ANALYSIS OF GENDER DIFFERENCES IN SPECTRAL CHARACTERISTICS OF HEART RATE AND QT DISPERSION IN YOUNG ALCOHOL-DEPENDENT PATIENTS

The aim of the paper is to study gender differences in spectral characteristics of heart rate and Q-Tcd dispersion in young alcohol-dependent patients. Materials and Methods. The authors examined 60 patients: 30 men and 30 women, their average age was 36.00 (33.75–40.00) and 37.50 (33.75–41.25) years old, respectively. The control group was composed of healthy individuals: 15 men aged 35.00 (29.00–39.00) years old and 15 women aged 31.00 (28.00–40.00) years old. Evaluation of heart rate variability was carried out on a high-resolution ECG apparatus "Poly-Spectrum 8/EX" (Russia), 5-minute recordings were made with further sampling of spectral heart rate indicators. Q-Tcd and QTc dispersion was assessed using a high-resolution ECG device "Poly-Spectrum 8/EX" (Russia) in 12 standard leads lasting 10 seconds each. Agilent 6850 chromograph (USA) was used to estimate blood ethanol concentration. Results. The data on the frequency and severity of the heterogeneity of ventricular myocardium repolarization indicated that men and women with Q-Tcd >70 ms in acute and withdrawal periods dominated over those with borderline Q-Tcd values. The acute period was characterized by a larger number of males with Q-Tcd dispersion >50 ms if compared with women. During the withdrawal period, the number of patients with pathological Q-Tcd dispersion increased. Moreover, the pathology was more obvious in males. There was also a significant decrease in all spectral characteristics of the heart rate in alcohol-dependent patients in the acute and withdrawal periods against the predominance of the sympathetic component (low-frequency heart rate fluctuations) over the parasympathetic one (high-frequency heart rate fluctuations). Conclusions. Alcohol excess in young patients without overt cardiac pathology is accompanied by a decrease in spectral characteristics of heart rate variability and an increase in the QT dispersion. Alcohol-dependent men have more pronounced abnormalities of the repolarization processes than alcohol-dependent women. Gender analysis of spectral parameters shows an equally directional decrease in parameters in alcohol-dependent men and women in comparison with the control group. Key words: spectral characteristics of heart rate variability, HRV, alcohol dependence, corrected Q-Tcd dispersion, corrected QTc interval, QT interval, Q-Td dispersion. Цель – изучение гендерных особенностей спектральных характеристик кардиоритма и дисперсии интервала Q-Tdc у алкогользависимых пациентов молодого возраста. Материалы и методы. Обследовано 60 пациентов: 30 мужчин и 30 женщин, средний возраст 36,00 (33,75–40,00) и 37,50 (33,75–41,25) года соответственно. Контрольную группу составили здоровые лица: 15 мужчин в возрасте 35,00 (29,00–39,00) года и 15 женщин в возрасте 31,00 (28,00–40,00) года. Оценка вариабельности ритма сердца проводилась на аппарате ЭКГ высокого разрешения «Поли-Спектр 8/ЕХ» (Россия) короткими записями длительностью 5 мин с дальнейшей выборкой спектральных показателей ритма сердца. Оценка дисперсии интервалов Q-Tcd и QTc проводилась на аппарате ЭКГ высокого разрешения «Поли-Спектр 8/ЕХ» (Россия) в 12 стандартных отведениях, длительность записи составила 10 с. Концентрация этанола в крови определялась хромографом Agilent 6850 (США). Результаты. Данные по частоте и выраженности гетерогенности процессов реполяризации миокарда желудочков свидетельствуют о преобладании лиц с продолжительностью Q-Tсd более 70 мс среди мужчин и женщин в острый и абстинентный периоды по сравнению с числом пациентов с пограничными значениями Q-Tсd. Острый период характеризуется большим количеством пациентов с дисперсией Q-Tсd более 50 мс у мужчин по сравнению с женской группой. В абстинентный период число лиц с патологической дисперсией Q-Tсd увеличивается, причем несколько быстрее у лиц мужского пола. Также отмечается значительное снижение всех спектральных характеристик кардиоритма у алкогользависимых пациентов в острый и абстинентный периоды алкогольного воздействия на фоне преобладания симпатической составляющей (низкочастотные колебания сердечного ритма) над парасимпатической (высокочастотные колебания сердечного ритма). Выводы. Алкогольный эксцесс у пациентов молодого возраста без манифестной кардиальной патологии сопровождается снижением спектральных характеристик вариабельности ритма сердца и увеличением дисперсии интервала QT. У алкогользависимых мужчин присутствуют более выраженные нарушения процессов реполяризации, чем у алкогользависимых женщин. Гендерный анализ спектральных параметров показывает равнонаправленное снижение показателей у алкогользависимых мужчин и женщин в сравнении с лицами контрольных групп. Ключевые слова: спектральные характеристики кардиоритма, ВРС, алкогольная зависимость, корригированная дисперсия интервала Q-Tcd, корригированный интервал QTc, интервал QT, дисперсия интервала Q-Td.

Electrocardiographic data of children with type 1 diabetes mellitus

Background: Adult patients diagnosed with type 1 diabetes mellitus are at risk for ventricular arrhythmias and sudden cardiac death. Aim: The objective of our study is to evaluate the electrocardiographic data of children diagnosed with type 1 diabetes mellitus and to determine the possibility of arrhythmia in order to prevent sudden death. Methods: Electrocardiographic data of 60 patients diagnosed with type 1 diabetes mellitus and 86 controls, who were compatible with the patient group in terms of age and gender, were compared. Results: The duration of diabetes in our patients with type 1 diabetes mellitus was 5.23 ± 1.76 years, and the haemoglobin A1c levels were 9.63% ± 1.75%. The heart rate, QRS, QT maximum, QT dispersion, QTc minimum, QTc maximum, QTc dispersion, Tp-e maximum, Tp-e maximum/QTc maximum and the JTc were significantly higher compared to the control group. There was no significant correlation between the duration of type 1 diabetes mellitus and HbA1c levels and the electrocardiographic data. Conclusion: We attributed the lack of a significant correlation between the duration of type 1 diabetes mellitus and the haemoglobin A1c levels and the electrocardiographic data to the fact that the duration of diabetes was short, since our patients were children. We believe that patients with type 1 diabetes mellitus should be followed up closely in terms of sudden death, as they have electrocardiographic changes that may cause arrhythmias compared to the control group. However, more studies with longer follow-up periods are necessary to support our data.

Differences in extent of mechano-induced QT-changes in SQTS, WT and LQTS rabbit models

Background Electro-mechanical (EMC) and mechano-electrical coupling (MEC) are essential for normal cardiac function. Alterations in these can result in increased arrhythmia formation. In “electrical” cardiac diseases, long-QT and short-QT syndrome, regional mechanical function is altered via EMC. Purpose In this study, we aimed to investigate how acute changes in mechanics may impact on electrical function (MEC) in these diseases. Methods To determine how acute changes in preload impact on QT duration, adult rabbits of both sexes were given a 6ml/kg BW bolus of 0.9% NaCl IV and 12-lead-ECGs were assessed first in wildtype (WT) and acquired drug-induced (E4031 to block IKr) LQT2 (“aLQT2”) rabbits, and in a second step in transgenic short-QT type 1 (“SQT1”, KCNH2-N588K) and WT littermate control rabbits (“WT-LMC”). Results At baseline, aLQT2 rabbits demonstrated a markedly prolonged heart-rate corrected QTc duration compared to WT (p<0.0001; n=13), with increased QT-dispersion (QTMax-Min [ms], WT 21.4±5.7 vs. aLQT2 25.8±5.8; p=0.003; n=13) and increased short-term variability of QT (STVQT [ms], WT 3.5±1.0 vs. aLQT2 5.3±1.7; p=0.02; n=13), markers for regional and temporal heterogeneity of repolarization, respectively. SQT1 rabbits (n=8) demonstrated a shorter QTc duration compared to WT-LMC (n=10; p=0.04), with no differences in QT-dispersion and STVQT between the two groups. Increased preload acutely prolonged QT and heart-rate corrected QTc in all groups (despite a slight increase in heart-rate by an average of 25 beats/min): in WT [ms] 171.6±11.6 to 213.3±20.3 (p<0.0001) vs. aLQT2 208.9±19.6 to 271.0±37.5 (p<0.0001; n=13 each), and in WT-LMC 171.3±4.8 to 199.2±5.4 (p<0.0001; n=10) vs. SQT1 156.0±4.7 to 177.3±3.5 (p=0.0004; n=8). Importantly, the extent of mechano-induced electrical changes differed among genotypes, with less pronounced QTc prolongation in SQT1 compared to WT-LMC (delta QTc [ms], SQT1 21.2±3.4 (n=8) vs. WT-LMC 27.9±2.8 (n=10; p=0.15)), and a more pronounced QTc prolongation in aLQT2 compared to WT (delta QTc [ms], WT 41.6±14.9 vs. aLQT2 62.1±32.1; p=0.006; n=13 each). Moreover, QT-dispersion was increased significantly upon global mechanical change only in aLQTS (QTMax-Min [ms], 25.8±5.5 to 32.7±12.3; p=0.03; n=13). Conclusion Acute changes in mechanical function result in electrical changes via MEC in SQT1, WT and aLQT2 rabbits. The extent of these changes, however, depends on the underlying QTc duration, with the least pronounced QTc prolongation in SQT1 rabbits, with the shortest QTc, and the most pronounced QTc prolongation in aLQT2 rabbits, with the longest QTc. The most pronounced MEC effects on global QT duration as well as on regional QT dispersion in aLQT2 indicate that acute MEC effects may play an additional role in LQTS-related arrhythmogenesis. FUNDunding Acknowledgement Type of funding sources: Foundation. Main funding source(s): German Research Foundation (DFG) andSwiss National Science Foundation (SNF)

Increased QT Dispersion and High Risk of Ventricular Arrhythmias is Associated with Hyperuricemia in Individuals with Normal Renal Function

Background and aim: Uric acid elevation has been shown to be an important risk factor for cardiovascular and cerebrobascular disease. QT dispersion (QTd) is a parameter that shows the heterogeneity of ventricular repolarization and can be calculated noninvasively from surface electrocardiography. Increased QTd has been associated with severe arrhythmia and risk of sudden death in many patients and disease groups. In this context, we aimed to investigate the effect of uric acid levels on QTd and the effects of decrease in uric acid levels on QTd. Methods: A total of 225 patients with normal renal function were included in the study; 133 of these patients were hyperuricemic (>7 mg/dL), and the remaining 72 patients were normouricemic (Group 1). The hyperuricemic patients were randomly divided into 2 groups, one group (n = 67) was given placebo (Group 2) for 4 months, and the remaining 66 patients were given allopurinol 300 mg/day (Group 3). Results: Hyperuricemic patients had higher hsCRP and QTd and lower eGFR values compared to the normouricemic control group. After 4 months of treatment, 66 patients treated with allopurinol showed a significant decrease in serum uric acid, systolic and diastolic blood pressure, and hsCRP levels, and a significant increase in eGFR. Although the QTd values in the treatment group did not decrease to the same levels as in the normouricemic control group, a statistically significant decrease was found compared to their baseline values. In hyperuricemic control and normouricemic control patients, there were no differences in the levels of uric acid, hsCRP, eGFR, systolic and diastolic blood pressure, and QTd values compared to baseline values. Conclusions: There was a significant association between elevated serum uric acid and QTd, as well as with inflammatory biomarkers. Also, patients who had received hypouricemic therapy during the follow-up period presented a significant decrease in inflammatory markers as well as QTd. This indicates the beneficial effects of decreasing uric acid levels in decreasing the risk for future major adverse events related to ventricular arrhythmias.

Electric myocardial inhomogeneity and stroke: connection and specifics

Funding Acknowledgements Type of funding sources: None. Background. The inconsistency of the literature data on the influence of different hemispheric localization of Cerebrovascular accident (CVA) on the development of cardiac arrhythmias suggests the expediency of further study of the so-called "zones" of the cerebral cortex associated with electrical instability of the myocardium. It is known that dispersion of QT interval and fragmented myocardial activity belong to the markers of electrical instability of the heart and are associated with arrhythmogenesis. The aim of the study. To study the severity of abnormalities of the parameters of electrical instability of myocardium in right and left hemispheric stroke localization in patients with hypertension. Material and methods. 111 patients with left hemispheric localization of ischemic stroke and 75 patients with right hemispheric stroke were examined. Hemorrhagic stroke was observed in 17 patients in the left hemisphere and in 13 patients in the right hemisphere. The average age was 58,2 ± 7,48 years. For all strokes, men prevailed (64% vs. 36%). For the first day of the stroke, all patients were evaluated for QT dispersion and fragmented myocardial activity on the device "Polyspectro-8EX" (Russia). Research results. Evaluation of the parameters of electrical instability of myocardium in patients with stroke revealed more pronounced disorders in hemorrhagic stroke of left hemispheric localization (Table 1). In ischemic stroke, the severity of electrophysiological parameters, reflecting the instability of the myocardium depending on the hemispheric localization, indicates the absence of differences. Conclusions. 1.The most pronounced disturbances in the parameters of electrical stability of the myocardium is observed in hemorrhagic stroke. 2.The severity of myocardial electrical instability in ischemic stroke is not associated with the localization of the focus.

Structural-electrical remodeling of myocardium in neurological deficits in patients with ischemic stroke: is there a connection?

Funding Acknowledgements Type of funding sources: None. Theoretical and clinical questions of the correlation between structural-electrical remodeling of the heart and the severity of neurological deficits at stroke have not been developed or remain controversial so far. Available data in the literature suggests the key role of structural myocardial disorders mainly in hemorrhagic stroke, and cardiocerebral syndrome is considered only from the standpoint of cardioembolic stroke. The aim of the study. To study the peculiarities of structural-electrical remodeling of myocardium with severity of neurological deficit in patients with ischemic stroke. Materials and methods. 111 patients with ischemic stroke in the left hemisphere and 75 patients in the right brain hemisphere were examined. The average age was 56.7 ± 5.58 years. All subjects underwent an ultrasound examination of the heart using the ALOKA SSD 5000 apparatus (Japan) and the QT dispersion using the Polyspectro-8EX apparatus (Russia). Duration of QT dispersion interval more than 50 ms was considered pathological. Research results. Structural remodeling of the heart in patients with ischemic stroke was manifested by the prevalence of high values of the finite-systolic volume of the left ventricle in comparison with patients without stroke (45.8 ± 21.0 vs. 37.7 ± 16.9 ml; p < 0.05), and the finite-diastolic volume of the left ventricle (114.3 ± 38.5 vs. 100.9 ± 35.3 ml; p < 0.05), mainly in the right hemispheric localization of the stroke. Hypertrophy of the ventricular septum (11.3 ± 2.1 and 11.1 ± 2.2) and the posterior wall of the left ventricle (10.4 ± 1.8 and 10.3 ± 2.1 mm) was observed irrespective of the localization of the stroke, which was higher in comparison with patients without stroke (9.4 ± 1.5 mm). Violations of repolarization processes and their severity were characterized by higher values of duration of the corrected QT interval in patients with structural changes of myocardium in comparison with the patients without structural remodeling (0,46 ± 0,03 and 0,44 ± 0,02 sec; p = 0,025). The conjugation of the severity of the neurological deficit (7 and more points on the NIHSS scale) was associated with the terminal-systolic size of the LV (p = 0.025) and myocardial hypertrophy (11.3 ± 1.86 vs. 10.96 ± 1.8 mm; p = 0.04) in comparison with patients with a neurological deficit of less than 7 points (31.7 ± 3.6 vs. 30.68 ± 3.86 mm; p < 0.025). The severity of the neurological deficit according to the Goldstein criteria correlated with higher values of the corrected (56.0 ± 23.93 vs. 41.6 ± 23.3 ms.; p = 0.043) and normalized QT (17.5 ± 6.533 vs. 12.8 ± 6.7 ms.; p = 0.019) values in comparison with the lower neurological deficit. A similar relationship was revealed by the Brott criteria. Conclusions. Thus, the direct connection between structural-electrical remodeling of the heart and neurological deficit revealed in the course of the study reflects the cardiocerebral relationships in ischemic stroke.

Proarrhythmia assessment in treatment with hydroxychloroquine and azithromycin hospitalized elderly COVID-19 patients - our experience

The aim of our study was to characterize the repolarization disorders propensity induced by drug-drug interaction. In this observational retrospective study, we report our experience on all elderly patients with ascertained diagnosis of coronavirus disease 2019 through nasopharyngeal swab with real time-polymerase chain reaction at our Pugliese-Ciaccio hospital in Catanzaro, who received hydroxychloroquine (HCQ), with or without azithromycin (AZY). 33 hospitalized patients were examined. We calculated QT value, cQT, QT dispersion, and cQT dispersion and examined possible progression on the basal electrocardiogram (T0) and after the insertion of the drug (T1). The QT value is increased by T0 vs T1 (370±40.74 vs 420±36.91 ms; P=0.000), as well as the cQT value (408±25.40 vs 451.54±58.81; P=0.003), the QT dispersion (QTd: 36.36±14.53 vs 50.90±13.12 ms; P=0.000); the dispersion of cQTc (cQTd 46.27±18.72 vs 63.18±21.93 ms; P=0.001). The ΔQT was 37.44±44.09 while the ΔcQT was 32.01±56.47). The main determinant of QTc prolongation is the number of drug at risk of prolongation of the QT that could influence the ventricular repolarization phase. The use of HCQ in combination with AZY, in patients suffering from severe acute respiratory syndrome-related coronavirus-2, can favor the onset of serious side effects, even potentially fatal. Finally, the measures of QTd and cQTd confirmed additional electrocardiographic parameters useful in identifying patients being treated with drugs at risk of potential adverse arrhythmic events following drug interaction.