In day-to-day life, one of the most commonly occurring contagions is a sore throat medically acknowledged as Pharyngitis or Streptococcal infection (strep throat). The cause is almost always by a bacterium called Group-A Beta-Hemolytic Streptococcus. The familiar symptoms are Discomfort or a prickly sensation in the throat, Dysphagia, scrambled voice. Generally, to overcome it many clinicians advise taking bed rest with a soft diet and plenty of fluids intake, in case severe unruly condition the prescribed medicine is antibiotics, analgesic, corticosteroids, and etc. The interesting doubt ascends i.e. why & how strep throat is it related to heart diseases? In general, the heart diseases are classified into various types such as atherosclerotic diseases, heart arrhythmias, cardiomyopathy, and congenital heart defects etc. Rheumatic Heart Disease is precisely triggered due to Rheumatic Fever.
Roughly 97-98 percent of the population can overcome to sore throat infection but for remaining, it can lead to Rheumatic Fever at post-sore-throat infection. This article mainly deals with a sore throat leading to Rheumatic fever. Which further may lead to chronic rheumatic heart disease, and comprises of numerous symptoms of this disease.
Initiation of Rheumatic Fever
Rheumatic fever is a non-contagious acute fever, marked as inflammation & pain in the joints. The word rheumatic generally termed as rheumatism which means inflammation and pain in the joints, muscles, or fibrous tissue stained by disease. And fever is an abnormal rise in body temperature.
All in all rheumatic fever caused to a very small percentage of the population, the prone individuals are children (5-15 years) and is rare after age 35 years. Rheumatic fever is an autoimmune inflammatory process that progresses as a corollary of streptococcal infection. The most significant complication of rheumatic fever is Rheumatic Heart Disease, which usually occurs after frequent bouts of severe illness.
Rheumatic Heart Disease
Initially, the human is attacked with Streptococcal Pharyngitis leading to Rheumatic Fever, typically occurs several weeks after Pharyngitis. Streptococcus cell membrane consists of a protein called M-Protein and the bacteria is highly antigenic to human. The immune system identifies the antigens through macrophages and counter attacks by producing antibodies against the M-protein cell membrane of Pharyngitis bacteria. But these antibodies also attack body own cells consist of M-protein which is similar to foreign body protein (this similarity is known as molecular mimicry) and finally leads to damage of body organs, which is known as the type-2 hypersensitivity reaction. The similar M-protein body cells or organs are myocardium of the heart, joints, subcutaneous layer (skin), Basal ganglia of the brain.
In rheumatic fever, there is a variety of clinical findings Jones’ criteria further classified as major and minor as follows
- Fever: the Abnormal rise in body temperature.
- Arthralgia: Pain in regular joints.
- In blood, there is an increase in ESR/CRP.
- The ECG shows a prolonged PR interval in heart-block.
- Previous repetitive episodes of Rheumatic fever.
- Migratory Polyarthritis: Multiple large joints Inflammation one after another in a symmetric way.
- Subcutaneous nodules: These are firm lumps under the lining of the skin made of collagen which is painless and extensor.
- Erythema marginatum: These are the reddish rash ring formed on trunk and arms.
- Sydenham’s chorea: It is categorized by rapid or awkward jerking moment primary affecting face, hands, and feet caused by the destruction of basal ganglia of the brain.
The Carditis/Pancarditis caused by Rheumatic Fever
In the main, the heart is affected by auto-immune response during Rheumatic fever known as Rheumatic Heart Disease. This occurs when attacks of Rheumatic fever cause scarring and damage to the heart. Normally heart consists of three layers namely: pericardium, myocardium, and endocardium, these consist of M-protein in their tissue cells. But the antibodies released from immune system cause inflammation to the layers of heart leads to Carditis/Pancarditis. The inflammation is fibers type due to an accumulation of fibrin.
Inflammation of outer covering of heart is called Pericarditis, leading to sharp localized chest pain and reliefs on flexion of the spine (forward bending). On auscultation doctors can notice friction rub/pericardial rub in additional it weak heart sound is observed. When fever subsites there is no long-term pericarditis issue is seen in future.
Another effect of Rheumatic Heart Disease is Myocarditis, caused due to inflammation in Myocardium of heart. In Myocardium there is a formation of Aschoff body, it is very small pin head inflammatory lesions and these are the immune-mediated granuloma. It also contains large ribbon-like nucleated macrophages called Anitschkow cells. Myocarditis is the most dangerous and recorded most common cause mortality in children if it is untreated. The Myocardium becomes loose and flabby, unable to contract which may lead to other complications like congestive heart failure. This complication is not a long-term issue.
The serious and long-term complication is Endocarditis, inflammation of endocardium of heart and attacks specifically on valves of the heart. During fever, tachycardia occurs that leads to rapid closing and the opening of valves. Due to inflammation, there is a rupture or erosion of leaflets at valves. However, ruptures lead to deposition of platelets and fibrin which results in the formation of multiple small vegetation (sterile) on the valves. During post-fever healing occurs but this vegetation leads to fibrosis due to this the valves become fibrotic and distorted.
Above three conditions Pericarditis, Myocarditis, and Endocarditis usually leading light to Acute Rheumatic Heart Disease during Rheumatic fever in children. Whereas Endocarditis leads to severe complications like mitral stenosis, mitral regurgitation, and aortic stenosis and regurgitation in adults because of untreated recurrent episodes of Rheumatic fever which finally result in Chronic Rheumatic Heart Diseases.
- Take bed rest, Intravenous fluids and a healthy diet.
- Conventional medications such as antibiotics (without carditis up to age 18/21 years, with carditis up to age 25/45 years), anti-inflammatory drugs.
- In-take of Cardiac drugs on doctor’s prescription.
- In severe, case surgical treatment of heart is required.