Health and medicine
- Overview of heart failure
- What is heart failure?
- Systolic heart failure pathophysiology
- Diastolic heart failure pathophysiology
- Compensation and decompensation in heart failure
- Symptoms of left sided heart failure
- Symptoms of right sided heart failure
- Heart failure diagnosis
- Heart failure treatment - Early stages
- Heart failure treatment - Late stages
- Heart failure treatment - Devices and surgery
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Want to join the conversation?
- Could calcium channel blockers reduce heart rate as presented ? I think this drug class is neutral at best regarding positive chronotropic effect.(2 votes)
- At the end of the lecture, should we also mention that vasolidalating beta blockers can reduce heart rate ?(1 vote)
- Calcium channel blockers are actually contraindicated in heart failure and can exacerbate symptoms.(0 votes)
- Only if the heart failure is caused by a systolic dysfunction. But calcium channel blockers can be used for diastolic heart failure.(0 votes)
- So in the early stages of heart failure, remember that treatments were more targeted at the risk factors for heart failure and this is usually before the symptoms of heart failure even come about to try and slow or stop these symptoms from ever appearing. But in the later stages, when the symptoms associated with heart failure have already started to crop up, there's going to be a different set of medications that we might try and use that are aimed at treating and controlling these symptoms that have already started to affect the patient's quality of life. And two of the main symptoms we're going to target are congestion, or fluid build up, and fatigue. So the first type that we look at are diuretics and these medications help treat the symptoms of congestion. But how do they do that? Well, they help the body get rid of excess fluid and this can have several effects, one of which is to reduce the symptoms that result from fluid buildup, right, that makes sense. Like shortness of breath from fluid in the lungs. And the second is that with less fluid, your blood volume also decreases, right? And so there's less blood in your blood vessels. When there's more blood in the blood vessels, they actually have to stretch more and this causes this higher pressure and so when you reduce this amount, one of the effects is actually a reduction in blood pressure and this can potentially help keep heart failure from getting worse in the future. And so one of the primary types of diuretics used are aldosterone inhibitors. And from this name, we can see that these are probably going to inhibit aldosterone in some form, right? But what's aldosterone? Well in short, it's this super important hormone that causes our body to retain sodium and when we retain sodium, we also retain fluid. So if aldosterone causes us to retain sodium and fluid, we'd expect aldosterone inhibitors to have the opposite effect and that's exactly what it does. It helps remove excess fluid. So aldosterone inhibitors act as a diuretic that help reduce fluid buildup and therefore, reduce the symptoms associated with fluid buildup. And the second type of medication that might be prescribed are calcium channel blockers. These, however are reserved for treating diastolic heart failture where your heart has trouble filling with enough blood. Again, the name is going to be pretty self-explanatory, right? These must block the channels for calcium. And the entry of calcium through these channels plays an important role as a messenger that tells certain muscle cells that it's time to contract. And one of these types of muscles is the smooth muscle around your arteries and so if this channel is blocked and this muscle isn't getting the signals to contract, that means they aren't as constricted so one of the effects is to dilate your arteries and this lowers the arterial blood pressure and makes it easier for your heart to pump blood out. And a second type of muscle that it affects is your heart muscle and when these contract, you get a heartbeat, right? So blocking these channels tend to make the heart contract less therefore lowering your heart rate and lowering your heart rate gives it more time to fill with blood and allows more blood to be pumped out, which is a big part of diastolic heart failure. And so if you're pumping more blood out, that means your body's receiving more blood so you might not feel as fatigued as you did before. Finally, the last type of medication that's not as often used anymore but sometimes for select patients is digoxin and it has two main effects. So the first effect is that it can increase the strength of your muscle contractions in your heart so it makes the heart pump harder and then it tends to slow down the heart rate so sometimes, it's used for patients that have uncontrollably fast heart rates and it just kind of brings it down to a reasonable level. And so in addition to these just listed, the ACE inhibitors and the Beta Blockers described in the early stages video may also still be used to control blood pressure in the later stages.