The Prevalence and Findings of Subclinical Influenza-associated Cardiac Abnormalities among Japanese Patients

Abstract

Objective Although life-threatening cardiac complications in influenza infection are rare, subclinical influenza-associated cardiac abnormalities may occur more frequently. We investigated the prevalence of subclinical cardiac findings. Methods After obtaining their written informed consent, 102 subjects were enrolled in the present study. The study subjects underwent a first set of examinations, which included electrocardiography (ECG), echocardiography, and the measurement of their cardiac enzyme levels. Those with one or more abnormal findings among these examinations were encouraged to undergo a repeat examination 2 weeks later. Results Among the 102 subjects enrolled, 22 (21.6%) were judged to have cardiac findings, including ST-T abnormalities, pericardial effusion, diastolic dysfunction, and cardiac enzyme elevation. Eighteen of these 20 subjects underwent a second screening at a median of 14 days later, and it was found that 11 of the 18 subjects were free from cardiac findings on this second examination. This suggested that the abnormalities were only transient and they therefore might have been associated with influenza. Approximately 20% of the influenza patients enrolled had cardiac findings, including ST-T segment abnormalities, pericardial effusion, and cardiac enzyme elevation. Conclusion Among the 102 patients who were studied, the cardiac findings were only mild and transient; however, physicians should be aware of influenza infection-associated cardiac abnormalities because such abnormalities may not be rare.

Transient depression of myocardial function after influenza virus infection: A study of echocardiographic tissue imaging

“…The present study was based on the data on our previous study [16], and thus was consistent with that study with respect to patient enrollment and study protocol. In the previous study, subjects recovering from IVI who presented 1 or more abnormal findings during the first assessment (electrocardiography for ST-T abnormalities, any arrhythmias, and others; echocardiography for reduced LV ejection fraction, diastolic dysfunction, and pericardial effusion; and elevated cardiac markers, namely, CKMB and/or cardiac troponin T) were advised to undergo a second set of assessment [16]. Clinical, echocardiographic, and biological characteristics at the initial set of examinations in patients who had any of the aforementioned abnormalities (n = 24) and in those who did not (n = 86) (4 excluded because of insufficient data acquisition) are presented in S1 Table, and how the 20 subjects were selected is shown in Fig 1.…”

Cardiac injury associated with severe disease or ICU admission and death in hospitalized patients with COVID-19: a meta-analysis and systematic review

“…In a study of 75 inpatients with SARS, acute myocardial infarction was the cause of 2 of 5 deaths [40]. Elevated TnI levels are also common in infections caused by other influenza virus subtypes [41][42][43][44][45]. TnI may play an important role in predicting the acute or long-term risk of influenza virus infection.…”

Prognostic impact of high sensitive troponin in predicting 30-day mortality among patients admitted to hospital with influenza

“…Several studies [13] , [14] , [15] , [24] have previously evaluated the impact of influenza viral infection on cardiac function and immediate mortality but only limited studies have determined the long term clinical consequences of severe influenza infection who require hospitalisation. These studies have indicated an increased incidence of arrhythmias, presence of regional wall motion abnormalities and a reduction in ejection fraction along with increased mortality during acute phase of viral illness.…”