Bradycardia is the medical term for a heart rate that is too slow — specifically, a heart rate less than 60 beats per minute in adults. However, under some circumstances, a heart rate less than 60 beats per minute is perfectly healthy and not a cause for intervention. For instance, a resting heart rate below 60 beats per minute in a person who is physically fit may be normal, and it can be normal for the heart rate to dip below 60 beats per minute in some older adults and in anyone during sleep.
The heart consists of two upper chambers (atria) and two lower chambers (ventricles). In a normal heartbeat, an electrical impulse originates from an area in the right atrium called the sinus node. This impulse travels first to the atria, causing them to contract and pump blood into the ventricles. The electrical impulse then continues along its circuit to the ventricles, signaling them to contract and pump blood out to the lungs and the body.
In bradycardia, there is a problem with this electrical impulse. For instance, it may trigger the atria to contract, but not reach the ventricles to signal their contraction (heart block), or the signal may travel too slowly along its pathway through the heart. As a result, the heart may not pump enough blood out to the body, which can cause a range of symptoms, such as dizziness, fatigue, shortness of breath, chest pain (angina), lightheadedness and fainting. In severe cases, bradycardia can even lead to cardiac arrest.
Problems with the heart’s electrical system can have many causes, including damage to the heart muscle related to aging or heart disease, an imbalance of electrolytes in the body, the use of certain medications, hypothyroidism, sleep apnea, high blood pressure and underlying heart conditions, including congenital defects.
If your doctor determines that bradycardia occurs as a result of an underlying condition, such as high blood pressure, hypothyroidism or sleep apnea, the first step will generally be to treat the underlying condition to see if this corrects the slow heart rate. If medications you take may be causing your bradycardia, you doctor may adjust or change your medication regimen. If these approaches do not resolve your bradycardia, your doctor may recommend the implantation of a pacemaker to help the heart maintain a healthy rate.
If you experience symptoms of bradycardia or any other abnormal heart rhythm, you can visit one of Emory’s new heart rhythm screening clinics located throughout the Atlanta area to determine if your condition is serious.
About Dr. Patel
Anshul M. Patel, MD , is an assistant professor of medicine and electrophysiologist who practices primarily at Emory Saint Joseph’s Hospital. He graduated magna cum laude from Harvard College and received his medical degree from the Johns Hopkins University School of Medicine. Dr. Patel completed his internship, residency and cardiology training at Massachusetts General Hospital and Harvard Medical School, where he also completed a fellowship in cardiac electrophysiology. He specializes in pacemaker and defibrillator implantation, as well as catheter ablation, with a particular interest in atrial fibrillation and ventricular arrhythmias.
About Emory’s Arrhythmia Center
Emory’s Arrhythmia Center is one of the most comprehensive and innovative clinics for heart rhythm disorders in the country. Our electrophysiologists have been pioneers in shaping treatment options for patients with arrhythmias such as atrial fibrillation, as well as for those with congestive heart disease. Our specialized electrophysiology (EP) labs host state-of-the-art equipment, including computerized three-dimensional mapping systems to assist with the ablation of complex arrhythmias, and an excimer laser system to perform pacemaker and defibrillator lead extractions.
Patients with devices, whether implanted at Emory or elsewhere, have access to Emory’s comprehensive follow-up care. Patients benefit from remote monitoring, quarterly atrial fibrillation support groups and 24-hour implantable cardiac device (ICD) and pacemaker monitoring services. Inpatient telemetry and coronary care units, as well as outpatient care and educational support of patients with pacemakers and ICDs, complete Emory’s comprehensive range of arrhythmia treatments and services.