OBJECTIVE: The aim of this study was to investigate the influence of circadian behavior of blood pressure, left ventricular hypertrophy, and autonomic function on QTc interval duration in untreated hypertensive patients. DESIGN: Hypertensive patients underwent simultaneous blood pressure and ECG 24-h ambulatory monitoring. Patients were classified into two groups on the basis of a lack of nocturnal fall in blood pressure, as dippers and nondippers. A group of normotensive healthy subjects was studied as controls. METHODS: QT and QTc intervals were automatically computed and spectral analysis was applied to RR interval time series from the same electrocardiogram (ECG) recordings. Left ventricular mass index (LVMI) was computed by echocardiogram. RESULTS: No difference among the three groups was found concerning mean values and circadian pattern of heart rate; by contrast, QTc was significantly longer in nondippers compared to dippers or to normotensive subjects, particularly at night-time, whereas all groups exhibited similar circadian variations in heart rate. Compared to dippers, nondippers showed significantly higher LVMI, which positively correlated with QTc, and parasympathetic withdrawal, which negatively correlated with QTc. CONCLUSIONS: Nondippers show a prolonged ventricular repolarization throughout the 24-h period, absent either in dippers or normotensives. The association of left ventricular hypertrophy and vagal deactivation may lead to prolongation of QTc, potentially facilitating ventricular arrhythmias in nondipper hypertensive patients.
OBJECTIVE: The aim of this study was to investigate the influence of circadian behavior of blood pressure, left ventricular hypertrophy, and autonomic function on QTc interval duration in untreated hypertensivepatients. DESIGN:Hypertensivepatients underwent simultaneous blood pressure and ECG 24-h ambulatory monitoring. Patients were classified into two groups on the basis of a lack of nocturnal fall in blood pressure, as dippers and nondippers. A group of normotensive healthy subjects was studied as controls. METHODS: QT and QTc intervals were automatically computed and spectral analysis was applied to RR interval time series from the same electrocardiogram (ECG) recordings. Left ventricular mass index (LVMI) was computed by echocardiogram. RESULTS: No difference among the three groups was found concerning mean values and circadian pattern of heart rate; by contrast, QTc was significantly longer in nondippers compared to dippers or to normotensive subjects, particularly at night-time, whereas all groups exhibited similar circadian variations in heart rate. Compared to dippers, nondippers showed significantly higher LVMI, which positively correlated with QTc, and parasympathetic withdrawal, which negatively correlated with QTc. CONCLUSIONS: Nondippers show a prolonged ventricular repolarization throughout the 24-h period, absent either in dippers or normotensives. The association of left ventricular hypertrophy and vagal deactivation may lead to prolongation of QTc, potentially facilitating ventricular arrhythmias in nondipper hypertensivepatients.
Authors: Elnur Alizade; Anıl Avcı; Serdar Fidan; Mustafa Tabakçı; Mustafa Bulut; Regayip Zehir; Zeki Simsek; Mert Evlice; Uğur Arslantaş; Hakan Çakır; Mehmet Yunus Emiroglu; Mustafa Akçakoyun Journal: Ann Noninvasive Electrocardiol Date: 2015-01-28 Impact factor: 1.468
Authors: Kemal Karaagac; Erhan Tenekecioglu; Osman Can Yontar; Mustafa Kuzeytemiz; Fahriye Vatansever; Ahmet Tutuncu; Ozlem Arican Ozluk; Mustafa Yilmaz; Mehmet Demir Journal: Int J Clin Exp Med Date: 2014-05-15
Authors: Bernhard Strohmer; Christiana Schernthaner; Bernhard Iglseder; Bernhard Paulweber; Maximilian Pichler Journal: Wien Klin Wochenschr Date: 2007 Impact factor: 1.704