Presented at the Neonatal Society 2010 Spring Meeting.
Parikh R1, Negrine RJS1, Chikermane A2, Rasiah SV1, Ewer AK1,3
1 Neonatal Intensive Care Unit, Birmingham Women’s Hospital, UK
2 Department of Paediatric Cardiology, Birmingham Children Hospital, UK
3 School of Clinical and Experimental Medicine, University of Birmingham, UK
Background: Patent Ductus Arteriosus (PDA) is common problem in premature infants with rates of 40-55% in babies born less than 29 weeks (1). Haemodynamically Significant Ductus Arteriosus (HSDA) can result in significant morbidity in VLBW infants. We recently reported that myocardial function can be assessed in premature babies with PDA using TDI (2). The effect of the size of the duct on myocardial function in premature babies in the first week of life has not been studied previously.
Aim: To assess left and right ventricular function in preterm babies with different sizes of PDA.
Methods: VLBW infants <30 weeks gestation underwent echocardiography by one investigator (RP), on day 3 of life. Subjects were categorised into three groups depending on size of PDA(1) – (a) HSDA Ductal Diameter >2.5mm and LA:Ao ratio >1.5, (b) PDA <2.5mm or LA:Ao ratio <1.5 and (c) No PDA. Those babies who had HSDA were treated with indomethacin according to local unit guidelines. Myocardial velocities were acquired from an apical four chamber view. With a Doppler pulse-wave, sample gate of 0.12cm was positioned at the lateral tricuspid and mitral annuli. Peak velocities in systole, early diastole and late diastole were obtained from each site. Average readings were taken from 3-5 cardiac cycles. Ethical approval was obtained from the Birmingham Research Ethics Committee.
Results: 20 babies were recruited in group (a), (c) and 18 babies in group (b). The table below shows mean (SD) velocities (cm/sec) in each group:
There were statistically significant lower velocities in HSDA group as compared to other groups (p < 0.0001). In the HSDA group, myocardial velocities were lower in babies whose PDA remained open (n = 12) then in babies whose PDA closed (n = 8) with indomethacin. These differences were statistically significant for biventricular systolic and late diastolic function.
Conclusion: Myocardial velocities in preterm infants with HSDA were lower than those with other sizes of PDA suggesting lower myocardial function in this group. Babies whose PDA remained open after indomethacin had initial lower velocities as compared to those babies whose PDA closed with indomethacin. Our study demonstrates that measurement of myocardial function in premature babies with different sizes of PDA is feasible and may be a helpful adjunct in the management of these babies although larger studies are required.
1. McNamara et al. Arch. Dis. Child. Fetal Neonatal Ed. 2007;92;424-427
2. Parikh et al. Acta Paediatrica. 2009; 98; 205