COMPARISON OF DIASTOLIC PARAMETERS BETWEEN SUPINE POSTURE AND SITTING POSITION ZAHRAA ALSAFI Alsafi Z. Comparison of diastolic parameters between supine posture and sitting position. Degree Project, 15 Credit Points. Biomedical Laboratory Science, Malmö University: Health and Society, Department of Biomedical Laboratory Science, 2010. Changes in body position entails changes in cardiac diastolic function. Studies have shown that diastolic parameters are higher at supine posture in comparison with for example upright posture. The studies were made using non-invasive techniques performed by echocardiography. The change in the diastolic function arises because of variations in preload and filling pressures when changed body position. The purpose of this study was to measure the heart's diastolic parameters at supine posture and sitting position for a comparison. Pulsed doppler echocardiography and tissue doppler imaging were used to assess the diastolic parameters in 30 consecutive patients in the Cardiology clinic of Malmo, SUS. With pulsed doppler echocardiography the peak early mitral inflow velocity (E) and peak late filling velocity (A) were measured at the opening of mitral valve. An E/A ratio was calculated for all patients. On the contrary tissue doppler imaging was used to measure peak rate of early mitral annular velocity (E'). This value was measured at the septal and the lateral wall of the heart, and later an E'-average was calculated from these two measurements. With this value and the previously measured E-wave velocity, an E/É-ratio was calculated for all patients. Using t-test paired sample test a comparison between E/A ratio in supine posture and sitting position was made. A comparison was made in a similar way with the E/E'-ratio. Results from t-test for both E/A and E/E'-ratio gave a p-value >0.05. This result means that this study can not show a significant difference in the diastolic parameters at supine posture and sitting position. Key words: Body position, Diastolic dysfunction, Diastolic function, E/A ratio, E/É ratio, Filling pressure, Preload, Pulsed Doppler imaging, Respiration, Tissue Doppler imaging.