Health Dictionary Find a Doctor

Noonan syndrome ECG findings

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Serge Korjian, Yazan Daaboul

Overview

The most common findings on ECG in patients with Noonan syndrome are left-axis deviation and abnormal R/S ratio in the left precordial leads.

ECG Findings

Electrocardiograms in patients with Noonan syndrome often show a combination of the following: left-axis deviation, abnormal R/S ratio in the left precordial leads, wide QRS complexes, inverted T waves in lead III and V1-V3, and giant Q waves.[1][2] ECG findings are often not related to detectable structural abnormalities of heart and chest wall and may be present independently of established heart disease.[3] Other findings may include sinus bradycardia, RBBB, and other signs of right and left ventricular overload depending on the phenotypic presentation of the disease.[4]

References

  1. Sanchez-Cascos A (1983). “The Noonan syndrome”. Eur Heart J. 4 (4): 223–9. PMID 6884370.
  2. Raaijmakers R, Noordam C, Noonan JA, Croonen EA, van der Burgt CJ, Draaisma JM (2008). “Are ECG abnormalities in Noonan syndrome characteristic for the syndrome?”. Eur J Pediatr. 167 (12): 1363–7. doi:10.1007/s00431-008-0670-9. PMID 18270737.
  3. Roberts AE, Allanson JE, Tartaglia M, Gelb BD (2013). “Noonan syndrome”. Lancet. 381 (9863): 333–42. doi:10.1016/S0140-6736(12)61023-X. PMID 23312968.
  4. Bertola DR, Kim CA, Sugayama SM, Albano LM, Wagenführ J, Moysés RL; et al. (2000). “Cardiac findings in 31 patients with Noonan’s syndrome”. Arq Bras Cardiol. 75 (5): 409–12. PMID 11080752.

Template:Phakomatoses and other congenital malformations not elsewhere classified


Template:WikiDoc Sources

© 2026 MyEClinic – IFTM Institut für Telematik in der Medizin GmbH