Test results at Tam Anh General Hospital in Hanoi revealed that Binh tested positive for influenza B and showed elevated heart enzymes. Doctor Phung Van Thao, from the cardiology department, explained that elevated heart enzymes indicate potential heart muscle damage. An ultrasound and CT scan revealed a significant decrease in Binh's heart's pumping function, down to about 50% of its normal capacity, along with small inflammatory nodules scattered in his lungs.

Binh received intensive care and an 8-day course of antibiotics. His heart muscle fully recovered without any lasting complications affecting its function.

Doctor Thao examining the patient. Photo: Tam Anh General Hospital

Doctor Thao examining the patient. Photo: Tam Anh General Hospital

Doctor Thao noted that myocarditis caused by influenza B accounts for about 0.7% of hospitalized flu cases and is a dangerous condition. If not detected and treated promptly, it can rapidly progress to acute heart failure and life-threatening arrhythmias. The mortality rate can be as high as 33% in cases of acute myocarditis.

Patients with mild cases are monitored and treated with medication and rest. Severe cases, especially those involving cardiogenic shock, respiratory failure, or severe arrhythmia, require intensive care treatment, potentially including extracorporeal membrane oxygenation (ECMO) to temporarily support heart and lung function.

Influenza B-induced myocarditis can occur at any age but is more severe in children and young adults. This is because their immune systems often react strongly to the virus, potentially triggering a "cytokine storm"—an excessive inflammatory response that can severely damage the heart muscle.

According to the World Health Organization (WHO), annual influenza vaccination is the best way to prevent influenza and reduce the risk of complications. People should wear masks in crowded places, wash their hands frequently, and avoid close contact with anyone showing flu symptoms. Anyone with a high fever, chest pain, shortness of breath, heart palpitations, or irregular heartbeat should seek immediate medical attention.

Ly Nguyen

*The patient's name has been changed.