Is myocarditis a serious condition?

Myocarditis is a common condition, involving the inflammation of the tissues in the heart. In his latest online article, esteemed consultant cardiologist Dr Kaushik Guha offers his expert insight into this condition, including the symptoms, causes and treatment options.

What is myocarditis?

Myocarditis is defined as inflammation affecting the heart tissues. This can lead to a chain reaction of inflammation and deterioration in cardiac function mediated by the deposition of scar tissue and further repeated attacks of inflammation.

What are the causes of myocarditis?

It remains unclear and is the subject of extensive scientific study, as to why some patients are more susceptible than others to the condition. Some postulate that this may be due to a 'double-hit' hypothesis. This involves some form of external exposure along with an abnormal genetic background. Large studies are ongoing globally to understand the condition in more detail.

The causes of myocarditis can vary greatly. They include:

• Multi system disorders.
• Sarcoidosis
• Lupus
• Giant cell
• Chemotherapy
• Immunotherapy
• Bacteria
• Legionella
• Meningococcus
• Virus
• Influenza
• COVID-19
• External toxins
• Cocaine or alcohol use

Some patients are more prone to myocarditis at the time of a viral infection. The cause for this enhanced susceptibility remains unknown, and is characterised by a more profound systemic reaction allied to cardiac symptoms. This means the patient may suffer from common viral symptoms such as a runny nose, muscular ache, fatigue, in addition to other cardiac symptoms such as chest pain, disproportionate breathlessness and palpitations.

If a virus does affect the heart as well as other organs, this leads to more serious illness and may lead to hospitalisation, intensive care support and may be fatal.

What are the outcomes generally associated with myocarditis?

Myocarditis may be associated with a range of outcomes. One end of the spectrum is the almost incidental discovery of cardiac involvement, based on heart tracing (ECG) and heart biomarkers (blood tests - troponin), to the other end whereby the patient develops rapid heart malfunction, leading to the sudden onset of heart failure, organ failure and the need to urgently consider special forms of cardiac support and even the consideration of cardiac transplantation. Where the patient lies on the spectrum may be unclear, without the passage of time and calls for careful comprehensive cardiology input with serial monitoring and reliable access to cardiac investigations and imaging.

For those patients, where there is a clear external trigger e.g COVID-19, then there should be enhanced vigilance at the time of each subsequent exposure due to the possibility of a further progressive inflammatory reaction which may lead to increased levels of heart deterioration and malfunction.

What are the symptoms of myocarditis?

The symptoms of myocarditis range from an asymptomatic status through to classic cardiac symptoms of chest pain, shortness of breath, palpitations (a sense of heart racing, skipping or pounding), blackouts (syncope), dizzy or funny turns and the collection of fluid around the abdomen or ankles.

Can myocarditis be prevented?

Myocarditis itself cannot be prevented, but the mainstay of prevention is to avoid environmental exposure in the first place, or to minimise the risk of myocarditis by careful observation and clinical monitoring. E.g for a bacterial or viral infection, the best prevention of myocarditis would be to consider vaccination and other basic infection control measures such as handwashing. For those patients who on certain types of chemotherapy it may be more prudent to consider increased vigilance with more heart scans.

How is myocarditis treated?

The treatment of myocarditis is dependent on three major concepts. In the acute phase, a root cause should be identified and targeted as well as serial close inspection of the heart, this may include blood tests (biomarkers e.g troponin), heart tracing, echocardiograms (heart scans) and cardiac MRI scans ( more detailed scans). From there the clinical team will be able to gauge the impact of the myocarditis upon the patient, if the patient has suffered a massive failure of the cardiac function, then he/she may require organ support and transfer with specialised equipment and teams to a specialist heart transplant centre.

Conversely, if the impact is much less than the patient may self heal with minimal cardiac damage. Beyond the initial episode, there should be further consideration as to the cause, the need for longer term monitoring of both cardiac function and rhythm. The scar tissue laid down from myocarditis may be associated with rhythm abnormalities leading to blackouts, funny turns or even cardiac arrest. Hence the longer term vigilance of such patients is equally as important as the acute care associated at the time of diagnosis.

Dr Kaushik Guha is a renowned consultant cardiologist based in Portsmouth & Farnham. If you would like to book a consultation with Dr Guha, you can do so today via his Top Doctors profile.