Echocardiographic Monitoring of the Myocardial Function in Critically Ill Children

Overview

The severity of disease is to a considerable degree determined by the extent of reduction of cardiac activity. For preparation of an optimal therapeutic plan it is essential to obtain rapid information on the function of both ventricles and the cardiac output which are not provided by standard monitoring. The critically sick child is exposed to a considerable therapeutic invasiveness. It is in the patient’s interest to reduce the aggressivity of diagnostic procedures.For common use at paediatric intensive care units (PICU) the authors tested and use successfully ECHO cardiographic examination:Calculation of the fraction of the shortened left ventricle (SF), cardiac output (CO), the dimensions of the valvular apparatus of the large arteries and the index of myocardial performance (IMP). IMP expresses the relationship of the interval of isovolumetric relaxation and ventricular contraction to the ejection time of the appropriate large artery. The paediatric modification relates every assessed value to the patient’s heart rate. Analysis of the result of assessment of the IMP index makes it possible to evaluate at the same time the left systolic and diastolic function (LIMP) and that of the right ventricle (RIMP). The diastolic function of the cardiac ventricle is expressed by the interval of the isovolumetric relaxation (IVRT), the systolic function by the interval of isovolumetric contraction (IVCT). Under defined conditions the examination provides some extra valuable information: an estimate of the systolic and diastolic pressure in the pulmonary arterial circulation!At the Plzeò unit the authors implemented and documented a total of 178 examinations in 55 critically sick children with a mean PRISM score of 26 points, the age bracket being from 7 days to 18 years (mean age 3.3 years). Critically sick patients had on average a global right ventricular function reduced to 80% and a cardiac output reduced to 60% of normal values.The objective of the paper is to draw attention to a tested and protective examination method of critically sick patients which with feasible accuracy provides a broad scale of valuable information of cardiac function and the pressure in the pulmonary arterial circulation.

Key words:
index of myocardial performance (IMP), cardiac output (CO), critically ill child