states is based upon the measurement of left ventricular ejection fraction (LVEF), usually by echocardiography. In patients with a normal or nearly normal LVEF it is assumed that as there is "preserved systolic function" the primary disorder is diastolic. Although LVEF assesses global function, it is a relatively crude measure of left ventricular systolic function. Measurement of the ventricular long axis velocities and amplitude using tissue Doppler and M mode imaging of the mitral annulus is thought to provide a more sensitive index of systolic function than LVEF. 2 Using t...