{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,11]],"date-time":"2026-06-11T18:03:52Z","timestamp":1781201032773,"version":"3.54.1"},"reference-count":28,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2026,2,12]],"date-time":"2026-02-12T00:00:00Z","timestamp":1770854400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Life"],"abstract":"<jats:p>Background: Cardiac arrhythmias are a frequent complication of acute SARS-CoV-2 infection. However, their long-term prevalence and clinical determinants among patients with post-COVID-19 syndrome, especially those previously hospitalized, remain poorly defined. Objectives: To assess the prevalence and types of arrhythmias in long COVID patients following hospitalization and to identify associated clinical risk factors. Methods: In this cross-sectional study, 53 patients previously hospitalized with confirmed COVID-19 were evaluated \u22653 months post-infection. All participants underwent a standardized clinical assessment, 12-lead electrocardiography, and 24 h Holter monitoring. Logistic and Cox regression analyses were performed to identify predictors of arrhythmia. Results: Arrhythmias were identified in 41.5% (n = 22) of patients. Atrial fibrillation (32%) was the most frequent arrhythmia, followed by sinus bradycardia (27%) and sinus tachycardia (18%). Age (OR 1.06, 95% CI 1.01\u20131.10, p = 0.01) and length of hospital stay (OR 1.1, 95% CI 1.01\u20131.2, p = 0.04) were independently associated with arrhythmia. Biguanide (metformin) therapy was inversely associated with the occurrence of arrhythmia (Exp(B) = 0.017, p = 0.008). Dyspnea (82.4%) and palpitations (41.5%) were the most commonly reported symptoms. Conclusions: Arrhythmias are common in patients with long COVID following severe disease. Advanced age and prolonged hospitalization are significant risk factors, while biguanide use may offer a protective effect. These findings underscore the need for targeted cardiac surveillance in this population.<\/jats:p>","DOI":"10.3390\/life16020319","type":"journal-article","created":{"date-parts":[[2026,2,12]],"date-time":"2026-02-12T09:48:34Z","timestamp":1770889714000},"page":"319","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Arrhythmias as Part of Long COVID Syndrome in Hospitalized Patients That Survived a Severe COVID-19 Infection and the Potential Protective Role of Metformin in These Patients"],"prefix":"10.3390","volume":"16","author":[{"given":"Haydee Ninette","family":"Morales-Vazquez","sequence":"first","affiliation":[{"name":"Unidad de Cardiolog\u00eda, Del Hospital Civil Fray Antonio Alcalde, Guadalajara 44200, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9470-2489","authenticated-orcid":false,"given":"David","family":"Cardona-M\u00fcller","sequence":"additional","affiliation":[{"name":"Instituto de Terap\u00e9utica Experimental y Cl\u00ednica, Centro Universitario de Ciencias de La Salud, Universidad de Guadalajara, Guadalajara 44340, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fernando","family":"Grover-Paez","sequence":"additional","affiliation":[{"name":"Instituto de Terap\u00e9utica Experimental y Cl\u00ednica, Centro Universitario de Ciencias de La Salud, Universidad de Guadalajara, Guadalajara 44340, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carlos Gerardo","family":"Ramos-Becerra","sequence":"additional","affiliation":[{"name":"Instituto de Terap\u00e9utica Experimental y Cl\u00ednica, Centro Universitario de Ciencias de La Salud, Universidad de Guadalajara, Guadalajara 44340, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ernesto Germ\u00e1n","family":"Cardona-Mu\u00f1oz","sequence":"additional","affiliation":[{"name":"Instituto de Terap\u00e9utica Experimental y Cl\u00ednica, Centro Universitario de Ciencias de La Salud, Universidad de Guadalajara, Guadalajara 44340, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maria Guadalupe","family":"Ramos-Zavala","sequence":"additional","affiliation":[{"name":"Instituto de Terap\u00e9utica Experimental y Cl\u00ednica, Centro Universitario de Ciencias de La Salud, Universidad de Guadalajara, Guadalajara 44340, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jaime","family":"Carmona-Huerta","sequence":"additional","affiliation":[{"name":"Instituto de Terap\u00e9utica Experimental y Cl\u00ednica, Centro Universitario de Ciencias de La Salud, Universidad de Guadalajara, Guadalajara 44340, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-4438-5875","authenticated-orcid":false,"given":"Jorge Eduardo","family":"Hernandez-del-Rio","sequence":"additional","affiliation":[{"name":"Instituto de Terap\u00e9utica Experimental y Cl\u00ednica, Centro Universitario de Ciencias de La Salud, Universidad de Guadalajara, Guadalajara 44340, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tomas","family":"Miranda-Aquino","sequence":"additional","affiliation":[{"name":"Unidad de Cardiolog\u00eda, Del Hospital Civil Fray Antonio Alcalde, Guadalajara 44200, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7086-2966","authenticated-orcid":false,"given":"Christian","family":"Gonzalez-Padilla","sequence":"additional","affiliation":[{"name":"Instituto de Terap\u00e9utica Experimental y Cl\u00ednica, Centro Universitario de Ciencias de La Salud, Universidad de Guadalajara, Guadalajara 44340, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0563-5294","authenticated-orcid":false,"given":"Christopher Josue","family":"Lopez-Gradilla","sequence":"additional","affiliation":[{"name":"Instituto de Terap\u00e9utica Experimental y Cl\u00ednica, Centro Universitario de Ciencias de La Salud, Universidad de Guadalajara, Guadalajara 44340, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,2,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Kingma, J., Simard, C., and Drolet, B. 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