Episode - Hyperthyroidism and the Heart


Hyperthyroidism and the Heart

Without question, excess thyroid hormones can have a negative impact on the cardiovascular system.

From elevated heart rate to atrial fibrillation, there are many cardiovascular symptoms associated with hyperthyroidism, and it’s critical to manage them alongside addressing the underlying causes of the thyroid hormone imbalance.

Today, I’m going to share the potential cardiac risks associated with hyperthyroidism and what you can do to support and protect your cardiovascular and thyroid health.


During this episode, you’ll learn about:

  • The effects of thyroid hormones on the cardiovascular system
  • Cardiac risks and symptoms associated with hyperthyroidism
  • The connection between atrial fibrillation and hyperthyroidism
  • Untreated hyperthyroidism and heart failure
  • What research shows about the relationship between subclinical hyperthyroidism and cardiovascular disease
  • The prevalence of hypertension and how thyroid hormone impacts blood pressure
  • Treatment options for cardiovascular symptoms
  • Why it’s crucial to address the underlying causes of hyperthyroidism
  • My experience with Graves’ disease and cardiovascular symptoms
  • Natural agents and medications that can help to lower thyroid hormones


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Here is the transcript for this episode:

In this episode, I am going to be talking about hyperthyroidism and the heart. Let’s first start off by discussing thyroid hormones and the heart. Thyroid hormones circulate the blood to regulate cells, tissues, and organs in the body. They exert several effects on the cardiovascular system as well. 

Thyroid hormones raise the heart rate and cardiac contractility. They improve the systolic and diastolic function of the heart, and they decrease systemic vascular resistance. As far as excess thyroid hormone in the heart, hyperthyroidism increases the risk of atrial fibrillation (afib), cardiovascular disease, and heart failure. Symptoms of hyperthyroidism include cardiac and hemodynamic symptoms such as heart palpitations, widened pulse pressure, difficulty breathing on exertion, tachycardia (elevated resting heart rate), exercise intolerance,and afib. Cardiac contractility as well as resting heart rate is increased by thyroid hormones. Cardiac output can increase by 50-300% under hyperthyroidism compared to that in normal conditions.

With patients with hyperthyroidism, exercise intolerance is caused by impaired ability to further increase the heart rate, cardiac contraction, and lower the systemic vascular resistance. Hyperthyroidism has been implicated by a 16% increase in the risk of major cardiovascular events. Cardiac arrhythmias or electrocardiogram abnormalities include sinus tachycardia, afib, and shortened PR and QT intervals. The most common rhythm disturbance of those with hyperthyroidism is what’s called sinus tachycardia. Sinus tachycardia is an irregular cardiac rhythm in which the heart beats faster than normal. Afibis an irregular and often very rapid heart rhythm, also known as an arrhythmia. 

In patients with hyperthyroidism, the presence of afib ranges between 2-20%. The risk of afib is approximately six-fold higher than that of healthy people. Controlling the heart rate is a key factor in the management of afib. Beta blockers are commonly used in the treatment of afib in cases of hyperthyroidism. Treatment of hyperthyroidism is optimal for long-term afib management. Beta blockers can play a role. Ideally, you don’t want to be on beta blockers permanently. 

Let’s talk a little bit about hyperthyroidism and heart failure, as untreated hyperthyroidism might lead to heart failure because of arrhythmias, cardiac hypertrophy, and increased blood volumes. Patients with severe hyperthyroidism can suffer from high output heart failure. In young patients with hyperthyroidism, the elevation in thyroid hormones is not associated with underlying heart disease and therefore, the heart is not damaged, which is of course good news. It has been reported that cardiovascular diseases related to thyroid function can be further improved by treating the thyroid gland.

I want to talk about subclinical hyperthyroidism and cardiovascular disease. Subclinical hyperthyroidism is when someone has a depressed TSH, and their thyroid hormone levels are within the normal lab reference range. Many times, the person doesn’t have any hyperthyroid symptoms. Several observational clinical studies have reported a relationship between subclinical hyperthyroidism and incident cardiovascular disease, afib, heart failure, and cardiovascular mortality. 

Even though it’s subclinical, still, these people are at an increased risk. Arguably, not as big of a risk as someone who has overt hyperthyroidism, but still, something you don’t want to take lightly. This is something I didn’t know before diving into the research. I didn’t know subclinical hyperthyroidism can lead to an increased risk of cardiovascular disease.

Let’s talk about hyperthyroidism and hypertension, high blood pressure. Hypertension affects 26.4% of the global adult population. Thyroid hormone does play a role in blood pressure regulation. Both hyperthyroidism and hypothyroidism can cause an increase in blood pressure. The correction of thyroid dysfunction may normalize blood pressure. It really depends on the situation. Many people with hyperthyroidism have normal blood pressure.When I was dealing with Graves’ back in 2008/2009, my blood pressure was normal. Again, that’s not the case with everybody with hyperthyroidism. 

Approximately, 1% of patients with hyperthyroidism will develop something called thyrotoxic cardiomyopathy. A cardiomyopathy refers to problems with your heart muscle that can make it harder for your heart to pump blood. Prompt identification is crucial, as it is a reversible cause of heart failure. 

Heart functioning can be recovered after achieving a euthyroid state. Euthyroid is when the thyroid hormones are in balance. It’s important to manage cardiovascular symptoms. Usually, it’s through antithyroid medication such as methimazole or taking a beta blocker. 

Let’s talk about management and treatment. The conventional approach involves taking antithyroid medication and/or beta blockers. Sometimes, just the antithyroid medication alone will help from a cardiovascular perspective. Sometimes, a person will be given antithyroid medication and a beta blocker. Some people of course can’t tolerate antithyroid medication, so they might just be put on a beta blocker alone. 

As you know, there are natural agents to lower thyroid hormones. That includes bugleweed, which is an herb with antithyroid properties; L-carnitine in higher doses; lithium orotate, which can lower thyroid hormone levels. In my practice, I use more bugleweed and L-carnitine for their antithyroid properties. 

You might be wondering about iodine. There are some people who want nothing to do with it, which I get. I am very cautious about iodine, too. Iodine in higher doses also can lower thyroid hormone levels. It also comes with risks as well. Sometimes, it can exacerbate hyperthyroidism.In people with Graves’, it sometimes can exacerbate the autoimmune response. 

As far as using iodine to lower thyroid hormone levels, I would say it should not be a first resort. I would look into the natural agents if you don’t want to take the medication. If you’re taking medication, there’s nothing wrong with that, if you’re tolerating it well. There are potential side effects, but everything comes down to risk versus benefits.

Also, the herbs motherwort and hawthorn can support the cardiovascular system. I took motherwort when dealing with Graves’. Hawthorn is also good. 

The goal is to address the underlying cause of hyperthyroidism. You want to find and remove triggers, correct underlying imbalances. I was on the herbs bugleweed and motherwort for approximately nine months, but I have not been on those herbs since 2009. That’s my goal when working with someone. If someone is taking medication or a natural agent, those are just managing the symptoms while ideally you try to address the cause of the problem.

Let’s summarize everything. Thyroid hormones exert several effects on the cardiovascular system. Two common symptoms of hyperthyroidism include heart palpitations and tachycardia. I experienced both of these when I dealt with Graves’, and I commonly see these in my patients with hyperthyroidism as well. Hyperthyroidism increases the risks of afib, cardiovascular disease, and heart failure. Hyperthyroidism has been implicated in a 16% increase in the risk of major cardiovascular events. The most common rhythm disturbance is sinus tachycardia. 

Untreated hyperthyroidism might lead to heart failure because of arrhythmias, cardiac hypertrophy, and increased blood volume. Both hyperthyroidism and hypothyroidism can cause an increase in blood pressure. Approximately 1% of patients with hyperthyroidism develop thyrotoxic cardiomyopathy. 

The conventional approach usually involves antithyroid medication and/or beta blockers although there are natural treatment approaches, like bugleweed, L-carnitine, motherwort, and hawthorn. Once again, the goal should be to address the underlying cause of hyperthyroidism. 

That is it with regard to this presentation. Again, the goal was not to scare you, but in a way, it is to scare you a little bit. Hyperthyroidism is serious, and you do want to take the proper precautions. You don’t want to have it unmanaged. That is where someone is at greater risk. I know some people are nervous or scared, and that’s why they choose to get radioactive iodine or thyroid surgery. Some people arguably don’t even know about all the potential risks I mentioned here. If you don’t manage hyperthyroidism, there could be great risk. Not just cardiovascularly, but it could also affect bone density and other risks as well. Of course, the focus here was on the heart.

The point here is not to jump to radioactive iodine or thyroid surgery because of the risks involved. Just be aware of the risks. Do what is necessary to manage the symptoms while addressing the cause of the problem. If you are able to manage the symptoms through herbs such as bugleweed, motherwort, or taking high doses of L-carnitine, that’s great. If you need to take antithyroid medication, and you are tolerating it well, that’s fine. If you need to take a beta blocker, I don’t love people taking medication, but if someone is doing fine on them, that’s great. I’m never going to tell someone to stop taking medication. 

If someone is unable to take antithyroid medication, and let’s say that the herbs aren’t doing a great job, that’s where there are other options, which I discuss on this podcast. I’ve discussed cholestyramine before; it binds the thyroid hormone and is an option if someone is unable to take antithyroid medication, and the natural agents don’t work. There is LDN as an option. It’s more hit or miss. Cholestyramine is more effective. It’s a little bit of an inconvenience because it’s in powder form, and you need to take it away from food and other medications and supplements. Everything is risk versus benefit. 

If I was dealing with Graves’ currently again, I would try to do everything I can to avoid radioactive iodine and thyroid surgery. That’s my goal. That’s why it’s called Save My Thyroid. I want to help people save their thyroid.

Hope you found this information to be helpful. As usual, I look forward to catching you in the next episode.


Hopefully you found this brief episode to be valuable. I honestly thought I would go longer, but I said what I needed to say. I wanted to reinforce that I understand that after listening to this episode, some people are going to have concerns with developing afib, arrhythmias, even heart disease. It comes down to risk versus benefits and safely managing your symptoms. 

Remember, I dealt with Graves’. I had an elevated resting heart rate and heart palpitations, and I took action. Admittedly, I took action a little bit later than I should have. It’s not like right when I was diagnosed with hyperthyroidism, I took the recommended beta blocker. I saw a regular doctor and had a beta blocker prescribed, and I did not take it. Eventually, I took bugleweed and motherwort, even though the antithyroid medication was prescribed by the endocrinologist. There was a bit of a lapse with me doing anything. Thankfully, everything turned out okay, even though my resting heart rate was anywhere between 90-110 beats per minute. Some people, it’s significantly higher. 

Either way, you want to be safe. You don’t want to go a significant period of time between when it comes to managing the symptoms. You want to take action quickly, whether it’s the medication or the natural agents. 

As far as lowering thyroid hormone levels, that should be the focus: getting those thyroid hormone levels under control, doing whatever it takes. If you do it through the herbs, that’s great. If you need to take medication or something like cholestyramine, that’s fine, too. 

I was surprised about subclinical hyperthyroidism. I still think if you have subclinical hyperthyroidism, it’s not nearly as big of a risk as elevated resting heart rate. Most people with subclinical hyperthyroidism, it’s called “subclinical” because the thyroid hormone levels are within the normal reference range. As a result, most of these people don’t have an elevated resting heart rate, and the risk will be lower. According to the literature, there is still some risk. I’m glad I brought it up, but if you have depressed TSH and normal thyroid hormone levels, I wouldn’t stress out about it. It was good to learn that.

As far as some of the agents to help support the cardiovascular system, beta blockers are not natural, so I hate to use the word “support.” They are just managing the symptoms. There are potential side effects of the beta blockers. Once again, there is a time and place to take beta blockers. 

If you’re able to get away with taking herbs such as motherwort and hawthorn, I focus on these two because these are more specific for the cardiovascular system. Bugleweed is an antithyroid herb. If you have hyperthyroidism, you might decide to take bugleweed to lower thyroid hormone levels. When it comes to the heart, motherwort and hawthorn. 

I should also mention in some cases, you might just need to take either antithyroid medication or an herb such as bugleweed. Those are lowering the thyroid hormone levels, so you might not need to take a beta blocker. A lot of my patients don’t take beta blockers. There are some who are on antithyroid medication and beta blockers. 

Similar with the herbs. I did take bugleweed and motherwort, but I can’t say everybody needs to take bugleweed and motherwort. If someone takes L-carnitine instead of bugleweed, you won’t necessarily need motherwort. In my case, I took bugleweed. I was still having some heart palpitations, so that’s why I added motherwort. 

See how you feel while taking either the antithyroid medication or bugleweed. If you still have an elevated resting heart rate, it might mean that you need a higher dose of whatever you’re taking, but you could also consider adding an herb such as motherwort or hawthorn. 

That’s all I wanted to chat about here when it comes to hyperthyroidism and the heart. Hope you learned a lot by listening to this. Look forward to presenting a future episode.