Left Ventricular Systolic Time Intervals in Preterm Infants With Patent Ductus Arteriosus

Abstract

Left ventricular systolic time intervals were recorded by a non-invasive technique, from the axillary artery, in 13 preterm infants with patent ductus arteriosus. At the onset of clinical symptoms, consistent with a large left-to right ductal shunt, the preejection intervals were shorter than in a control group of nine preterm infants without a patent ductus. The most pronounced difference was found in the shortening of the isovolumic contraction time, 10.7 msec in the ductus group compared with 22.4 msec in the control group. Ductal closure normalized the isovolumic contraction time to 22.1 msec. The very short preejection intervals, associated with a large ductal shunt, are suggested to reflect a combination of reduced aortic diastolic pressure and increased left ventricular filling pressure. In spite of increased volume load to the left ventricle there were no detectable changes in the systolic time intervals indicating impaired left ventricular function. The left ventricle seems to be competent to handle increased volume load in the presence of reduced afterload in preterm infants with symptomatic left-to right ductal shunts.

Digoxin Therapy and Left Ventricular Performance in Premature Infants With Patent Ductus Arteriosus

“…Ductal closure shortened LVET and lengthened ICT and PEP which is in agreement with previous reports (9,10). Withdrawal of digoxin therapy, after ductal closure, was associated with lengthening of LVET whereas the pre-ejection intervals remained unchanged.…”

Changes of the cardiovascular system during the perinatal period

“…Again, in the majority of these investigations an increase of the end-diastolic left ventricular volume [31,33,69] and of myocardial performance [45,46,48,68] was observed in the human newborn after birth while one study yielded contradictory results [18].…”

“…The high cardiac output and the preservation of left ventricular performance in pre-term lambs with an open ductus is facilitated by the concomitant reduction of impedance to ejection into the lower resistance combined systemic and pulmonary vascular beds [3,4,5,46].…”

Prediction of Symptomatic Patent Ductus Arteriosus in Preterm Infants Using Doppler and M‐mode Echocardiography

“…It is well known that preterm infants may develop a hemodynamically significant ductus shunt several days before it becomes clinically apparent (10,11,12). A ductal left to right shunt can be detected by Doppler echocar- diography (13, 14) and may, if it is significant, cause characteristic changes in the M-mode echocardiogram (15, 16). The aim of this study was to test the hypothesis that sPDA can be predicted from the results of combined Doppler and M-mode echocardiography performed during the first 3 days of life.…”