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Andersen-Tawil syndrome electrocardiogram

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Vamsikrishna Gunnam M.B.B.S [2]

Overview

Overview

An ECG may be very helpful in the diagnosis of Andersen-Tawil Syndrome. Findings on an ECG diagnostic of Andersen-Tawil Syndrome include a long QTc (LQT) interval, U waves, wide T-U junction and T-waves.

Electrocardiogram

Electrocardiogram

An ECG may be helpful in the diagnosis of Andersen-Tawil Syndrome. Findings on an ECG diagnostic of Andersen-Tawil Syndrome include:^[1]

A long QTc (LQT) interval
T-U patterns which are very characteristic to the syndrome^[2]
Prominent U-wave enlargement which are biphasic in limb leads
A wide T-U junction
Prolonged terminal T-wave
Premature ventricular contractions (PVC) especially at “rest” in Andersen-Tawil syndrome (ATS) patients
- PVC’s at rest helps in differentiating ATS from catecholaminergic polymorphic ventricular tachycardia (CPVT)
Polymorphic ventricular tachycardia (PMVT) which is called bidirectional ventricular tachycardia (BiVT)^[3]^[4]
- PMVT is defined as when the beats are more than 100/min with variation in QRS axis.
In ATS when the patient deteriorates we can see VF which can lead to sudden death

“U on P” sign and U-wave masquerading P-wave — “U on P” sign (black arrow). “U on P” sign (U-wave masquerading P-wave) ; the P-wave during sinus tachycardia is inscribed on the U-wave of the preceding beat. Case courtesy by Piotr Kukla et al^[5]

Pseudo – LQTS pattern — Post- extrasystolic “pseudo – LQTS pattern” (arrows). This is detected in a sinus beat following a PVC. The fusion of T+U-waves can mimic LQTS. This pattern is not observed in the subsequent sinus beats. Case courtesy by Piotr Kukla et al^[6]

Pseudo “Tee – Pee sign” (black arrow). Pseudo “Tee-pee sign” during a PVC, there is a prolongation of the descending limb of the T+U-wave. In ATS1, the QT interval can appeared prolonged and difficult to quantify because of a prominent U-wave. In order to properly determine the QT interval, the tangent technique should be carefully applied.Case courtesy by Piotr Kukla et al^[7]

References

References

↑ Kukla P, Biernacka EK, Baranchuk A, Jastrzebski M, Jagodzinska M (2014). “Electrocardiogram in Andersen-Tawil syndrome. New electrocardiographic criteria for diagnosis of type-1 Andersen-Tawil syndrome”. Curr Cardiol Rev. 10 (3): 222–8. doi:10.2174/1573403×10666140514102528. PMC 4040873. PMID 24827800.
↑ Zhang L, Benson DW, Tristani-Firouzi M, Ptacek LJ, Tawil R, Schwartz PJ; et al. (2005). “Electrocardiographic features in Andersen-Tawil syndrome patients with KCNJ2 mutations: characteristic T-U-wave patterns predict the KCNJ2 genotype”. Circulation. 111 (21): 2720–6. doi:10.1161/CIRCULATIONAHA.104.472498. PMID 15911703.
↑ Khan IA (2002). “Clinical and therapeutic aspects of congenital and acquired long QT syndrome”. Am J Med. 112 (1): 58–66. doi:10.1016/s0002-9343(01)01011-7. PMID 11812408.
↑ Passman R, Kadish A (2001). “Polymorphic ventricular tachycardia, long Q-T syndrome, and torsades de pointes”. Med Clin North Am. 85 (2): 321–41. doi:10.1016/s0025-7125(05)70318-7. PMID 11233951.
↑ “Electrocardiogram in Andersen-Tawil Syndrome. New Electrocardiographic Criteria for Diagnosis of Type-1 Andersen-Tawil Syndrome”.
↑ “Electrocardiogram in Andersen-Tawil Syndrome. New Electrocardiographic Criteria for Diagnosis of Type-1 Andersen-Tawil Syndrome”.
↑ “Electrocardiogram in Andersen-Tawil Syndrome. New Electrocardiographic Criteria for Diagnosis of Type-1 Andersen-Tawil Syndrome”.

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