Many things can make your heart beat faster than normal, including anxiety, excitement, fear or exertion. However, if your heart starts beating rapidly for no apparent reason, you may have a type of heart rhythm disorder called tachycardia.
The average normal resting heart rate for an adult ranges from 60 to 100 beats per minute. A person with tachycardia has a heart rate faster than 100 beats per minute and also may experience symptoms, such as a pounding or irregular heartbeat, dizziness, shortness of breath, lightheadedness and actually passing out.
There are different types of tachycardias, and some are more concerning than others. Supraventricular or top tachycardias start in the two upper chambers of the heart. Atrial fibrillation and atrial flutter are two examples of more serious top tachycardias because they’re linked to a higher risk of stroke. Others, such as atrial tachycardia, can cause symptoms but are considered less dangerous.
Ventricular or bottom tachycardias, which start in the two lower chambers of the heart, are always serious and have been associated with sudden cardiac death.
Tachycardia risk factors include lifestyle factors, such as using tobacco and excessive use of alcohol or caffeine. Electrolyte disorders may make the heart more irritable and raise the risk of irregular heartbeat. Other risk factors include stress, anemia, thyroid disorders, abnormal heart structure and heart disease.
“There’s a wide variety of entities that can drive these heart rhythm abnormalities,” says Dr. Cork. “We need to tease through symptoms with each patient with a comprehensive evaluation to make sure we've looked for an underlying cause.”
Depending on your symptoms, your physician may perform a painless, noninvasive procedure called a 12-lead electrocardiogram (EKG), which uses sensors attached to your body to capture your heart’s electrical signals and check your heart rhythm.
Without treatment for an ongoing heart rhythm abnormality, patients tend to develop serious symptoms, says Dr. Cork.
“If your heart rate exceeds 150 beats per minute for hours or days, you just won’t feel well,” he explains. “Fluid can back up into the lungs and you’ll ultimately end up with swelling, shortness of breath and excessive fatigue.”
With supraventricular tachycardias, the first step is usually to consider any lifestyle issues that may be contributing and take steps to change them; for example, by reducing alcohol intake or treating stress.
Once you’ve addressed these issues and your physician has identified which type of heart rhythm disorder you have, treatment may involve therapies to treat underlying conditions, such as anemia or drugs to slow down the electrical signals in the heart.
If medication for fast heart rate is not effective, a heart rhythm expert known as an electrophysiologist may perform what’s called an electrophysiology study. This minimally invasive procedure uses catheters to place sensors inside the heart chambers to pinpoint where the abnormal heart rate is coming from.
Once the electrophysiologist locates the source, they can perform a process called an ablation that uses heat or cold energy to destroy the cells that are causing the irregular heart rate.
Another option may be an implantable defibrillator. Implanted under the skin, this tiny device constantly monitors heart rate. Should it detect an abnormal rhythm, it delivers a shock to correct the rhythm; in many cases, it can be life-saving.
Dr. Cork recommends seeing your physician if you have any symptoms of tachycardia to determine the cause and severity of the condition.
“It’s important to initiate a diagnostic workup,” says Dr. Cork. “Certainly, if symptoms arise very suddenly or you’re having new dramatic symptoms — if you pass out, for example, or have new, unexplained palpitations or chest pain — we would want to see you more urgently.”