Cardiac asystoles in preterm infants: are these a risk factor for SIDS? - abstract

ABSTRACT

In spite of significant advances in perinatal/neonatal care, preterm infants remain at high risk for unexplained death in infancy. Using continous documented monitoring as a predischarge screen for persistance of apneas and bradycardias in preterm infants (mean GA 30.5 weeks) prior to hospital discharge, 21 of 332 infants (6.3 per cent) had asystolic events defined as cardiac pauses > 3 seconds. All affected infants had a history of O2 desaturation < 85 per cent and/or colour change in the weeks prior to event monitor screening. Concurrent 72-hour Holter monitoring confirmed sinus pauses of 3 - 10 seconds. Echocardiogram revealed pulmonary artery branch stenosis in 9 of the 21 infants, but no other structural abnormalities. Gastroesophageal reflux was diagnosed by pH probe and/or Milk-Scan in all 21 infants; clinical symptoms improved after specific therapy but asystoles and bradycardias persisted. All infants were followed with home monitoring until asystole-free for 2 months. Asystoles decreased with age with a mean of 33.7 events/wk at 36 wks post-conceptional age, 24.7 at 47 wks and only 1 infant had asystolic events beyond 58 weeks. Pacemakers were recommended in 3 infants, but only placed in one. None of the infants died. Conclusion: asystolic events occur in preterm infants without significant anatomical cardiac abnormalities and can be diagnosed by continuous documented monitoring. Resolution occurs spontaneously, but long-term cardiology follow-up is necessary to determine later outcome and complications. The significance of these events and their relationship to sudden death in infancy need to be explored (AU)