For assessment of hemodynamic status and cardiac function, cardiac output is usually used as a surrogate parameter. Many minimally invasive and non invasive devices are used for cardiac output measurement in ICU. For minimally invasive cardiac output measurement the arterial pressure cardiac output measuring device(FloTrac) will be used in this study. It is minimally invasive and continuous cardiac output measuring device and works on arterial pressure waveform analysis. Transthoracic echocardiography is a non invasive method of measurement of cardiac output which is going to be used in this study. By this method left ventricular outflow tract diameter ( in parasternal long axis view) and velocity time integral ( in apical 5 chamber view) is derived and used for cardiac output measurement 

All consecutive patients with clinical diagnosis / suspicion of septic shock at ICU admission will be enrolled. Echocardiography and 12 lead ECG will be performed to rule out aortic stenosis and atrial fibrillation. Written informed consent from first degree relatives will be taken. After connecting the patient to minimally invasive device monitor, Transthoracic Echocardiography will beperformed by investigator within the first 6 hours of ICU admission and again after every 24 hours unless the monitor get disconnected or patient develops atrial fibrillation. The study will continue for maximum of 48 hrs after first transthoracic echocardiographic examination. The cardiac output data from the minimally invasive device will be taken at the time of echocardiographic cardiac output measurement. Analysis of transthoracic cardiac output data will be done by the investigator blinded to arterial pressure cardiac output data.