Electromechanical coupling in patients with the short QT syndrome: Further insights into the mechanoelectrical hypothesis of the U wave

Schimpf, Rainer; Antzelevitch, Charles; Haghi, Dariush; Giustetto, Carla; Pizzuti, A; Gaïta, Fiorenzo; Veltmann, Christian; Wolpert, Christian; Borggrefe, Martin

doi:10.1016/j.hrthm.2007.10.015

Cited by 65 publications

(56 citation statements)

References 25 publications

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“…It is important to recognize that the T wave is rarely notched in all 12 leads and that the interval between the 2 summits of a notched T wave is usually less than the interval between the peak of a monophasic T wave and the U wave, which usually exceeds 150 ms at heart rates of 50 to 100 bpm. 26 …”

Section: T-wave Abnormalitiesmentioning

confidence: 99%

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AHA/ACCF/HRS Recommendations for the Standardization and Interpretation of the Electrocardiogram

Rautaharju¹,

Surawicz²,

Gettes³

2009

Circulation

391

222

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Section: T-wave Abnormalitiesmentioning

confidence: 99%

“…The U wave is a mechanoelectric phenomenon 26 that results in a low-amplitude, low-frequency deflection that occurs after the T wave. It is frequently absent in the limb leads and is most evident in leads V 2 and V 3 , where its amplitude has been suggested to be approximately 0.33 mV or 11% of the T wave.…”

Section: The U Wavementioning

confidence: 99%

AHA/ACCF/HRS Recommendations for the Standardization and Interpretation of the Electrocardiogram

Rautaharju¹,

Surawicz²,

Gettes³

2009

Circulation

391

222

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“…A previous study that evaluated SQTS patients by conventional echocardiography did not show any significant alteration in LV function. 9 Tissue Doppler imaging (TDI) and speckle tracking echocardiography (STE) have been proven to be superior for assessment of global and regional LV function. 10 We hypothesized that contraction duration (CD) is inhomogeneously distributed through the left ventricle, leading to mechanical dispersion.…”

Section: Introductionmentioning

confidence: 99%

New echocardiographic insights in short QT syndrome: More than a channelopathy?

et al. 2015

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BACKGROUND Short QT syndrome (SQTS) is a congenital ion channel disease characterized by an increased risk of sudden cardiac death. Little is known about the possibility that accelerated repolarization alters mechanical function in SQTS.OBJECTIVES The study investigated the presence of left ventricular dysfunction and mechanical dispersion, assessed by tissue Doppler imaging (TDI) and speckle tracking echocardiography (STE), and their correlation with QT interval duration and genetics.METHODS Fifteen SQTS patients (7 with HERG and 3 with KCNQ1 mutation) were studied. Electrocardiographic and echocardiographic parameters were compared with age-and sex-matched healthy controls.RESULTS When compared to the control group, SQTS patients showed reduced left ventricular contraction (global longitudinal strain: À16.0% Ϯ 3.4% vs À22.6% Ϯ 1.7%, P o .001; myocardial performance index 0.59 Ϯ 0.17 vs 0.34 Ϯ 0.08, P o .001) and a higher incidence of ejection fraction o55% (odds ratio 11, 95% confidence interval 1.045-374, P ¼ .04). Mechanical dispersion assessed by TDI (P o .01) and STE (P o .001) was higher in the SQTS group than in controls; each parameter showed a significant inverse correlation with QT interval but not with QT dispersion.CONCLUSION This study showed that in SQTS systolic function may also be affected. SQTS patients presented a significant dispersion of myocardial contraction. TDI and STE could become part of the evaluation of this rare disease.

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“…Abbreviation of cardiac repolarization in SQTS as well as prolongation in LQTS does not alter mechanical function with a time course of mechanical systole similar to that of controls [43,44]. As the T wave and U wave are clearly separated, further insights into the determinants of the electrocardiographic U wave were obtained by examination of patients with SQTS (Fig.…”

Section: Short Qt Syndrome and Electromechanical Couplingmentioning

confidence: 96%

Clinical and molecular genetics of the short QT syndrome

Schimpf

Borggrefe

Wolpert

2008

Current Opinion in Cardiology

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The short QT syndrome is clinically associated with atrial fibrillation, syncope and sudden cardiac death. A shortened QT interval (QTc <360 ms) and reduced ventricular refractory period together with an increased dispersion of repolarization constitute the potential substrate for reentry and life-threatening ventricular tachyarrhythmia. To date, gain-of-function mutations in KCNH2, KCNQ1, KCNJ2, encoding potassium channels and loss-of-function mutations in CACNA1C and CACNB2b, encoding L-type calcium channel subunits have been identified. The therapy of choice is the implantable cardioverter defibrillator in symptomatic patients. Quinidine has been shown to prolong the QT interval and to normalize the effective refractory periods of the atrium and ventricle in patients with short QT-1 syndrome.

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Electromechanical coupling in patients with the short QT syndrome: Further insights into the mechanoelectrical hypothesis of the U wave

Cited by 65 publications

References 25 publications

AHA/ACCF/HRS Recommendations for the Standardization and Interpretation of the Electrocardiogram

AHA/ACCF/HRS Recommendations for the Standardization and Interpretation of the Electrocardiogram

New echocardiographic insights in short QT syndrome: More than a channelopathy?

Clinical and molecular genetics of the short QT syndrome

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