Sinus tachycardia refers to a faster-than-usual heart rhythm. It can occur with exercise, anxiety, or stress, but it can sometimes signal an underlying health condition.
Sinus tachycardia refers to a faster-than-typical heart rhythm.
Your heart has a natural pacemaker called the sinus node, which generates electrical impulses that move through your heart muscle and cause it to contract, or beat. When these electrical impulses are transmitted normally, it’s referred to as normal sinus rhythm. Normal sinus rhythm typically results in a heart rate of
Sometimes, these electrical impulses are sent out faster than this typical rhythm, causing sinus tachycardia. This results in a heart rate of
If you have sinus tachycardia with no known cause, it’s called inappropriate sinus tachycardia (IST). This can cause an inexplicably fast heart rate even while you’re resting.
In addition to rapid heart rate, IST can cause:
- shortness of breath
- chest pain
- dizziness or fainting
- trouble exercising
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:
- anxiety or emotional distress
- some medications, such as those used in allergy or mental health treatment
- stimulants, such as caffeine or nicotine
- recreational drugs, such as cocaine
Other potential but less common causes of sinus tachycardia may include the following underlying health conditions:
- an infection
- damage to your heart muscle, such as from a previous heart attack
- low blood pressure
- lung disease
- pulmonary embolism
- severe bleeding
Doctors aren’t sure about the exact cause of IST, but it likely involves a combination of factors. These may include:
- a problem with your sinus node
- unusual nerve signaling that causes your heart rate to increase
- dysfunction of the nerves that work to lower your heart rate
- heart palpitations
- chest pain
- dizziness or lightheadedness
- breathing difficulties
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 your heart rate.
In severe cases that don’t respond to medication or lifestyle changes, you may need a cardiac ablation procedure. This involves using energy to destroy a tiny part of the heart tissue in the area causing tachycardia.
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)
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. You may 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
- achieving or maintaining a moderate 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. These may help prevent possible complications, such as cardiomyopathy or cardiac arrest.
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.