QT Interval Dispersion as a Predictor of Clinical Outcome in Acute Ischemic Stroke

Background and Purpose: QT dispersion (QTd) abnormalities are widely documented in stroke patients. This study aims to investigate the association between QTd and clinical outcomes in IS patients.Methods: IS patients registered in the Blood Pressure and Clinical Outcome in transient ischemic attack (TIA) or IS (BOSS) registry between 2012 and 2014 within 24 h of onset were analyzed. In this prospective observational study, we identified 1,522 IS cases with adequate electrocardiographic evaluations to assess QTd after the index stroke. Patients were classified into four groups based on the quartile of QTd, with the lowest group as the reference. The primary stroke outcome was defined as a modified Rankin Scale score ≥3 at 1-year. Multiple logistic regressions were utilized to investigate the association between QTd and outcome events.Results: The mean QTd across all cases was 57 ms (40–83). Functional dependency or death was documented in 214 (14.98%) cases at 1 year. After adjusting for confounders, the prevalence of death and major disability (mRS ≥ 3) showed significant differences according to the quartile of QTd, with the risk of death and major disability (mRS ≥ 3) at 1 year being significantly higher for patients in Q4 than for those in Q1 (adjusted OR = 1.626, 95% CI:1.033–2.560). However, there were no significant correlation between QTd and the event outcomes at 1 year.Conclusions: QTd was associated with poor functional outcomes at 1 year. QTd is a useful surrogate marker for adverse functional prognosis, which might help to stratify risk in patients with acute IS.

VASCULAR ENDOTHELIAL GROWTH FACTOR AND MYOCARDIAL ELECTRICAL INHOMOGENEITY IN ALCOHOL-DEPENDENT YOUNG PEOPLE

The aim of the study is to examine the relationship between the serum concentration of vascular endothelial growth factor and myocardial electrical inhomogeneity in alcohol-dependent young patients. Materials and Methods. The study enrolled 60 patients: 30 men (37.23±4.38 years old) and 30 women (35.97±4.60 years old). During hospitalization all patients were diagnosed with acute alcohol intoxication and alcohol dependence syndrome of the second stage. The control group consisted of healthy individuals: 15 men (34.20±6.33 years old) and 15 women (32.86±6.88 years old). Q-Td interval dispersion was assessed using a high-resolution ECG device “Poly-Spectrum 8/EX” (Russia) in 12 standard leads. The ethanol concentration in the blood was determined with Agilent 6850 (USA). Serum concentration of vascular endothelial growth factor (VEGF) was assessed in blood serum using a set of Vector-Best reagents (Russia) on an immunoassay analyzer Hospitex diagnostics Plate Screen (Italy). Results. During acute alcohol intoxication, gender differences were characterized by a higher frequency of Q-Td occurrence (>50 ms) in men, if compared with women. The changes in the frequency of Q-Td pathological dispersion in the withdrawal period were unidirectional and they were characterized by an increase in both men and women, with some predominance among men. The indicator values of myocardial electrical inhomogeneity in both acute and withdrawal periods were higher in men. Significant differences in the electrophysiological parameters of the heart and serum VEGF concentration were revealed in examined patients and in the control group. These parameters increased in alcohol-dependent individuals. The withdrawal period was accompanied by negative dynamics of Q-Td interval dispersion increase in men and women. At the same time, the severity of the changes was significantly higher in women than in men. Conclusion. The maximum alcohol-induced increase in VEGF concentration was observed during the period of acute intoxication. An increase in serum VEGF concentration was associated with myocardial electrical inhomogeneity. Keywords: VEGF, QT-d interval dispersion, QT interval, QTc interval, alcohol dependence. Цель – изучить связь сывороточной концентрации сосудисто-эндотелиального фактора роста с электрической негомогенностью миокарда у алкогользависимых пациентов молодого возраста. Материалы и методы. Обследовано 60 пациентов: 30 мужчин (средний возраст – 37,23±4,38 года) и 30 женщин (35,97±4,60 года), у которых на момент поступления в стационар была диагностирована острая интоксикация алкоголем и синдром алкогольной зависимости второй стадии. Контрольную группу составили здоровые лица: 15 мужчин (34,20±6,33 года) и 15 женщин (32,86±6,88 года). Оценка дисперсии интервала Q-Td проводилась на аппарате ЭКГ высокого разрешения «Поли-Спектр 8/ЕХ» (Россия) в 12 стандартных отведениях. Концентрация этанола в крови определялась хромографом Agilent 6850 (США). Сывороточная концентрация фактора сосудисто-эндотелиального роста (VEGF) оценивалась в сыворотке крови набором реактивов «Вектор-Бест» (Россия) на иммуноферментном анализаторе Hospitex diagnostics Plate Screen (Италия). Результаты. В период острой алкогольной интоксикации гендерные различия характеризовались большей частотой встречаемости показателя Q-Td>50 мс у мужчин по сравнению с женщинами. Динамика изменений частоты патологической дисперсии Q-Td в абстинентный период была однонаправленной и характеризовалась ее увеличением у мужчин и женщин с некоторым преобладанием среди мужчин. Значения показателей электрической негомогенности миокарда как в острый, так и в абстинентный периоды были выше у мужчин. Выявлены достоверные различия по электрофизиологическим параметрам сердца и сывороточной концентрации VEGF между обследуемыми пациентами и контрольной группой в сторону возрастания их у алкогользависимых лиц. Абстинентный период сопровождался негативной динамикой в виде увеличения дисперсии интервала Q-Td у мужчин и женщин. При этом выраженность изменений была достоверно выше у женщин по сравнению с мужчинами. Выводы. Максимальное алкогольиндуцированное повышение концентрации VEGF наблюдается в период острой интоксикации. Повышение сывороточной концентрации VEGF сопряжено с электрической негомогенностью миокарда. Ключевые слова: VEGF, дисперсия интервала QT-d, интервал QT, интервал QTс, алкогольная зависимость.

Abnormalities in electrocardiographic ventricular repolarization in patients with dengue virus infection

Introduction: Dengue virus infection (DENV) is an arboviral disease that affects millions of people in many countries throughout the world every year. The disease is caused by the bite of a mosquito (Aedes aegypti and / or Aedes albopictus). The symptoms/signs observed in this arboviral disease are unspecific, and the blood count usually shows leukopenia and thrombocytopenia. Although ECG changes may be observed in DENV, little is known about parameters of ventricular repolarization in patients with this condition. Accordingly, the aim of this study was to evaluate the QTc and QT interval dispersion to detect ventricular repolarization changes in patients with DENV. Methodology: Ninety-three consecutive patients seen during DENV epidemics in a small town with non-complicated DENV were included; 93 normal individuals served as controls. Clinical data, blood count and the 12-lead ECG were obtained from each individual. Results: The QTc duration was higher in patients with DENV in comparison to controls. Furthermore, 5% of DENV patients had abnormal lengthening of the QTc interval. No difference regarding QT interval dispersion was observed between DENV patients and controls. No DENV patient had increased lengthening of the QT interval dispersion. Conclusions: Myocardial repolarization changes do occur in patients with DENV. Having into account the potential impact of these changes on patients’ outcome, and because 12-lead ECG is not routinely recommended in the setting of DENV in our country, we recommend that a 12-lead ECG be taken from each patient with this condition during DENV epidemics.

FEATURES OF STRUCTURAL AND ELECTRICAL REMODELING OF THE HEART ASSOCIATED WITH HIGH RISK OF LIFETHREATENING VENTRICULAR TACHYARRHYTHMIAS IN PATIENTS WITH ISCHEMIC AND NON-ISCHEMIC CARDIOMYOPATHIES

Objective: to identify the features of myocardial fibrosis and ventricular repolarization disorders associated with malignant ventricular tachyarrhythmias (VT) in patients with ischemic (ICM) and non-ischemic cardiomyopathy (NICM).Material and Methods. Fifty consecutive patients (41 men and 9 women aged 60±13 years; 30 patients with ICM and 20 patients with NICM) underwent contrast magnetic resonance imaging (MRI) of the heart, QT dispersion analysis of 12-lead Holter ECG followed by implantation of cardioverter-defibrillator (ICD) or resynchronizing device with defibrillator (CRTD) to prevent sudden cardiac death.Results. According to data of 32 (28–43)-month follow up, VT paroxysms were registered in 20 of 30 patients (67%) with ICM and in 5 of 20 patients (25%) with NICM on follow-up. Data of successive univariate and ROC analyses of MRI indices differed between patients with and without recurrence of VTs in ICM and NICM patient groups. In ICM patients, VTs were associated with the values of QT (peak) interval dispersion over 80 mc according to data of Holter ECG monitoring and higher gray zone in the left ventricle (≥27%) according to contrast-enhanced MRI. Similar analyses in NICM patients showed that the most valuable diagnostic signs associated with the right ventricular tachycardias were the values of QT (peak) interval dispersion over 90 mc according to data of Holter ECG monitoring and the presence of non-transmural fibrosis of the left ventricle (≥27%) according to contrast-enhanced MRI.Conclusion. The features of structural remodeling of the left ventricle predisposing to VTs significantly differ in patients with ICM and NICM. Nevertheless, the presence of ventricular repolarization disorders, associated with onset of VTs, is universal in patients with ischemic and non-ischemic cardiomyopathies.

FEATURES OF STRUCTURAL AND ELECTRICAL REMODELING OF THE HEART ASSOCIATED WITH HIGH RISK OF LIFETHREATENING VENTRICULAR TACHYARRHYTHMIAS IN PATIENTS WITH ISCHEMIC AND NON-ISCHEMIC CARDIOMYOPATHIES

Objective: to identify the features of myocardial fibrosis and ventricular repolarization disorders associated with malignant ventricular tachyarrhythmias (VT) in patients with ischemic (ICM) and non-ischemic cardiomyopathy (NICM).Material and Methods. Fifty consecutive patients (41 men and 9 women aged 60±13 years; 30 patients with ICM and 20 patients with NICM) underwent contrast magnetic resonance imaging (MRI) of the heart, QT dispersion analysis of 12-lead Holter ECG followed by implantation of cardioverter-defibrillator (ICD) or resynchronizing device with defibrillator (CRTD) to prevent sudden cardiac death.Results. According to data of 32 (28–43)-month follow up, VT paroxysms were registered in 20 of 30 patients (67%) with ICM and in 5 of 20 patients (25%) with NICM on follow-up. Data of successive univariate and ROC analyses of MRI indices differed between patients with and without recurrence of VTs in ICM and NICM patient groups. In ICM patients, VTs were associated with the values of QT (peak) interval dispersion over 80 mc according to data of Holter ECG monitoring and higher gray zone in the left ventricle (≥27%) according to contrast-enhanced MRI. Similar analyses in NICM patients showed that the most valuable diagnostic signs associated with the right ventricular tachycardias were the values of QT (peak) interval dispersion over 90 mc according to data of Holter ECG monitoring and the presence of non-transmural fibrosis of the left ventricle (≥27%) according to contrast-enhanced MRI.Conclusion. The features of structural remodeling of the left ventricle predisposing to VTs significantly differ in patients with ICM and NICM. Nevertheless, the presence of ventricular repolarization disorders, associated with onset of VTs, is universal in patients with ischemic and non-ischemic cardiomyopathies.