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Evolution of the QT interval in premature infants: a preliminary study

Published online by Cambridge University Press:  19 December 2011

Pierre-Emmanuel Séguéla*
Affiliation:
Pediatric Cardiology Unit, University Hospital of Nantes, Nantes, France
Jean-Christophe Rozé
Affiliation:
Pediatric and Neonatal Intensive Care Unit, University Hospital of Nantes, Nantes, France
Véronique Gournay
Affiliation:
Pediatric Cardiology Unit, University Hospital of Nantes, Nantes, France
*
Correspondence to: Dr P.-E. Séguéla, Pediatric Cardiology Unit, Children's Hospital, Toulouse University Hospital, 330 Avenue de Grande-Bretagne, 31059 Toulouse Cedex 9, France. Tel: +33 234557459; Fax: +33 534558663; E-mail: [email protected]

Abstract

Background

The association between long QT interval and sudden infant death syndrome has been clearly established. Several studies have been conducted to determine the evolution of the QT interval in childhood from birth, but only in full-term newborns. However, data on the QT interval in pre-term infants are extremely scarce. The objective was to describe the development of the QT interval in premature infants.

Material and methods

In a prospective monocentric study in a neonatal intensive care unit, pre-term newborns born before 37 weeks of gestation without congenital heart disease, family history of long QT, unstable haemodynamic status, or administration of drugs inducing QT interval prolongation were included with parental consent. An electrocardiogram was recorded in similar conditions weekly until discharge in each child. The corrected QT was calculated with Bazett's formula.

Results

In all, 309 echocardiograms were recorded in 87 children, with gestational age ranging from 24–36 weeks. QT first increased after birth in very premature infants – less than 30 weeks of gestation – and then started to decrease, whereas it only decreased in more mature infants. When plotted against postmenstrual age, QT first increased, and then decreased after 32 weeks.

Discussion

Our data suggest that the QT interval varies with postmenstrual age in very premature infants, reaching a peak at 32 weeks. These developmental changes may induce specific vulnerability to QT-lengthening medications in premature infants. This study underlines the need for specific pharmacological studies in this population.

Type
Original Article
Copyright
Copyright © Cambridge University Press 2012

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References

1. Schwartz, PJ, Stramba-Badiale, M, Segantini, A, et al. Prolongation of the QT interval and the sudden infant death syndrome. N Engl J Med 1998; 338: 17091714.CrossRefGoogle Scholar
2. Bednar, MM, Harrigan, EP, Anziano, RJ, Camm, AJ, Ruskin, JN. The QT interval. Prog Cardiovasc Dis 2001; 43: 145.Google ScholarPubMed
3. Ariagno, RL, Mirmiran, M, Adams, MM, Saporito, AG, Dubin, AM, Baldwin, RB. Effect of position on sleep, heart rate variability, and QT interval in preterm infants at 1 and 3 months’ corrected age. Pediatrics 2003; 111: 622625.CrossRefGoogle ScholarPubMed
4. Sarma, JS, Venkataraman, SK, Samant, DR, Gadgil, U. Hysteresis in the human RR–QT relationship during exercise and recovery. Pacing Clin Electrophysiol 1987; 10: 485491.CrossRefGoogle ScholarPubMed
5. Lau, CP, Freedman, AR, Fleming, S, Malik, M, Camm, AJ, Ward, DE. Hysteresis of the ventricular paced QT interval in response to abrupt changes in pacing rate. Cardiovasc Res 1988; 22: 6772.CrossRefGoogle ScholarPubMed
6. Eberle, T, Hessling, G, Ulmer, HE, Brockmeier, K. Prediction of normal QT intervals in children. J Electrocardiol 1998; 31: 121125.CrossRefGoogle ScholarPubMed
7. Rijnbeek, PR, Witsenburg, M, Schrama, E, Hess, J, Kors, JA. New normal limits for the paediatric electrocardiogram. Eur Heart J 2001; 22: 702711.CrossRefGoogle ScholarPubMed
8. Schwartz, PJ, Garson, A Jr, Paul, T, Stramba-Badiale, M, Vetter, VL, Wren, C. European Society of Cardiology. Guidelines for the interpretation of the neonatal electrocardiogram. A task force of the European Society of Cardiology. Eur Heart J 2002; 23: 13291344.CrossRefGoogle Scholar
9. Semizel, E, Oztürk, B, Bostan, OM, Cil, E, Ediz, B. The effect of age and gender on the electrocardiogram in children. Cardiol Young 2008; 18: 2640.CrossRefGoogle ScholarPubMed
10. Schwartz, PJ, Montemerlo, M, Facchini, M, et al. The QT interval throughout the first 6 months of life: a prospective study. Circulation 1982; 66: 496501.CrossRefGoogle Scholar
11. Kähler, C, Schleussner, E, Grimm, B, et al. Fetal magnetocardiography: development of the fetal cardiac time intervals. Prenat Diagn 2002; 22: 408414.CrossRefGoogle ScholarPubMed
12. Stinstra, J, Golbach, E, van Leeuwen, P, et al. Multicentre study of fetal cardiac time intervals using magnetocardiography. BJOG 2002; 109: 12351243.CrossRefGoogle ScholarPubMed
13. Van Leeuwen, P, Lange, S, Klein, A, Geue, D, Grönemeyer, DH. Dependency of magnetocardiographically determined fetal cardiac time intervals on gestational age, gender and postnatal biometrics in healthy pregnancies. BMC Pregnancy Childbirth 2004; 4: 6.CrossRefGoogle ScholarPubMed
14. Horigome, H, Takahashi, MI, Asaka, M, Shigemitsu, S, Kandori, A, Tsukada, K. Magnetocardiographic determination of the developmental changes in PQ, QRS and QT intervals in the foetus. Acta Paediatr 2000; 89: 6467.CrossRefGoogle ScholarPubMed
15. De Rogalski Landrot, I, Roche, F, Pichot, V, et al. Autonomic nervous system activity in premature and full-term infants from theoretical term to 7 years. Auton Neurosci 2007; 136: 105109.CrossRefGoogle ScholarPubMed
16. Wang, L, Feng, ZP, Kondo, CS, Sheldon, RS, Duff, HJ. Developmental changes in the delayed rectifier K+ channels in mouse heart. Circ Res 1996; 79: 7985.CrossRefGoogle ScholarPubMed
17. Kato, Y, Masumiya, H, Agata, N, Tanaka, H, Shigenobu, K. Developmental changes in action potential and membrane currents in fetal, neonatal and adult guinea-pig ventricular myocytes. J Mol Cell Cardiol 1996; 28: 15151522.CrossRefGoogle ScholarPubMed
18. Tanaka, H, Namekata, I, Nouchi, H, Shigenobu, K, Kawanishi, T, Takahara, A. New aspects for the treatment of cardiac diseases based on the diversity of functional controls on cardiac muscles: diversity in the excitation–contraction mechanisms of the heart. J Pharmacol Sci 2009; 109: 327333.CrossRefGoogle ScholarPubMed
19. Cuomo, S, De Caprio, L, Di Palma, A, et al. Influence of autonomic tone on QT interval duration. Cardiologia 1997; 42: 10711076.Google ScholarPubMed
20. Pladys, P, Beuchée, A, Hernandez, A, Carrault, G. Heart rate variability in paediatrics: principles and applications. Arch Pediatr 2008; 15: 611613.CrossRefGoogle Scholar
21. Patural, H, Barthelemy, JC, Pichot, V, et al. Birth prematurity determines prolonged autonomic nervous system immaturity. Clin Auton Res 2004; 14: 391395.CrossRefGoogle ScholarPubMed
22. Patural, H, Pichot, V, Jaziri, F, et al. Autonomic cardiac control of very preterm newborns: a prolonged dysfunction. Early Hum Dev 2008; 84: 681687.CrossRefGoogle ScholarPubMed
23. Kahn, A, Groswasser, J, Franco, P, et al. Sudden infant deaths: stress, arousal and SIDS. Early Hum Dev 2003; 75: 147166.CrossRefGoogle ScholarPubMed
24. Qu, J, Robinson, RB. Cardiac ion channel expression and regulation: the role of innervation. J Mol Cell Cardiol 2004; 37: 439448.CrossRefGoogle ScholarPubMed
25. Helfenbein, ED, Ackerman, MJ, Rautaharju, PM, et al. An algorithm for QT interval monitoring in neonatal intensive care units. J Electrocardiol 2007; 40 (Suppl 6): S103S110.CrossRefGoogle ScholarPubMed