The evolution of QT interval and its dispersion (QTd) were studied in 135 newly diagnosed nondiabetic patients, as well as the relationship between changes of these left ventricular (LV) repolarization parameters with blood pressure (BP) and LV mass changes, which were prospectively studied for a median period of 3.8 years. At baseline and at last follow-up visit, all patients underwent ambulatory BP monitoring, echocardiographic assessment, and 12-lead electrocardiography. At the end of follow-up, responders of antihypertensive treatment based on a reduced 24-hour systolic BP (n=122) exhibited a reduction in LV mass index (by 7.6 g/m2, P<.001) and corrected QT (by 4.3, P=.038), while corrected QTd was unchanged. In nonresponders (n=13), although no difference in LV mass index was observed, corrected QT increased by 12.4 ms (P=.048) and corrected QTd by 8.2 ms (P=.027). Changes in parameters of LV repolarization were related to BP changes but not to changes of myocardial size.
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http://dx.doi.org/10.1111/jch.12275 | DOI Listing |
Cardiovasc Res
January 2025
Department of Pathophysiology, Shenzhen University Medical School, Shenzhen 518060, China.
Aims: Decrease in repolarizing K+ currents, particularly the fast component of transient outward K+ current (Ito,f), prolongs action potential duration (APD) and predisposes the heart to ventricular arrhythmia during cardiac hypertrophy. Histone deacetylases (HDACs) have been suggested to participate in the development of cardiac hypertrophy, and class I HDAC inhibition has been found to attenuate pathological remodeling. This study investigated the potential therapeutic effects of HDAC2 on ventricular arrhythmia in pressure overload-induced cardiac hypertrophy.
View Article and Find Full Text PDFCureus
December 2024
Pediatric Cardiology, Centro Hospitalar Lisboa Central, Unidade Local de Saúde de São José, Lisbon, PRT.
Long QT Syndrome (LQTS) is a rare hereditary canalopathy, characterized by prolonged ventricular repolarization, which can lead to malignant tachyarrhythmias at a young age. Treatment typically involves healthy lifestyle changes and β-blocker therapy. In specific cases, the implantation of an implantable cardioverter defibrillator (ICD) can be an option.
View Article and Find Full Text PDFHealthcare (Basel)
January 2025
Faculty of Medicine, Physical Medicine and Rehabilitation, Ondokuz Mayis University, 55270 Samsun, Turkey.
This study aimed to examine the effects of endurance and high-intensity resistance training on arterial stiffness and ventricular repolarization in elite athletes. A total of 50 male athletes from different sports disciplines (volleyball, football, judo, and wrestling) and a sedentary group of 30 males participated in this study. Data collected from all participants included age, height, body weight, cardiovascular hemodynamic parameters, arterial stiffness parameters, and ECG measurements.
View Article and Find Full Text PDFComput Methods Programs Biomed
January 2025
Department of Physiology II, Kanazawa Medical University, Uchinada 920-0293, Japan. Electronic address:
Background And Objective: It has been believed that polymorphic ventricular tachycardia (VT) such as torsades de pointes (TdP) seen in patients with long QT syndromes is triggered by creating early afterdepolarization (EAD)-mediated triggered activity (TA). Although the mechanisms creating the TA have been studied intensively, characteristics of the arrhythmogenic (torsadogenic) substrates that link EAD developments to TA formation are still not well understood.
Methods: Computer simulations of excitation propagation in a homogenous two-dimensional ventricular tissue with an anisotropic conduction property were performed to characterize torsadogenic substrates that potentially form TA.
Sci Rep
January 2025
International UNESCO Center for Health-Related Basic Sciences and Human Nutrition, Mashhad University of Medical Sciences, Mashhad, Iran.
Premature ventricular contraction (PVC) is characterized by early repolarization of the myocardium originating from Purkinje fibers. PVC may occur in individuals who are otherwise healthy. However, it may be associated with some pathological conditions.
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