Sinus tachycardia refers to a faster-than-usual heart rhythm. It may occur with exercise, anxiety, or stress, but it can also signal an underlying health condition.
Your heart has a natural pacemaker called the sinus node. This node generates electrical impulses that move through your heart muscle and cause it to contract or beat.
When transmitted normally, these electrical impulses produce a healthy sinus rhythm, which results in a heart rate of
However, these electrical impulses are sometimes sent out faster than a healthy rhythm, causing sinus tachycardia and a resulting heart rate of
Keep reading to learn more about sinus tachycardia, including potential causes, symptoms, and treatment.
In some situations, sinus tachycardia can be completely natural. For example, a fast heart rate is expected during strenuous exercise or after being startled.
Other causes of sinus tachycardia may include:
Other potential but less common causes of sinus tachycardia may include the following underlying health conditions:
- anemia
- an infection
- damage to your heart muscle, such as from a previous heart attack
- hyperthyroidism
- low blood pressure
- lung disease
- pulmonary embolism
- severe bleeding
What to know about inappropriate sinus tachycardia (IST)
Sinus tachycardia with no known cause is called inappropriate sinus tachycardia (IST). IST can cause an inexplicably fast heart rate even while you’re resting. It may also cause:
- shortness of breath
- chest pain
- dizziness or fainting
- headaches
- difficulty exercising
- anxiety
In
- heart palpitations
- chest pain
- dizziness or lightheadedness
- fainting
- breathing difficulties
To diagnose sinus tachycardia, a doctor may order tests to measure how your heart is working. These may include:
- an electrocardiogram (EKG), which measures electrical activity in your heart
- a Holter monitor, which measures your heart rate over 24 hours
- chest X-rays
- pulse oximetry
- blood testing for cardiac enzymes, glucose, and complete blood count (CBC)
- thyroid function tests
- cardiac testing that includes a tilt table test, exercise stress test, and echocardiogram
- cardiac MRI or CT scan
Occasional sinus tachycardia from exercise and other factors that cause short-term increases in your heart rate generally don’t require treatment. However, a doctor may consider treatment if you have a consistently higher heart rate than typical, especially during times of rest.
First, a doctor will need to determine the underlying cause of sinus tachycardia before prescribing treatment. Depending on how fast your heart rate is, a doctor might prescribe beta-blockers or calcium channel blockers to lower it. A medication called
In severe cases that don’t respond to medication or lifestyle changes, you may need a cardiac ablation procedure. This involves using small bursts of radiofrequency energy to destroy a tiny part of the heart tissue in the area, causing tachycardia.
Preventing sinus tachycardia may depend on treating any underlying causes.
For example, if you have hyperthyroidism and it’s causing a higher-than-typical heart rate, then treating your overactive thyroid gland may help prevent sinus tachycardia.
In other cases, you may be able to prevent sinus tachycardia with certain lifestyle changes. Consider talking with a doctor to see if the following strategies may help:
- limiting caffeine intake
- limiting or avoiding alcohol
- quitting smoking if you smoke
- participating in an exercise program
- eating a heart-healthy diet
- maintaining a healthy weight
- managing stress
Sinus tachycardia is an increase in your heart rate. In many cases, it’s a sign of something simple, such as vigorous exercise or having too much caffeine. Such cases are usually temporary and may resolve on their own.
In the case of IST, however, there’s no known cause.
If you have IST, a doctor will work closely with you to determine a treatment plan. Treatment will likely involve a combination of medications and lifestyle changes. The treatment combination may help prevent possible complications, such as tachycardia-induced cardiomyopathy.
Sinus tachycardia is a faster-than-typical heart rhythm. It may occur with exercise, anxiety, or stress.
IST refers to sinus tachycardia with no known cause that can occur even when resting.
Underlying health issues, such as infections, lung disease, or conditions like pulmonary embolism can cause sinus tachycardia.
If you’re experiencing persistent sinus tachycardia, see a doctor for a diagnosis. They can provide treatment recommendations to help prevent more serious complications.