Electrocorticography Analysis in Patients With Dual Neurostimulators Supports Desynchronization as a Mechanism of Action for Acute Vagal Nerve Stimulator Stimulation.

PURPOSE: Both vagal nerve stimulation (VNS) and responsive neurostimulation (RNS System) are treatment options for medically refractory focal epilepsy. The mechanism of action of both devices remains poorly understood. Limited prior evidence suggests that acute VNS stimulation may reduce epileptiform activity and cause EEG desynchronization on electrocorticography (ECoG). Our study aims to isolate effects of VNS on ECoG as recorded by RNS System in patients who have both devices, by comparing ECoG samples with and without acute VNS stimulation. METHODS: Ten 60-second ECoGs each from 22 individuals at 3 epilepsy centers were obtained-5 ECoGs with VNS "off" and 5 ECoGs with VNS "on." Electrocorticograps containing seizures or loss of telemetry connection artifact were excluded from analysis (total of 169 ECoGs were included). Electrocorticographs were analyzed for differences in spectral content by generating average spectrograms for "on" and "off" states and using a linear mixed-effects model to isolate effects of VNS stimulation. RESULTS: Acute VNS stimulation reduced average power in the theta band by 4.9%, beta band by 3.8%, and alpha band by 2.5%. The reduction in theta power reached statistical significance with a P value of <0.05. CONCLUSIONS: Our results provide evidence that acute VNS stimulation results in desynchronization of specific frequency bands (salient decrease in theta and beta bands, smaller decrease in alpha band) in ECoGs recorded by the RNS device in patients with dual (VNS and RNS) neurostimulators. This finding offers support for desynchronization as a theorized mechanism of action of VNS. Further research may lead to future improved neurostimulator efficacy by informing optimal stimulation programming parameters.

Thiamine supplementation in hospitalized patients with altered mental status: does it help?

OBJECTIVE: To describe thiamine-prescribing patterns and to study the association of thiamine supplementation with clinical outcomes in hospitalized patients with altered mental status (AMS). METHODS: We conducted a retrospective cohort study of all adult hospitalized patients with AMS with index admission in calendar year 2017. We studied the association of a) supplemental thiamine and b) timing of thiamine relative to glucose, with hospital outcomes - length of stay (LOS), 90-day readmission rates, and mortality rates - using linear, logistic, and extended Cox models, respectively. We also modeled association of supplemental thiamine on time to resolution of AMS using extended Cox models in patients admitted with AMS. RESULTS: Of 985 patients, 178 (18%) received thiamine, including 123 (12.5%) who received thiamine before, with, or without glucose (thiamine first). We identified 365 (37%) patients who received intravenous glucose before or without thiamine (glucose first). We found that patients who received glucose first had longer LOS and higher rate of in-hospital deaths compared to those who did not. Patients who received thiamine supplementation had longer LOS compared to those who did not. There were no significant differences in other hospital outcomes or AMS resolution by discharge compared to their respective reference groups. CONCLUSION: Although thiamine supplementation was not associated with better hospital or cognitive outcomes, we do not have enough evidence to suggest a change in current practice. Thiamine must be administered prior to glucose in hospitalized patients with AMS.

Household secondary attack rate in SARS-CoV-2 infection during the second wave of the COVID-19 pandemic in South India.

Background: Coronavirus disease 2019 (COVID-19) has become a major public health problem since its inception disrupting public life and crippling health systems. The mutated variant of the causative virus, Delta, has been notorious in causing rapid upsurge in cases compared to the Alpha variant. The current study tries to find out the household secondary attack rate (HSAR) of COVID-19 and factors associated with it during the second wave of cases in Kerala. Methodology: A retrospective cohort study was performed among 313 household contacts of 76 COVID-19 patients who had been admitted in Government Medical College, Thrissur, in the southern state of India, Kerala. Data from the participants were collected via phone using a semi-structured interview schedule, and analysis was performed with SPSS software. Results: The HSAR among household contacts was 59.1% (53.4-64.6%). The risk of acquiring COVID infection among household contacts was higher among contacts of symptomatic index cases with a P value of 0.001 and an odds ratio of 11 (3.7-32.4). index cases were having a home isolation P value of 0.001 and an odds ratio of 3.2 (2-5.1), with delay in COVID-19 testing for index cases with a P value of 0.006. Regarding characteristics of household contacts, higher age groups (p = 0.048), groups living in the same room with an index case P value of 0.021 and an odds ratio of [1.71 (1-2.8)], groups having physical contact with an index case P value of 0.001 and an odds ratio of [3.7 (2.1-7)], groups with touched or cleaned linen/articles with an index case P value of 0.02 and an odds ratio of [1.8 (1-3.1)], and groups having co-morbidities, especially diabetes mellitus (p = 0.0020), were significantly associated with chances of acquiring infection. However, the history of previous COVID positivity in household contacts was a protective factor against the infection P value of 0.009 with an odds ratio of [0.09 (0.01-0.78)]. Conclusion: The study concludes that the second wave of COVID-19 in Kerala was primarily caused by a high SAR, especially among household contacts, and this could have been the reason for the difficulty in control measures during the wave.

Assessment of mitral valve function in children and young adults with hypertrophic cardiomyopathy using three-dimensional echocardiography.

OBJECTIVE: The objective of this study was to assess papillary muscle (PM) and mitral valve (MV) structure and function in children and young adults with mild and moderate hypertrophic cardiomyopathy (HCM) using real-time three-dimensional echocardiography (3DE) and to correlate them with HCM related adverse outcomes. METHODS: Transthoracic research 3DE was performed in HCM patients and controls matched for age and gender. Anterolateral and posteromedial PM mass, apical displacement of anterolateral PM, and left ventricular (LV) mass were measured and indexed to body surface area. The MV annulus and leaflet structure and function were analyzed. Individual PMs were manually planimetered by tracing the endocardial borders on each mid systole frame, taking care to distinguish PMs as distinct from the LV wall. Apical PM displacement was expressed as ratio of the distance between the apex and the base of the anterolateral PM to the entire length of the LV lateral wall (APL index). All 3DE measurements were correlated to adverse outcomes. RESULTS: Forty subjects were studied, including 20 HCM patients (age 18.1 ± 9.6 years, 16 male and 4 female), and 20 controls (18.2 ± 9.6 years, 16 male and 4 female). The indexed LV mass in HCM was 74.8 ± 25.8 g/m2 compared to 50.8 ± 12.4 g/m2 in controls (p = 0.001). The anterolateral, posteromedial and combined PM mass were 3.1 ± 2.2 g/m2, 1.7 ± 1.2 g/m2 and 4.9 ± 2.7 g/m2 in HCM, in contrast to respective measurements of 1.1 ± 0.6 g/m2, 1.2 ± 0.6 g/m2 and 2.3 ± 0.8 g/m2 in controls (p < 0.001, p = 0.062, and p < 0.001, respectively). The mitral valve annular parameters (annulus circumference, height and area) in HCM were not significantly different from controls. The APL index in HCM was less than in controls (0.44 ± 0.07 vs. 0.55 ± 0.04, p < 0.001). The LV lateral wall length and LV mass correlated with adverse HCM outcomes, while the APL index and PM total mass were not associated with adverse events. CONCLUSION: It is feasible to evaluate PM muscles and MV annulus geometry in children and young adults with HCM using 3DE. The morphologic and functional changes of anterolateral PM may occur in the absence of MV annulus changes. Prospective validation will be required to determine if LV lateral wall length and LV mass may be used as predictors of adverse events.

Association of left ventricular size with regional right ventricular mechanics in Hypoplastic Left Heart Syndrome.

BACKGROUND: In Hypoplastic Left Heart Syndrome (HLHS), RV dysfunction is associated with poor outcomes. However, the effect of varying LV size on regional RV mechanics and outcome has not been studied. METHODS: Twenty newborns (0-7 days) with HLHS had pre-stage 1 and pre-stage 2 echocardiograms prospectively protocoled for strain analysis of the apical 4-chamber view. RV longitudinal strain was analyzed, and LV size was classified as diminutive (no visible LV chamber) or moderate size (visible LV chamber). Clinical outcome was reported as alive vs death or transplant (D-TP) at final clinical follow-up (pre-stage 3). Groups were compared with t-test, Fisher's Exact, and ANOVA tests as appropriate. RESULTS: At pre-stage 1, infants with a diminutive LV (7/20, 35%) vs a moderately hypoplastic LV (13/20, 65%) did not have significantly different global RV strain (-18.4 ±â€¯2.6% vs -18.8 ±â€¯3.2%; p = 0.83). However, basal septal strain was significantly diminished in the moderately hypoplastic LV group vs the diminutive LV group (-4.4 ±â€¯6.0% vs -14.7 ±â€¯3.3%; p < 0.005). There was severely diminished septal strain in nearly all (11/13) of the moderately hypoplastic group. At the pre-stage II echo, global RV strain between groups remained similar (p = 0.76) as did the diminished septal strain in the moderate LV group (p = 0.86). The moderately hypoplastic LV group had worse clinical outcomes (6/13 D-TP vs 0/7 D-TP; p = 0.05). CONCLUSIONS: In this small HLHS cohort, diminished septal strain leading to asymmetric RV mechanics may be associated with poor outcomes in those with larger LV/septal size.

Association of Pediatric Medical Emergency Teams With Hospital Mortality.

BACKGROUND: Implementation of medical emergency teams has been identified as a potential strategy to reduce hospital deaths, because these teams respond to patients with acute physiological decline in an effort to prevent in-hospital cardiac arrest. However, prior studies of the association between medical emergency teams and hospital mortality have been limited and typically have not accounted for preimplementation mortality trends. METHODS: Within the Pediatric Health Information System for freestanding pediatric hospitals, annual risk-adjusted mortality rates were calculated for sites between 2000 and 2015. A random slopes interrupted time series analysis then examined whether implementation of a medical emergency team was associated with lower-than-expected mortality rates based on preimplementation trends. RESULTS: Across 38 pediatric hospitals, mean annual hospital admission volume was 15 854 (range, 6684-33 024), and there were a total of 1 659 059 hospitalizations preimplementation and 4 392 392 hospitalizations postimplementation. Before medical emergency team implementation, hospital mortality decreased by 6.0% annually (odds ratio [OR], 0.94; 95% confidence interval [CI], 0.92-0.96) across all hospitals. After medical emergency team implementation, hospital mortality continued to decrease by 6% annually (OR, 0.94; 95% CI, 0.93-0.95), with no deepening of the mortality slope (ie, not lower OR) in comparison with the preimplementation trend, for the overall cohort (P=0.98) or when analyzed separately within each of the 38 study hospitals. Five years after medical emergency team implementation across study sites, there was no difference between predicted (hospital mean of 6.18 deaths per 1000 admissions based on preimplementation trends) and actual mortality rates (hospital mean of 6.48 deaths per 1000 admissions; P=0.57). CONCLUSIONS: Implementation of medical emergency teams in a large sample of pediatric hospitals in the United States was not associated with a reduction in hospital mortality beyond existing preimplementation trends.

Abnormal right atrial performance in repaired tetralogy of Fallot: A CMR feature tracking analysis.

BACKGROUND: We hypothesized that right atrial (RA) performance is abnormal in repaired tetralogy of Fallot (TOF). METHODS: TOF patients were prospectively enrolled for cardiovascular magnetic resonance (CMR), echocardiography and exercise stress following a standardized 14-center protocol. Peak RA longitudinal strain (RALS) and right ventricular longitudinal strain (RVLS) were measured using CMR feature tracking (FT) and correlated to RA and RV end diastolic volumes (EDVi) and ejection fraction (EF). RESULTS: The cohort had 311 subjects: 171 TOF (94 male, age 18.2±8years) and 140 healthy controls (69 male, 16.4±11years). RAEDVi, RALS, RVEDVi, RVLS, RAEF, and RVEF in TOF were 60.8±17.1ml/m2, 13.6±5.7%, 120.3±30.3ml/m2, 12.3±4.2%, 32.5±9.9% and 51.2±8.4% and differed from respective indices in controls: 51.7±15.7ml/m2, 27±10.1%, 74±19.0ml/m2, 18.5±5.3%, 54±8% and 62.5±5.5% (p<0.001). RAEDVi and RALS correlated with RVLS (p=0.004, <0.001, r=0.2,0.3). RAEDVi was higher in older TOF, while RALS did not increase with age. RAEDVi but not RALS correlated with RV systolic pressure(r=0.2, 0). Neither RAEDVi nor RALS was associated with tricuspid regurgitation grade or peak oxygen uptake (r=0.1, 0). Positive correlation was observed for RVEDVi with RAEDVi (p=0.035, r=0.2) and a trend toward negative correlation with RALS (p=0.09, r=0.1). CONCLUSION: RALS, RAEDVi and RAEF are abnormal in TOF. Reduced RALS indicates decreased RA reservoir function. Because they correlate with other functional RV indices, these abnormalities may represent RA diastolic burden from chronic RV dysfunction in TOF. The young cohort age might explain the absence of RALS correlation to tricuspid regurgitation and peak oxygen uptake.