Postextrasystolic U Wave Augmentation, a New Marker of Increased Arrhythmic Risk in Patients Without the Long QT Syndrome

Viskin, Sami; Heller, Karin; Barron, Hal V.; Kitzis, Ilan; Hamdan, Mohamed H.; Olgin, Jeffrey E.; Wong, Mary J.; Grant, Stanley E.; Lesh, Michael D.

doi:10.1016/s0735-1097(96)00382-8

Cited by 29 publications

(22 citation statements)

References 34 publications

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“…A role for U waves in arrhythmogenesis has previously been proposed for right ventricular outflow tract VT and organic heart disease. [21][22][23] However, arrhythmia risk in these settings was related to postextrasystolic augmentation of the U wave. In contrast, the enlarged U waves in ATS1 subjects were observed during sinus rhythm and were distinct from the preceding T wave.…”

Section: Discussionmentioning

confidence: 99%

Electrocardiographic Features in Andersen-Tawil Syndrome Patients With KCNJ2 Mutations

et al. 2005

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Background-The ECG features of Andersen-Tawil syndrome (ATS) patients with KCNJ2 mutations (ATS1) have not been systematically assessed. This study aimed to define ECG features of KCNJ2 mutation carriers, to determine whether characteristic T-U-wave patterns exist, and to establish whether T-U patterns predict the ATS1 genotype. Methods and Results-In phase I, evaluation of T-U morphology in ECGs of 39 KCNJ2 mutation carriers identified characteristic T-U patterns: prolonged terminal T downslope, wide T-U junction, and biphasic and enlarged U waves. In phase II, ATS1 genotype prediction by T-U pattern was evaluated in the next 147 ECGs (57 other KCNJ2 mutation carriers, 61 unaffected family members, and 29 ATS patients without KCNJ2 mutations), with a sensitivity of 84% and specificity of 97%. Characteristic T-U patterns were present in 91% (87/96), in whom an enlarged U wave was predominant (73%). In phase III, QTc, QUc, and T-and U-wave duration/amplitude were compared in the 96 ATS1, 29 non-KCNJ2 ATS, and 75 normal subjects. In ATS1 patients, QUc, U-wave duration and amplitude, and QTc were all increased (PϽ0.001), but median QTc and interquartile range (IQR) were just 440 ms (IQR, 28 ms) compared with 420 ms (IQR, 20 ms) in normal subjects and 425 ms (IQR, 48 ms) in ATS non-KCNJ2 patients. Conclusions-In ATS1 patients, gene-specific T-U-wave patterns resulting from decreased I K1 owing to KCNJ2 mutations can aid diagnosis and direct genotyping. The normal QTc, distinct ECG, and other clinical features distinguish ATS1 from long-QT syndrome, and it is best designated as ATS1 rather than LQT7. (Circulation. 2005;111:2720-2726.)

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Section: Discussionmentioning

confidence: 99%

Electrocardiographic Features in Andersen-Tawil Syndrome Patients With KCNJ2 Mutations

et al. 2005

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“…They occur in normal subjects as often as in patients with coronary disease: not a poor man's exercise test, just a poor test. 5 …”

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confidence: 99%

Atrioventricular block induced by atrial premature beats

Nikolić

2008

Heart & Lung

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“…Changes in the amplitude of the U-wave might be observed in some patients with ischemic heart disease during exercise stress testing 6,8) or following a pause after premature ventricular contraction in patients with idiopathic ventricular tachycardia 11) or long QT syndrome, 27) but alternans of the U-wave has not been reported. Similarly, though an inverted U-wave is considered as a hallmark for the presence of myocardial ischemia or hypertrophy, [6][7][8][9][10] a prompt change after a pause has not been previously reported as found in the present study.…”

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confidence: 99%

“…Macroscopic T-wave alternans is often observed in heart failure patients 28) or in patients with long QT syndrome 27) and is associated with a poor prognosis and can be a marker of arrhythmogenic risk. Furthermore, microvoltage T-wave alternans, which is a heart rate-dependent measure of repolarization, 22) has been shown to be a strong predictor of spontaneous ventricular arrhythmias or death.…”

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confidence: 99%

Distinct U Wave Changes in Patients With Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT)

et al. 2006

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SUMMARYAlthough catecholaminergic polymorphic ventricular tachycardia (CPVT) is associated with fatal ventricular arrhythmias and sudden death, the ECG findings are not fully understood. In this paper, we report on alterations in the U-wave.Seven patients from 6 families with CPVT in which bidirectional tachycardia and polymorphic VT were induced by exercise or isoproterenol infusion visited our hospitals. VT was not inducible by programmed electrical stimulation. A novel gene mutation of the ryanodine receptor 2 (RyR2) was confirmed in 2 families.In one of these patients, U-wave alternans was observed following ventricular pacing at 160 beats/min. In the other patient, U-wave alternans was observed during the recovery phase after the exercise stress test, which was terminated because of polymorphic VT. In both cases, leads V 3 -V 5 were the leads showing alternans most clearly. In the third patient, a negative U-wave became positive following a pause from sinus arrest and a change in T-wave was also noted.Since such findings were not found in the other subjects who underwent electrophysiologic study, isoproterenol infusion or exercise stress testing, the phenomenon seems to be relevant to the underlying pathogenesis of CPVT. The genesis and significance of Uwave alteration need to be determined. (Int Heart J 2006; 47: 381-389)

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Postextrasystolic U Wave Augmentation, a New Marker of Increased Arrhythmic Risk in Patients Without the Long QT Syndrome

Abstract: Postextrasystolic T wave changes are common and lack predictive value. Postextrasystolic U wave changes may be a specific marker of a tendency to the development of spontaneous ventricular arrhythmias. Prospective studies should be performed to confirm this association.

Cited by 29 publications

References 34 publications

Electrocardiographic Features in Andersen-Tawil Syndrome Patients With KCNJ2 Mutations

Electrocardiographic Features in Andersen-Tawil Syndrome Patients With KCNJ2 Mutations

Atrioventricular block induced by atrial premature beats

Distinct U Wave Changes in Patients With Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT)

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