UNASSIGNED: Electrocardiogram (EKG) is a commonly used diagnostic tool for the evaluation of the electrical activity of the heart. The purpose of this study was to assess the knowledge and interpretation proficiency of EKG among healthcare professionals (HCPs) in Pakistan.
UNASSIGNED: This prospective cross-sectional study was conducted among HCPs working in different healthcare settings. A structured questionnaire was used to assess the participants\' theoretical knowledge and ability to interpret EKG findings. The data were analyzed using descriptive statistics and χ2 tests. The study indicates that EKG knowledge and interpretation proficiency among HCPs in Pakistan is unsatisfactory. The inadequacy of training periods of EKG training sessions and insufficient participation of HCPs in offered training opportunities put forward the need for the formation and introduction of better structured and efficient EKG training programmes.
UNASSIGNED: A total of 511 HCPs participated in the study, 28% of whom reportedly had received formal training for EKG interpretation. About 80% of the participants correctly identified theoretical questions pertaining to EKG, while 58% of the participants were able to accurately interpret EKG findings, and most HCPs (69.9%) read fewer than ten EKGs per week.
UNASSIGNED: This study demonstrates a lack of expertise and a poor understanding of EKG in HCPs of Pakistan. The low level of EKG knowledge and interpretation proficiency among HCPs may lead to diagnostic errors and poor patient outcomes. Therefore, efforts should be made to improve EKG education and training among HCPs in Pakistan.

Cxcr4a is involved in multiple organ development including coronary vasculature formation and heart left-right (LR) patterning, whether it is involved in heart progenitor determination and cardiac rhythm regulation is not addressed. Here we showed that in cxcr4a mutants, from 2 days post fertilization (dpf) to 4dpf the embryos transiently displayed pericardial edema and increased cardiac rhythm. While from 5dpf, the heart phenotype disappeared. Detailed analysis demonstrated that, at 36hpf and 48hpf, even though there was no distinct difference in the heart size between cxcr4a mutants and controls, the expression of myl7 was decreased. Further data showed that, the heart progenitors were decreased at 18SS(Somite Stage). Mechanically, RNA-seq, RT-qPCR and in situ experiments showed that the retinoic acid (RA) signaling was upregulated, and the up-regulation of RA signaling may mediate the role of cxcr4a in regulating heart progenitor development. In addition, we also identified that low dose of RA treatment accelerated the cardiac rhythm, being similar to that in cxcr4a mutants. Decreasing RA signaling partially restored the rapid cardiac rhythm in cxcr4a mutants, implying the possibility that RA signaling partially mediates the role of cxcr4a in regulating cardiac rhythm. In conclusion, our study identified cxcr4a simultaneously regulates heart progenitor determination and cardiac rhythm.

Traditional temporary cardiac pacemakers (TCPs), which employ transcutaneous leads and external wired power systems are battery-dependent and generally non-absorbable with rigidity, thereby necessitating surgical retrieval after therapy and resulting in potentially severe complications. Wireless and bioresorbable transient pacemakers have, hence, emerged recently, though hitting a bottleneck of unfavorable tissue-device bonding interface subject to mismatched mechanical modulus, low adhesive strength, inferior electrical performances, and infection risks. Here, to address such crux, we develop a multifunctional interface hydrogel (MIH) with superior electrical performance to facilitate efficient electrical exchange, comparable mechanical strength to natural heart tissue, robust adhesion property to enable stable device-tissue fixation (tensile strength: ∼30 kPa, shear strength of ∼30 kPa, and peel-off strength: ∼85 kPa), and good bactericidal effect to suppress bacterial growth. Through delicate integration of this versatile MIH with a leadless, battery-free, wireless, and transient pacemaker, the entire system exhibits stable and conformal adhesion to the beating heart while enabling precise and constant electrical stimulation to modulate the cardiac rhythm. It is envisioned that this versatile MIH and the proposed integration framework will have immense potential in overcoming key limitations of traditional TCPs, and may inspire the design of novel bioelectronic-tissue interfaces for next-generation implantable medical devices.

OBJECTIVE: Selecting the appropriate candidates for extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest (OHCA) is challenging. Previously, the Extracorporeal Life Support Organization (ELSO) guidelines suggested the example of inclusion criteria. However, it is unclear whether patients who meet the inclusion criteria of the ELSO guidelines have more favorable outcomes. We aimed to evaluate the relationship between the outcomes and select inclusion criteria of the ELSO guidelines.
METHODS: We conducted a post-hoc analysis of a multicenter prospective study conducted between 2019 and 2021. Adult patients with OHCA treated with ECPR were included. The primary outcome was a favorable neurological outcome (Cerebral Performance Category of 1 or 2) at 30 days. An ELSO criteria score was assigned based on four criteria: (i) age < 70 years; (ii) witness; (iii) bystander CPR; and (iv) low-flow time (<60 min). Subgroup analysis based on initial cardiac rhythm was performed.
RESULTS: Among 9,909 patients, 227 with OHCA were included. The proportion of favorable neurological outcomes according to the number of ELSO criteria met were: 0.0% (0/3), 0 points; 0.0% (0/23), 1 point; 3.0% (2/67), 2 points; 7.3% (6/82), 3 points; and 16.3% (7/43), 4 points. A similar tendency was observed in patients with an initial shockable rhythm. However, no such relationship was observed in those with an initial non-shockable rhythm.
CONCLUSIONS: Patients who adhered more closely to specific inclusion criteria of the ELSO guidelines demonstrated a tendency towards a higher rate of favorable neurological outcomes. However, the relationship was heterogeneous according to initial rhythm.

UNASSIGNED: We aimed to investigate the association between estimated glomerular filtration rate and prognosis in out-of-hospital cardiac arrest patients and explore the heterogeneity of the association.
UNASSIGNED: Patients experiencing out-of-hospital cardiac arrest due to medical causes and registered in the JAAM-OHCA Registry between June 2014 and December 2019 were stratified into shockable rhythm, pulseless electrical activity, and asystole groups according to the cardiac rhythm at the scene. The primary outcome was a 1-month favorable neurological status. Adjusted odds ratios with 95% confidence intervals were calculated to investigate the association between estimated glomerular filtration rate and outcomes using a logistic model.
UNASSIGNED: Of the 19,443 patients included, 2769 had initial shockable rhythm at the scene, 5339 had pulseless electrical activity, and 11,335 had asystole. As the estimated glomerular filtration rate decreased, the adjusted odds ratio for a 1-month favorable neurological status decreased among those with initial shockable rhythm (estimated glomerular filtration rate, adjusted odds ratio [95% CI]: 45-59 mL/min/1.73 m2, 0.61 [0.47-0.79]; 30-44 mL/min/1.73 m2, 0.45 [0.32-0.62]; 15-29 mL/min/1.73 m2, 0.35 [0.20-0.63]; and <15 mL/min/1.73 m2, 0.14 [0.07-0.27]). Estimated glomerular filtration rate was associated with neurological outcomes in patients aged <65 years with initial shockable rhythm but not in those aged >65 years or patients with initial pulseless electrical activity or asystole.
UNASSIGNED: The estimated glomerular filtration rate is associated with neurological prognosis in out-of-hospital cardiac arrest patients with initial shockable rhythm at the scene but not in those with initial non-shockable rhythm.

Tritium is a betta emitter radionuclide. Being an isotope of hydrogen, it is easily transferred to different environmental compartments, and to human and non-human biota. Considering that tritium levels are expected to rise in the upcoming decades with the development of nuclear facilities producing tritium using fission processes, investigating the potential toxicity of tritium to human and non-human biota is necessary. Tritiated thymidine, an organic form of tritium, has been used in this study to assess its toxicity on fish embryo development. Zebrafish embryos (3.5 hpf; hours post fertilization) have been exposed to tritiated thymidine at three different activity concentrations (7.5; 40; 110 kBq/mL) for four days. These experiments highlighted that zebrafish development was affected by the exposure to organic tritium, with smaller larvae at 3 dpf after exposure to the two lowest dose rates (22 and 170 µGy/h), a delayed hatching after exposure to the two highest dose rates (170 and 470 µGy/h), an increase in the spontaneous tail movement (1 dpf) and a decrease in the heartbeat (3 dpf) after exposure to the highest dose rate. The results also highlighted an increase in ROS production in larvae exposed to the intermediate dose rate. A dysregulation of many genes, involved in apoptosis, DNA repair or oxidative stress, was also found after 1 day of exposure to the lowest tritium dose rate. Our results thus suggest that exposure to tritiated thymidine from a dose rate as low as 22 µGy/h can lead to sublethal effects, with an effect on the development, dysregulation of many genes and increase of the ROS production. This paper provides valuable information on toxic effects arising from the exposure of fish to an organic form of tritium, which was the main objective of this study.

Out-of-hospital cardiac arrest (OHCA) is a leading cause of death worldwide. Cardiac rhythms of OHCA patients can change during transportation and transfer from emergency medical services (EMS) to the emergency department (ED).
Our objective was to study the prevalence of cardiac rhythm changes during transfer from the EMS to the ED in OHCA patients and the possible association with clinical outcomes.
We retrospectively studied adult OHCA patients admitted to the ED between January 2017 and December 2019. The primary outcome was the incidence of cardiac rhythm changes during transfer from EMS to the ED. Secondary outcomes were: ED survival, intensive care unit survival, hospital survival, and maximum Glasgow Coma Scale score during admission.
We included 625 patients, of whom there were 49 (7.8%) in the rhythm change group and 576 in the no rhythm change group. ED survival was significantly lower in the rhythm change group (26.5%) vs. the no rhythm change group (78.5%, p < 0.01).
Cardiac rhythm changes can occur in OHCA patients during transfer from EMS to the ED. Our results showed some evidence that these changes are associated with a lower ED survival.

OBJECTIVE: Atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF) are intimately associated disorders; HFpEF may be overlooked in AF when symptoms are simply attributed to dysrhythmia, and incident AF may identify patients at risk for developing diastolic dysfunction (DD). This study aimed to investigate the prevalence and incidence of DD in patients with new-onset AF compared with sinus rhythm (SR).
METHODS: Adults with new-onset AF (n = 1747) or SR (n = 29 623) and no structural heart disease were identified. Propensity score matching was performed (1:3 ratio) between AF and SR based on age, sex, body mass index, and comorbidities. Severe DD (SDD) was defined by ≥3/four abnormal parameters (medial e\', medial E/e\', tricuspid regurgitation velocity, and left atrial volume index) and ≥moderate DD (>MDD) by ≥2/4. Annualized changes in DD indices were determined.
RESULTS: New-onset AF was independently associated with SDD (8% vs. 3%) and ≥MDD (25% vs. 16%); 62% of patients with AF had high-risk H2FPEF scores, and 5% had clinically recognized HFpEF. Over a median follow-up of 3.2 (interquartile range 1.6-5.8) years, DD progressed two-four-fold more rapidly in those with new-onset AF (P < .001 for all). The risk for incident DD was increased in new-onset AF [hazard ratio (95% confidence interval) 2.69 (2.19-3.32) for SDD and 1.73 (1.49-2.02) for ≥MDD].
CONCLUSIONS: Patients with new-onset AF display high-risk features for HFpEF at diagnosis, emphasizing the importance of evaluating for HFpEF among symptomatic patients with AF. Patients with new-onset AF have accelerated progression in DD over time, which may identify patients with preclinical HFpEF, where preventive therapies may be tested.

Pulseless electrical activity (PEA) and asystole account for 81% of initial in-hospital cardiac arrest (IHCA) rhythms in the U.S.A. These \"non-shockable\" rhythms are often grouped together in resuscitation research and practice. We hypothesized that PEA and asystole are distinct initial IHCA rhythms with distinguishing features.
This was an observational cohort study using the prospectively collected nationwide Get With The Guidelines®-Resuscitation registry. Adult patients with an index IHCA and an initial rhythm of PEA or asystole between the years of 2006 and 2019 were included. Patients with PEA vs. asystole were compared with respect to pre-arrest characteristics, resuscitation practice, and outcomes.
We identified 147,377 (64.9%) PEA and 79,720 (35.1%) asystolic IHCA. Asystole had more arrests in non-telemetry wards (20,530/147,377 [13.9%] PEA vs. 17,618/79,720 [22.1%] asystole). Asystole had 3% lower adjusted odds of ROSC (91,007 [61.8%] PEA vs. 44,957 [56.4%] asystole, aOR 0.97, 95%CI 0.96-0.97, P < 0.01); there was no statistically significant difference in survival to discharge (28,075 [19.1%] PEA vs. 14,891 [18.7%] asystole, aOR 1.00, 95%CI 1.00-1.01, P = 0.63). Duration of resuscitation for those without ROSC were shorter for asystole (29.8 [±22.5] minutes in PEA vs. 26.2 [±21.5] minutes in asystole, adjusted mean difference -3.05 95%CI -3.36--2.74, P < 0.01).
Patients suffering IHCA with an initial PEA rhythm had patient and resuscitation level differences from those with asystole. PEA arrests were more common in monitored settings and received longer resuscitations. Even though PEA was associated with higher rates of ROSC, there was no difference in survival to discharge.

Background and Objectives: Hydroxychloroquine (HCQ) combined with azithromycin (AZM) has been widely administered to patients with COVID-19 despite scientific controversies. In particular, the potential of prolong cardiac repolarization when using this combination has been discussed. Materials and Methods: We report a pragmatic and simple safety approach which we implemented among the first patients treated for COVID-19 in our center in early 2020. Treatment contraindications were the presence of severe structural or electrical heart disease, baseline corrected QT interval (QTc) > 500 ms, hypokalemia, or other drugs prolonging QTc that could not be interrupted. Electrocardiogram and QTc was evaluated at admission and re-evaluated after 48 h of the initial prescription. Results: Among the 424 consecutive adult patients (mean age 46.3 ± 16.1 years; 216 women), 21.5% patients were followed in conventional wards and 78.5% in a day-care unit. A total of 11 patients (2.6%) had contraindications to the HCQ-AZ combination. In the remaining 413 treated patients, there were no arrhythmic events in any patient during the 10-day treatment regimen. QTc was slightly but statistically significantly prolonged by 3.75 ± 25.4 ms after 2 days of treatment (p = 0.003). QTc prolongation was particularly observed in female outpatients <65 years old without cardiovascular disease. Ten patients (2.4%) developed QTc prolongation > 60 ms, and none had QTc > 500 ms. Conclusions: This report does not aim to contribute to knowledge of the efficacy of treating COVID-19 with HCQ-AZ. However, it shows that a simple initial assessment of patient medical history, electrocardiogram (ECG), and kalemia identifies contraindicated patients and enables the safe treatment of COVID-19 patients with HCQ-AZ. QT-prolonging anti-infective drugs can be used safely in acute life-threatening infections, provided that a strict protocol and close collaboration between infectious disease specialists and rhythmologists are applied.