March 25th, 2015
Bacterial endocarditis is an infection of the inner surface of the heart or the heart valves caused by bacteria. It is quite severe and dangerous, and usually found in people with heart problems, whether at the heart valve or at the interatrial septum (the wall of tissue that separates the upper right and left chambers of the heart). The main culprit is bacteria but in some cases fungus can be the cause, too. Furgusinfection is more common in people with impaired immune system.
Infection at the heart valve is quite rare because the heart has blood flowing through all the time, so if bacteria had a chance to get to the heart, they are usually flushed away by the blood flow, like a person falling into a rushing river. However, if your heart has problems, especially at the wall or the valve, the blood flow will have higher pressure. The pressure is hard enough to hit the wall on the other side of the heart, causing scrapes on the tissue which is supposed to be smooth.
Generally, bacteria can sometimes get into our body, but in a small amount. They would find a place to stay but cannot thrive because the heart and the blood vessels are normally smooth and slippery, making it hard for them to hang on to. However, when the surface is scraped and not smooth, it is possible for these bacteria to call the place home and thrive.
Those lucky bacteria are in for a treat. The heart gets plenty of blood all day long, so it is practically an open buffet for them. Moreover, the antibiotic medicine that we take, by the time it gets to the heart, is so diluted that it hardly has any effect. The bacteria are also exposed to blood inside the heart only, as the heart does not have capillaries like other organs.
So, the bacteria at the heart valve only come in contact with medicine that is diluted in the blood, and it takes a very long time to accumulate enough of the medicine’s strength to battle these bacteria. The lucky bacteria in that neighborhood therefore live happily and safely.
To treat this problem, the patient needs to take medicine via blood vessel for weeks. There are also complications that may occur, such as some of the bacteria leave the heart and go to the brain or the legs, causing insufficient blood supply at those organs. It might even cause brain abscess.
In many cases, after medication, the patient might need an operation. Sometimes the bacteria are ungrateful and destroy their own home, which is the heart. In this case, the heart valve will be so damaged that the patient might have heart failure. In this case, an operation is needed to remove the bacteria together with the heart valve in exchange for a new one.
Since the treatment can be long and difficult, it is better to prevent it. Formerly, it was believed that people with unhealthy heart condition should take antibiotic to prevent infection at the heart valve. During some medical processes, bacteria might get into the body. Before, for dental work, it was believed that there are plenty of bacteria in the mouth, so it was recommended that the heart disease patients should take antibiotics to prevent infection, too. However, recent studies showed that taking antibiotics before dental work is not a good recommendation, so it was lifted, except for very high risk cases.
A patient of mine was about 40 years old. He came to see me about mitral valve insufficiency (leakage of the valve), which he had found out accidentally. His symptoms were not severe. After health check-up and EKG and ECHO tests, I found that his mitral valve (the valve that controls the flow of blood between the two chambers on the left side of the heart) did not close properly. His heart was enlarged as well. In this case, even without severe symptoms, he needed an operation to replace or repair the valve. It could be too late if he waited until the symptoms showed.
He told me that he needed a few weeks to think it over, as he had to take care of something at work and at home. I did not disagree, as a few weeks could not be dangerous for him. However, we were both surprised when just less than a week later, he came to see me because of high fever and numbness in his left arm, leg and body. I found that he had bacterial endocarditis. I had no idea where the bacteria had come from, as he did not have any open wound and he had not been to the dentist.
Worse yet, the bacteria at his heart were not really harmonious. They were scattered away and clogged his brain, causing the numbness. Luckily, he came to the hospital in time, and antibiotics could still help get rid of the bacteria at his heart and brain. However, he still needed medication through his vein for months. After that, he had an operation to remove the infected valve and change for a mechanical valve. He is now fine, so are his heart and his brain.
Prof Nithi Mahanonda is consultant cardiologist and interventionist, Perfect Heart Institute.
ข้อคิดเห็นทั้งหมดนี้เป็นความคิดเห็นส่วนบุคคลของผู้อ่าน ไม่เกี่ยวข้องกับเจ้าของเว็บไซต์แต่อย่างใด โปรดแสดงความเห็นด้วยความสุภาพ ถ้าเป็นครั้งแรกที่คุณโพสต์แสดงความเห็น อาจจะมีการคัดกรองเนื้อหาได้ การแสดงความคิดเห็นควรอยู่ในประเด็น ห้ามโจมตีใส่ร้ายบุคคลอื่น หรือทำลิงค์ไปยังเว็บไซต์ที่มีเนื้อหาไม่เกี่ยวข้องกัน ผู้ดูแลเว็บไซต์สามารถแก้ไขหรือลบความคิดเห็นได้ทุกกรณี
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