Table 1.
The epidemiology, demographics, clinical presentation, diagnostic findings, and outcome of influenza myopericarditis cases.
| Demographic Characteristics | n | M to F Ratio | Age Range (Years) | Mean Age (Years) |
| Adult | 55 (73.3%) | 28:27 | 18–75 | 40.5 ± 14.8 |
| Pediatric | 20 (26.7%) | 3:17 | 0.25–17 | 9.7 ± 4.9 |
| Total | 75 (100%) | 31:44 | 0.25–75 | 32.3 ± 18.8 |
| Co-morbidities | ||||
| Adult | ||||
| Not present | 26 (47.3%) | |||
| Present | 29 (52.7%) | |||
| Hypertension and alcohol use | each in 4 (7.3%) | |||
| CAD (previous MI), advanced CKD/ESRD, asthma, tobacco dependence | each in 3 (5.4%) | |||
| Obesity and hyperlipidemia | each in 2 (3.6%) | |||
| Previous Influenza B myocarditis (16 years prior), DMT2, hypothyroidism, primary biliary cirrhosis, diverticulitis, breast cancer, SLE, MS, TBI, Down syndrome, schizophrenia, marijuana and cocaine use, previous infection with TB, syphilis, gonorrhea | each in 1 (3.6%) | |||
| Pediatric | ||||
| Not present | 17 (85%) | |||
| Present | 3 (15%) | |||
| Viral myocarditis | 1 (5%) | |||
| Asthma | 1 (5%) | |||
| Rheumatic fever | 1 (5%) | |||
| Clinical presentation | Symptom duration | Range (days) | Mean (days) | |
| Febrile (“flu-like”) illness | 71 (94.7%) | Reported–66 (88%) | 1–42 | 6.9 ± 6.4 |
| Tachycardia | 62 (82.7%) | Not reported–9 (12%) | ||
| Hypotension/Shock | 54 (72%) | |||
| Chest pain | 36 (48%) | |||
| Dyspnea | 34 (45.3%) | |||
| Pericardial friction rub | 15 (20%) | |||
| Elevated JVP | 10 (13.3%) | |||
| Abdominal pain | 8 (10.7%) | |||
| Muffled heart sound | 8 (10.7%) | |||
| Nausea/vomiting | 8 (10.7%) | |||
| Collapse/syncope | 6 (8%) | |||
| Pulsus paradoxus | 5 (6.7%) | |||
| Altered mental status/lethargy | 5 (6.7%) | |||
| ECG findings | ||||
| Normal or not reported | 14 (18.7%) | |||
| Abnormal | ||||
| ST elevation and/or PR depression | 26 (42.6%) | |||
| Low voltage QRS complexes | 22 (36.1%) | |||
| Electrical alternans | 2 (3.3%) | |||
| Echocardiography findings | ||||
| Performed | 62 (82.7%) | |||
| Decreased EF or diffuse hypokinesis | 42 (67.7%) | |||
| Pericardial effusion | ||||
| Without tamponade physiology | 38 (61.3%) | |||
| With tamponade physiology | 24 (38.7%) | |||
| Not reported, although authors reported pericardial effusion in all 13 cases with tamponade in 3 cases | 13 (17.3%) | |||
| Treatment | ||||
| Antivirals (Oseltamivir/Peramivir/Zanamivir) | 33 (44%)/6 (8%)/3 (5%) | |||
| NSAIDs | 13 (17.3%) | |||
| Corticosteroids | 12 (16%) | |||
| Colchicine | 8 (10.7%) | |||
| IVIG | 8 (10.7%) | |||
| Circulatory support | ||||
| Inotropes/vasopressors | 44 (58.7%) | |||
| Mechanical | ||||
| ECMO | 18 (24%) | |||
| Intra-aortic balloon pump | 9 (12%) | |||
| Ventricular assist device | 7 (9.3%) | |||
| Pericardiocentesis | 28 (37.3%) | |||
| Pericardiectomy/Pericardial window | 4 (5.3%)/3 (4%) | |||
| Outcome and complications | ||||
| Recovered | 63 (84%) | |||
| Long-term complications | ||||
| No | 55 (87.3%) | |||
| Yes | 8 (12.7%) | |||
| Chronic (constrictive) pericarditis | 3 (4.8%) | |||
| Recurrent pericardial effusions | 2 (3.2%) | |||
| Mild LV dysfunction | 2 (3.2%) | |||
| LV pseudoaneurysm | 1 (1.6%) | |||
| Awaiting transplant | 1 (1.3%) | |||
| Deceased | 11 (14.7%) |
Legend: CKD—chronic kidney disease; ESRD—end-stage renal disease; CAD—coronary artery disease; MI—myocardial infarction; DMT2—diabetes mellitus type 2; SLE—systemic lupus erythematosus; MS—multiple sclerosis; TBI—traumatic brain injury; TB—tuberculosis; JVP—jugular venous pressure; EF—ejection fraction; NSAIDs—non-steroidal anti-inflammatory drugs; IVIG—intravenous immunoglobulin; ECMO—extracorporeal membrane oxygenation; LV—left ventricular.