Background: Noninvasive assessment of diastolic filling by Doppler echocardiography provides important information about left ventricular (LV) status in selected subsets of patients. This study was designed to assess whether the lateral mitral annular velocity as assessed by tissue Doppler imaging is associated with invasive measures of diastolic LV performance in patients with diastolic and systolic heart failure. Aim of the study was to compare the diagnostic accuracy of lateral mitral annular E/E′ as an estimate of LV filling pressure with invasive LVEDP measurement in subjects with systolic or purely diastolic heart failure.Methods: Total 100 patients were studied, 50 patients with diastolic heart failure and 50 patients with systolic heart failure in patients undergoing diagnostic coronary angiogram. Detailed 2D Echocardiography, Trans mitral Doppler and Tissue Doppler velocities of lateral mitral annulus was obtained. The ratio of peak mitral velocity (E) to lateral mitral annular velocity (E′) by TDI (E/E′) was calculated.Results: The ratio of E/E′ in diastolic group was 13.4±4.9 and in systolic group it was 13.7±5.2. The mean LVEDP in diastolic heart failure patients was 14.3±4.5 and 14.2±4.9 in systolic heart failure patients. The ratio of E/E′ showed a better correlation with LVEDP. E/E′ <8 accurately predicted normal LVEDP, and E/E′ >15 identified increased LVEDP ≥15mmHg.Conclusions: E/E′ is a reliable estimate of LV filling pressures in subjects with systolic and diastolic heart failure. In subjects with diastolic heart failure, E/E′ seems helpful to identify those with truly elevated LV filling pressures. In patients with diastolic heart failure and normal E/E′, a search for other causes of symptoms (pulmonary disease, obesity and so forth) may be warranted.