Reliability of Echocardiographic Assessment of Cardiac Dimensions and Function From Subcostal View

Assessment of the function and dimensions of the right and left ventricles is a key part of Point-of-Care ultrasound in critically ill patients. According to the recent guidelines, this evaluation is performed from apical and parasternal views. However, these views may not be clearly visible in the clinical setting of critical illness and subcostal view is often preferred for its higher feasibility. Before clinical adoption, it is necessary to assess whether the isolated examination from subcostal view is reliable enough in the detection of the impairment of systolic function and the size of both ventricles and the investigators decided to evaluate this issue.

Transverse and longitudinal dimensions and function of both ventricles will be measured calculated by transthoracic echocardiography in critically ill patients in the intensive care unit from parasternal and apical views following the recent guidelines. Systolic function of the left ventricle will be expressed by the left ventricular ejection fraction (calculated by biplane method of disc summation) and by the fraction shortening. Systolic function of the right ventricle will be assessed by the tricuspid annular plane systolic excursion, fractional area change, tricuspid lateral annular systolic velocity, and right ventricular index of myocardial performance. From subcostal view, transverse dimensions of both ventricles and novel parameters of systolic function (subcostal tricuspid annular plane systolic excursion, right ventricular subcostal fraction shortening, right ventricular modified subcostal fraction shortening, left ventricular subcostal fraction shortening and left ventricular modified fraction shortening) will be measured.

Then, the reliability of parameters measured in subcostal view will be tested by comparison with conventional parameters taken from apical and parasternal view by correlation analysis and diagnostic test evaluation. The most reliable thresholds of parameters from subcostal view will be calculated by receiver operating characteristic analysis.