Bacterial myocarditis, as every other type of myocarditis, features extremely variable clinical manifestations, with the symptoms ranging from none to an acute cardiac shock and heart failure [1]. Due to the fact that it is caused by a bacterial infection, known or unknown to the patient, the symptoms that predominate in the clinical picture at first are those pertaining to the preceding infection. Depending on the type of infection, a patient may experience fever, sweating, chills, tachycardia, weakness, abdominal pain and other symptoms; at this time, although a bacterial inflammation of the myocardium may exist, the cardiac condition is considered still asymptomatic.

At the onset of substantial myocardial inflammation, symptoms originating from the cardiovascular system include angina pectoris, mild or profound arrhythmia, thoracic pain, dyspnea upon exertion, palpitations or an acute decompensation of heart failure, with no preceding risk [2]. Bacterial myocarditis that is caused by a group A streptococcal infection (rheumatic fever), will lead to the patient experiencing additional symptoms, such as polyarthralgia, and subcutaneous nodules, chorea and/or erythema marginatum will be observed.

The extremely variable clinical presentation of bacterial myocarditis, further complicated by the symptoms associated with the initial infection, renders the diagnosis a challenging task. Even though a set of diagnostic criteria has been established, the final diagnosis is set after a biopsy result, consistent with a bacterial infiltration of the myocardium [3] [4].

Bacterial myocarditis is suspected when a priorly confirmed or suspected bacterial infection is followed by an arrhythmia or acute heart failure. The complete workup encompasses a plethora of tests, such as an electrocardiogram (ECG), cardiac enzyme laboratory tests, echocardiography, cardiac magnetic resonance imaging scans (MRI) and, eventually, a biopsy.

• ECG

May reveal an atrioventricular or bundle branch block, arrhythmias of a ventricular or supraventricular origin, ST or T wave abnormalities and irregular Q waves. The electrocardiographic evaluation may mislead the physician to diagnose an ischemic phenomenon.

• Laboratory blood tests

Enzymes associated with myocardial ischemia may be elevated, such as troponins or CK-MB.

• Echocardiography

May illustrate pericardial effusion, LV (left ventricular) or RV (right ventricular) dysfunction, dilatation and thrombi, located intracardially. The findings are non-pathognomonic of bacterial myocarditis and echocardiography is primarily employed in order to eliminate other conditions, such as valvular disease, from the differential diagnosis [5]

• Cardiac MRI scan

It's wider availability has greatly contributed to the diagnosis, as it can help to evaluate the heart both from a functional and morphological aspect while retaining the advantage of a non-invasive technique [6] [7] [8]. It can aid in the assessment of necrotic or fibrotic changes, pericardial effusion, edema or functional irregularities.
In symptomatic patients, myocarditis is suspected in the clinical setting when 1 clinical indication and 1 diagnostic indication is present. Thoracic pain, acute or chronic heart failure and arrhythmia, including syncope, palpitations and sudden cardiac death, constitute the clinical indications. The diagnostic indications encompass abnormal ECG findings, elevated cardiac enzymes or echocardiographic abnormalities. The final and assertive diagnosis of bacterial myocarditis is established after a biopsy histological examination reveals inflammation of the myocardium, with a culture that is positive for a specific pathogen.

The treatment of bacterial myocarditis focuses on eradicating the bacterial infection and managing symptoms. Antibiotics are the cornerstone of treatment and are selected based on the type of bacteria identified. Supportive care, such as medications to manage heart failure symptoms and arrhythmias, may also be necessary. In severe cases, hospitalization and advanced therapies like intravenous antibiotics or mechanical support for the heart may be required.

The prognosis for bacterial myocarditis varies depending on the severity of the infection and the timeliness of treatment. With prompt and appropriate antibiotic therapy, many patients recover fully. However, if the condition is severe or treatment is delayed, complications such as chronic heart failure, arrhythmias, or even death can occur. Long-term follow-up with a cardiologist may be necessary to monitor heart function and manage any ongoing symptoms.

Bacterial myocarditis is caused by bacterial infections that reach the heart muscle. Common bacteria that can lead to myocarditis include Staphylococcus, Streptococcus, and Borrelia burgdorferi (the bacteria responsible for Lyme disease). The infection can spread to the heart from other parts of the body, such as the skin, throat, or lungs, or through the bloodstream.

Bacterial myocarditis is less common than viral myocarditis but can occur in individuals of any age. It is more likely to develop in people with weakened immune systems, pre-existing heart conditions, or those who have recently had a bacterial infection elsewhere in the body. The incidence of bacterial myocarditis is not well-documented, but it is considered a rare condition.

In bacterial myocarditis, bacteria invade the heart muscle, triggering an inflammatory response. This inflammation can damage heart muscle cells, leading to impaired heart function. The body's immune response to the infection can further exacerbate the damage, resulting in symptoms of heart failure and arrhythmias. The extent of heart damage depends on the virulence of the bacteria and the body's immune response.

Preventing bacterial myocarditis involves reducing the risk of bacterial infections. This can be achieved through good hygiene practices, such as regular handwashing and proper wound care. Vaccinations, where applicable, can also help prevent infections that might lead to myocarditis. For individuals with known risk factors, such as weakened immune systems, close monitoring and prompt treatment of bacterial infections are crucial.

Bacterial myocarditis is a rare but serious condition caused by bacterial infection of the heart muscle. It presents with symptoms like chest pain, fatigue, and shortness of breath. Diagnosis involves clinical evaluation and various tests, while treatment focuses on antibiotics and supportive care. The prognosis depends on the severity and timeliness of treatment, with prevention centered on reducing infection risks.

If you or someone you know is experiencing symptoms such as chest pain, fatigue, or difficulty breathing, it is important to seek medical evaluation. Bacterial myocarditis is a condition that requires prompt diagnosis and treatment to prevent complications. Understanding the symptoms and risk factors can help in early detection and management of this condition.

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