This study sought to evaluate the range and variability of the QT and corrected QT (QTc) intervals over 24 h and to assess their pattern and relation to heart rate variability.Recent Holter monitoring data have revealed a high degree of daily variability in the QTc interval. The pattern of ...
In 12-lead resting electrocardiography (ECG) the QTc interval was 498ms (Figure 1). Physical examination and laboratory results were unremarkable, and she was not on QTc-prolonging therapy. Echocardiography showed no structural heart disease. On 24-hour Holter ECG, the predominant rhythm was sinus...
(3) In the presence of a corrected QT interval (QTc) ⩾ 500 ms on repeated 12-lead ECGs using Bazett's formula in the absence of a secondary cause for QT prolongation. They adjunctively mentioned that LQTS can be diagnosed when the QTc is between 480 and 499 ms on repeated 12-lead...
596 infants at 3–4 weeks of age. Among them, 1.4% had a corrected QT (QTc) interval between 440 and 469 ms and 0.7/1,000 had a QTc ≥ 470 ms, regarded as markedly
Among patients without bundle branch block, digitalis and quinidine, those below 66 years of age who died within the first six months tended to have longer QTc> intervals than the survivors. It is concluded that measurements of QTc interval at discharge have no long-term predictive value. This...
and mean QT interval; maximum, minimum, and mean heart rate corrected QT interval (QTc); QT and QTc dispersion (the difference between the maximum and minimum QT interval among the 12 leads); and adjusted QT and QTc dispersion (dispersion divided by the square root of the number of leads ...
Gouas L, Nicaud V, Berthet M, Forhan A, Tiret L, Balkau B, Guicheney P: Association of KCNQ1, KCNE1, KCNH2 and SCN5A polymorphisms with QTc interval length in a healthy population. Eur J Hum Genet. 2005, 13 (11): 1213-1222. 10.1038/sj.ejhg.5201489. Article CAS PubMed Google...
If the patient is clinically affected (prolonged QTc with or without syncope) the index patient has a chance of about 60–70% carrying a variant affecting function. But only in very rare cases there is an indication for performing LQTS genetic testing in a clinically unaffected relative when th...
The QTc interval returned to normal following discontinuation of fluoxetine. Four additional cases suggesting fluoxetine-associated QTc prolongation or torsades de pointes have been reported.[Ref]Other Very common (10% or more): Fatigue (up to 12%) Common (1% to 10%): Accidental overdose, ...
Her 7-year-old son had a QTC interval of 450 ms. He was started on beta-blocker therapy and restricted from playing any sports, with the concern that he might have LQTS too. Should this family be referred for genetic testing of LQTS? What would that entail? This article will explore...