We report a 35-year-old woman at 31 weeks and 5 days' gestation with severe pre-eclampsia and acute kidney injury who developed symptomatic hypermagnesemia (4.49 mmol/L) and 2:1 second-degree atrioventricular block after receiving a standard Pritchard magnesium sulfate regimen. Magnesium sulfate was discontinued, intravenous calcium gluconate was administered, and emergency cesarean delivery was performed. The atrioventricular block resolved completely, and the mother recovered well. This case highlights a rare but reversible manifestation of magnesium toxicity and the importance of early recognition in patients with deteriorating renal function.
BACKGROUND:Ventricular tachycardia (VT) is a major cause of morbidity and mortality in patients with structural heart disease, yet real-world comparisons between ischemic cardiomyopathy (ICM) and non-ischemic dilated cardiomyopathy (NIDCM) remain limited. METHODS:The national readmission database (2016-2020) was used to identify hospitalizations for VT. Cohorts were stratified based on underlying cardiomyopathy. A Propensity Score Matching (PSM) model matched ICM to NIDCM patients. Pearson's x2 test was applied to PSM-matched cohorts to compare outcomes. RESULTS:We identified 622,092 VT hospitalizations, of which 575,312 (92.4%) had ICM and 46,780 (7.5%) had NIDCM. Outcomes were compared using multivariable logistic regression and propensity score matching (25,919 matched pairs). Despite being younger, NIDCM patients had higher in-hospital mortality (10.4% vs. 9.6%, p < 0.001; aOR 1.08), stroke (1.7% vs. 1.2%, aOR1.42), acute heart failure (65% vs. 59%, aOR 1.36), acute kidney injury (46.1% vs. 41.7%, aOR1.35), endotracheal intubation (13.1% vs. 14.5%, aOR 1.06), ICD implantation (3.9% vs. 3.5%, aOR1.23), and VT ablation (1.0% vs. 0.5%, aOR1.76). Readmission rates were significantly higher in NIDCM at 30 days (10.4% vs. 8.7%, p = 0.019), 90 days (22.7% vs. 20.0%, p = 0.483), and 180 days (30.7% vs. 27.3%, p = 0.001). In contrast, ICM patients had higher rates of sudden cardiac arrest (10.6% vs. 5.9%, aOR0.55), major adverse cardiovascular events (78.9% vs. 52.2%, aOR0.24), cardiogenic shock (18.4% vs. 12.1%, aOR0.59), ECMO (0.9% vs. 0.4%, aOR0.48), and LVAD use (0.5% vs. 0.3%, aOR0.58). Mortality declined over time in ICM (8.5% in 2016 to 8.2% in 2020, p-trend = 0.006), but not in NIDCM. CONCLUSION:These findings highlight distinct clinical profiles and emphasize the need for targeted management strategies for VT based on the cardiomyopathy subtype.
The electrocardiogram (ECG) is a low-cost, readily available test that may detect dysrhythmia, chamber enlargement, and ischemia in an acquired heart disease population. Use of resting ECG to predict adverse events in an adult congenital heart disease (ACHD) population is unknown. ECG characteristics, outcomes, and vital status of 8130 adults born between 1945 and 2001 with at least two available ECGs during a 10-year surveillance period (2010-2019) were evaluated at baseline and at the end of surveillance. Outcomes included cardiac hospitalizations, cardiac surgery or intervention, or death during surveillance. Broad CHD anatomic groups were analyzed as follows: "left-sided," "right-sided," "single-ventricle," and "neither" to account for differences in loading conditions. Of the cohort, 7.2% died, and 33.0% remained alive without adverse events. ECG parameters associated with mortality include wider QRS duration (QRSd), longer corrected QT (QTc), greater QRS-T angle, left bundle branch block, and rhythm change. Those who died had longer mean baseline QRSd (107.3 ms vs. 101.83 ms, p < 0.0001) and QTc (434.94 ms vs. 425.20 ms, p = 0.0004). Change in QRSd (∆QRSd) was greater in the deceased group than alive (5.18 ms vs. 2.01 ms, p < 0.0001), and in alive with an adverse event compared to those alive without an event (2.78 ms vs. 0.42 ms, p < 0.0001). Mean QRS-T angle remained concordant in those without an adverse event but deviated in the adverse event group (5.65° vs. 22.91°) (p < 0.0001). ECG characteristics and changes over time are associated with adverse cardiac events and mortality in a CHD population. Further study is needed to develop an ECG-based risk model to identify at-risk CHD patients.
BACKGROUND:Machine learning (ML) applications in clinical medicine are vulnerable to data leakage, particularly temporal leakage from post-diagnostic features and patient-level leakage from improper partitioning, compromising electrocardiogram (ECG) abnormality detection systems. This study addresses these vulnerabilities through patient-level data splitting and systematic evaluation across multiple classification scenarios. METHODS:ECG data from 4419 observations representing 2180 unique patients were analyzed using Random Under-Sampling Boosting (RUSBoost). Three binary classification scenarios were defined: Scenario 1 (Abnormal vs. Normal, excluding borderline), Scenario 2 (Abnormal + Borderline vs. Normal), and Scenario 3 (Abnormal vs. Normal + Borderline). Patient-level stratified partitioning (60:20:20) prevented information leakage. Models were evaluated using accuracy, sensitivity, specificity, F1-score, learning curves, and precision-recall curves across all partitions. RESULTS:Scenario 1 demonstrated optimal generalization with test accuracy of 70.79%, sensitivity of 60.30%, specificity of 86.50%, and F1-score of 0.712, exhibiting monotonic decline across partitions (73.98%→71.50%→70.79%). Scenario 2 achieved 65.26% test accuracy with greater degradation (6.17 percentage points), reflecting increased difficulty when borderline cases were grouped with abnormal findings. Scenario 3 exhibited problematic non-monotonic patterns (71.84%→67.71%→69.36%) with premature convergence, indicating fundamental generalization challenges despite near-balanced classes (1.07:1 ratio). CONCLUSIONS:Aggregate metrics alone inadequately support clinical deployment decisions. Medical AI evaluation must examine learning dynamics, generalization stability, and precision-recall calibration across partitions. Process-focused standards assessing monotonic decline, convergence characteristics, and calibration stability are essential for reliable ECG abnormality detection deployment.
BACKGROUND:Cardiac implantable electronic devices (CIEDs) frequently detect brief, often subclinical atrial fibrillation (AF), but their value for predicting progression to persistent AF remains uncertain. Statistical and machine learning (ML) approaches may enable dynamic risk stratification using this longitudinal device data. OBJECTIVE:To develop a risk stratification model using clinical and CIED-derived AF burden measured over a rolling 6-month window to predict progression to persistent AF. METHODS:We analyzed continuous CIED data from 1985 patients without prior persistent AF implanted between 2016 and 2024 at a tertiary medical center. AF burden and clinical variables were summarized using overlapping 6-month rolling windows to estimate 1-year risk of persistent AF. Associations were evaluated using Kaplan-Meier and Cox proportional hazards models. A gradient-boosted decision tree model (XGBoost) was used to predict progression. RESULTS:During a mean follow-up of 1192 days, 874 patients (44%) developed paroxysmal AF, of whom 257 (29%) progressed to persistent AF after a mean of 813 days. Patients with no AF or < 1 h/day of AF in the prior 6 months had > 97% 1-year freedom from persistent AF, whereas those with > 8 h/day had a 63% progression rate. Higher AF burden was strongly associated with progression (maximum HR 8.66, p < 0.001). The ML model demonstrated high predictive performance (sensitivity 99.4%, specificity 95.7%). CONCLUSION:CIED-detected AF burden is strongly associated with progression to persistent AF. ML-based analysis of 6-month device data enables accurate, point-in-time risk stratification to support earlier and more targeted clinical management.
BACKGROUND:Lower socioeconomic status (SES), reflected by greater socioeconomic deprivation, lower household income, and lower educational attainment (EA), has been associated with atrial fibrillation (AF). This study aimed to examine the causal influence of SES on AF risk. METHODS:Single-nucleotide polymorphisms (SNPs) associated with Townsend deprivation index (TDI) or household income from the UK Biobank (N = 462,464 and N = 397,751, respectively) and EA from the Social Science Genetic Association Consortium (N = 3,037,499) were selected as instrumental variables. AF-associated SNPs were extracted from FinnGen data freeze 8 (N = 208,594) and a meta-analysis (N = 1,030,836) by Nielsen et al. Two-sample Mendelian randomization (MR) was used to estimate causal relationships, with validity assessed via sensitivity analyses. RESULTS:TDI showed no association with AF risk in either FinnGen (odds ratio (OR) = 0.972, 95% confidence interval (CI): 0.607-1.556, p = 9.00E-01) or Nielsen et al. (OR = 0.805, 95% CI: 0.470-1.381, p = 4.30E-01). Similarly, genetically proxied household income was not associated with AF risk (OR = 1.233, 95% CI: 0.808-1.881, p = 3.30E-01; OR = 0.941, 95% CI: 0.755-1.173, p = 5.90E-01). However, higher genetically proxied EA was associated with lower AF risk in FinnGen (OR = 0.745, 95% CI: 0.653-0.849, p = 1.00E-05) and Nielsen et al. (OR = 0.849, 95% CI: 0.784-0.920, p = 5.90E-05). CONCLUSION:Our MR study found that higher genetically proxied EA was associated with lower AF risk, whereas no evidence of association was found for genetically proxied TDI or household income.
ABSTRACT We present the case of a 72‐year‐old female with Fabry disease who developed an advanced interatrial conduction block and atrial fibrillation, a condition known as Bayés' syndrome. Fabry disease is an X‐linked inherited lysosomal storage disorder that results in the accumulation of globotriaosylceramide in various organs, including the heart. While this condition has been shown to cause cardiac conduction disease, Bayés' syndrome as a result of Fabry disease has not been reported in the literature. This case report suggests that Fabry disease may precipitate atrial cardiomyocyte damage at Bachmann's bundle leading to interatrial block and supraventricular arrhythmia.
ABSTRACT Introduction Sex steroid hormones influence ventricular repolarization and QT interval duration. Testosterone has been associated with shorter QT intervals, whereas androgen deprivation may prolong repolarization indices. However, the effects of orchiectomy on ECG parameters in humans remain insufficiently characterized. Methods We conducted a retrospective analysis of 233 consecutive patients who underwent orchiectomy at our hospital between 2006 and 2021. ECG parameters were compared in 44 patients who had ECG recorded both before and after surgery. Furthermore, the effects of surgery were stratified by unilateral ( n = 20) and bilateral orchiectomy ( n = 24) groups to assess differential effects. Results The mean age was 59.5 years old. Patients in the unilateral group were significantly younger, taller, and heavier ( p < 0.05). Orchiectomy was performed for prostate cancer in 22 patients (50%) and for testicular tumors in 19 patients (43%). No significant differences were observed in QRS width before and after surgery. However, QT and corrected QT (QTc) intervals were significantly prolonged following orchiectomy (QT 383 ± 42 to 403 ± 42 ms, p < 0.01, QTc 416 ± 35 to 433 ± 35 ms, p < 0.001). Post‐surgery, there were no significant differences in the QT and QTc interval prolongation between the two groups. Conclusion Orchiectomy was associated with prolongation of QT/QTc intervals, particularly after bilateral orchiectomy. These findings suggest that patients after orchiectomy may be more susceptible to additional factors that prolong ventricular repolarization, including electrolyte abnormalities and QT‐prolonging medications. Careful ECG monitoring may be warranted in selected patients.
ABSTRACT Background The study investigated an innovative algorithm to improve the diagnosis of different atrioventricular (AV) block types and to improve patient treatment by expanding knowledge in the field of accurate AV‐block identification. Implementing an innovative algorithm holds great potential to assist junior healthcare professionals and those with less expertise in electrocardiogram (ECG) interpretation. Methods In this quantitative study, 40 junior doctors and medical students were randomly assigned to a training group (n = 20) and a control group (n = 20). The training group received a 1‐h teaching session on the algorithm and subsequently interpreted standardized ECGs for AV‐block diagnosis. Data were analyzed using SPSS software. Diagnostic accuracy between groups was compared using an independent t‐test; effect sizes were assessed using Cohen's d. A p value of < 0.05 indicated statistical significance. Results The implementation of the novel ECG interpretation method improved the accuracy of diagnosing AV blocks owing to its reliable and practical application, high accuracy, and impact on the grouped beating in AV‐block diagnosis. Conclusions The suggested algorithm can improve AV‐block detection in clinical practice owing to its high accuracy and structured approach. The research findings will enhance the existing knowledge base on the diagnosis of AV block and positively impact overall patient treatment.
ABSTRACT Cardiac metastases are rare in clinical practice. Herein, we describe the case of a 61‐year‐old male patient who underwent radical left lung cancer surgery > 2 years before the current admission. The postoperative diagnosis was left lung squamous cell carcinoma (stage pT2N1M0/IIB). Post‐surgery, he received adjuvant chemotherapy and did not undergo chest radiotherapy. At the current admission, the patient presented with a dull pain in the left side of his chest. Electrocardiography (ECG) revealed ST‐segment elevation; repeat troponin and cardiac enzyme levels were negative. Coronary CT showed 55%–77% stenosis in the proximal‐mid left anterior descending artery, but no severe occlusive disease in the other major branches. Cardiac ultrasound revealed a 104 × 49 mm hypoechoic mass at the lateral apex without regional wall motion abnormalities or pericardial effusion. Contrast‐enhanced chest CT revealed a metastatic tumor in the left anterior mediastinum with invasion of the pericardium and local left ventricular wall. ST‐segment elevation on ECG does not always indicate acute myocardial infarction. In patients with advanced cancer, if unexplained persistent ST elevation without pathological Q waves is observed, the possibility of cardiac metastasis should be considered.
A 70-year-old man with a history of prior ablation for atrial fibrillation presented with atrial tachycardia (AT). Electrophysiological studies revealed roof-dependent and localized-reentrant ATs. During each AT, widespread breakthrough activation was observed just anterior to the low-voltage area on the anterior wall, suggesting that Bachmann's bundle served as an epicardial bypass within the tachycardia circuits. This case highlights the potential role of Bachmann's bundle in the development of ATs in the remodeled left atrium.
ABSTRACT Introduction Many patients do not benefit from cardiac resynchronization therapy (CRT) with current guideline parameters. The objective of this study was to examine the relationship between left ventricular activation time (LVAT) from the standard 12‐lead surface electrocardiogram (ECG) and clinical outcome from CRT. Methods A retrospective study was performed on patients receiving CRT implants at a large‐volume tertiary care center. Digital ECGs were collected pre‐ and post‐implant. LVAT was defined as the time from QRS onset to maximum deflection in lead V6. The primary combined endpoint was heart failure hospitalization or all‐cause mortality. Results The study group comprised 415 patients (median age [Q1–Q3] of 72.8 years [65.1–78.7], 77.3% male, median baseline LVEF 27.5% [22–30], and 43.1% with ischemic heart failure etiology) who were followed for up to 7.6 years (median 2.8). LVAT was measured pre‐implant (median 78 ms [66–98]) and post‐implant (median 88 ms [74–106]). In Kaplan–Meier analysis, a longer pre‐implant LVAT was associated with a reduced risk of reaching the primary endpoint in patients with LBBB (log‐rank p = 0.046). Post‐implant LVAT was not associated with clinical outcome. Conclusion Our results show that a longer baseline LVAT is associated with a lower risk of heart failure hospitalization and all‐cause mortality. This relationship was of borderline significance in multivariable analysis. Prospective trials would be useful to further explore the potential role of pre‐implant LVAT in patient selection for CRT.
ABSTRACT Background Cardiac implantable electronic device (CIED) implantation, including pacemakers, implantable cardioverter‐defibrillators, and cardiac resynchronization therapy systems, is increasingly performed worldwide. Despite advances in implantation techniques, device pocket‐related complications such as infection, hematoma, and wound dehiscence remain clinically important. The optimal skin closure technique for preventing these complications remains uncertain. Objective To evaluate and compare the safety and effectiveness of different skin closure techniques following CIED implantation. Methods A systematic review and meta‐analysis were conducted according to PRISMA guidelines. PubMed/MEDLINE, Embase, Scopus, Web of Science, and CINAHL were searched from database inception to March 2026. Studies evaluating wound closure techniques after CIED implantation were included. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using a random‐effects model. Primary outcomes included pocket infection, hematoma, and wound dehiscence. Results Nine studies involving 1616 patients were included. Closure methods evaluated included conventional sutures, cyanoacrylate tissue adhesives, skin staplers, and noninvasive closure devices. Pooled analysis showed no significant difference in pocket infection between closure techniques (OR 0.91, 95% CI 0.58–1.42; p = 0.68; I 2 = 29%). Similarly, no significant differences were observed for pocket hematoma (OR 1.08, 95% CI 0.67–1.74; p = 0.74; I 2 = 34%) or wound dehiscence (OR 1.14, 95% CI 0.52–2.51; p = 0.75; I 2 = 21%). Conclusion Different wound closure techniques following CIED implantation demonstrate comparable safety outcomes. Closure method selection may therefore be guided by operator preference, procedural efficiency, and cosmetic considerations.
