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Titolo:
Prolongation of the QT interval in heart failure occurs at low but not at high heart rates
Autore:
Davey, PP; Barlow, C; Hart, G;
Indirizzi:
John Radcliffe Hosp, Nuffield Dept Med, Oxford OX3 9DU, England John Radcliffe Hosp Oxford England OX3 9DU Med, Oxford OX3 9DU, England Fac Med, Liverpool L69 3GA, Merseyside, England Fac Med Liverpool Merseyside England L69 3GA L69 3GA, Merseyside, England Papworth Hosp, Cambridge CB3 8RE, England Papworth Hosp Cambridge England CB3 8RE Hosp, Cambridge CB3 8RE, England
Titolo Testata:
CLINICAL SCIENCE
fascicolo: 5, volume: 98, anno: 2000,
pagine: 603 - 610
SICI:
0143-5221(200005)98:5<603:POTQII>2.0.ZU;2-G
Fonte:
ISI
Lingua:
ENG
Soggetto:
SUDDEN CARDIAC DEATH; ACUTE MYOCARDIAL-INFARCTION; AUTONOMIC NEUROPATHY; SENSITIVITY; EXERCISE; DISEASE; TRIAL;
Keywords:
exercise; heart failure; QT interval; QT/heart rate slope;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
28
Recensione:
Indirizzi per estratti:
Indirizzo: Davey, PP John Radcliffe Hosp, Nuffield Dept Med, Oxford OX3 9DU, England John Radcliffe Hosp Oxford England OX3 9DU rd OX3 9DU, England
Citazione:
P.P. Davey et al., "Prolongation of the QT interval in heart failure occurs at low but not at high heart rates", CLIN SCI, 98(5), 2000, pp. 603-610

Abstract

Abnormal left ventricular structure and function as in, for example, left ventricular hypertrophy or chronic heart failure, is associated with suddencardiac death and, when the ejection fraction is depressed, with prolongation of the QT interval. The dependence on heart rate of QT interval prolongation in these conditions, and the relationship of any abnormalities eitherto deranged autonomic nervous system function or to an adverse prognosis, has not been well studied. We therefore investigated (1) the dependence on heart rate of the QT interval, and (2) the relationship between both QT interval and the QT/heart rate slope and markers of adverse prognosis in thesetwo conditions. The QT interval was measured at rest and during exercise in 34 subjects with heart failure, 16 subjects with left ventricular hypertrophy and 16 age-matched controls with normal left ventricular structure andfunction. QTc (corrected QT) intervals at rest were significantly longer in heart failure patients (471 +/- 10 ms) than in controls (421 +/- 6 ms) orin subjects with hypertrophy (420+/-6 ms) (P < 0.05). At peak exercise, despite the attainment of similar heart rates, the QT intervals no longer differed from each other, being 281+/-7 ms for controls, 296+/-11 ms in hypertrophy and 303+/-10 ms in heart failure (no significant difference). The QT/heart rate slope was significantly increased in heart failure [2.3 +/- 0.1 ms.(beats/min)(-1)] compared with controls [1.55 +/- 0.06 ms.(beats/min)(-1)] and hypertrophy [1.66 +/- 0.1 ms.(beats/min)(-1)] (P < 0.001). In left ventricular hypertrophy, despite animal data suggesting that QT interval prolongation should occur, no abnormalities were found in QT intervals at restor during exercise. The QT/heart rate slope did not relate to any markers for an adverse prognosis, except that of prolongation of QT interval. Long QT intervals were associated principally with impairment of left ventricular systolic function. Our data emphasize the dynamic nature of the QT interval abnormalities found in heart failure.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/12/20 alle ore 03:57:47