Short QT Syndrome

There is controversy whether short QT intervals are associated with sudden death. One trial found QTc intervals < 300ms to be associated with sudden death.[1] However, a recent Finnish study in a random selection of healthy subjects (n=10 822) did not find an increased incidence of sudden death in patients with short QTc intervals. They defined QTc < 320ms as 'very short' and QTc < 340ms as 'short'. In total, 15 deaths occured in the group with QTc <340ms, with only one possible sudden death (cause of death unknown). They used Friderica's method for QTc correction: .[2] They conclude that the ECG is not a good screening tool to find patients with a short QTc interval at risk of sudden death.[3]

References

1. Gaita F, Giustetto C, Bianchi F, Wolpert C, Schimpf R, Riccardi R, Grossi S, Richiardi E, and Borggrefe M. Short QT Syndrome: a familial cause of sudden death. Circulation. 2003 Aug 26;108(8):965-70. DOI:10.1161/01.CIR.0000085071.28695.C4 |

2. Fridericia LS. Die Systolendauer im Elektrokardiogramm bei normalen

   Menschen und bei Herzkranken. Acta Med Scand. 1920;53:469–486.

3. Anttonen O, Junttila MJ, Rissanen H, Reunanen A, Viitasalo M, and Huikuri HV. Prevalence and prognostic significance of short QT interval in a middle-aged Finnish population. Circulation. 2007 Aug 14;116(7):714-20. DOI:10.1161/CIRCULATIONAHA.106.676551 |

4. Bazett HC. An analysis of the time-relations of electrocardiograms. Heart 1920;7:353-370.

5. LEPESCHKIN E and SURAWICZ B. The measurement of the Q-T interval of the electrocardiogram. Circulation. 1952 Sep;6(3):378-88. DOI:10.1161/01.cir.6.3.378 |