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Comparison between measured and synthesized posterior lead electrocardiograms during percutaneous coronary intervention-induced myocardial ischemia.

BACKGROUND: Posterior/inferolateral myocardial ischemia is frequently underrecognized on standard 12&#x2011;lead electrocardiography (ECG). Synthesized posterior leads derived from the standard 12&#x2011;lead ECG have been proposed as an alternative to directly measured posterior leads; however, their accuracy under controlled ischemic conditions has not been fully validated. METHODS: We prospectively enrolled 26 consecutive patients undergoing percutaneous coronary intervention (PCI) in whom simultaneously recorded measured and synthesized posterior lead ECGs (V7-V9) were obtained during balloon-induced myocardial ischemia. ST-segment deviation was measured at the ST junction (STJ), 40&#xa0;ms (ST1), and 80&#xa0;ms (ST2) thereafter. Agreement between measured and synthesized posterior leads was assessed using Pearson correlation and Bland-Altman analyses. As an exploratory patient-level analysis, diagnostic performance was compared with reciprocal anterior ST-segment depression (V1-V4). RESULTS: Strong correlations were observed between measured and synthesized posterior lead ST-segment deviations (V7: r&#xa0;=&#xa0;0.89; V8: r&#xa0;=&#xa0;0.86; V9: r&#xa0;=&#xa0;0.83; all P&#xa0;<&#xa0;0.001). Bland-Altman analysis demonstrated minimal systematic bias (within &#xb1;0.004&#xa0;mV) and narrow limits of agreement. Synthesized posterior leads showed higher diagnostic performance than reciprocal anterior ST-segment depression (AUC 0.917 vs. 0.708), although the difference was not statistically significant (DeLong test, P&#xa0;=&#xa0;0.197). Using a 0.05&#xa0;mV threshold, synthesized posterior leads demonstrated 83.3% sensitivity, 100% specificity, and 96.2% overall accuracy. CONCLUSIONS: Synthesized posterior leads closely reproduced measured posterior lead ST-segment deviations during percutaneous coronary intervention (PCI)-induced myocardial ischemia, supporting the technical validity of posterior lead reconstruction. Larger prospective studies are warranted to determine whether synthesized posterior leads provide incremental diagnostic value beyond careful interpretation of the standard 12&#x2011;lead ECG.

Humans

Teaching Acute Coronary Syndrome High-Risk ECG Interpretation and Clinical Decision-Making Through FOAMed Videos and Podcast Versus Print-Based Materials Among Emergency Care Providers: Randomized Controlled Mixed Methods Trial.

BACKGROUND: Accurate interpretation of high-risk acute coronary syndrome (ACS) electrocardiograms (ECGs) is essential for early diagnosis and timely reperfusion, yet substantial deficits persist across health care professions. Digital self-learning formats such as FOAMed (Free Open Access Medical Education) are widely used, but their effectiveness has rarely been evaluated for complex, high-risk ACS ECG patterns. Existing ECG education studies often focus on students or single professional groups and established ST-segment elevation myocardial infarction (STEMI) criteria, leaving newer guideline-recognized STEMI equivalents, selected emerging occlusion myocardial infarction (OMI)-related patterns, and interprofessional emergency care underrepresented. OBJECTIVE: This study aimed to compare the effectiveness of FOAMed podcast and videos versus traditional print-based materials for teaching high-risk ACS ECG patterns and related clinical decision-making in emergency providers. METHODS: We conducted a prospective, interprofessional, controlled mixed methods trial across 5 training sites in Germany. Paramedics, prehospital emergency physicians, and emergency department clinicians received either a FOAMed multimedia module or print-based materials through concealed allocation; deviations from the intended 1:1 ratio resulted from participant no-shows. The intervention consisted of a 30-minute supervised self-learning session. In total, 103 participants were allocated to FOAMed (n=45) or print-based materials (n=58). Two coprimary outcomes were assessed: ECG interpretation accuracy and text-based ACS clinical decision-making. Secondary outcomes included subjective confidence, learning experience, and exploratory qualitative free-text responses. Outcome assessment was automated and blinded; mixed ANOVA was the primary analysis. The study was not prospectively registered because it assessed educational outcomes in health care professionals rather than patient health outcomes. RESULTS: All 103 participants completed the study. Both groups improved, with greater gains in the FOAMed group: ECG interpretation increased from 55% to 65.5% and text-based ACS clinical decision-making from 45% to 68%, versus 57% to 60% and from 47% to 63%, respectively, in the print-based group. Effect sizes were &#x3b7;&#xb2;=0.055 for ECG interpretation and &#x3b7;&#xb2;=0.044 for clinical decision-making. Exploratory subgroup analyses provided no evidence of differential effects across age, gender, or professional background and were likely underpowered. Qualitative responses (46 and 37 entries) provided contextual insights into perceived clarity, engagement, and practical relevance supporting the quantitative findings. CONCLUSIONS: This study is innovative in directly comparing a curated FOAMed multimedia module with selected print-based materials in an interprofessional emergency care population. It differs from existing research by focusing on subtle, emerging ischemic patterns and evaluating realistic, time-limited self-learning formats. The findings provide evidence that curated FOAMed resources can produce greater short-term improvements in ECG interpretation and text-based ACS clinical decision-making than traditional print-based materials in this setting. Although implications for clinical performance remain hypothetical, concise, high-quality digital modules may represent a practical supplement to structured continuing education in emergency care.

Humans

Reliability-aware hierarchical learning for Chagas disease screening from 12-lead ECGs: tackling label uncertainty and class imbalance.

Objective.Chagas disease, a neglected tropical disease (NTD) with significant cardiovascular impact, remains underdiagnosed in resource-limited regions. Electrocardiogram (ECG) screening offers a low-cost tool for detecting cardiac involvement, yet algorithm development is challenged by label noise, data scarcity, and the latent nature of infection. This study proposes a robust ECG-based screening framework that explicitly addresses these constraints.Approach.We introduce aReliability-Aware Hierarchical Learningstrategy that calibrates supervision according to data provenance, prioritizing serology-confirmed labels over noisy self-reports. To mitigate data scarcity, we compare a specialized convolutional neural network (CNN) trained from scratch with a transfer learning approach based on a Spatio-Temporal ECG foundation Model (FM). Performance is evaluated across varying data scales, and the representation structure is analyzed to interpret model behavior.Main results.On the official hidden test set of the George B. Moody PhysioNet/Computing in Cardiology Challenge 2025, our approach achieved a Challenge Score of 0.163. We observe that while the specialized CNN performs competitively in data-rich regimes, the FM exhibits superior robustness in extreme low-resource settings. Furthermore, performance reaches a plateau imposed by underlying disease physiology. Bimodal score distributions suggest that models distinguish established cardiomyopathy from indeterminate infection, which remains electrophysiologically indistinguishable from healthy controls.Significance.These findings clarify both the potential and intrinsic limits of ECG-based AI screening for NTD-associated cardiac involvement. Reliability-aware supervision and data-efficient transfer learning provide a practical framework toward scalable and clinically meaningful ECG screening systems in resource-constrained environments.

Humans

Electrocardiographic correlates of pacing induced cardiomyopathy and response to cardiac resynchronization therapy.

BACKGROUND: Chronic right ventricular (RV) pacing (RVP) causes pacing-induced cardiomyopathy (PICM) in only a small number of patients. We evaluated ECG correlates of (i) PICM and (ii) response to cardiac resynchronization therapy (CRT) upgrade. METHODS: We conducted a retrospective case-control study by including all CRT upgrades for PICM (LVEF <50%) at our center between 2014 and 2018. Controls were patients with &#x2265;5 ECGs all demonstrating RVP over &#x2265;2&#xa0;years and all echocardiographic LVEF &#x2265;50%. Root-summed-squared (3D) ECG was obtained from reconstructed vectorcardiographic X-Y-Z leads. Predictors of PICM and CRT response were assessed as area under ROC curve (AUC) for pre-CRT and &#x394; (post-CRT - pre-CRT) ECG intervals and QRS voltage-time-integrals (VTI). RESULTS: We included 104 patients with CRT upgrade for PICM (age 73.7&#xa0;&#xb1;&#xa0;10.5&#xa0;years, female 29.1%, QRS duration 167.8&#xa0;&#xb1;&#xa0;25.2&#xa0;ms, LVEF 28.8&#xa0;&#xb1;&#xa0;8.0%, &#x394;LVEF 13.8&#xa0;&#xb1;&#xa0;10.3%) and 178 controls without PICM (age 73.2&#xa0;&#xb1;&#xa0;14.9&#xa0;years, female 52.8%, QRS duration 144.0&#xa0;&#xb1;&#xa0;20.9&#xa0;ms, LVEF 56.7&#xa0;&#xb1;&#xa0;5.2%). PICM was best identified by VTIQRS-3D (AUC 0.851; VTIQRS-3D&#xa0;&#x2265;&#xa0;80 &#x3bc;Vs sensitivity 87.5%, specificity 63.5%), VTIQRS-Y (0.846), and QRS duration (0.775). CRT response (LVEF increase &#x2265;10% at 3-12&#xa0;months) occurred in 73/104 (70.2%) patients. Lack of CRT response was best predicted by longer pre-CRT QRS duration (AUC 0.640; QRS duration &#x2265;180&#xa0;ms sensitivity 45.2%, specificity 83.6%), and less &#x394;VTIQRS-3D (0.609) and &#x394;VTIQRS-X (0.608). CONCLUSION: In patients with chronic RVP, VTIQRS-3D&#xa0;&#x2265;&#xa0;80 &#x3bc;Vs can be used as a screening test for echocardiographic confirmation of PICM. RV-paced QRS duration >180&#xa0;ms, on the other hand, identifies those who may not respond to CRT upgrade.

Humans

Bedtime tetrahydrocannabinol ingestion reduces morning orthostatic cardiovascular reactivity in adults: An exploratory study.

Acute cannabis use and its primary psychoactive constituent tetrahydrocannabinol (THC) can induce postural dizziness, indicating increased risk of orthostatic instability. However, it is unknown if vulnerabilities persist the morning after bedtime THC consumption. This study investigated the influence of bedtime THC consumption on cardiovascular variables during an orthostatic challenge. Nine individuals with no cannabis use and eight individuals who regularly use cannabis participated in a tilt table test associated with a 3-day in-laboratory stay. Participants underwent an acclimatization day, followed by a placebo dosing day, and a 10&#x2009;mg THC dosing day. Placebo and THC pills were given 1&#x2009;h before a participant's habitual bedtime, and the tilt table test was performed ~1&#x2009;h upon awakening. Participants were instrumented with an electrocardiogram and an automated sphygmomanometer. Fluid intake and output were measured throughout the study. The morning after THC administration, individuals with no cannabis use reported a higher frequency of dizziness and exhibited a significant reduction in both diastolic blood pressure and heart rate reactivity to tilt (reactivity&#x2009;=&#x2009;tilt - baseline) compared to the morning after placebo. Our results indicate a potential increased risk for orthostatic instability the morning after cannabis consumption in individuals with no cannabis use history.

Humans

A First-in-Japanese Phase 1, Double-Blind, Placebo-Controlled, Parallel-Cohort Study of Sefaxersen, an Antisense Oligonucleotide Targeting Complement Factor B, in Healthy Participants.

Increased activity in the complement alternative pathway (AP) plays a key role in diseases such as IgA nephropathy (IgAN). This first-in-Japanese double-blind Phase 1 study investigated the pharmacokinetics (PK), pharmacodynamics (PD), safety, and tolerability of sefaxersen (RO7434656), an antisense oligonucleotide targeting complement factor B messenger RNA. Healthy participants were randomized equally into four cohorts: placebo or sefaxersen 20, 40, or 70&#xa0;mg. The PK, PD, and safety endpoints were monitored throughout the study and during the 90-day follow-up period. All 24 participants completed the study, with no new safety signals or clinically meaningful changes in blood chemistry, electrocardiogram, or vital signs observed. Plasma sefaxersen concentration demonstrated a biphasic PK profile, characterized by an initial rapid decline followed by a slow elimination. Sefaxersen decreased PD markers related to the complement AP selectively, without affecting the classical pathway, in a dose-dependent manner, and the PD effects persisted over 2 to 3 months. Sefaxersen was well tolerated by healthy Japanese participants, with a manageable safety profile. These findings support the inclusion of Japanese patients with IgAN in the global Phase 3 study (IMAGINATION, NCT05797610).

Humans

Physical reconfiguration of limb electrodes for Precordial Bipolar Lead acquisition: Morphological validation against digital subtraction.

BACKGROUND: The V2&#xa0;-&#xa0;V1 Precordial Bipolar Lead (PBL) selectively evaluates the right-to-left retrosternal axis and has shown diagnostic value beyond the standard 12&#x2011;lead electrocardiogram. However, its use has been limited by the need for raw electrocardiographic data and post-processing software. This study evaluated whether a simple physical reconfiguration of limb electrodes could reproduce the digitally derived V2&#xa0;-&#xa0;V1 morphology with sufficient accuracy for clinical application. METHODS: Thirty-seven subjects underwent two sequential 10-s 12&#x2011;lead recordings using a Cardiovit FT-1 electrocardiograph sampled at 1000&#xa0;Hz. In the standard recording, the digital PBL was calculated as V2&#xa0;-&#xa0;V1. In the second recording, the right-arm and left-arm electrodes were repositioned to the V1 and V2 sites so that Lead I directly recorded the retrosternal dipole. Signals were filtered, synchronized, and analyzed using median beats. Morphological agreement was assessed with Pearson correlation on Z-normalized signals, while absolute agreement was evaluated using Lin's concordance correlation coefficient (CCC), intraclass correlation coefficient (ICC (Lewis, 1931; Nehb, 1938 [1,2])), root mean square error (RMSE), and Bland-Altman analysis. RESULTS: Mean Pearson correlation between digital and physical PBL was 0.955 (SD 0.043), with segment-specific correlations of 0.953 (SD 0.054) for QRS and 0.967 (SD 0.052) for ST-T. Lin's CCC and ICC(2,1) were both 0.871 (SD 0.110), and RMSE was 0.091 (SD 0.049) mV. Bland-Altman analysis showed minimal bias (-0.008&#xa0;mV). CONCLUSIONS: Physical acquisition of the V2&#xa0;-&#xa0;V1 PBL achieved high agreement with the digitally derived signal, supporting a simplified analog method for broader clinical implementation.

Humans

Ameliorating Effects and Autonomic Mechanisms of Transcutaneous Auricular Vagus Nerve Stimulation on Abdominal Pain in Patients With Functional Dyspepsia and Irritable Bowel Syndrome.

BACKGROUND: Patients with functional dyspepsia (FD) and irritable bowel syndrome (IBS) often experience abdominal pain and reduced quality of life and need effective treatments. This exploratory study aimed to evaluate whether transcutaneous auricular vagus nerve stimulation (taVNS) could improve abdominal pain and quality of life in patients with FD and IBS, and whether the effects were mediated via the autonomic mechanisms. METHODS: A total of 64 patients with abdominal pain (43 FD and 21 IBS) with a pain score of 3 out of 10 or higher were randomized to receive 2&#x2009;weeks of taVNS or sham-taVNS treatment. The primary outcome was numeric rating scale (NRS) for abdominal pain. The dyspeptic symptom scales (DSS), IBS symptom severity scale score (IBS-SSS), anxiety and depression scores, and the SF36 quality of life scale were assessed before and after the treatment. The electrocardiogram was also recorded for the assessment of autonomic function at baseline and after the treatment. KEY RESULTS: (1) taVNS reduced the abdominal pain score (p&#x2009;<&#x2009;0.001 for both FD and IBS), the frequency of abdominal pain (p&#x2009;<&#x2009;0.001 for both FD and IBS), and overall symptom scores in both FD patients and IBS patients (p&#x2009;<&#x2009;0.001 for FD and IBS). There was no significant difference in the effect of taVNS on abdominal pain between FD and IBS patients. (2) taVNS improved quality of life compared with baseline in both FD and IBS patients. (3) taVNS decreased anxiety (p&#x2009;<&#x2009;0.001) and depression (p&#x2009;<&#x2009;0.001). (4) taVNS increased vagal activity. At the end of the taVNS treatment, the vagal activity was negatively correlated with the pain score (r&#x2009;=&#x2009;-0.491, p&#x2009;=&#x2009;0.004). CONCLUSIONS: Non-invasive taVNS improves abdominal pain, quality of life, and anxiety and depression in patients with FD and patients with IBS, possibly attributed to the enhancement of vagal activity. TRIAL REGISTRATION: Chinese Clinical Trial Registry: ChiCTR2400085697.

Humans

Impact of Commercial Artificial Intelligence on Radiologist Reading Time for Pulmonary Nodule Evaluation at Chest CT.

Background Chest CT is a primary method for identifying pulmonary nodules, yet interpreting scans remains time-intensive and demanding. Currently, artificial intelligence (AI) is expected to reduce reading times, but the effect of AI on reporting times in this setting is unknown. Purpose To evaluate the impact of a commercial AI software on radiologists' reading time for pulmonary nodule assessment on chest CT scans within a real-world clinical setting. Materials and Methods This retrospective study included patients who underwent chest CT examinations at a tertiary medical center between September 2021 and May 2024. The study period was divided into pre- and post-AI phases. The primary outcome was radiology reporting time. The association between AI implementation and reporting time was evaluated using a multivariable parametric Weibull shared frailty survival model adjusted for reader function, examination type, patient location, and requesting specialty, with clustering at the radiologist level. Interaction analyses assessed heterogeneity across prespecified subgroups. An exploratory extrapolation estimated projected workforce and financial impact. Results This study included 19&#x2009;433 patients (mean age, 62 years &#xb1; 14.2 [SD]; 21&#x2009;814 men; 39&#x2009;323 chest CT examinations, 19&#x2009;190 pre-AI, and 20&#x2009;133 post-AI). AI implementation was associated with faster report completion (adjusted hazard ratio, 1.17; 95% CI: 1.14, 1.21; P < .001). The adjusted median reporting time decreased from 21.3 minutes pre-AI to 18.2 minutes post-AI (14.6% reduction; P < .001). Heterogeneity was observed across reader function (P < .001), examination type (P = .048), and requesting specialty (P = .03). The largest relative reductions were observed for CT thorax electrocardiogram-gated examinations (-41.1%; P < .001) and thoracic radiologists (-25.0%; P < .001), whereas emergency department examinations showed increased median reporting time (7.1%; P < .001). At institutional scan volumes (approximately 20&#x2009;000-22&#x2009;000 chest CT examinations annually), exploratory modeling suggested an approximate reduction of 0.5 full-time equivalent radiologist workload. Conclusion Implementation of commercial AI-assisted pulmonary nodule assessment on chest CT scans reduced radiologist reporting time in a real-world clinical setting. &#xa9; The Author(s) 2026. Published by the Radiological Society of North America under a CC BY 4.0 license. Supplemental material is available for this article. See also the editorial by Iwasawa in this issue.

Humans