Almost everyone has felt their heart beat very fast, felt a “fluttering” in their chest or thought that their heart was “skipping a beat.” These can be signs of arrhythmia, or abnormal or irregular heartbeat.
Don’t panic if you’ve occasionally had these symptoms. Arrhythmias are extremely common, especially as you get older. Each year millions of people have them.
Most cases are harmless, but some arrhythmias are extremely dangerous and require treatment and management. See your doctor if you have felt any of these symptoms to rule out other problems, such as heart disease, and to give you peace of mind.
There are different types of Arrhythmias:
- Atrial Fibrillation – upper heart chambers contract irregularly
- Bradycardia – slow heart rate
- Conduction Disorders – heart does not beat normally
- Premature contraction – early heart beat
- Tachycardia – very fast heart rate
- Ventricular Fibrillation – disorganized contraction of the lower chambers of the heart
To understand abnormal heart rhythms (arrhythmias), it is best to understand a normal heart rhythm.
The normal heart is a strong, muscular pump a little larger than a fist. It pumps blood continuously through the circulatory system.
- Each day the average heart beats (expands and contracts) 100,000 times and pumps about 2,000 gallons of blood.
- In a 70-year lifetime, an average human heart beats more than 2.5 billion times.
The American Heart Association has a great animation of the heart. You can also select a condition– Please watch it here:
Electrocardiography (ECG or EKG) (MAKE THIS A LINK TO THE ECG PAGE) is a painless, non-invasive procedure that records the heart’s electrical activity and can help diagnose arrhythmias.
So, what are arrhythmias?
Arrhythmias are abnormal beats. The term “arrhythmia” refers to any change from the normal sequence of electrical impulses, causing abnormal heart rhythms. Arrhythmias may be completely harmless or life-threatening.
Some arrhythmias are so brief (for example, a temporary pause or premature beat) that the overall heart rate or rhythm isn’t greatly affected. But if arrhythmias last longer, they may cause the heart rate to be too slow or too fast or the heart rhythm to be erratic – so the heart pumps less effectively.
- A fast heart rate (in adults, more than 100 beats per minute) is called tachycardia.
- A slow heart rate (less than 60 beats per minute) is referred to as bradycardia.
- Normally, the heart’s most rapidly firing cells are in the sinus (or sinoatrial or SA) node, making that area a natural pacemaker.
- Under some conditions almost all heart tissue can start an impulse of the type that can generate a heartbeat. Cells in the heart’s conduction system can fire automatically and start electrical activity. This activity can interrupt the normal order of the heart’s pumping activity.
- Secondary pacemakers elsewhere in the heart provide a “back-up” rhythm when the sinus node doesn’t work properly or when impulses are blocked somewhere in the conduction system.
Why Arrhythmia Matters?
When the heart’s ability to work is greatly reduced for a prolonged time, a life-threatening situation can arise. This may result from ventricular tachycardia and ventricular fibrillation, an extremely fast, chaotic rhythm during which the lower chambers quiver and the heart can’t pump any blood, causing cardiac arrest. This is sudden cardiac arrest, which is a medical emergency.
If the heart can continue to pump normally, though, some ventricular tachycardias may be tolerated without fainting (syncope) or cardiac arrest.Tachycardia may be nonsustained (lasting only seconds) or sustained (lasting for minutes or hours).
Tachycardias also can cause serious injury to other organs. For example, the brain, kidneys, lungs or liver may be damaged during prolonged cardiac arrest.
Blood clots can form in the heart’s upper chambers because of atrial fibrillation, a disorder in which the atria quiver instead of beating effectively. Blood that isn’t pumped completely out of the atria when the heart beats may pool and clot. If a piece of a blood clot in the atria breaks free, it can enter into the circulation. Then it can flow within the bloodstream until it lodges in a narrowed artery leading to or within the brain, causing a stroke. Such clots can also damage other organs.
What is sudden cardiac arrest?
Sudden cardiac arrest is the abrupt loss of heart function in a person who may or may not have diagnosed heart disease. The time and mode of death are unexpected. It occurs instantly or shortly after symptoms appear.
Each year about 383,000 emergency medical services-treated out-of-hospital cardiac arrests occur in the United States.
The term “massive heart attack” is often mistakenly used to describe sudden cardiac arrest. While a heart attack may cause cardiac arrest and sudden death, the terms don’t mean the same thing. The term “heart attack” (or myocardial infarction) refers to death of heart muscle tissue due to the loss of blood supply, not necessarily resulting in the death of the heart attack victim.
Arrhythmias can cause stroke
Stroke is a cerebrovascular disease that affects the blood vessels supplying blood to the brain. A stroke occurs when a blood vessel bringing oxygen and nutrients to the brain bursts or is clogged by a blood clot or some other particle. Because of this rupture or blockage, part of the brain doesn’t get the blood flow it needs. Deprived of oxygen, brain cells in the affected area can’t function and die within minutes. And when brain or nerve cells can’t function, the part of the body they control can’t function either. The devastating effects of stroke are often permanent because dead brain cells aren’t replaced.
The most common cause of stroke from an arrhythmia is atrial fibrillation. Atrial fibrillation can cause blood clots to form in the atria (top chamber of the heart) where they can be pumped out of the heart, to the brain, blocking a blood vessel and causing a stroke.
Treatment for atrial fibrillation focuses in part on reducing the risk of stroke. It’s important to know and manage all your risk factors for stroke, including atrial fibrillation.
Risk factors for atrial fibrillation
Atrial fibrillation (AFib or AF) can develop in people who have heart failure or have had a heart attack. It’s also found in people with heart valve disease, an inflamed heart muscle or lining (endocarditis) or recent heart surgery. Atrial fibrillation is common in persons with hypertension or diabetes. Sometimes it’s related to congenital heart defects. A problem with your lungs can also affect your heart. That’s why AFib often appears in people with chronic lung disease, pulmonary embolism, emphysema and asthma.
Gender and age also affect the odds of developing AFib and its severity. Men are slightly more likely than women to develop AFib, but women diagnosed with it carry a longer-term risk of premature death. Older people are somewhat more likely to have AFib than younger people. Other factors that affect risk are thyroid disorders, diabetes, high blood pressure, excessive alcohol consumption and cigarette or stimulant drug use (including caffeine).
Manage your risk factors
Just having an arrhythmia increases your risk of heart attack, cardiac arrest and stroke (View an animation of arrhythmia). Work with our team and follow our instructions to control other risk factors:
- Reduce high blood pressure
- Control cholesterol levels
- Lose excess weight
- Eat a heart-healthy diet
- Avoid tobacco smoke
- Enjoy regular physical activity
Arrhythmias can produce a broad range of symptoms, from barely perceptible to cardiovascular collapse and death. A single premature beat may be felt as a “palpitation” or “skipped beat.” Premature beats that occur often or in rapid succession may cause a greater awareness of heart palpitations or a “fluttering” sensation in the chest or neck.
When arrhythmias last long enough to affect how well the heart works, more serious symptoms may develop:
- Fainting (syncope) or near-fainting spells
- Rapid heartbeat or pounding
- Shortness of breath
- Chest pain
- In extreme cases, collapse and sudden cardiac arrest
To diagnose a heart arrhythmia, your doctor will review your symptoms and your medical history and conduct a physical examination. Your doctor may ask about — or test for — conditions that may trigger your arrhythmia, such as heart disease or a problem with your thyroid gland. Your doctor may also perform heart-monitoring tests specific to arrhythmias. These may include:
- Electrocardiogram (ECG). During an ECG, sensors (electrodes) that can detect the electrical activity of your heart are attached to your chest and sometimes to your limbs. An ECG measures the timing and duration of each electrical phase in your heartbeat. Click here to learn more..
- Holter monitor. This portable ECG device can be worn for a day or more to record your heart’s activity as you go about your routine. Click here to learn more
- Event monitor. For sporadic arrhythmias, you keep this portable ECG device available, attaching it to your body and pressing a button when you have symptoms. This lets your doctor check your heart rhythm at the time of your symptoms.Click here to learn more
- Echocardiogram. In this noninvasive test, a hand-held device (transducer) placed on your chest uses sound waves to produce images of your heart’s size, structure and motion. Click here to learn more
If your doctor doesn’t find an arrhythmia during those tests, he or she may try to trigger your arrhythmia with other tests, which may include:
- Stress test. Some arrhythmias are triggered or worsened by exercise. During a stress test, you’ll be asked to exercise on a treadmill or stationary bicycle while your heart activity is monitored. If doctors are evaluating you to determine if coronary artery disease may be causing the arrhythmia, and you have difficulty exercising, then your doctor may use a drug to stimulate your heart in a way that’s similar to exercise. Click here to learn more.
Source: American Heart Association