Health and medicine
- Heart disease and heart attacks
- Stenosis, ischemia and heart failure
- Thromboemboli and thromboembolisms
- What is coronary artery disease?
- Risk factors for coronary artery disease
- Heart attack (myocardial infarction) pathophysiology
- Heart attack (myocardial infarct) diagnosis
- Heart attack (myocardial infarct) medications
- Heart attack (myocardial infarction) interventions and treatment
- Healing after a heart attack (myocardial infarction)
- Complications after a heart attack (myocardial infarction)
Heart attack (myocardial infarction) interventions and treatment
Created by Vishal Punwani.
Want to join the conversation?
- For a CABG, what happens to the artery that gets a piece cut out of it? Is it just stretched out and sewn back together?(13 votes)
- Why are two of the grafts arteries and one a vein? How can a vein do the job of an artery?(4 votes)
- Short Answer: It only has to act as a vessel for a short distance to bypass the plaque. It is not ideal, but it is better than dying of a heart attack.
Long Answer: The first bypass surgery performed in 1967 utilized saphenous vein harvested from the leg. That vein has been the workhorse conduit for over 40 years. The problem with the conduit is that it has a significant failure or occlusion rate. Several recent studies have found an early occlusion rate of 20% at one year after CABG primarily due to intimal hyperplasia or thickening of the vein graft wall due to the arterial pressure effect. (Veins are thin walled delicate vessels designed to exist in the low pressure venous circulation). The two arteries mentioned, Left Internal Thoracic Artery (LITA) and Radial Artery Conduits are more modern additions to surgery and are better suited and have better long term results.
The surgeon has to decide which grafts to use depending on the location of the blockage, the amount of the blockage, and the size of the patient's coronary arteries. The other thing to consider is that there are not many areas of the body in which you can safely cut out major blood vessels without causing damage to the areas to which it supplies blood so you have to work with what you've got!(5 votes)
- So, I'm a bit curious about the CABG, while they are doing the surgery, do they stop blood from flowing in the vessel so the blood doesn't spout out of the vessel, or it doesn't matter whether the patient has some spouted blood in between their muscles? Thanks for any answers :)(5 votes)
- CABG can be performed while on cardiopulmonary bypass (https://en.wikipedia.org/wiki/Cardiopulmonary_bypass), or using off-pump coronary artery bypass (https://en.wikipedia.org/wiki/Off-pump_coronary_artery_bypass).(1 vote)
- When the surgeons take the arteries from elsewhere in the body, what happens to that place? Do they insert some kind of new artery for that place?(3 votes)
- I believe the leave the vessel bisected, but close the ends. The locations they harvest from all have their own bypass routes for blood flow, formed by smaller vessels, so even with the artery or vein interrupted, the surrounding tissues can still receive blood, albeit not as effectively. This is not optimal, but when weighed against the importance of the heart's blood supply, it is clear choice to sacrifice a small amount of function elsewhere in the circulatory system. Making this choice easier is the fact that over time, the body can further compensate for some of the lost function by growing new blood vessels in the affected area. At least that is how I understand it.(4 votes)
- why cant they simply remove the colesterol(3 votes)
- because if they try to remove the cholesterol, you might die because it would be fatal to cut open an artery.(2 votes)
- How do they make the blood not go straight but re-route it through the bypass vein? Do they block it of?(2 votes)
The "straight route" is already blocked off by a plaque or athersclerosis. They are putting in another vein to allow the blood to travel past that blockage to the tissue that is not getting blood. By doing that, the tissue is given oxygen and glucose and hopefully saved from further injury.(3 votes)
- Is that true that there is extra veins in our legs?(2 votes)
- By using thrombolytics or performing angioplasty, isn't there a risk of embolism (clogging of smaller blood vessels by the broken up plaque)?(1 vote)
- There is a risk of embolism. However, the benefits would need to outweigh the risk of further damage(2 votes)
- I thought that catheters were used as a mobile bathroom for injured people who can't move much. Why aren't they called something else if they don't always work the same way?(1 vote)
- A catheter is just a term for a hollow tube which can be inserted into the patient. There are a great variety of catheters, including the urinary catheters you are thinking of, as well as venous catheters which allow healthcare practitioners to administer drugs and fluids to a patient.(2 votes)
- So if I'm right, angioplasty is short-term but the use of a stent is long term right?(1 vote)
- That is correct. With an angioplasty, there is still a chance of plaque building up again, but it saves time and reduces complications. Stents are more risky but if successful they will keep the vessel open for life. It also depends on how serious the blockage is(1 vote)
- In addition to treatment with medications after a heart attack, as part of your overall treatment, you might also have some procedures done. And these range from smaller interventional procedures to big open heart surgeries. Generally these are reserved for patients with STEMIs, ST-Elevation Myocardial Infarcts The more serious type of Infarct. But they can be done for patients with NSTEMIs, Non ST-Elevation Myocardial Infarcts, as well, if they're not responding to treatment with medication alone, or if they have a lot of risk factors for bad coronary vessel disease. So, once you've been given some medications to deal with your myocardial infarct, the first thing that happens, from a interventional point of view, is you'll get a coronary angiogram done. Which is where an interventional cardiologist, a specialized heart doctor, will take a sort of unique type of x-ray of your heart's blood vessels. And normally on a normal x-ray you can't really see people's blood vessels, so in an angiogram, the cardiologist will inject a special type of dye into the patient's circulation. And that dye will help the cardiologist to really see the blood vessels of the heart really clearly. So, coronary angiograms are to check how badly, and also where your coronary arteries are blocked or narrowed. And depending on how the bad the clogging is inside the coronary arteries, the cardiologists will then make a recommendation for what procedure that you need to go on to next to fix the underlying problem with your heart. So, this is what a coronary angiogram looks like. You can see, it's really a cool, sort of, dynamic picture. You can get a real-time look at how healthy the person's coronary arteries are. So, yes, these are blood vessels and this is actually the outline of the heart here. In this coronary artery here, there's a pretty severe blockage, a pretty severe narrowing of this coronary artery. And over here on the right, it's resolved, it's opened up. And that's after treatment. So depending on how bad the clogging is inside a given person's coronary arteries, the cardiologist will then go on to make a recommendation for what procedure to move on to next to fix the underlying problem with someone's heart. So, let's actually have a look at a few of these procedures. Percutaneous Coronary Intervention, or PCI, is where a doctor will insert a catheter. So, here I'm drawing a catheter now, this purple thing. So this is actually a wire-like tube that a doctor will thread into your femoral artery, or actually sometimes some other arteries, but usually the femoral artery. So, he'll thread it into your artery, sort of put it into your artery, and thread it up to your heart and into your coronary vessels. Which, as it probably sounds like, it takes a lot of skill and knowledge to do this. And depending on what they find in your coronary vessels, depending on how bad the blockage in your vessels is, they'll either just do something called an angioplasty, which is where they blow a balloon up, that's on the end of the catheter. So, there's a balloon on the end of the catheter and when they blow it up, it sort of opens up the blockage, pushes all that atherosclerotic plaque aside, and allows blood through again. Or they'll do an angioplasty, so what we saw here, and insert a stent, which is a tough, mesh-like cylinder made out of metal, that gets left behind in your coronary vessel to prop it open. So that's PCI, that's Percutaneous Coronary Intervention. Either just angioplasty, so opening up a clogged artery with a balloon by using a catheter with a balloon on the end, or by doing angioplasty, so the ballooning technique, plus inserting a stent and leaving it in there long-term. So, i.e., forever, right, indefinitely. So, that's PCI. Now, the next sort of grade up, in terms of interventions, is Coronary Bypass Grafts. So, this one is really a whole different ball game. This is an open heart surgery. So, let me clear off some space here. Let me clear off some room here. Because now this is the big time. So, here I'll draw in some more coronary arteries here. And the reason I'm drawing more on, is because I just want to show you that Coronary Artery Bypass Grafts, or cabbage, as the acronym sort of allows us to pronounce it, cabbage, is really only done in patients who have really severe coronary artery disease. And so by severe coronary artery disease I mean if they have pretty significant plaques built up in at least three of their coronary vessels. And we call this condition triple vessel disease. And so you can just kind of imagine that if somebody has triple vessel disease it's really not going to be easy for them to get oxygen, say, from their coronary artery up here, right, down to this part of the heart down here because there's this huge blockage in the way. And that's the same sort of thing goes for this plaque and this plaque right here. So, in the situation like this, you've got huge areas of heart, so basically all of this area of heart that this vessel supplies, actually it supplies more than that but I won't bother drawing it in, and, you know, all of this area of heart and all of this area of heart, that's essentially being deprived of oxygen. So, we have to do something about that. That's really, really serious. So, what happens? What happens in Coronary Artery Bypass Grafting? Well, just as the name suggests, bypassing, we take blood vessels from elsewhere in the body and use them to bypass the atherosclerotic plaque. So, I'll draw some on here to show you exactly what I mean. And I'll actually use pink to draw on the new blood vessels. So a blood vessel might be sort of attached on here before the plaque, and then sort of used to re-route blood around the plaque, so it'd be obviously attached again on the other side, after the plaque. And by doing this, you can restore blood flow to that affected area that I sort of highlighted before, that wasn't getting much oxygen at all. And so the same sort of procedure will happen with the rest of your blocked vessels. And, let me just say, that I'm not drawing it exactly how it's done in theater, in the operating theater, but this is really the general idea of what happens. So, just for interest's sake, blood vessels are usually taken from three main places. So, on the inside of your rib cage. So, what I'm drawing now is on the inside, not on the outside, on the inside of your rib cage, there's one that's really popular for use in bypass graft. That's called your internal mammary artery and there's one on each side. In the forearm, you've got a good one. So, in the forearm you've got a radial artery. And on your inner leg and thigh, you've got another one, a vein, called the great saphenous vein. And, again, just to reiterate, the purpose of Coronary Artery Bypass Grafting is to re-route blood around plaques. So, the blood can get to the heat muscle where it's needed. So this is a really cool surgery. I mean it sounds super complex and difficult and it really is. But I remember the first time I scrubbed into one of these procedures, and the whole time I was really just amazed at the skill and the composure of the surgeons who were doing it. They're really well trained. So the rate of complications is low.