Echocardiographic changes of cardiac structures and LV function in newborns. A comparative study between normally delivered babies and babies born by caesarian section with regional anaesthesia.

Cardiac chamber size and function indices were studied repeatedly over the first months of life in two groups of babies, born either spontaneously or by caesarian section under peridural anaesthesia. For cardiac chamber size, no significant differences were found between the two groups: cardiac structures increased in size as a linear function of age and weight in all babies. Right ventricular systolic time interval ratios, however, were higher at birth in babies born by caesarian section, and dropped more rapidly during the first 24h. The decrease of RV systolic time interval ratios followed a parabolic function for both groups, thus reflecting the physiological decrease of pulmonary vascular resistance after birth. The possible causes of more rapid decrease in pulmonary vascular resistance in babies born by caesarian section is discussed.