Major depression, bipolar disorder, and schizophrenia are common mental illnesses, and their potential association with arrhythmias has long been a focus of clinical and research interest. To explore the possible causal relationship between these mental disorders and arrhythmias, we conducted a bidirectional two-sample Mendelian randomization (MR) analysis using publicly available GWAS summary statistics. The primary analysis employed the inverse-variance weighted (IVW) method, with sensitivity analyses including MR-Egger regression and the weighted median estimator to assess robustness and address potential pleiotropy. Results indicated that genetic predisposition to major depression was associated with increased risks of atrial fibrillation/flutter (IVW: OR = 1.214, 95% CI: 1.092-1.349, p < 0.001), paroxysmal tachycardia (IVW: OR = 1.493, 95% CI: 1.261-1.769, p < 0.001), and atrioventricular block (IVW: OR = 1.257, 95% CI: 1.147-1.377, p < 0.001). Reverse MR also suggested a modest effect of atrioventricular block on depression risk (IVW: OR = 1.045, 95% CI: 1.011-1.079, p = 0.008). In conclusion, from the perspective of genetic liability and using the MR framework, our analysis supports a causal role of major depression in increasing the risk of several arrhythmias and suggests potential bidirectional causal effects between depression and atrioventricular block.

Background: There is insufficient data in the literature regarding the relationship between bidirectional conduction block (BCB) parameters and right atrial dimension (RAd). In our study, we aimed to evaluate the relationship between RAd and BCB parameters in typical atrial flutter (AFL) patients. Methods: This prospective study included 197 patients who underwent successful RFA with a diagnosis of typical AFL between 2020 and 2025. We performed RAd and BCB measurements in addition to routine assessments in all patients. The presence of BCB was confirmed by measurement of the CTI double-potential peak-to-peak interval (DPPPI) during CSp pacing, as well as by the difference between the conduction times from isthmus lateral-to-medial pacing to the CSp stimulus (ΔI-CS = LI-to-CSp - MI-to-CSp) and the difference between the conduction times from CSp pacing to the lateral and medial isthmus sites (ΔCS-I = CSp-to-LI - CSp-to-MI). Patients were divided into 3 groups according to RAd: Group-I: <2.2 cm/m[2], Group-II: 2.2-2.4 cm/m[2], and Group-III: >2.4 cm/m[2]. Results: The number of patients in Groups I, II, and III was determined to be 99, 55, and 43, respectively. RA-volume, LVEF, RAd, and LAd values, as well as LI-to-CSp, ΔI-CS, CSp-to-LI, ΔCS-I, and DPPPI durations, significantly increased from Group I to Group III. MI-to-CSp and CSp-to-MI durations also increased from Group I to Group III; being Group I was significantly lower than Groups II and III. When DPPPI durations were categorized as ≤110 ms, 110-119 ms, 120-129 ms, and ≥130 ms, a significant difference was observed among the groups, and all Group II-III cases were found to have a DPPPI duration of ≥120 ms. In Groups II and III, the proportions of patients with DPPPI ≥ 130 ms were 46% and 84%, respectively. Conclusions: Our study showed that cavotricuspid-isthmus BCB parameters, which are indicators of successful AFL ablation, are closely and significantly related to RAd.

Bundibugyo virus disease (BVD) remains a high-consequence threat in Eastern and Central Africa, where cross-border mobility, nonspecific early symptoms, and delayed recognition can obscure transmission. In this case report, we describe Uganda's 2026 BVD index case: a male patient who traveled from the Democratic Republic of the Congo to Uganda and was admitted to a private hospital in Kampala on 11 May 2026 after more than two weeks of vomiting and diarrhea, with epigastric pain, weakness, and hiccups. He deteriorated rapidly, developing acute kidney injury, pulmonary edema, hepatic dysfunction, hypoxemia, delirium, atrial flutter, possible disseminated intravascular coagulation, and multiorgan failure, and died on 14 May. A posthumous EDTA whole-blood specimen tested at the Central Emergency Response and Surveillance Laboratory was positive for orthoebolavirus RNA and confirmed as Bundibugyo virus (BDBV) by RT-qPCR. Sequencing achieved 99% genome coverage at ≥100× depth. The 2026 BDBV genome formed a distinct lineage approximately equidistant from the 2007-2008 Butalya and 2012 Isiro variants, differing by 216-227 nucleotides (~1.2% sequence divergence). Here, we demonstrate the value of fatality surveillance, private-sector surveillance, diagnostic optimization through national specimen referral, and rapid molecular-genomic diagnostics for early detection, transmission chain interruption, and public health response coordination.