Electrocardiographic findings in COVID-19: analysis of tele-ECGs in Moscow ECG IT Center

BACKGROUND: Coronavirus disease (COVID-19) affects the cardiovascular system and the primary damage to the respiratory system involved in the pathological process. However, in the available literature, the electrocardiography (ECG) analyses are based only on small-sample studies and case reports, which determine the relevance of larger-scale studies to clarify the nature and prevalence of ECG abnormalities in subjects with confirmed coronavirus infection. AIM: To determine the distribution of ECG changes in COVID-19 patients representing a non-selective population of Moscow residents. MATERIALS AND METHODS: We performed a retrospective analysis of ECGs from 42,799 patients from March 10, 2020 to March 10, 2021 with a verified diagnosis of COVID-19 was performed. The study included patients admitted to Moscow clinical hospitals connected to the ECG IT Center. A standard 12-lead ECG was obtained and transmitted via an Internet connection to the server of the ECG IT Center, where the ECG interpretation was performed. RESULTS: ECG changes were detected in 54% of patients. The most common cardiac arrhythmias were supraventricular extrasystole (12.6%) and atrial fibrillation (12.0%) reported in patients. Signs of the overloaded right heart were detected in 12.5% of cases, of which the ECG pattern of pulmonary embolism was confirmed in 485 patients (1.13%). Infarction ECG pattern was observed in 4.5% of patients, among which 3 cases of Brugada ECG pattern were reported. The incidence of ST-T changes was 2.2% of all study patients. Prolonged QT and QTc intervals were recorded in 540 patients (1.26%). In addition, individual cases of ventricular fibrillation, Frederick syndrome, and atrioventricular block of various degrees were reported. CONCLUSION: The distribution of incidence of ECG changes in COVID-19 was shown based on the data obtained. The high incidence of atrial fibrillation, which is a risk factor for thromboembolic complications, was confirmed. Moreover, a significant prevalence of ECG patterns of overloaded right heart was shown, some are associated with pulmonary embolism. Other reported ECG changes were characterized by a significantly lower prevalence, which does not reduce their clinical significance. The data obtained may be used to improve COVID-19 patient management strategy in the future.

Sub-spreading events limit the reliable elimination of heterogeneous epidemics

We show that sub-spreading events, i.e. transmission events in which an infection propagates to few or no individuals, can be surprisingly important for defining the lifetime of an infectious disease epidemic and hence its waiting time to elimination or fade-out, measured from the time-point of its last observed case. While limiting super-spreading promotes more effective control when cases are growing, we find that when incidence is waning, curbing sub-spreading is more important for achieving reliable elimination of the epidemic. Controlling super-spreading in this low-transmissibility phase offers diminishing returns over non-selective, population-wide measures. By restricting sub-spreading, we efficiently dampen remaining variations among the reproduction numbers of infectious events, which minimizes the risk of premature and late end-of-epidemic declarations. Because case-ascertainment or reporting rates can be modelled in exactly the same way as control policies, we concurrently show that the under-reporting of sub-spreading events during waning phases will engender overconfident assessments of epidemic elimination. While controlling sub-spreading may not be easily realized, the likely neglecting of these events by surveillance systems could result in unexpectedly risky end-of-epidemic declarations. Super-spreading controls the size of the epidemic peak but sub-spreading mediates the variability of its tail.

Sub-spreading events limit the reliable elimination of heterogeneous epidemics

We show that sub-spreading events i.e., transmission events in which an infection propagates to few or no individuals, can be surprisingly important for defining the lifetime of an infectious disease epidemic and hence its waiting time to elimination or fade-out, measured from the time-point of its last observed case. While limiting super-spreading promotes more effective control when cases are growing, we find that when incidence is waning, curbing sub-spreading is more important for achieving reliable elimination of the epidemic. Controlling super-spreading in this low-transmissibility phase offers diminishing returns over non-selective population-wide measures. By restricting sub-spreading we efficiently dampen remaining variations among event reproduction numbers, which minimises the risk of premature and late end-of-epidemic declarations. Because case-ascertainment rates can be modelled in exactly the same way as control policies, we concurrently show that the under-reporting of sub-spreading events during waning phases will engender overconfident assessments of epidemic elimination. While controlling sub-spreading may not be easily realised, the likely neglecting of these events by surveillance systems could result in unexpectedly risky end-of-epidemic declarations. Super-spreading controls the size of the epidemic peak but sub-spreading mediates the variability of its tail.

Prenatal diagnosis and pregnancy determination of sex chromosome aneuploidy screened by non-invasive prenatal testing from 52,453 unselected singleton pregnancies: a retrospective analysis of 4-year experience

Objective To estimate the positive predictive value (PPV) of fetal sex chromosome aneuploidy (SCA) screened in non-selective population and explore the rate of pregnancy termination and ultrasound findings for fetal SCA and the factors influencing parents’ decisions in South China. Methods This is a large-scale retrospective cohort of positive SCA screened from unselected singleton pregnancies by non-invasive prenatal testing (NIPT) from a single prenatal center of a tertiary hospital, from January 2016 to November 2019. Clinical information, indications, diagnostic results, ultrasound findings, pregnancy determinations, and follow-up were reviewed and analyzed. Results 248 cases of SCA positive were screened out of 52453, giving a positive detection rate of 0.47%. The majority of indications (42.7%) were low-risk pregnancies. After genetic counseling, 43 pregnancies (17.3%) declined to prenatal diagnosis, the rest of 205 cases (82.7%) conducted with amniocentesis to detect fetal chromosome, of which 95 were confirmed as true positive of SCA with PPV of 46.3% (95/205). The SCA consisted of 68 sex chromosomal trisomies (26 cases of 47,XXY, 20 cases of 47,XXX and 22 cases of 47,XYY), 17 cases of monosomy X (45,X), three cases of 48,XXYY, three cases of mosaicisms (45,X/46,XX), four cases with sex chromosomal deletions, included two cases of 46,X,del(Y)(q11.21), one case of 46,X,del(X)(p11) and one case of 46,X,i(X)(q10). Of the 95 cases confirmed as true positive SCA, 50 cases (52.6%)chose to terminate the pregnancy (82.6%, 64.3%, 17.6% and 33.3% for 45,X, 47,XXY, 47,XXX and 47,XYY, respectively), 45 cases (47.4%) elected to continue the pregnancy. Ninety-three pregnant were also continued pregnancy after the exclusion of SCA. Conclusions NIPT, as a first-tier routine method for screening autosomal aneuploidies, also could play an important role in screening SCA. Low-risk pregnant women are the main indication for the detection of SCA as NIPT test provides to non-selective population. The trend of overall termination rates of SCA-affected pregnancies is decreased. For 47,XXX and 47,XYY with mild phenotype, couples would like to continue the pregnancy. But for 45,X and 47,XXY, parents apt to terminate pregnancy no matter ultrasound abnormalities were found or not. pregnancy determinations are affected by types of SCA, sonographic findings, maternal age, and presence of infertility.

Simple spike dynamics of Purkinje cells in the macaque vestibulo-cerebellum during passive whole-body self-motion

Theories of cerebellar functions posit that the cerebellum implements internal models for online correction of motor actions and sensory estimation. As an example of such computations, an internal model resolves a sensory ambiguity where the peripheral otolith organs in the inner ear sense both head tilts and translations. Here we exploit the response dynamics of two functionally coupled Purkinje cell types in the vestibular part of the caudal vermis (lobules IX and X) to understand their role in this computation. We find that one population encodes tilt velocity, whereas the other, translation-selective, population encodes linear acceleration. We predict that an intermediate neuronal type should temporally integrate the output of tilt-selective cells into a tilt position signal.

Prenatal diagnosis and pregnancy determination of sex chromosome aneuploidy screened by non-invasive prenatal testing from 52,453 unselected singleton pregnancies: a retrospective analysis of 4-year experience

Objective To estimate the positive predictive value (PPV) of fetal sex chromosome aneuploidy (SCA) screened in non-selective population and explore the rate of pregnancy termination and ultrasound findings for fetal SCA and the factors influencing parents’ decisions in South China.Methods This is a large-scale retrospective cohort of positive SCA screened from unselected singleton pregnancies by non-invasive prenatal testing (NIPT) from a single prenatal center of a tertiary hospital, from January 2016 to November 2019. Clinical information, indications, diagnostic results, ultrasound findings, pregnancy determinations, and follow-up were reviewed and analyzed.Results 248 cases of SCA positive were screened out of 52453, giving a positive detection rate of 0.47%. The majority of indications (42.7%) were low-risk pregnancies. After genetic counseling, 43 pregnancies (17.3%) declined to prenatal diagnosis, the rest of 205 cases (82.7%) conducted with amniocentesis to detect fetal chromosome, of which 95 were confirmed as true positive of SCA with PPV of 46.3% (95/205). The SCA consisted of 68 sex chromosomal trisomies (26 cases of 47,XXY, 20 cases of 47,XXX and 22 cases of 47,XYY), 17 cases of monosomy X (45,X), three cases of 48,XXYY, three cases of mosaicisms (45,X/46,XX), four cases with sex chromosomal deletions, included two cases of 46,X,del(Y)(q11.21), one case of 46,X,del(X)(p11) and one case of 46,X,i(X)(q10). Of the 95 cases confirmed as true positive SCA, 50 cases (52.6%)chose to terminate the pregnancy (82.6%, 64.3%, 17.6% and 33.3% for 45,X, 47,XXY, 47,XXX and 47,XYY, respectively), 45 cases (47.4%) elected to continue the pregnancy. Ninety-three pregnant were also continued pregnancy after the exclusion of SCA.Conclusions NIPT, as a first-tier routine method for screening autosomal aneuploidies, also could play an important role in screening SCA. Low-risk pregnant women are the main indication for the detection of SCA as NIPT test provides to non-selective population. The trend of overall termination rates of SCA-affected pregnancies is decreased. For 47,XXX and 47,XYY with mild phenotype, couples would like to continue the pregnancy. But for 45,X and 47,XXY, parents apt to terminate pregnancy no matter ultrasound abnormalities were found or not. pregnancy determinations are affected by types of SCA, sonographic findings, maternal age, and presence of infertility.

Селективное возбуждение и создание инверсной населенности в квантовых системах с помощью униполярных аттосекундных и терагерцовых импульсов

The possibility of selective population of the energy levels of quantum systems was studied using a single unipolar subcycle pulse and a pair of pulses. Selective population of quantum levels is clearly illustrated based on the numerical solution of the system of equations for the density matrix of a three-level medium interacting with a pair of subcycle attosecond and terahertz pulses. The possibility of creating an population inversion in a three-level medium is shown using a pair of such pulses. The dynamics of population density gratings in a three-level medium is studied at the impact on the system of a pair of large-amplitude Gaussian pulses. If in a weak field the shape of the gratings is harmonic, according to analytical calculations performed according to perturbation theory, then in in the case of a strong field, the spatial profile of the gratings can differ from the sinusoidal one and has complex spike structure.