This study was intended to assess left ventricular systolic and diastolic functions together with right ventricular systolic function in various grades of sepsis, possibility of ischaemic nature of myocardial dysfunction in various degrees of sepsis, and to correlate measurements of echocardiography and radionuclide scintigraphy as regard RVEF and LVEF.A total number of 40 patients diagnosed to had various degrees of sepsis admitted to Critical Care Department (Cairo University) from October 2002 to December 2004, were recruited in the study.They included 22 males, 18 females with mean age 46+12 yrs and divided into two group.Group I patients with SIRS, consisted of 15 patients 10 M, 5 F and group II patients with septic shock, consisted of 25 patients 12 M and 13 F.All patients were subjected to APACH II score on admission and repeated on day I, day 2 and day 7, first pass technique, perfusion study, and echocardiography were also done on admission and 5 to 7 days later.Group I patients showed smaller LVESD & LVEDD and higher LVEF and RVEF compared to group II patients on admission (4.8+0.26 vs 5.4+0.39, P: 0.02 and 3.37+0.28 vs 3.92+0.2, P: 0.018 and 56.4+4.4 vs 48.1+2.9, P: 0.01 and 51.4+3.3 vs 45.1+4.3, P: 0.03) respectively.Group I patients showed impaired relaxation pattern of diastolic dysfunction on admission which became normal or follow up compared to group II patients who showed pseudo-normal pattern of diastolic dysfunction which worsened to type three diastolic dysfunction "restrictive pattern" on the follow up.Myocardial performance index were significantly lower in group I compared to group II on admission & follow up (0.56+0.03 vs 0.66+0.12, P: 0.004 & 0.53+0.03 vs 0.68+0.14, P: 0.001).Group II patients showed 11 (44%) survivor 14 (56%) non survivors, while group I showed no mortality. Survivors showed significantly larger LVEDD and LVESD, RVEF and lower LVEF compared to non survivors on admission (5.8+0.13 vs 5.09+0.18, P: 0.001 & 43.2+0.17 vs 3.7+0.1, P: 0.04 & 47.5+3.7 vs 44+6.3, P: 0.04 & 45.1+3.7 vs 51.7+3.8, P: 0.03) respectively.While on follow up survivors had more or less the same LVEDD with lower LVESD and higher LVEF and RVEF compared to non survivors (5.09+0.2 vs 5.15+0.4, P: 0.09, 3.51+0.17 vs 3.9+0.22, P: 0.04, 59.1+2.4 vs 48+3.2 & 50.1+2.5 vs 45.2+5.4, P: 0.04) respectively.Survivors showed pseudo normal pattern of diastolic dysfunction on admission which returned back to normal on follow up while non survivors showed restrictive pattern of diastolic dysfunction on admission and follow up.Myocardial performance index were significantly higher in non survivors compared to survivors on both admission and follow up (0.75+0.09 vs 0.56+0.05 & 0.8+0.05 vs 5.53+0.04, P: 0.001).Out of 25 patients in group II 8 patients had perfusion defects in their (MPI) while group I showed no perfusion defects.Survivors had relatively larger defects size with major reversibility compared to non survivors.APACHE II score were significantly higher with no changes over time in non survivors compared to survivors whom showed significant decline over time in APACH II score values.There were good positive correlation between LVEF measured by echocardiography and first pass technique (r: 0.87) and moderate positive correlation between RVEF measured by echocardiography and first pass techniques (r: 0.57).