Fast but Stable Heart Rate in Hyperthyroidism Patients

Stable but slightly elevated heart rate?

Hello, Doctor.
I have been experiencing issues with hyperthyroidism.
My levels were normal previously, but after stopping medication, it relapsed.
At one point, my heart rate reached 149 beats per minute, and I felt dizzy, which led to an emergency room visit.
During that time, an electrocardiogram was performed, and the cardiologist stated that my heart rate was stable but slightly elevated, and he believed there was no issue with my heart as long as I continued to manage my hyperthyroidism.
A few years ago, my heart rate consistently ranged between 80-100 beats per minute, but I did not feel any discomfort, so I was only taking medication for hyperthyroidism.
Now, however, I feel uncomfortable when my heart rate exceeds 90.
The endocrinologist has prescribed additional medication to lower my heart rate.
Currently, as per medical advice, my heart rate mostly stays between 70-85 beats per minute, but occasionally it spikes to around 95 for a minute or two, and after resting for about ten minutes, it gradually decreases to around 80.
I would like to know if this puts a significant burden on my heart.
Is there a possibility that this elevated heart rate could lead to heart failure? Twenty years ago, I was diagnosed with mitral valve insufficiency, but it has not significantly affected my daily life.
I am unsure why I am feeling so uncomfortable this time, which makes me a bit worried.
Thank you for your response, Doctor.

Niming, 40~49 year old female. Ask Date: 2021/05/11

Dr. He Dongjin reply Cardiology

Hello, a rapid heartbeat does not place a significant burden on the heart.
However, if hyperthyroidism is not well-controlled, there is a possibility of heart failure, so it is important to prioritize managing hyperthyroidism.
Once the thyroid is stabilized, the heart will improve.
Changhua Hospital cares about you.

Reply Date: 2021/05/11

More Info

Understanding the relationship between hyperthyroidism and heart rate is crucial for managing symptoms and preventing complications. Hyperthyroidism, a condition characterized by excessive thyroid hormone production, can significantly affect the cardiovascular system. The symptoms you describe, including episodes of increased heart rate (tachycardia) and feelings of discomfort, are common in individuals with hyperthyroidism.

When thyroid hormone levels are elevated, they can increase the heart's metabolic rate, leading to a faster heart rate. In your case, a heart rate of 149 beats per minute (bpm) is indeed concerning, especially when accompanied by dizziness. However, it is reassuring that your cardiologist found your heart rhythm to be stable despite the elevated rate. This suggests that your heart is functioning well mechanically, even if the rate is higher than normal.

Your current heart rate, which fluctuates between 70-85 bpm with occasional spikes to 95 bpm, is generally considered acceptable, especially if you are asymptomatic during these episodes. The fact that your heart rate returns to baseline after a short rest is a positive sign. It indicates that your autonomic nervous system is effectively regulating your heart rate, which is crucial for maintaining cardiovascular health.

Regarding your concerns about heart failure, it is important to note that a fast heart rate alone does not directly cause heart failure. However, if the heart is consistently overworked due to prolonged periods of tachycardia, it can lead to complications over time. Given your history of mitral valve regurgitation, it is wise to monitor your heart health closely. Mitral valve regurgitation can lead to volume overload on the heart, and if combined with the effects of hyperthyroidism, it could potentially increase the risk of heart failure if not managed properly.

Your endocrinologist's decision to prescribe medication to control both your hyperthyroidism and heart rate is appropriate. Beta-blockers, such as the one you mentioned, can help manage symptoms of tachycardia and provide relief from the discomfort associated with elevated heart rates. It is essential to adhere to your prescribed medication regimen and attend regular follow-ups with both your endocrinologist and cardiologist to monitor your condition.

In summary, while your current heart rate and history of mitral valve regurgitation warrant careful monitoring, the management strategies you are employing should help mitigate risks. It is crucial to maintain open communication with your healthcare providers about any new symptoms or concerns you may have. Regular check-ups, medication adherence, and lifestyle modifications, such as stress management and a balanced diet, can significantly contribute to your overall cardiovascular health. If you experience any worsening symptoms, such as increased shortness of breath, chest pain, or persistent dizziness, seek medical attention promptly.

Similar Q&A

Understanding Hyperthyroidism: Heart Rate, Anxiety, and Symptoms

I would like to ask about hyperthyroidism. My heart rate has been consistently high. Recently, during the day, my heart rate is quite fast, sometimes reaching 80-90 beats per minute while sitting, but at night when I sleep, it drops to about 50 beats per minute. I had a blood tes...

Dr. Hong Yuanbin reply Internal Medicine
Based on your description and the examination data, it does not appear to be a case of hyperthyroidism. In a normal individual, the heart rate should be between 50 and 100 beats per minute, so your heart rate should still be within the normal range. As for the palpitations, there...

Understanding the Connection Between Hyperthyroidism and Rapid Heartbeat

Hello, doctor. I would like to ask about my hyperthyroidism, which has been ongoing for four years. I also have a swollen neck and nodules that are being monitored. Currently, I take one medication daily and have follow-up appointments every three months. However, I have a troubl...

Dr. Yuan Tianmin reply Breast and Thyroid
Patients with hyperthyroidism often experience symptoms such as tachycardia or arrhythmias. If these symptoms can be managed with medication, a conservative treatment approach is preferred. However, if these issues cannot be controlled, options such as radioactive iodine therapy ...

Managing Hyperthyroidism: Key Questions on Medication and Recovery

Hello, Doctor! My heart rate increased from 70-80 to around 100 due to hyperthyroidism, and my systolic blood pressure rose from 88 to about 103. After taking thyroid medication and the beta-blocker Inderal (propranolol) for two weeks, my systolic blood pressure is around 94, hea...

Dr. Chen Taicheng reply Family Medicine
● Entacapone can lower heart rate and partially suppress thyroid function, generally used when the heart rate exceeds 90 beats per minute; if the heart rate returns to normal and there are no other discomforts, it is acceptable to discontinue the medication directly. ● Antithyroi...

Managing Arrhythmias in Hyperthyroidism: Insights and Recommendations

Hello, Doctor. I was diagnosed with Graves' disease and hyperthyroidism at the age of 40. I have been taking medication for hyperthyroidism for a year now, but I still occasionally experience arrhythmias, with a heart rate of about 120, especially in situations of stress and...

Dr. Xie Rongyuan reply Internal Medicine
Hello: You should go to the hospital for further examination of thyroid function abnormalities. As for your daughter's T4 and TSH levels, they are within the normal range. If her symptoms persist, you should promptly visit the hospital to identify the underlying cause. Thank...