According to a recent case study published in the Journal of the American College of Cardiology (JACC: Case Reports), a week after the onset of monkeypox symptoms, a 31-year-old man with confirmed monkeypox infection reportedly developed acute myocarditis - an inflammation of the heart muscle typically caused by a viral infection.
While the patient is reported to have had a SARS-CoV-2 infection two months before contracting monkeypox, in this case, researchers suspect the monkeypox illness may have caused acute myocarditis.
Since the man had already recovered from COVID-19 and had monkeypox symptoms, doctors believe monkeypox was the source of the heart illness.
Commenting about the same, the study authors state, “There have been few cases of histologically confirmed myocarditis, and viral myocarditis caused directly by SARS-CoV-2 has not been definitively confirmed but assumed because of epidemiologic context.”
The man supposedly visited a health clinic five days following the onset of symptoms which included malaise, myalgia, fever and multiple swollen lesions on the face, hands and genitalia.
Monkeypox infection was confirmed with a PCR swab sample of a skin lesion. However, the patient returned to the emergency department three days later complaining of chest tightness radiating through the left arm.
When the patient returned to the health clinic, he was admitted to an intensive care unit after initial routine examination with the clinical suspicion of acute myocarditis, a report featured in the American College of Cardiology (ACC) informs.
The initial ECG showed abnormalities and routine laboratory tests too revealed elevated levels of C-reactive protein, creatine phosphokinase (CPK), high-sensitivity troponin I and brain natriuretic peptide (BNP), all of which indicates stress injury to the heart.
Additionally, the results of the cardiac magnetic resonance (CMR) study performed on the patient were consistent with myocardial inflammation and a diagnosis of acute myocarditis.
The authors of the study also note that monkeypox is a virus closely related to others that “already have an established direct or indirect association with cardiac tissue injury.” For instance, smallpox has been associated with cardiovascular problems, Medical News Today reports.
Lead author of the study, Dr Ana Isabel Pinho who also works in the cardiology department at São João University Hospital Center in Portugal, is quoted as saying, “This case highlights cardiac involvement as a potential complication associated with monkeypox infection.”
She adds, “We believe that reporting this potential causal relationship can raise more awareness of the scientific community and health professionals for acute myocarditis as a possible complication associated with monkeypox. [It] might be helpful for close monitoring of affected patients for further recognition of other complications in the future.”
Julia Grapsa, editor-in-chief of JACC: Case Reports is quoted as saying, “Through this important case study, we are developing a deeper understanding of monkeypox, viral myocarditis and how to accurately diagnose and manage this disease.”
Though the patient fully recovered and was discharged after a week, the authors of the study have said that further research is needed to identify the relationship between monkeypox and heart injury.
Monkeypox is transmitted through close contact with lesions, bodily fluids or respiratory droplets, and though most infections are mild, symptoms can last between two to four weeks.
More than 50,000 monkeypox cases have been recorded globally and the WHO has listed 50,496 cases and 16 deaths as reported this year.
Anti-Racism protesters come out in support of refugees outside the Cladhan Hotel on September 13, 2025 in Falkirk, Scotland. (Photo by Jeff J Mitchell/Getty Images)