by AK Team
WHAT IS MYOCARDITIS?
In cardiology, myocarditis is a rare condition that causes inflammation of myocardium, that is the heart muscle.
This inflammation of myocardium, enlarges and weakens the heart reducing its ability to pump and causes rapid or abnormal heart rhythms that is known as arrhythmias.
Myocarditis is not related to any specific age group and can affect people of any age and it can affect children as well. It is more common is males than in females and it is the 3rd leading cause of sudden death in children and young adults.
STRUCTURE AND FUNCTION OF HEART
- The study of heart is known as cardiology and a human heart is a four chambered organ, that pumps blood throughout the entire body.
- The normal size of a heart is about the size of an adult fist.
- The normal range of heartbeat ranges about 60 to100 times per minute.
- Its four chambers are- right atria, left atria, right ventricle, left ventricle.
- In the heart, basically two types of circulation takes place – Systemic circulation and pulmonary circulation.
- Systemic circulation is carrying of oxygenated blood from the right side of the heart to the entire body and then bringing deoxygenated blood from the entire body to the left side of the heart.
- Pulmonary circulation is carrying of deoxygenated blood from the left side of the heart to the lungs and bringing back purified oxygenated blood from the lungs to the right side of the heart which will then go into the systemic circulation and the cycle goes on.
- Firstly, deoxygenated blood that is present in the right atria, goes to the right ventricle through tricuspid valve as the right atria contracts (systole).
- Now this deoxygenated blood from the right ventricle goes to the lungs through pulmonary trunk which further divides into four pulmonary arteries.
- Deoxygenated blood after reaching the lungs gets purified there and the purified oxygenated blood is carried back to the left atria through pulmonary vein.
- This oxygenated blood goes from left atria to the left ventricle through the bicuspid/mitral valve as the left atria contracts.
- The oxygenated blood from the left ventricle is now carried to the entire body through aorta.
- The oxygenated blood is given off to the body tissues and deoxygenated blood is collected through them which is carried back to the right atria through superior and inferior vena cava, and in this way the heart pumps blood through the entire body.
TYPES OF MYOCARDITIS
There are basically 5 types of myocarditis:
- Acute myocarditis : Acute myocarditis is basically the inflammation of heart muscles without any specific symptoms. Patients that suffer with heart dysfunction, may respond to treatment.
- Chronic active myocarditis : In this the patient has an indistinct onset with moderate ventricular dysfunction on presentation and active or borderline myocarditis by biopsy. These patients initially respond to treatment, but then relapse and then finally develop heart dysfunction.
- Chronic persistent myocarditis : It is characterized by a persistent histologic infiltration. These patients have persistent inflammation, but minimal to no heart dysfunction.
- Fulminant myocarditis : this is an uncommon syndrome and is characterized by sudden severe diffuse cardiac inflammation which often leads to death resulting from cardiogenic shock.
CAUSE OF MYOCARDITIS
There are several causes of myocarditis the most common one being the viral infection. Some other causes of myocarditis are listed below:
- Cytotoxic effect of micro-organisms like virus, bacteria, parasites, etc.
- The chemicals released during myocardial cell death also lead to myocarditis.
- Autoimmune responses may also be of the cause of myocarditis sometimes.
- Some medications or toxins such as radiation therapy, clozapine.
- Spider bites
- Snake bites
- Hepatitis C
SYMPTOMS OF MYOCARDITIS
Generally, myocarditis does not have any symptoms.
If someone is in the mild stage of myocarditis he or she may do not any obvious symptoms in the early stages, or just mild symptoms such as chest pain or shortness of breath.
In severe stages the person might have the following symptoms :
- Shortness of breath
- Abnormal heartbeat, which may cause fainting in few cases
- Light – headedness
- Chest pain
- Fluid retention with swelling of legs, ankles and feet
- If it is because of viral infection the symptoms may include fever, heachache, body aches
Myocarditis in children
In children the symptoms may include
- Rapid breathing
- Breathing difficulties
- Arrhythmias (abnormal heart rhythms)
DIAGNOSIS OF MYOCARDITIS
Majority of myocarditis cases do not have any major symptoms and hence they cannot be diagnosed. However if a person develops some symptoms, he or she may undergo the following common tests for myocarditis:
- Electrocardiogram : This is a non-invasive test that shows the heart’s electrical rhythms and is also able to detect any abnormal rhythm of the heart.
- MRI : Cardiac MRI shows the patient’s heart size, shape and structure and this test can also show the signs of inflammation of the heart muscle, if any.
- Chest X-ray : This shows the size and shape of heart and also the presence of fluid in or around the heart that may indicate heart failure.
- Blood tests :This measures the white blood cells and red blood cells count and also the level of certain enzymes that can indicate damage to the heart muscle.
- Cardiac catheterization and endomyocardial biopsy : In this a small tube (catheter) is inserted into a vein in the patient’s leg or neck and then it is threaded into his heart and this is done to check for inflammation or infection.
TREATMENT FOR MYOCARDITIS
Majority of the cases of myocarditis get cured by its own without the help of any treatment. Myocarditis treatment mainly focus on the cause and the symptoms, such as the heart failure.
Below listed are some drugs that the doctor will prescribe if myocarditis is causing heart failure or arrhythmias:
- Angiotensin-converting enzyme (ACE) inhibitors
- Angiotensin II receptor blockers (ARBs)
- Beta blockers
For the treatment of severe cases the following might be done:
- Intravenous (IV) medications
- Intra-aortic balloon pump
- Ventricular assist devices
- Extracorporeal membrane oxygenation (ECMO)
In the most severe cases the doctor might recommend going for heart transplantation.
PREVENTION OF MYOCARDITIS
There is no specific way of prevention myocarditis it can only be done by living a healthy lifestyle by doing some of the following things :
- Having vaccination records up to date
- Having good hygiene habits
- Avoid coming in contact with people having viral diseases or any kind of infection
- Avoid tick exposure
In majority of the cases myocarditis recover on its own, still the doctors recommend a resting period of about three to six months after viral myocarditis to allow the heart tissue to heal without intense physical activity.