The heart is supplied with the blood by coronary arteries. Anatomically, coronary system of the heart is divided into 2 parts: left and right. There are two major coronary arteries: right coronary artery, also called RCA, and left main coronary artery, also called LMCA. These coronary arteries originate from the right and left sinuses of Valsava respectively just above the level of the aortic valve. At first, we will speak about the left main coronary artery that is sometimes called as the left main stem. It’s short but its diameter is the largest. It bifurcates into the left anterior descending artery and circumflex artery. About 30% of people additionally have intermediate artery. Left anterior descending artery (also called LAD) is located in the anterior interventricular sulcus and it goes to the apex. It gives septal branches to the interventricular septum and diagonal branches to the lateral wall of the left ventricle. There are 2-4 diagonal branches, that are called first diagonal, additional first diagonal, second diagonal, additional second diagonal branches. From the angiographic point of view, left anterior descending artery is divided into three parts: proximal, mid and distal. As the last one is located near the apex, sometimes it’s called apical. Left anterior descending artery may wrap over the apex and feed some part of the posterior wall of the left ventricle.
Circumflex artery gives rise to several atrial branches, obtuse marginal and left posterolateral branches. In 15% of all people circumflex artery gives rise the posterior descending artery, this state is known as left dominant circulation. Circumflex artery has 2 divisions: proximal and intermediate. In 35-40% of people the sinoatrial node artery is branch of the circumflex artery, in other people it branches out from the right coronary artery. Circumflex and left anterior descending arteries feed the left atrium, the entire anterior wall and major part of the posterior wall of the left ventricle, major part of the anterior wall of the right ventricle, the anterior 2/3 of the interventricular septum, and the anterolateral papillary muscle of the left ventricle. Right coronary artery originates from the aorta above the right cusp of the aortic valve. It is located in the right coronary sulcus. Often conus artery is the first branch. In approximately 85% of people it gives off posterior descending artery; it’s known as right dominant circulation. Right coronary artery is divided into three parts: proximal, mid and distal. Usually the distal segment of the RCA gives 2-4 posterolateral branches. It’s important, that typically sinoatrial and atrioventricuar nodes are supplied by the right coronary artery, and rare they may be supplied by the circumflex artery. Often acute marginal branches from the RCA are collateral source.
Also, RCA gives short branches to the interventricular septum. So, right coronary artery feeds right atrium, entire posterior wall of the right ventricle, minor part of the posterior wall of the left ventricle, posterior 1/3 of the interventricular septum, papillary muscles of the right ventricle and posteromedial muscle of the left ventricle. It’s important that anterolateral papillary muscle is supplied by both circumflex and left anterior descending arteries. But posteromedial papillary muscle is supplied only by the RCA. So, posteromedial papillary muscle is less protected against ischemia, as it’s supplied by only one coronary artery.
Hello, welcome everybody, this is doctor Bolad, board certified physician in cardiology, interventional cardiology and internal medicine. I am here to help you with all the information you need for your heart health and to inform you about all the latest treatments in cardiology. If you are new to this channel then definitely consider hitting the subscribe button below and switch on the notification bell so you don’t miss any new videos that I post. Today, I will be talking to you about Heart catheterization, also called Cardiac catheterization also known as “cardiac cath," for short is a procedure that we perform to evaluate certain heart problems to understand how the patient’s heart is working. Common reasons for performing this procedure is to diagnose possible cardiac causes of chest pain, to evaluate the coronary arteries after having an abnormal heart stress test, to evaluate abnormal heart valve conditions such as a narrowed or leaky heart valves, to evaluate high blood pressure in the arteries of the lungs, or to evaluate an enlarged or weak heart. The procedure takes about an hour or so, and you are awake during the procedure but you are given medicines to make you relaxed and take any pain away. This is an invasive procedure that is done in the cardiac catheterization laboratory or the operating room. There are two types of heart catheterizations. Left heart catheterization evaluates issues in the left side of the heart and heart catheters are passed through the aorta to the left side of the heart. The other type is right heart catheterization and this is done to evaluate issues in the right side of the heart, and catheters are passed through the veins to the right side of the heart. In this presentation, I will be talking about left heart catheterization. There are two components of the left heart catheterization. When the catheters are passed to the heart to evaluate blockages in the coronary arteries that are on the surface of the heart, the procedure is known as CORONARY ANGIOGRAPHY. When catheters are passed to the chambers of the left side of the heart, either to measure pressure, or to evaluate the heart function or perform invasive work in the chamber of the heart, the procedure is labelled as CARDIAC CATHETERIZATION. Here is how I perform the procedure. The patient is brought to the cardiac catheterization laboratory and either the wrist or the groin is cleaned and prepared for access to the arterial circulation. The choice of the access site whether through the wrist or the groin depends on multiple factors such as operator preference and experience, medical issues such as blood thinning or anatomical issues or medical issues that the patient might be experiencing. Here is an example of how I access the radial artery by a small needle followed by insertion of a short sheath. If I chose the groin to access the arterial circulation through the femoral artery, I usually take a check shot, and this is how it looks on the X-ray monitor. After I gain arterial access, I insert a short sheath either in the wrist or the groin. A long wire is passed through the artery and then into the ascending aorta. Using a long wire, I load longer tubes, called CATHETERS, and pass them all the way to the ascending aorta, very close to the origin of the coronary arteries. Here is how I load the wire into the catheter ……………… and here is how it looks like on the X-ray machine bringing the tip of the catheter close to the origin of the coronary arteries. I then remove the long wire and remove air from the catheter, and then I direct the tip of the catheter under X-ray imaging to the origin of the coronary arteries. Commonly, I engage first the left main stem artery by pointing the tip of the catheter to the left side. This artery acts like a tree trunk, and two main arteries that feed the left side of the heart, branch from it. One artery is called the left anterior descending artery, abbreviated as LAD, and this is the main artery that delivers oxygenated blood to the main muscle of the heart, the LEFT VENTRICLE. This artery runs on the front of the heart and has branches such as the diagonal arteries and septal arteries and extends to the apex of the heart. This is how it looks like on the X-ray monitor during the procedure………….. The second artery that originates from the left main stem is known and the CIRCUMFLEX ARTERY and is generally abbreviated as Cx. This artery turns left immediately after its origin and continues to course on the left side of the heart and then to the back of the heart, giving branches known as obtuse marginal arteries on its way. This is how it looks like on the X-ray monitor during the procedure ………… After completing visualization of the arteries on the left side of the heart, I remove the catheter and replace it by another catheter with a differently shaped tip, shaped to engage the origin of the right coronary artery. Contrast is injected to visualize that artery as it courses on the right side and then the back of the heart giving branches such as the acute marginal artery, the posterior descending artery and the posterolateral artery. This is how it looks like on the X-ray monitor during the procedure …………. After that, I remove the right coronary artery catheter and replace it by another catheter with a curled tip and that catheter is medically known as the PIGTAIL catheter. This catheter is designed to cross the AORTIC VALVE into the left ventricle, the main pumping chamber of the heart that pushes blood out of the heart into the circulation. When the catheter is in place, I inject contrast into the left ventricle to evaluate the contraction of the heart to assess whether the function is reduced or not. This is how it looks on the X-ray monitor during the procedure …………. Subsequently I remove the pigtail catheter from the heart and the access sheath in the wrist or the groin is removed and pressure applied for a short while to control bleeding. To recap what you have just seen me doing in the catheterization laboratory, I am going to demonstrate it on this heart model. ------- After the procedure, I discuss the findings with the patient and family, and I also discuss the treatment options if the finding warrants that. If you have any questions about what I presented to you today, or any cardiology question in general, then subscribe to my channel and share your question in the comments section below and I will reply to you.
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