During the last years the echocardiography was approved as the most useful method for analysis of the diastolic left ventricular (LV) function in routine practice. However, for an assessment of the tau constant of isovolumic LV relaxation, the mural stresses and the diastolic myocardial stiffness (requiring a LV pressure measurement), the direct invasive evaluation remains a “gold standard”. Moreover, no universal method is available for a complete analysis of the diastolic LV function. An invasive method for a complex quantitative assessment of the different phases of the LV diastole, including authentic elaborations of the authors, has been presented in this monograph. Using this method, the extent of the diastolic dysfunction has been evaluated in patients with a chronic forms of ischaemic heart disease: with and without LV hypertrophy in stable angina, with a preserved and reduced global ejection fraction after a myocardial infarction. The monograph is mainly directed to post-graduate students of cardiology – to expand their knowledge and practical capabilities for research, study and assessment of the LV diastolic function, and also for invasive and clinical cardiologists.