Interview with Consultant Cardiologist Dr Sabiha Gati on FAQ’s about myocarditis
Myocarditis is an inflammatory process involving the heart muscle. It can present acutely, subacutely or as a chronic disease process. It may present with focal involvement or diffuse involvement of the heart muscle. When individuals have symptoms, these can be highly variable from generalised fatigue, malaise, chest pain, breathlessness, electrical abnormalities of the heart and even a cardiac arrest.
Viral infections are the most common cause of myocarditis in the developed world.
How common is viral myocarditis?
The incidence i.e. the number of new cases of myocarditis is approximately 1.5 million worldwide per year and estimated at 10 to 20 cases per 100,000 persons. The exact incidence or prevalence of viral myocarditis is unknown as many cases are subclinical and follow a benign course. According to some estimates, 1-5% of patient with acute viral infection may involve the myocardium. So, a small number.
The majority of patients are young and healthy. Individuals who are susceptible include children, pregnant women and those who are immunocompromised.
Does exercise make it more likely you will develop viral myocarditis?
Myocarditis accounts for 5-10% of sudden cardiac deaths (SCD) in athletes and up to 20% of SCD in military recruits, suggesting that exercise may be a trigger for sudden death in this condition.
Clinical data linking intensive physical activity to manifestation of myocarditis have not been assessed in humans, but clinical observations do suggest it, given that we do identify a higher prevalence in athletes particularly as they are more likely exposed to microbes than the general population. There may be an increased risk of infection with contact sports or team sports with a higher potential for droplet infections.
We know from animal studies, specifically in the coxsackievirus B3, that there is a reduction in our immunity induced by intensive exercise that predisposes us to upper respiratory tract viral infection and possible involvement of the heart muscle.
How many days after a viral illness should you wait before exercising again?
Exercising individuals should be careful when they experience symptoms of coughing, sore throat, running nose or diarrhoea. Viral infection not only affects the heart muscle, but can also cause muscular soreness, joint pains and generalised body fatigue. If an athlete has these symptoms that may or may not be accompanied by a sub-febrile temperature, they should refrain from any strenuous exercise as this may further impair the immune system and increase the potential for..
Read Sabiha's full interview here.