Aim To identify possible predictors of tachycardia-induced cardiomyopathy (TICMP) in patients with newly developed decompensated chronic heart failure (CHF) of nonischemic origin with reduced left ventricular ejection fraction (LV EF) and with persistent atrial tachyarrhythmias. Material and methods This study included 88 patients with newly developed decompensated CHF of nonischemic origin with reduced LV EF and persistent atrial tachyarrhythmias. Resting 12-lead electrocardiography (EGC) and transthoracic echocardiography (EchoCG) were performed upon admission and following the electrical impulse therapy for all patients. Also, 24-h ECG monitoring was performed to confirm sinus rhythm stability. After recovery of sinus rhythm, outpatient monitoring was performed for three months, including repeated EchoCG to evaluate the dynamics of heart chamber dimensions and LV EF. Results The patients were divided into two groups based on the increase in LV EF: 68 responders (TICMP patients with a LV EF increase by >10%) and 20 non-responders (patients with an increase in LV EF by <10% during 3 months following the sinus rhythm recovery). According to results of the baseline EchoCG, LV EF did not significantly differ in the two subgroups (TICMP, 40±8.3 %, 18–50 % and non-responders, 38.55±7.9 %, 24–50 %); moreover, the incidence of cases with LV EF <30% did not differ either (9 patients TICMP and 2 non-responders, р=1.0). TICMP patients compared to non-responders, had significantly smaller left atrial dimensions (4.53±1.14 (2–7) cm and 5.68±1.41 (4–8) cm, р=0.034; 80.8±28.9 (27–215) ml and 117.8±41.3 (46–230) ml, р=0.03, respectively) and left ventricular end-systolic volume (ESV) (67.7±33.1 (29–140) ml and 104.5±44.7 (26–172) ml, р=0.02, respectively). The effect of major EchoCG parameters on the probability of TICMP development was assessed by one-factor and multifactor regression analyses with adjustments for age and sex. The probability of TICMP increased with the following baseline EchoCG parameters: end-diastolic volume (EDV) <174 ml [odd ratio (OR), 0.115, 95 % confidence interval (CI): 0.035–0.371], ESV <127 ml [OR, 0.034, 95 % CI: 0.007–0.181], left atrial volume <96 ml [OR, 0.08 , 95 % CI: 0.023–0.274], right ventricular dimension <4 cm [OR, 0.042 , 95 % CI: 0.005–0.389]. Conclusion Among patients with newly developed decompensation of CHF with reduced LV EF of non-ischemic origin and persistent atrial arrhythmias, TICMP was detected in 72 % of patients. The probability of TICMP did not depend on baseline EF and duration of arrhythmias, but increased with the following baseline EchoCG parameters: EDV< 174 ml, ESV< 127 ml, left atrial volume <96 ml, right ventricular dimension <4 cm. The multifactorial analysis showed that a right atrial volume <96 ml is an independent predictor for the development of TICMP.

Tachycardia-induced cardiomyopathy (TIC) is a reversible subtype of dilated cardiomyopathy (DCM) resulting from sustained supraventricular or ventricular tachycardia and diagnosed by the normalization of left ventricular ejection fraction (LVEF) after stable sinus rhythm restoration. The aim of this study was to determine the contribution of cardiac magnetic resonance (CMR) to the differential diagnosis of TIC and DCM with persistent atrial arrythmias in patients hospitalized for the first time with heart failure (HF) with reduced LVEF of nonischemic origin. A total of 29 patients (age: 58.2 ± 16.9 years; males: 65.5%; average EF: 37.0 ± 9.5%) with persistent atrial tachyarrhythmia and first decompensation of HF without known coronary artery diseases were included in this study. The patients successfully underwent cardioversion and were observed for 30 days. The study population was divided into groups of responders (TIC patients; N = 16), which implies achieving FF > 50% or its increase > 10% in 30 days of TIC, and non-responders (N = 13). The increase in left ventricle (LV) volumes measured using CMR was significantly higher in the non-responder group when compared with the responders (114.8 mL ± 25.1 vs. 68.1 mL ± 10.5, respectively, p < 0.05). Non-responders also demonstrated decreased interventricular septum thickness (9.1 ± 0.8 vs.11.5 ± 1.3, respectively, p < 0.05). Late gadolinium enhancement (LGE) was observed in 12 patients (41.4%). The prevalence of LGE was increased in the non-responder group (25.0% vs. 65.1%, respectively, p = 0.046). Notably, a septal mid-wall LGE pattern was found exclusively in the non-responders. Epicardial adipose tissue thickness was decreased in the non-responder group versus the TIC patients. Conclusion: Patients with TIC were found to have smaller atrial and ventricular dimensions in comparison to patients with DCM. In addition, LGE was more common in DCM patients.

Introduction. Due to the fact that manned space flights beyond Earth orbit are planned in the near future, it becomes relevant to study the effects of the Earth’s reduced magnetic field on humans.Objective. To evaluate the features of sensorimotor reactions, quality of night sleep (nocturnal sleep) and the development of daytime sleepiness during a 24-hour stay under hypomagnetic conditions (HMC).Materials and methods. Experimental studies with the participation of 6 male volunteers aged 26 to 37 years were conducted in 2023. In total, four experimental series were carried out, lasting 24 hours each. The subjects were exposed to hypomagnetic conditions in three groups (the average value was between 0.05–0.14 µT). There was no exposure to such conditions in the placebo group.The research methods included questionnaires regarding the quality and characteristics of night sleep, daytime wakefulness, as well as the study of sensorimotor functions. Statistical processing was carried out by the Statistica 13.0 software package.Results. Daytime sleepiness was found to increase under hypomagnetic conditions in 66% of observations as compared to 33% of cases in the placebo series (p=0.003). Immediately following the cessation of experimental exposure, a rapid activation of the central nervous system was observed, which was expressed in a statistically significant decrease in the total visual-motor reaction time.Conclusions. Under hypomagnetic conditions, the work of brain sleep mechanisms is preserved. Daytime drowsiness that develops under hypomagnetic conditions indicates the possibility of changes in circadian rhythmicity in brain activating systems. The rapid activation of the central nervous system reported immediately following the termination of hypomagnetic conditions has a compensatory character. The revealed features of hypomagnetic conditions influence on the sleep-wake cycle and sensorimotor functions suggest further studies of daytime sleepiness using additional subjective and objective methods of wakefulness level and activity of the central nervous system assessment.

ЦЕЛЬ ИССЛЕДОВАНИЯ Оценка отдаленных прогнозов и исходов у пациентов с тахикардия-индуцированной кардиомиопатией (ТиКМП, вариант аритмия-индуцированной кардиомиопатии) при наблюдении в течение 24 мес. МАТЕРИАЛ И МЕТОДЫ Проведено ретроспективное обсервационное исследование. В исследование включали пациентов клиники кардиологии Университетской клинической больницы №1, госпитализированных в 2020—2021 гг. по поводу сердечной недостаточности (СН) со сниженной фракцией выброса левого желудочка (ФВ ЛЖ) на фоне тахиаритмии (фибрилляции/трепетания предсердий, ФП/ТП). РЕЗУЛЬТАТЫ Из 788 больных, госпитализированных с нарушениями сердечного ритма и СН со сниженной и умеренно сниженной ФВ ЛЖ, в исследование включены 54 (6,9%) пациента, соответствовавших критериям ТиКМП. Среди них преобладали мужчины (n=42; 78%); средний возраст пациентов составил 64,2±10,2 года. При трансторакальной эхокардиографии (ЭхоКГ) ФВ ЛЖ при госпитализации составила 39,5±7,7%, при этом ФВ ЛЖ <35% выявлена у 15 (27,8%) пациентов. При контрольной ЭхоКГ на фоне терапии получена достоверная положительная динамика с увеличением ФВ ЛЖ до 48,3±7,7% (p=0,001). В группе пациентов без рецидива ТиКМП на фоне терапии СН наблюдали значимое уменьшение конечного систолического объема левого желудочка (КСО ЛЖ) — с 88±42,1 до 78,9±32,7 мл (p=0,02). За период наблюдения рецидив отмечен у 18 (33,3%) пациентов. Факторами риска рецидива оказались прием других, за исключением амиодарона, антиаритмических препаратов и наличие в анамнезе артериальной гипертензии. ВЫВОД ТиКМП является причиной обратимой дисфункции левого желудочка у 6,9% пациентов, госпитализированных по поводу СН, при наличии предсердной аритмии. ТиКМП ассоциируется с хорошей долгосрочной выживаемостью, однако у значительной (33,3%) части пациентов отмечается рецидив заболевания.