{"id":14561,"date":"2026-04-29T13:22:54","date_gmt":"2026-04-29T10:22:54","guid":{"rendered":"https:\/\/dryavuzbesogul.com\/?p=14561"},"modified":"2026-05-22T10:30:49","modified_gmt":"2026-05-22T07:30:49","slug":"endocardium-inner-lining-of-the-heart","status":"publish","type":"post","link":"https:\/\/dryavuzbesogul.com\/en\/endocardium-inner-lining-of-the-heart\/","title":{"rendered":"Endocardium (inner lining of the heart)"},"content":{"rendered":"<p>The endocardium, also known as the inner lining of the heart, is a thin, smooth, and vital protective layer that continuously lines the four chambers of the heart and all heart valves, allowing blood to be pumped without clotting, friction, and in an extremely fluid manner. This membrane, located at the center of the circulatory system, is not merely a passive covering; it is an active safety barrier that regulates blood fluidity. With every rhythmic contraction of the heart muscle, it resists mechanical stress and ensures the smooth functioning of the cardiovascular system. The healthy journey of blood inside the heart depends entirely on the integrity and flawless structure of this tissue.<\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_83 counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Yaz\u0131 \u0130\u00e7eri\u011fi<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #ffffff;color:#ffffff\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #ffffff;color:#ffffff\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/dryavuzbesogul.com\/en\/endocardium-inner-lining-of-the-heart\/#What_Is_the_Endocardium_That_Lines_the_Inner_Surface_of_Our_Heart\" >What Is the Endocardium That Lines the Inner Surface of Our Heart?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/dryavuzbesogul.com\/en\/endocardium-inner-lining-of-the-heart\/#How_Does_the_Endocardium_Heal_When_the_Inner_Lining_of_the_Heart_Is_Damaged\" >How Does the Endocardium Heal When the Inner Lining of the Heart Is Damaged?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/dryavuzbesogul.com\/en\/endocardium-inner-lining-of-the-heart\/#What_Is_Infective_Endocarditis_and_Why_Does_the_Heart_Lining_Become_Infected\" >What Is Infective Endocarditis and Why Does the Heart Lining Become Infected?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/dryavuzbesogul.com\/en\/endocardium-inner-lining-of-the-heart\/#How_Does_the_Diagnostic_Process_Work_in_Suspected_Infective_Endocarditis\" >How Does the Diagnostic Process Work in Suspected Infective Endocarditis?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/dryavuzbesogul.com\/en\/endocardium-inner-lining-of-the-heart\/#Which_Patients_Need_Emergency_Surgery_in_Infective_Endocarditis\" >Which Patients Need Emergency Surgery in Infective Endocarditis?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/dryavuzbesogul.com\/en\/endocardium-inner-lining-of-the-heart\/#How_Are_Inflamed_Tissues_Cleaned_in_Heart_Lining_Surgeries\" >How Are Inflamed Tissues Cleaned in Heart Lining Surgeries?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/dryavuzbesogul.com\/en\/endocardium-inner-lining-of-the-heart\/#How_Are_the_Cleaned_Heart_Valves_and_Endocardium_Repaired_Again\" >How Are the Cleaned Heart Valves and Endocardium Repaired Again?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/dryavuzbesogul.com\/en\/endocardium-inner-lining-of-the-heart\/#How_Does_Endocardial_Fibroelastosis_EFE_Disease_Affect_the_Heart_Lining\" >How Does Endocardial Fibroelastosis (EFE) Disease Affect the Heart Lining?<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"What_Is_the_Endocardium_That_Lines_the_Inner_Surface_of_Our_Heart\"><\/span>What Is the Endocardium That Lines the Inner Surface of Our Heart?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>The endocardium is not a simple structure consisting of only a single layer. When examined under a microscope, it is seen that this thin membrane consists of four distinct intertwined layers, each with different functions that are vital for heart health.<\/p>\n<p>The main layers forming this structure are:<\/p>\n<ul>\n<li>Endothelium<\/li>\n<li>Subendothelium<\/li>\n<li>Musculoelastic<\/li>\n<li>Subendocardial<\/li>\n<\/ul>\n<p>The first of these layers and the one directly in contact with blood is the endothelial layer. We can compare this surface to the surface of the highest-quality nonstick pans we use in our kitchens, which do not allow anything to stick. The cells in the endothelial layer produce special substances that prevent the clotting cells in the blood from adhering to the heart walls. This is how the surface remains completely clean and smooth despite tons of blood passing through it every day.<\/p>\n<p>When we move down to the layer just beneath it, we encounter the subendothelial layer. This layer has a very surprising feature; it does not contain any blood vessels within itself. It obtains the oxygen and nutrients it needs by absorbing them from the blood flowing immediately over it. Although this is a wonderful design on healthy days, when the heart lining becomes infected, this vessel-free structure turns into a disadvantage. Because the body\u2019s defense cells have great difficulty reaching an area without vessels.<\/p>\n<p>When we go a little deeper, the musculoelastic layer we encounter is the structure that gives the tissue its tremendous flexibility. The heart contracts and relaxes strongly every second. The membrane covering the inner surface must also adapt to these movements, stretch without tearing, and then return to its former state. The dense elastic fibers inside this layer adapt to this endless rhythmic dance of the heart.<\/p>\n<p>The subendocardial layer, located on the outermost side and tightly attached to the main muscle tissue of the heart, is quite sensitive. Because this is the main corridor through which the heart\u2019s electrical wiring passes. Special fibers that carry the electrical signals enabling the heart to beat with that regular rhythm are hidden inside this layer. When any repair is performed inside the heart, extreme care must be taken not to damage these electrical lines.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"How_Does_the_Endocardium_Heal_When_the_Inner_Lining_of_the_Heart_Is_Damaged\"><\/span>How Does the Endocardium Heal When the Inner Lining of the Heart Is Damaged?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Just as a wound forms on our skin when we cut our hand and then this wound closes, damage occurring in the inner lining of the heart also has its own healing process. This damage may occur as a result of an infarction caused by blockage of the vessels feeding the heart, severe inflammation, or an incision that must necessarily be made. After the damage occurs, the body immediately goes into alarm mode and begins working at incredible speed to repair that area.<\/p>\n<p>The main stages in this healing process are:<\/p>\n<ul>\n<li>Cellular proliferation<\/li>\n<li>Granulation<\/li>\n<li>Scar tissue<\/li>\n<\/ul>\n<p>If the damage that occurs is very mild and superficial, the body covers that area with brand-new and healthy cells in accordance with its original form through a method we call \u201ccellular proliferation.\u201d However, if the damage extends deeper, that area of the heart cannot regain its former flexible and smooth structure. In order to repair that area, the body builds a temporary tissue called \u201cgranulation,\u201d filled with dense repair cells.<\/p>\n<p>As time progresses, this temporary tissue hardens and turns into the scar we call \u201cscar tissue.\u201d Although this hard scar prevents that area from tearing, it destroys the flexibility of the heart. Especially after major damage, these scar tissues create a dangerous surface that is very prone to blood clot formation because they lose their smooth structure. In later periods, these hardened areas may reduce the contraction power of the heart or cause its shape to become distorted.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"What_Is_Infective_Endocarditis_and_Why_Does_the_Heart_Lining_Become_Infected\"><\/span>What Is Infective Endocarditis and Why Does the Heart Lining Become Infected?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>We call the inflammation of the heart lining, but most commonly the heart valves that control the passage of blood, caused by invasion by bacteria or fungi, Infective Endocarditis. This is a very serious condition in which time is critical. Under normal circumstances, even if microbes entering our body reach the heart through the bloodstream, they slide off that nonstick endothelial surface. However, in some cases, tiny rough areas or injuries may occur on the surface of the heart valves.<\/p>\n<p>The most common conditions that cause microbes to enter the blood are:<\/p>\n<ul>\n<li>Dental treatments<\/li>\n<li>Oral infections<\/li>\n<li>Tonsil infections<\/li>\n<li>Long-term vascular access lines<\/li>\n<li>Skin infections<\/li>\n<\/ul>\n<p>A congenital valve disorder, a previous rheumatic fever, or a prosthetic valve in the heart disrupts blood flow in that area and creates small whirlpools. These whirlpools irritate the surface of the membrane. Bacteria entering the blood after a tooth extraction or a simple skin infection firmly hook onto these rough areas on the heart valves when they find them.<\/p>\n<p>The microbes that attach there combine with clotting cells in the blood and form cluster-shaped inflammatory masses. This is called vegetation. Bacteria create such a strong armor for themselves inside these masses that the body\u2019s defense cells cannot reach them. Moreover, because there are no vessels in the heart valves to carry blood to them, bacteria multiply rapidly in this protected area and begin to virtually melt and destroy the heart valve.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"How_Does_the_Diagnostic_Process_Work_in_Suspected_Infective_Endocarditis\"><\/span>How Does the Diagnostic Process Work in Suspected Infective Endocarditis?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Infective endocarditis is an extremely insidious disease that can easily hide behind its symptoms. A fever that continues for days and whose cause cannot be found, newly developing shortness of breath, night sweats, fatigue, or suddenly appearing heart murmurs may be signs of this disease. As soon as it is suspected, performing the correct tests without losing time is of vital importance.<\/p>\n<p>The basic methods used for diagnosis are:<\/p>\n<ul>\n<li>Echocardiography<\/li>\n<li>Blood cultures<\/li>\n<li>Blood tests<\/li>\n<\/ul>\n<p>The most important step is to be able to visually see those inflammatory masses (vegetations) inside the heart. For this, an echocardiography device that works with ultrasound waves is used. Sometimes the standard examination performed through the chest may be insufficient to show tiny inflammations deep inside the heart or hidden behind the valve. In such cases, after giving the patient a mild sedative, a special probe is lowered through the esophagus toward the stomach. Thanks to this detailed examination performed from just behind the heart, even the smallest inflammation on the valves, whether the valve is perforated, or whether the inflammation has formed an abscess toward the heart muscle is detected millimetrically.<\/p>\n<p>Another step as important as imaging is recognizing the enemy circulating in the blood. When the fever rises, blood samples are taken from different arms of the patient and sent to the laboratory. In these blood cultures, which bacterium or fungus has grown is determined, and thus the correct antibiotic that will deliver the most precise blow to that microbe is selected.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Which_Patients_Need_Emergency_Surgery_in_Infective_Endocarditis\"><\/span>Which Patients Need Emergency Surgery in Infective Endocarditis?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>As soon as the disease is diagnosed, very strong antibiotic treatment, which will be administered intravenously and last for weeks, is started immediately. Many patients can recover with only this drug treatment. However, in cases where the infection is very aggressive or causes irreversible damage to the valves, antibiotics alone are not sufficient. To save the patient\u2019s life, the problem must be solved physically, that is, with surgery.<\/p>\n<p>The most critical conditions that lead to the decision for surgery are:<\/p>\n<ul>\n<li>Heart failure<\/li>\n<li>Resistant infection<\/li>\n<li>Abscess formation<\/li>\n<li>Fungal infection<\/li>\n<li>Large clot masses<\/li>\n<\/ul>\n<p>The most common condition requiring the most urgent intervention is heart failure. When microbes consume the heart valve, rupture the chord-like structures holding the valve, or create large holes in the valve, the valve can no longer close. Blood that constantly leaks backward through the valve that cannot close rapidly tires the heart and causes fluid accumulation in the lungs. The patient suddenly experiences shortness of breath with a feeling of suffocation. When this picture develops, there is not even a single minute to lose; that valve must be replaced or repaired immediately within the first twenty-four hours.<\/p>\n<p>A second scenario is the infection not surrendering to medications. If the patient\u2019s fever does not go down for days despite the strongest antibiotics given, if microbes have passed beyond the valve and formed abscesses in the walls of the heart, or if the agent causing the infection is a very stubborn type of fungus, waiting for the medications to take effect is a great risk. Those inflammatory foci must urgently be scraped out and removed from the heart.<\/p>\n<p>Another great danger is embolization. Those inflammatory masses on the valves, standing like a leaf swaying in the wind, are very fragile. If these masses are larger than one centimeter, the risk of breaking off with each heartbeat and entering the bloodstream is enormous. If a detached mass goes to the brain, it can cause a stroke; if it goes to the kidney, it can cause organ failure. Before these large masses break off, that area must be safely cleaned with surgery.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"How_Are_Inflamed_Tissues_Cleaned_in_Heart_Lining_Surgeries\"><\/span>How Are Inflamed Tissues Cleaned in Heart Lining Surgeries?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Surgeries performed due to infective endocarditis are much more difficult and meticulous processes than standard heart surgeries. The basic logic behind these operations is similar to saving a tree trunk that has begun to rot. If you cover the rotten part without completely carving it out, the decay continues from the inside and destroys the tree from within. In exactly the same way, not even a single inflamed cell inside the heart can be left in place.<\/p>\n<p>When the heart is stopped and opened, the scene encountered is usually damaged tissues, ruptured structures, and infection foci. All damaged, melted tissues that have lost their viability are cut out and removed with great meticulousness using special instruments. Calcified areas are carefully scraped. This cleaning process is so detailed that sometimes even a portion of the heart tissues that appear healthy may be sacrificed within safety margins.<\/p>\n<p>The issue of greatest concern during this deep cleaning is approaching the electrical system of the heart. If the inflammatory foci have spread to the walls separating the heart chambers, the electrically conducting pathways inevitably have to be intervened with while cleaning this area. However, leaving the inflammation inside out of fear that \u201cthe heart rhythm will be disrupted\u201d is like closing the door without putting out the fire. If necessary, the electrical line in that area is sacrificed, as long as the infection is completely removed from the body. After surgery, very reliable pacemakers can be used to regulate the rhythm of the heart.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"How_Are_the_Cleaned_Heart_Valves_and_Endocardium_Repaired_Again\"><\/span>How Are the Cleaned Heart Valves and Endocardium Repaired Again?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>After the infection is completely removed from the heart, a devastated area remains behind. Large gaps have formed where the valves should be, and deep craters have formed in the walls of the heart. From this point on, the reconstruction process begins. Materials that are so strong and compatible with the tissue must be placed instead of the destroyed structures that the heart can fully perform its powerful pump function again.<\/p>\n<p>The repair materials and methods used are:<\/p>\n<ul>\n<li>Valve repair<\/li>\n<li>Mechanical valves<\/li>\n<li>Biological valves<\/li>\n<li>Autologous pericardium<\/li>\n<li>Synthetic patches<\/li>\n<\/ul>\n<p>The first and most ideal goal is always to try to save the patient\u2019s own valve without discarding it. If the infection has only created small holes in the valve, these holes are carefully closed with various patches. If the structures that allow the valve to open and close and resemble parachute cords have ruptured, brand-new chordae are created using artificial cords that are completely compatible with tissue. Preserving the patient\u2019s own valve is very valuable because it saves the patient from having to use difficult blood-thinning medications for life.<\/p>\n<p>However, sometimes the microbe melts and destroys the valve so much that it cannot be repaired. In this case, that valve is completely removed and a brand-new prosthetic valve is placed instead. In young patients, mechanical valves made from carbon-based metals, which generally provide lifelong durability, are preferred. The only disadvantage of these valves is that they require regular blood thinner use so that clots do not form on them. In elderly patients or in those who cannot use blood thinners, biological valves prepared by processing bovine or porcine heart tissues through special procedures are used. These valves behave like the patient\u2019s own tissue, but they have a share of wear over the years.<\/p>\n<p>If large damages and cavities have also opened in the walls of the heart, patches are used to close these gaps. The best material for this purpose is again the membrane surrounding the patient\u2019s own heart from the outside (autologous pericardium). Since it is the patient\u2019s own tissue, the body does not reject it in any way, and it is tremendously resistant to infection. In very extensive damages where the patient\u2019s own tissue is insufficient, synthetic patches produced from special fabrics resistant to high pressure or ready-made processed bovine pericardial membranes are used.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"How_Does_Endocardial_Fibroelastosis_EFE_Disease_Affect_the_Heart_Lining\"><\/span>How Does Endocardial Fibroelastosis (EFE) Disease Affect the Heart Lining?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Problems affecting the inner lining of the heart are not always related to microbes coming from outside. Sometimes, very rare and difficult structural diseases that appear especially in infancy and early childhood also disrupt the functioning of the endocardium. The best known of these is Endocardial Fibroelastosis, briefly EFE disease.<\/p>\n<p>Normally, in order for the heart to relax and fill with blood, the membrane covering its inner surface must be very thin, soft, and flexible. However, in EFE disease, this inner membrane reacts abnormally. The connective tissue and fibers that provide flexibility inside it increase uncontrollably and thicken. The structure that should be a very thin membrane turns into a thick, hard, and non-stretching porcelain-like shell.<\/p>\n<p>This porcelain-like structure usually affects the largest and most hardworking left ventricle of the heart. A heart chamber that cannot stretch cannot fill itself with enough blood. When it cannot fill with blood, it cannot pump the blood the body needs. This condition causes severe heart failure in a very short time. The underlying causes of the disease are usually infections experienced in the womb or congenital valve stenoses that place stress on the heart. If there is a clear obstruction or stenosis causing this stress, they are intervened with; however, if this thickening that has completely surrounded the membrane itself is very advanced, the condition is quite serious.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The endocardium, also known as the inner lining of the heart, is a thin, smooth, and vital protective layer that continuously lines the four chambers of the heart and all heart valves, allowing blood to be pumped without clotting, friction, and in an extremely fluid manner. This membrane, located at the center of the circulatory [&#8230;]\n","protected":false},"author":7,"featured_media":14560,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[380],"tags":[],"class_list":["post-14561","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-kalp-hastaliklari-en"],"_links":{"self":[{"href":"https:\/\/dryavuzbesogul.com\/en\/wp-json\/wp\/v2\/posts\/14561","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/dryavuzbesogul.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/dryavuzbesogul.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/dryavuzbesogul.com\/en\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/dryavuzbesogul.com\/en\/wp-json\/wp\/v2\/comments?post=14561"}],"version-history":[{"count":2,"href":"https:\/\/dryavuzbesogul.com\/en\/wp-json\/wp\/v2\/posts\/14561\/revisions"}],"predecessor-version":[{"id":14563,"href":"https:\/\/dryavuzbesogul.com\/en\/wp-json\/wp\/v2\/posts\/14561\/revisions\/14563"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/dryavuzbesogul.com\/en\/wp-json\/wp\/v2\/media\/14560"}],"wp:attachment":[{"href":"https:\/\/dryavuzbesogul.com\/en\/wp-json\/wp\/v2\/media?parent=14561"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dryavuzbesogul.com\/en\/wp-json\/wp\/v2\/categories?post=14561"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dryavuzbesogul.com\/en\/wp-json\/wp\/v2\/tags?post=14561"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}