Interval Changes Research Articles

Effect of Atracurium versus Cisatracurium on QT interval changes in patients undergoing cataract surgery: a randomized clinical trial

BackgroundMuscle relaxants are used during surgery, but their impact on ECG may differ, potentially affecting cardiac safety. This study aimed to compare the effects of Atracurium versus Cisatracurium on QT interval changes in patients undergoing cataract surgery.MethodThis double-blind, parallel-group randomized clinical trial (RCT) was conducted in 2023 in Hamadan, Iran. A total of 80 patients undergoing cataract surgery under general anesthesia were randomly assigned to receive either Atracurium (n = 40) or Cisatracurium (n = 40). QT interval changes were measured at four time points to assess and compare the corrected QT interval (QTc) between the two groups. Data were analyzed using SPSS version 29, and a p-value < 0.05 was deemed significant.ResultsCisatracurium demonstrated significant reductions in QTc from pre-anesthesia to post-anesthesia and through recovery, with values of -9.325 ms (P = 0.045), -9.925 ms (P = 0.038), and − 19.359 ms (P = 0.016), respectively. Atracurium also showed reductions but a notable increase in QTc after anesthesia to the end of surgery (32.322 ms, P = 0.0019). Throughout the procedure, Cisatracurium maintained shorter QTc intervals compared to Atracurium (e.g., T0: 420.07 ms vs. 434.75 ms, P = 0.03), but post-recovery, no significant differences were observed (Cisatracurium: 440.05 ms; Atracurium: 439.80 ms, P = 0.489).ConclusionsAtracurium causes more QT prolongation than Cisatracurium. While both affect QTc intervals, Cisatracurium has a more stable impact on cardiac repolarization, making it safer for patients at risk of QT prolongation. Cisatracurium’s minimal impact on cardiovascular function, especially in patients with low ejection fraction, makes it the preferred choice for maintaining cardiac stability.Trial registrationIRCT20120215009014N441.

Abstract 4136989: Association of alternating PR intervals with paroxysmal atrioventricular block in patients with right bundle branch block following cardiac surgery

Background: We previously observed a positive correlation between QRS duration and the preceding RP interval in sinus rhythm in certain patients experiencing new onset left bundle branch block (LBBB) after transcatheter aortic valve replacement (TAVR). This unique phenomenon, termed inverse decremental conduction ( IDC ) or Yan conduction, prompted us to investigate whether IDC in the left bundle could manifest as AV conduction in an IDC pattern in patients with preexisting right bundle branch block (RBBB) and its association with atrioventricular block (AVB). Methods: 12 lead ECGs, available in-patient telemetry and mobile cardiac outpatient telemetry were reviewed in patients with sinus rhythm and preexisting RBBB who developed paroxysmal AVB requiring temporary or permanent pacemaker within 7 days following any types of cardiac surgery from 2014 to 2023 in Lankenau Medical Center. Results: A total of 9 patients (5 males) with a mean age of 71±15 years were identified to exhibit PR interval changes consistent with IDC prior to paroxysmal AVB. Among these patients, 6 had undergone TAVR, while the remaining 3 had undergone surgical aortic valve replacement, mitral valve repair, and ventricular septal defect repair, respectively. Specifically, PR interval alternation in the setting of RBBB occurred during sinus rhythm in a pattern that the longer RP interval is followed by a longer PR interval (Figure 1). This pattern exhibits the following features: 1) 8 of 9 patients had RBBB plus left anterior fascicular block (LAFB); 2) PR alternation occurred at sinus rates from 68 to 91 bpm within 5 days following surgical procedures; 3) proximal AVB occurred within 1 to 12 hours after PR interval alternation began. A positive correlation was established between PR and preceding RP interval in 2 of 9 patients whose telemetry data were available for analysis ( Figure 2A ). In a patient with RBBB who developed paroxysmal AVB without IDC changes in the PR interval post TAVR, intracardiac recording showed a decrease in AH interval but an increase in HV interval with slowing heart rates ( Figure 2B ), indicating that decremental conduction in AV node can mask IDC in Purkinje system. Conclusion: 1) PR alternation with longer PR following longer preceding RP interval in presence of RBBB, likely due to IDC in left bundle, heralds paroxysmal AVB; 2) PR interval changes resulting from IDC in left bundle in the setting of RBBB may be masked by decremental conduction in AV node.

Prognostic significance of right atrial volume and interval changes in patients with idiopathic pulmonary arterial hypertension

IntroductionIdiopathic pulmonary arterial hypertension (IPAH) is a severe condition characterized by a poor prognosis, rapid deterioration, and high mortality in the absence of lung transplantation. However, non-invasive prognostic markers in assessing IPAH remain uncertain. We aimed to investigate the prognostic significance of chest CT and alterations in heart contours on chest radiography (CXR) in predicting adverse outcomes in IPAH patients. MethodsA retrospective study analyzed medical records of IPAH patients who underwent right heart catheterization and chest CT at a tertiary center between 2001 and 2023. Clinical, hemodynamic, and CT findings, and changes (Δ) in heart contours on CXR were assessed. Adverse events were defined as IPAH-related death or lung transplantation. Cox regression models evaluated the predictive power of these parameters. ResultsIn 80 patients with IPAH (mean age 42.6 years; 75 % females), the 3- and 5-year survival rates were 65.8 % and 55.1 %, respectively. Adverse events were associated with a history of cardiac arrest (Hazard ratio [HR], 11.67, p = 0.02), mean pulmonary artery pressure (HR, 1.04, p = 0.001), creatinine (HR, 4.12, p < 0.001), 6-min walk distance (HR, 0.997, p = 0.03), CT-derived right atrial (RA) volume index (HR, 1.01, p = 0.02), and ΔRA contour on CXR (HR, 1.27, p < 0.001). Combined clinical, CT, and CXR findings showed a 3-year event-free survival predictive accuracy of 82.2 % (95 % CI, 69.8–94.7), outperforming clinical factors alone. ConclusionRapid increases in RA contour on CXR and CT-derived RA volume index were associated with adverse outcomes in IPAH. Assessing these parameters may be helpful in identifying patients who require proactive treatments.

Abstract 4134990: Body Fat Quantitation Predicts Progressive Cardiac Dysfunction with Age: Sex-Dependent Variations And Clinical Outcomes

Background: Among older adults whose body mass index (BMI) readings may be spuriously reduced due to loss of skeletal muscle, BMI alone may lack specificity for body fat quantitation. In addition, sex-based hormones differentially influence body fat composition between the sexes with aging. To evaluate the cardiometabolic effect of body fat on older adults, we hypothesize that sex would exert differential effects on baseline and progression of cardiac dysfunction in older adults. Methods: Community older adults without cardiovascular disease (CVD) underwent prospective transthoracic echocardiography with simultaneous body fat quantitation (body fat mass (BFM), percentage body fat (PBF), and waist-hip ratio (WHR) by bioimpedance, at baseline and five-year intervals. Mitral early diastolic inflow velocity to early diastolic annular tissue velocity (E/e') and early to late diastolic inflow velocity (E/A) ratios were recorded. Multivariable regression models were adjusted for significant clinical variables. Adverse clinical outcomes were defined as mortality or hospitalization during follow-up. Results: Baseline and interval annotation of 409 older adults (mean age 61±12.7 years, 52% females) demonstrated deteriorations in E/A ratios of -0.1 ± 0.3 and E/e' ratios of 1.8 ± 2.8, over a mean duration of 4.9 ± 0.4 years. Baseline BFM (β -0.01, p&lt;0.001; β 0.023, p=0.352) and PBF (β -0.008, p=0.002; β -0.007, p=0.759) predicted interval changes in E/A but not E/e' respectively independent of covariates (Table 1). In sex-specific analyses, higher baseline PBF was associated with deteriorations in E/A (β 0.010, p=0.028) among women and E/e' among men (β -0.069, p=0.020). Increases in PBF over time were particularly associated with reductions in E/A among women (β -0.005, p=0.047) independent of higher baseline PBF, in addition to significant interactions between sex and PBF in predicting changes in E/A. (Figure 1). Higher baseline WHR predicted adverse clinical outcomes [w1] among women (HR 1.09, 95%CI 1.03-1.16, p=0.005). Conclusion: Baseline and longitudinal increases in fat quantity defined a trajectory of deteriorations in cardiac function among older adults, and prognosticated poorer future outcomes, particularly among women with central adiposity as represented by WHR. Refining CVD risk based upon quantitative sex-specific fat targets for older adults may be a strategy in the future.

Defining Objective BASDAI Cut-Offs for Disease Activity States and Improvement Scores in Axial Spondyloarthritis: A Multicentric Collaboration.

To estimate objective cut-off values for Bath ankylosing Spondylitis Disease Activity Index (BASDAI) corresponding to Ankylosing Spondylitis Disease Activity Score with CRP (ASDAS) cut-off values (1.3, 2.1, and 3.5), and for interval changes (ΔBASDAI) corresponding to ΔASDAS (1.1 and 2). In this multicentric study, adult patients with active axial spondyloarthritis (axSpA) treated with either tofacitinib 5 mg twice daily or adalimumab 40 mg subcutaneously fortnightly were recruited. Available paired data on BASDAI and ASDAS and paired interval change of these parameters (taken at least 3-months apart) were analyzed. Cut-off values for BASDAI were determined from a multinomial logistic regression and that for ΔBASDAI were determined with ordinal logistic regression with predicted probabilities. Diagnostics were assessed with correct classification rate (CRR), polychoric correlations (PCC), Goodman and Kruskal Gamma (GKG), and Matthew's correlation coefficient (MCC). Total 962 observations of paired data and 670 interval change data were available from 266 patient (mean age 35 years, mean disease duration 7 years, mean BASDAI 2.7, and mean ASDAS 2.1). Following ASDAS classes were observed: inactive disease 131 (13.6%), moderate disease activity 322 (33.5%), high disease activity 420 (43.65%), and very high disease activity 89 (9.25%). The three cut-offs generated for BASDAI were 0.8, 2.5, and 6 for BASDAI and those for ΔBASDAI were 2 and 4. The CRR for BASDAI cut-offs was 65.59 and that for ΔBASDAI was 54.9. For the BASDAI cut-offs, both PCC and GKG showed high values (> 0.85) and the MCC was 0.471. In patients with axSpA, without any clinical or serological confounders, BASDAI values 0.8, 2.5, and 6 corresponded to ASDAS-CRP values 1.3, 2.1, and 3.5, respectively, and ΔBASDAI values of 2 and 4 correspond to ΔASDAS cut-offs of 1.1 and 2.

Climate controls on speleothem initial 234U/238U ratios in midlatitude climate over two glacial cycles

Despite early hydrological studies of 234U/238U in groundwaters, their utilization as a paleoclimatic proxy in stalagmites has remained sporadic. This study explores uranium isotope ratios in 235 datings (230Th) from six stalagmites in Ejulve cave, northeastern Iberia, covering the last 260 ka. The observed 234U enrichment is attributed to selective leaching of 234U from damaged lattice sites, linked to the number of microfractures in the drip route and wetness frequency, which under certain conditions, may result in the accumulation of 234U recoils. This selective leaching process diminishes with enhanced bedrock dissolution, leading to low δ234U. Temperature variations significantly influence bedrock dissolution intensity. During stadial periods and glacial maxima, lower temperatures likely reduced vegetation and respiration rates, thereby decreasing soil CO2 and overall rock dissolution rates. This reduction could enhance the preferential leaching of 234U from bedrock surfaces due to lower bulk rock dissolution. Additionally, the temperature regime during cold periods may have facilitated more frequent freeze–thaw cycles, resulting in microfracturing and exposure of fresh surfaces. Conversely, warmer temperatures increased soil respiration rates and soil CO2, accelerating rock dissolution rates during interstadials and interglacials, when low δ234U is consistent with high bedrock dissolution rates. The contribution of a number of variables sensitive to bedrock dissolution and wetness frequency processes successfully explains 57 % and 74 % of the variability observed in the δ234U in Andromeda stalagmite during MIS 3–4 and MIS 5b-5e, respectively. Among these variables, the growth rate has emerged as crucial to explain δ234U variability, highlighting the fundamental role of soil respiration and soil CO2 in δ234U through bedrock dissolution. I-STAL simulations provides the potential for a combination of Prior Calcite Precipitation (PCP) indicators like Mg/Ca with PCP-insensitive indicators of bedrock dissolution such as δ234U, along with growth rate data, may be useful to diagnose when PCP variations reflect predominantly changes in drip intervals and when changes in bedrock dissolution intensity contribute. The relationship between stalagmite δ234U, bedrock dissolution, and initial dripwater oversaturation suggests two significant advancements in paleoclimate proxies. First, δ234U could serve as a valuable complement to δ13C since it is significantly influenced by soil respiration and soil CO2, thereby reflecting soil and vegetation productivity sensitive to both humidity and temperature. Secondly, since PCP does not fractionate uranium isotopes, δ234U could be used in combination with Mg/Ca or δ44Ca to deconvolve PCP variations due to changing drip rates from those due to changes in initial saturation state. This study emphasizes the overriding climatic control on δ234U, regardless of the absolute 234U/238U activity ratios among samples and their proximity or distance from secular equilibrium, and advocates for its application in other cave sites.

Electrocardiographic Changes in Second and Third Trimester in Bangladesh: A Comparative Study

Background: During pregnancy, there are notable changes in cardiovascular function to meet the increasing needs of the developing baby. The objective of this study was to compare ECG in pregnant women during their second and third trimesters with a control group of non-pregnant women in Bangladesh. This study aims to offer valuable insights into the cardiovascular changes that happen during pregnancy. This study's findings are important for maternal health research and clinical practice in Bangladesh and beyond. Objective: The purpose of this study is to analyze and compare the ECG variations in women during the second and third trimesters of pregnancy. Methods: The study took place in the gynecology Department at CMH Saidpur, Bangladesh. This study was conducted from March 2023 to August 2023. During this period, 75 pregnant patients in their 2nd trimester and 75 patients in their 3rd trimester were chosen as cases from antenatal outdoor, while 75 non-pregnant women of the same age were selected as the control group. We use the purposive sampling method. Results: During pregnancy, there were notable changes in BMI, heart rate, and PR interval. BMI decreased in the second trimester and increased in the third trimester.22.67% were nulliparous and 77.33% were multiparous in 2nd trimester. In the third trimester, 26.67% were nulliparous and 73.33% multiparous. So, no significant difference in parity. Heart rate increased in both trimesters, while the PR interval shortened in both trimesters. No significant changes were observed in the durations of the QRS complex or QT interval. In our study, the QTc interval displayed a significant rise. ST depression, which may suggest decreased blood flow, was exclusively seen in pregnant women, particularly in the third trimester. Conclusion: We found no significant changes in age, but BMI, heart rate, and PR interval were significantly different from the control group throughout pregnancy. No significant QRS complex or QT interval duration changes were identified. The QTc interval rose. ST depression, more prominent in the third trimester, only affected pregnant women. As shown by ST depression, pregnancy may change cardiac function, electrical activity, and ischemia.

Clinical implication of electrocardiogram change in patients experiencing lung transplantation with end stage lung disease.

End-stage lung disease causes cardiac remodeling and induces electrocardiogram (ECG) changes. On the other way, whether lung transplantation (LTx) in end-stage lung disease patients are associated with ECG change is unknown. The object of this study was to investigate ECG changes before and after LTx in end-stage lung disease patients and whether these changes had clinical significance. This was a single-center retrospective cohort study of 280 end-stage lung disease patients who consecutively underwent LTx at a tertiary referral hospital. ECG findings before LTx and within 1 week and 1, 3, and 6 months after LTx were obtained and analyzed. To find clinical meaning, the ECG at 1 month after LTx was analyzed according to 1-year survival (survivor vs non-survivor groups). Survival data were estimated using the Kaplan-Meier method. Significant differences were observed in the PR interval, QRS duration, QT interval, QTc interval, and heart rate before LTx and 1 month after LTx; the PR interval, QRS duration, QTc interval, and heart rate were decreased. Particularly, the QTc interval was significantly decreased 1 month after LTx, whereas there was no significant change in the QTc interval from 1 to 6 months thereafter. The PR interval, QT interval, QTc interval, and heart rate were significantly different between the survivor and non-survivor groups. The serial changes in QTc interval before LTx and 1 and 3 months after LTx were also significantly different between the survivor and non-survivor groups (p = 0.040 after adjusting for age and body mass index). Upon dividing the patients based on the range of QTc interval change ≤ -8 ms, >-8-10 ms, >10-35 ms, >35 ms), the survival rate was significantly lower in the group whose QTc interval at 1 month after LTx decreased by > 35 m (p = 0.019). LTx in patients with end-stage lung disease may induce ECG changes. Patients whose QTc interval at 1 month after LTx decreased by > 35 ms have a significantly higher 1-year mortality rate. Hence, these ECG changes may have clinical and prognostic significance.

Dynamic QTc interval changes observed in real-world patients with implanted insertable cardiac monitors taking class III antiarrhythmic drugs

Abstract Background QT prolongation can lead to sustained ventricular arrhythmias . Class III Antiarrhythmic drugs (AAD) are known to cause QT prolongation. Insertable cardiac monitors (ICM) have the capability to continuously monitor and detect dynamic changes in QT. Purpose To investigate the characteristics of QTc interval changes before and after antiarrhythmic drug loading in real-world ICM patients administered with Sotalol, Amiodarone, and Dofetilide in hospital. Methods The QT detection algorithm detects the T-waves and determines the QTc intervals for every beat, thus providing continuous long-term QTc trends from ICM ECG. Real-world patients from de-identified Electronic Health Record (EHR) database linked with ICM device data warehouse with implanted ICM being administered sotalol, amiodarone or dofetilide AAD for the first time in the hospital were analyzed. The patients were broken down into groups based on the AAD taken. Patients not taking AAD were selected as control. QTc intervals 7-days pre and post administered AAD are reported, and a random 14-day period was used for control patients. The paired difference in median QTc 7 days pre and post administered AAD were analyzed using the Wilcoxon signed rank test. The Wilcoxon rank-sum test was used to analyze QTc between the different groups. Results A total of 487 patients with ICM were included in this analysis: 56 sotalol patients (avg. age: 67±10 years, 50% male), 100 amiodarone patients (avg. age: 72±10 years, 50% male), 52 dofetilide patients (avg. age: 66±12 years, 50% male), and 248 control patients (avg. age: 70±13 years, 50% male). Sotalol, amiodarone, and dofetilide patients showed significant increase in QTc 1-7 days post AAD compared to 1-7 days pre AAD (figure 1). For sotalol (post AAD median[IQR] = 426.5[408.8,446.6] msec, pre AAD median[IQR] = 415.9[391,437.3] msec, p=0.004); Dofetilide (post median[IQR] = 432.4[413,458.7] msec; pre median[IQR] = 409.3[397.5,435.2] msec, p&amp;lt;0.001); Amiodarone (post median[IQR] = 426.3[400.9,449] msec, pre median[IQR] = 415.5[397.5,435.2] msec, p = 0.037). The QTc 1-7 days pre AAD compared to 1-7 days post AAD for control patients was insignificant p&amp;gt;0.05. The median change in QTc 1-7 days post AAD from 1-7 days pre AAD was 13.0, 7.5, 21.25 and -1.0 msec for sotalol, amiodarone, dofetilide, and control patients respectively (figure 2). Dofetilide patients had a significantly higher change in QTc compared to the amiodarone patients, p=0.018. QTc for all three AAD groups when compared to control group post AAD were significantly higher, p&amp;lt;0.001. QTc was also higher pre AAD compared to control, p=0.003, p&amp;lt;0.001, p=0.009 for sotalol, amiodarone, and dofetilide respectively. Conclusions There is a significant increase in QTc detected by ICM in patients receiving index drug loading of Sotalol, amiodarone and dofetilide. QTc monitoring via ICM can detect these dynamic changes in QTc allowing for early intervention.Figure 1Figure 2

Effects of anakinra on patients with heart failure below and above 60 years of age

Abstract Background Anakinra, an interleukin-1 (IL-1) blocker, is being explored in heart failure (HF) to improve cardiorespiratory fitness (CRF). CRF declines with increasing age. Purpose We aimed to determine the influence of anakinra on CRF in aging patients with HF. Methods We analyzed data from 73 patients with HF (55 [51-62] years, 37 (51%) female) treated with anakinra 100 mg subcutaneously daily. Patients were stratified into two groups according to a predetermined cut-off age of 60 years. We measured peak oxygen consumption (peak VO2) and C-reactive protein (CRP), a surrogate for IL-1 activity. Results We included 49 (67%) patients with age &amp;lt;60 years and 24 (33%) with age ≥60 years. The duration of treatment with anakinra was 4 [2-12] weeks. Age was negatively correlated with peak VO2 at baseline and during treatment with anakinra (Spearman’s Rho= -0.375, p=0.001 and Rho= -0.334, p=0.004, respectively). Younger patients had higher baseline peak VO2 (15.2 [12.4–17.7] vs 12.4 [10.3–14.3] mLO2·kg-1·min-1, p=0.001) but similar CRP (6.6 [3.6-16.6] vs 5.1 [2.7-11.2] mg/L, p=0.18). In both groups, anakinra decreased CRP (&amp;lt;60 years: from 6.6 [3.6–16.6] to 1.5 [0.9–3.8] mg/L, p&amp;lt;0.001; ≥60 years: from 5.1 [2.7–11.2] to 1.0 [0.5–3.4] mg/L, p&amp;lt;0.001)(Figure 1A) and increased peak VO2 (&amp;lt;60 years: from 15.2 [12.4–17.7] to 16.0 [14.0–18.7] mLO2·kg-1·min-1, p=0.036; ≥60 years: from 12.4 [10.3–14.3] to 13.7 [11.7–15.8] mLO2·kg-1·min-1, p&amp;lt;0.001)(Figure 1B). No significant differences in interval changes were observed between the groups. Conclusions Older patients with HF have a greater impairment in CRF than younger patients, yet they appear to benefit similarly from treatment with anakinra.Figure 1

How does lead selection impact diagnosis through AI? Implications for continuous monitoring systems using convolutional neural networks

Abstract Background and Objectives Recently, there has been a surge in non-invasive diagnosing methods leveraging the dipolar 12-lead ECG information using Convolutional Neural Networks (CNNs). However, the traditional ECG contains 12 projections of the cardiac dipole in a three-dimensional space can result in redundancy. Furthermore, in continuous monitoring systems such as Holter and wearables, not all 12 leads are consistently available. This study aims to quantify redundancy and determine the best lead configuration for improved classification results using a CNN. It evaluates the level of redundancy in ECG leads and its impact on CNN classification. Methods The degree of redundancy was quantified by means of lead entropies (H) as depicted in Figure 1.A. The standard 12-lead ECG was chosen as the baseline input. From it, various subsets of leads were selected (6, 3, 1 leads) with the objective of attaining maximal orthogonality between leads while minimizing redundancy (Figure 1.B). A 2D-CNN model was trained for multiclass classification: Hypertension (HYP), ST-T interval Changes (STTC), Conduction Disturbances (CD), Myocardial Infarction (MI) and Normal (NORM). The designed inputs were employed to evaluate how redundancy impacts the performance of the CNN (see Figure 1.C). Results Reducing redundancy in input leads led to notable improvements in model prediction for all pathological conditions in terms of Area Under the Curve (AUC). Reducing to 6 and 8 leads were the most suitable input for the CNN (Table 1) increasing by 1.18% in HYP, 0.23% in STTC, 0.52% in CD, and 0.33% in MI. However, a significant reduction in redundancy may result in the loss of essential clinical information for classification, as observed in scenarios involving only 3 or 1 leads. Conclusions When diagnosing pathologies with systems featuring fewer leads, its combinations should aim for maximum orthogonality to reduce redundancy while preserving unique information. By strategically selecting a set of leads with reduced input redundancy, the effectiveness of the standard 12-lead ECG can be improved, thereby enhancing the utility of such continuous monitoring systems for automated diagnosis and also decreasing training and prediction times.

Analysis of ventricular repolarization parameters and heart rate variability in obesity: a comparative study

Obesity is associated with dysfunctional electrocardiographic and cardiac autonomic parameters, which may lead to increased cardiovascular morbidity. Novel electrocardiographic repolarization markers such as Tpeak-Tend (Tpe) interval have not yet been deeply studied in obese patients. We aimed to investigate the association between ventricular repolarization parameters and heart rate variability (HRV) and how they are affected by changes occurring in the cardiac autonomic nervous system. Ninety subjects categorized by Southeast Asian BMI (kg/m2) standards - normal (18-22.9), overweight (23-24.9), and obese (> 24.9), underwent assessment of ventricular repolarization parameters and HRV. Linear correlation between different parameters was also conducted. Obese subjects exhibited longer QTc and Tpe intervals compared to normal-weight subjects (p-value < 0.001, 0.026 respectively). The QTc interval showed a significant correlation (p < 0.05) with all HRV parameters by linear correlation, while the Tpe interval did not. Anthropometric parameters (BMI, WC, and WHR) were also correlated to both ventricular repolarization variables and HRV. While changes in the QTc interval may be due to obesity and/or autonomic changes occurring in the obese state, the Tpe interval does not show a relation with autonomic parameters. Thus, implicating that a change in the Tpe interval is primarily due to the direct effect of either cardiac or visceral obesity. The observed associations between ECG parameters, obesity indices, and HRV parameters suggest a role for ECG in screening for cardiovascular morbidity.

Change in left bundle branch potential-ventricular interval during lead implantation: what is the mechanism?

A 75-year-old male with sick sinus syndrome (SSS) underwent left bundle branch (LBB) pacing (LBBP) implantation. Intraoperative recordings showed that the LBB potential-ventricular (LBB-V) interval gradually decreased from 47 to 19 ms (ms). Two-year follow-up indicated stable pacing parameters and consistent electrocardiogram (ECG) results. Despite potential conduction delays caused by lead implantation, a watchful waiting strategy demonstrated recovery potential without impacting long-term prognosis or pacing parameters.

Gentamicin Pharmacokinetics in Neonates Undergoing Therapeutic Hypothermia for Hypoxic Ischemic Encephalopathy.

The purpose of this study was to review the pharmacokinetic profile of gentamicin among neonates with hypoxic ischemic encephalopathy (HIE) undergoing therapeutic hypothermia (TH) treatment. This was a retrospective study of neonates with HIE undergoing TH in the neonatal intensive care unit who received gentamicin between 2009 and 2014. Demographic information, diagnoses, laboratory test results, and medication administration and monitoring information were collected, and data were analyzed using SciPy. A total of 57 neonates were analyzed. The median birth weight was 3.25 kg (interquartile range [IQR] 2.8-3.68), and median gestational age was 39 weeks (IQR 38-40). An elevated gentamicin trough level (defined as > 2 mg/L) was observed in 61% (35/57) of neonates. Half of the neonates (49%) had multiple gentamicin trough levels obtained, and 4% of the neonates were switched to an alternate agent. There was a significant difference in the number of dosing interval changes in neonates with elevated gentamicin trough levels compared with those with therapeutic gentamicin trough levels (P < 0.001). Of the neonates with elevated gentamicin trough levels, 14% (5/35) failed their hearing screen (P = 0.389). Neonates with HIE undergoing TH may have an altered pharmacokinetic profile, requiring multiple blood draws so medication levels can be monitored and doses adjusted.Traditional gentamicin dosing regimens may not be ideal for this patient population, and further guidance is required for alternative treatment regimens.

Mitigating effects of agmatine on myocardial infarction in rats subjected to isoproterenol.

Isoproterenol (ISO) usage is limited by its potential for cardiotoxicity. We sought to investigate the potential of agmatine in mitigating ISO-induced cardiotoxicity. Agmatine (100mg/kg/day) was intraperitoneally administered to Wistar rats for 7days in the presence or absence of cardiotoxicity induced by subcutaneous injection of ISO (85mg/kg) on the sixth and seventh days. ECG parameters, lactate dehydrogenase (LDH), malondialdehyde (MDA), and creatinine phosphokinase (CPK) were investigated. Changes in cardiac tissue were also investigated using H&E staining. The heart weight/body weight ratio increased in ISO-treated rats. In the agmatine + ISO group, the increased heart rate observed in ISO-treated rats was reversed (317.2 ± 10.5 vs 452.2 ± 10.61, P < 0.001). Agmatine ameliorated the change in PR, RR, and ST intervals and the QRS complex, which was reduced by ISO. Treatment with saline, ISO, and agmatine had no significant effect on papillary muscle stimulation (P > 0.05). The administration of agmatine to ISO-receiving group could mitigate several parameters when compared to ISO-receiving group including increasing papillary muscle contraction (0.83 vs 0.71 N/M2 respectively, P < 0.01), decreasing LDH levels (660ng/ml vs 1080ng/ml, respectively, P < 0.05), decreasing CPK levels (377 U/l vs 642 U/l, respectively, P < 0.05) and decreasing MDA levels (20.32µM/l vs 46.83µM/l, P < 0.001). Coadministration of agmatine and ISO is capable of ameliorating ISO cardiotoxicity by antioxidant effects and controlling the hemostasis of calcium in myocytes.

Preventive treatment effects on brain structures and functions in patients with chronic migraine: A multimodel magnetic resonance imaging study.

Patients with chronic migraine (CM) often exhibit structural and functional alterations in pain-matrix regions, but it remains unclear how preventive treatment affects these changes. Therefore, this study aimed to investigate the structural and functional changes in pain-matrix regions in CM patients after 6-month treatment. A total of 24 patients with CM and 15 healthy controls were recruited for this study. Patients were divided into responder group (N = 9) and non-responder group (N = 15). After completing the Migraine Disability Assessment (MIDAS) questionnaire, all patients underwent whole-brain high-resolution T1-weighted images, diffusion-weighted imaging, and resting-state functional magnetic resonance imaging at baseline and 6-month follow-up. Whole brain gray matter volume and white matter diffusion indices were analyzed using voxel-based analysis. Structural and functional connectivity analyses were performed to understand brain changes in patients after 6-month preventive treatment. The responder group exhibited significantly higher MIDAS scores than the non-responder group at baseline, but no significant difference between the two groups at follow-up. No significant interval change was noted in gray matter volume, white matter diffusion indices, and structural connectivity in CM patients after 6-month treatment. Nonetheless, the functional connectivity was significantly increased between occipital, temporal lobes and cerebellum, and was significantly decreased between parietal and temporal lobes after 6-month preventive treatment. We concluded that resting-state functional connectivity was suitable for investigating the preventive treatment effect on CM patients.

Effectiveness of accelerated diagnostic protocols for reducing emergency department length of stay in patients presenting with chest pain: A systematic review and meta-analysis.

In recent years, there has been an increase in the use of accelerated diagnostic protocols (ADPs) and high-sensitivity troponin assays (hsTn) for the assessment of chest pain in emergency departments (EDs). This study aimed to quantitatively summarize the operational and clinical outcomes of ADPs implemented for patients with suspected cardiac chest pain. To be considered eligible for inclusion, studies must have implemented some form of ADP within the ED for evaluating adult (age ≥18 years) patients presenting with chest pain using Tn assays. The primary outcome was ED length of stay (LOS). Secondary outcomes included the proportion of patients admitted and the proportion with 30-day major adverse cardiac events (MACE). Thirty-seven articles involving 404,566 patients met the inclusion criteria, including five randomized controlled trials (RCTs) and 32 observational studies. A significant reduction in total ED LOS was reported in 22 observational studies and four RCTs. Emergency departments with longer baseline ED LOS showed significantly larger reductions in LOS after ADP implementation. This observed association persisted after adjusting for both the change in serial Tn measurement interval and transition from conventional Tn assay to an hsTn assay (β = -0.26; 95% CI, -0.43 to -0.10). Three studies reported an increase in the proportion of patients admitted after introducing an ADP, one of which was significant while 15 studies reported a significant decrease in admission proportion. There was moderate heterogeneity among the 13 studies that reported MACE proportions, with a non-significant pooled risk ratio of 0.95 (95% CI, 0.86-1.04). Implementation of ADPs for chest pain presentations decreases ED LOS, most noticeably within sites with a high baseline LOS; this decreased LOS is seen even in the absence of any change in troponin assay type. The decrease in LOS occurred alongside reductions in hospital admissions, while not increasing MACE. The observed benefits translated across multiple countries and health regions.

Phase-transition of hydrophobic dipeptide l-phenylalanyl-l-alanine under high pressure via Raman spectroscopy

The study conducted on l-Phenylalanyl-l-Alanine (C12H16N2O3) dehydrated crystals under high-pressure conditions up to 7.0 GPa using Raman spectroscopy revealed significant modifications in both lattice and internal modes. Particularly, alterations were observed in modes associated with carbonyl and NH2 functionalities around 1600 cm−1. The Raman spectra exhibited distinct changes in modes related to torsions and stretching of the ring, suggesting a potential conformational change in specific pressure intervals: 2.6–3.0 GPa, and 5.0–5.1 GPa. Furthermore, notable changes between 0.4 and 1.0 GPa hinted at a structural transformation in the crystal. Additionally, Scanning Electron Microscopy-Field Emission Gun (SEM-FEG) was employed to elucidate the crystal pattern of Phe-Ala·2H2O. The ambient study, incorporating calculations, infrared, and Raman spectroscopy, contributed to a comprehensive understanding of vibrational mode assignments. This research sheds light on the behavior of l-Phenylalanyl-l-Alanine dehydrated crystals under varying pressure conditions, offering valuable insights for medicinal and pharmacological applications.

Artificial intelligence evaluation of electrocardiographic characteristics and interval changes in transgender patients on gender-affirming hormone therapy

Abstract Aims Gender-affirming hormone therapy (GAHT) is used by some transgender individuals (TG), who comprise 1.4% of US population. However, the effects of GAHT on electrocardiogram (ECG) remain unknown. The objective is to assess the effects of GAHT on ECG changes in TG. Methods and results Twelve-lead ECGs of TG on GAHT at the Mayo Clinic were inspected using a validated artificial intelligence (AI) algorithm. The algorithm assigns a patient’s ECG male pattern probability on a scale of 0 (female) to 1 (male). In the primary analysis, done separately for transgender women (TGW) and transgender men (TGM), 12-lead ECGs were used to estimate the male pattern probability before and after GAHT. In a subanalysis, only patients with both pre- and post-GAHT EGCs were included. Further, the autopopulated PR, QRS, and QTc intervals were compared before and after GAHT. Among TGW (n = 86), the probability (mean ± SD) of an ECG male pattern was 0.84 ± 0.25 in the pre-GAHT group, and it was lowered to 0.59 ± 0.36 in the post-GAHT group (n = 173, P &amp;lt; 7.8 × 10−10). Conversely, among TGM, male pattern probability was 0.16 ± 0.28 (n = 47) in the pre-GAHT group, and it was higher at 0.41 ± 0.38 in the post-GAHT group (n = 53, P &amp;lt; 2.4×10−4). The trend persisted in the subanalysis. Furthermore, both the PR (P = 5.68 × 10−4) and QTc intervals (P = 6.65×10−6) prolonged among TGW. Among TGM, the QTc interval shortened (P = 4.8 × 10−2). Conclusion Among TG, GAHT is associated with ECG changes trending towards gender congruence, as determined by the AI algorithm and ECG intervals. Prospective studies are warranted to understand GAHT effects on cardiac structure and function.

TDCS Cranial Nerve Co-Stimulation: Unveiling Brainstem Pathways Involved in Trigeminal Nerve Direct Current Stimulation in Rats.

The effects of transcranial direct current stimulation (tDCS) are typically attributed to the polarization of cortical neurons by the weak electric fields it generates in the cortex. However, emerging evidence indicates that certain tDCS effects may be mediated through the co-stimulation of peripheral or cranial nerves, particularly the trigeminal nerve (TN), which projects to critical brainstem nuclei that regulate the release of various neurotransmitters throughout the central nervous system. Despite this, the specific pathways involved remain inadequately characterized. In this study, we examined the effects of acute transcutaneous TN direct current stimulation (TN-DCS) on tonic (i.e. mean spike rate and spike rate over time) and phasic (number of bursts, spike rate per burst, burst duration, and inter-burst interval) activities while simultaneously recording single-neuron activity across three brainstem nuclei in rats: the locus coeruleus (LC), dorsal raphe nucleus (DRN), and median raphe nucleus (MnRN). We found that TN-DCS significantly modulated tonic activity in the LC, with notable interactions between stimulation amplitude, polarity, and time epoch affecting mean spike rates. Similar effects were observed in the DRN regarding tonic activity. Further, phasic activity in the LC was influenced by TN-DCS, with changes in burst number, duration, and inter-burst intervals linked to stimulation parameters. Conversely, MnRN tonic activity following TN-DCS remained unchanged. Importantly, xylocaine administration to block TN abolished the effects on tonic activities in both the LC and DRN. These results suggest that tDCS effects may partially arise from indirect modulation of the TN, leading to altered neuronal activity in DRN and LC. Besides, the differential changes in tonic and phasic LC activities underscore their complementary roles in mediating TN-DCS effects on higher cortical regions. This research bears significant translational implications, providing mechanistic insights that could enhance the efficacy of tDCS applications and deepen our understanding of its neurophysiological effects.