• diastole
• left ventricular function
• heart failure
• systole

The concept of “diastolic” heart failure grew out of the observation that many patients who had the symptoms and signs of heart failure had an apparently normal left ventricular (LV) ejection fraction (> 0.45). Thus it was assumed that since systolic function was “preserved” the problem must lie in diastole, although it is not clear by whom or when this assumption was made. Nevertheless, many guidelines followed on how to diagnose “diastolic” heart failure backed up by indicators of diastolic dysfunction derived from Doppler echocardiography,^1–3 and it was found to be common.⁴ This edifice is, however, built on a number of assumptions that are looking increasingly shaky. For example, is the ejection fraction a good index of LV systolic function? Can diastolic function or dysfunction be measured accurately? And in any case can systole be separated so neatly from diastole?