Images in Clinical Medicine
Kim Eagle, M.D., Editor
Long-QT Syndrome
N Engl J Med 1995; 333:355August 10, 1995
- Article
Figure 1 A two-year-old boy came to medical attention because he lost consciousness four times over a period of five months. Three of the episodes occurred when the child became upset. These episodes had previously been diagnosed as “breath-holding spells.” He was also found to have severe sensorineural hearing loss. The child was taking no medication. There was no family history of sudden cardiac death.
Panel A is a 12-lead electrocardiogram, showing marked prolongation of the QT interval (QT corrected for heart rate, 0.75 sec) with T-wave alternans. Panel B compares the flattened and diminished auditory evoked responses of this patient (an indication of severe sensorineural hearing loss) with the responses of a subject with normal hearing. A single auditory stimulus (a click) was presented at time 0, and the electroencephalogram was recorded continuously. Peaks I, III, and V represent recordings of activity in the acoustic nerve, the pons, and the midbrain, respectively.
These findings are consistent with the autosomal recessive form of the congenital long-QT syndrome (called the Jervell and Lange-Nielsen syndrome). This syndrome, along with the more common Romano-Ward form of the long-QT syndrome (autosomal dominant inheritance, normal hearing), is associated with sudden cardiac death. Syncopal episodes are probably due to nonsustained polymorphic ventricular tachycardia (torsade de pointes). The patient has been asymptomatic since being treated with a beta-blocker.
Kim Eagle, M.D.
Wayne H. Franklin, M.D.
Robert W. Hickey, M.D.
Columbus Children's Hospital, Columbus, OH 43205- Citing Articles (1)
Citing Articles
1
Judith M. MacCormick, Hugh McAlister, Jackie Crawford, John K. French, Ian Crozier, Andrew N. Shelling, Carey-Anne Eddy, Mark I. Rees, Jonathan R. Skinner. (2009) Misdiagnosis of Long QT Syndrome as Epilepsy at First Presentation. Annals of Emergency Medicine 54:1, 26-32
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