The rhythm of the heart is normally controlled by its natural pacemaker (the sinus node), which produces electrical impulses that create the heartbeat. A normal, healthy heart beats about 60 to 100 times per minute, depending on what a person is doing.

However, when electrical abnormalities cause abnormal heart rhythms, or arrhythmia, you may experience palpitations, which feel like the heart is skipping, fluttering, or beating too hard or too fast. A person suffering from arrhythmia can feel these sensations in the chest, throat, or neck. Very severe heart rhythm abnormalities may cause fainting.

While heart arrhythmias can be due to a variety of conditions, doctors at Yale Medicine are experts at diagnosing and treating the underlying causes. “We offer a number of state-of-the-art treatments, including medications, lifestyle treatments, and the ablation procedure,” which is removal of tissue causing the problem, says Yale Medicine cardiologist Rachel Lampert, MD.

There are several types of arrhythmia, classified by the speed of the heartbeat.

• Tachycardia is a fast heartbeat—greater than 100 beats a minute when the body is at rest. Some forms of tachycardia include atrial arrhythmias, such as atrial fibrillation or supraventricular arrhythmia; sinus tachycardia, in which the heart’s natural pacemaker goes too fast; or the most serious form, ventricular arrhythmia, which can cause cardiac arrest.
• Bradycardia is a slow heartbeat—less than 60 beats a minute at rest. Bradycardia can be due to sick sinus syndrome or conduction block.
• Extra beats can also be experienced as an irregular pulse or palpitations.
• Atrial fibrillation, is when there is an abnormal firing of electrical impulses in the top chambers of the heart. This causes the muscles of the heart to quiver.

Besides a fluttering or racing sensation in the heart, there might be other symptoms of heart arrhythmia, including:

• Fatigue
• Dizziness
• Lightheadedness
• Fainting (syncope) or near-fainting spells
• Heart palpitations (fluttering or pounding heartbeat)
• Shortness of breath
• Chest pain

Our heartbeats are controlled by electrical signals, and arrhythmia can happen if those electrical signals are delayed or blocked. This can happen because of problems with heart muscle cells or blockages in the heart’s electrical system, or when extra circuits or spots in the heart give off extra beats.

While some arrhythmias are due to problems purely of the heart’s electrical system, others can be caused by underlying heart problems, or made worse by poor health habits. Occasionally other medical problems, such as hyperthyroidism, can bring on or worsen some types of arrhythmia.

Benign extra beats can be exacerbated by smoking, alcohol, caffeine, or stress.

More serious arrhythmias can be due to underlying heart disease, such as blockages in the arteries or heart attack, heart failure, or congenital heart defects.

However, heart palpitations are very common. Sometimes, they are a sign of other medical conditions unrelated to the heart, including an overactive thyroid, anemia, low blood pressure, dehydration, hormonal changes, or low potassium levels. Also, certain medications, stress, strong emotions, and vigorous physical activity can cause heart palpitations.

It’s easy to chalk heart palpitations or irregular heart rhythms up to stress, says Dr. Lampert. However, it’s important to thoroughly test for underlying heart problems.

“We use state-of-the-art monitors to look for arrhythmias, including both implantable monitors, injected just under the skin, and externally-worn varieties,” said Dr. Lampert.

After doctors have monitored the heart rhythm, sometimes they evaluate patients for heart abnormalities with echocardiograms, or test them while they’re exercising on a treadmill, depending on the situation.

After the diagnosis is made and other related testing is performed, doctors determine which treatments to administer for each patient. Mild forms of heart arrhythmia can sometimes be treated by lifestyle changes. Other patients may need procedures like ablation, where abnormal heart tissues are removed either chemically or surgically. 

For some arrhythmias, medications may be the best choice.  Life-threatening arrhythmias may require implanting a device to regulate the heart rhythm from inside the body. For example, individuals with severe bradycardia may require a pacemaker, while those with dangerous rhythms from the ventricle, the heart’s lower chamber, may require an implanted defibrillator.

As the heart beats and blood flows through its four chambers, it makes a “lub-dub” sound. The sounds come from four valves that regulate blood flow through the chambers and out of the heart to the lungs and rest of the body. 

These valves open to allow blood to pass through and close to stop blood from flowing backwards. When two of the valves close, they make a “lub” sound. Shortly after, the other two valves close, making the “dub” sound.

A heart murmur is an extra “whooshing” sound that comes from the heart. The extra sound occurs when something disturbs the passage of blood through the heart, making the blood flow more turbulent than normal. Murmurs are often deemed “innocent,” a term used to indicate they are harmless. Other murmurs, however, may be caused by an abnormality in one or more of the heart valves and/or another heart problem.

Heart arrhythmias differ from a murmur in that they are caused by an interruption in the electrical signals that control the rhythm at which the heart beats.

Yale Medicine Cardiovascular Medicine offers the full spectrum of care for arrhythmia. Our doctors also participate in clinical studies that allow them to bring the most modern techniques to patients before they are widely available.