|Who’s at risk?|
|Who’s at risk?|
Arrhythmias can develop when the heart becomes weakened or damaged, disrupting electrical function. Factors that contribute to arrhythmias include:
- an abnormality in the heart’s structure
- coronary artery disease or a previous heart attack
- thyroid problems
- certain drugs and supplements, such as some cold medications that contain pseudoephedrine and diet aids and supplements that contain ephedra, guarana or ginseng
- high blood pressure
- obstructive sleep apnea
- an imbalance of potassium, sodium, calcium and magnesium
- heavy alcohol consumption
- use of stimulants such as caffeine, nicotine, amphetamines and cocaine
Most everyone has experienced an odd heartbeat—feeling your heart race, pound, flutter, pause or skip a beat. These episodes of unusual heart rhythm, or arrhythmia, caused by abnormal electrical impulses in the heart, are often minor and harmless. Sustained or more serious irregular rhythms, however, can pose a danger and lead to cardiac arrest.
Some people don’t notice any symptoms. Others feel palpitations or a galloping or sluggish heartbeat, shortness of breath, chest pain or discomfort, fatigue or weakness, dizziness, unexplained falls or fainting. If you experience any of these symptoms suddenly or frequently, seek urgent care.
What’s going on?
A normal heart rate is between 60 and 100 beats a minute and fluctuates during the day and in response to anxiety, excitement or some medications. Heart rate speeds up during exercise and slows during sleep.
Physicians classify the many types of arrhythmias by where they originate and the type of heart rate they cause. A rate faster than 100 beats a minute is called tachycardia and slower than 60 beats a minute is called bradycardia.
For example, in ventricular tachycardia, abnormal impulses in one of the heart’s ventricular chambers cause it to beat too fast. Atrial fibrillation, the most common arrhythmia, affecting 2 million Americans, refers to very fast and chaotic contracting of the heart’s atrial chambers. The uncoordinated impulses cause the atria to beat so fast—300 to 400 beats a minute—they quiver. Sinus node dysfunction occurs in the area of the heart that serves as a natural pacemaker. When the heart’s normal electrical pathways shut down or allow only intermittent signals, heart block (also called conduction block) occurs, which can slow heart rate at varying degrees of severity.
Treating your arrhythmia
Not all arrhythmias require treatment, but patients need to manage arrhythmias that cause significant symptoms, increase risk for a more serious condition or impair the heart’s efficiency and circulation. Treatment depends on the type and degree of the arrhythmia and may include:
The bottom line
- Lifestyle measures. Because many arrhythmias arise from underlying heart disease, doctors may recommend more exercise, an improved diet, better stress management, not smoking and limiting caffeine and alcohol as ways to reduce episodes.
- Vagal maneuvers. Some types of tachycardia can be treated by stimulating your vagal nerves—the part of the nervous system that regulates your heart rate—which respond by slowing your heart rate. These “maneuvers” include holding your breath and straining, coughing and dunking your face in ice water.
- Drugs. Sodium channel blockers, beta-blockers, potassium channel blockers, calcium channel blockers and digitalis may slow or suppress tachycardia. However, these drugs may produce unwanted side effects, cause an arrhythmia to occur more frequently or produce a new arrhythmia.
- Implantable devices. Surgery to implant an artificial pacemaker is a common treatment for bradycardia. This device, implanted under the skin and attached to the heart, sends an electrical impulse whenever the heart rhythm slows or becomes erratic. Another device, the implantable cardioverter defibrillator, can be placed in the chest to correct an abnormally fast heartbeat.
- Cardioversion. This treatment uses drugs or an electrical shock to reset the heart to its regular rhythm.
- Catheter ablation. Catheters are threaded through blood vessels to the heart and deliver radiofrequency energy to carefully destroy (ablate) the abnormal
portions of the heart causing the arrhythmia. This method is highly successful in treating tachycardia.
- Open-heart surgery. Cardiologists use open-heart surgery to regulate electrical impulses usually only after patients haven’t responded to other treatments. Patients suffering severe coronary artery disease in addition to ventricular tachycardia may require coronary bypass to improve blood supply to the heart.
It’s important to tell your doctor about any symptoms of arrhythmia you experience. Even if symptoms pass quickly, your heart’s ability to work may be compromised. Over time, a seemingly harmless arrhythmia could lead to a more serious condition.