Bradycardia is a heart condition characterized by an abnormally slow heart rate.
Here’s what you need to know about bradycardia, including its symptoms, its causes, how it’s diagnosed and the treatment options available.
What’s a normal heart rate?
The normal heart rate for adults at rest typically ranges between 60 to 100 beats per minute (bpm). Heart rate varies based on factors such as age, fitness level and overall health.
Bradycardia occurs when the heart rate slows down, typically below 60 bpm in adults, leading to inadequate blood flow to the organs and tissues.
Bradycardia vs. tachycardia: What’s the difference?
Bradycardia stands in contrast to tachycardia, where the heart beats too quickly, usually above 100 bpm. Both conditions may be symptomatic of underlying health issues and require medical attention to assess and manage appropriately.
How to check your heart rate at home
Measuring your heart rate at home is easy and may be done using various methods.
Check your heart rate manually: Place your index and middle fingers on your wrist or neck to find your pulse. Count the beats for 30 seconds and multiply by 2 to get your heart rate in beats per minute.
Use a blood pressure cuff: Wrap a blood pressure cuff around your upper arm, press the start button and it will display your heart rate along with blood pressure readings.
Use a smartwatch with a heart rate monitor (such as an Apple Watch): Activate the heart rate feature on your smartwatch and follow the device's instructions to obtain your heart rate.
Use a pulse oximeter monitor: Place the device’s clip on your fingertip to get an immediate reading.
These methods offer convenient ways to track your heart rate regularly from the comfort of your home. However, it’s important to understand that sometimes these readings may not be accurate and professional evaluation is needed.
Bradycardia symptoms
The symptoms of bradycardia may vary depending on the severity of the condition and how significantly it affects blood flow to vital organs. Common bradycardia symptoms may include:
Dizziness or lightheadedness
Fatigue
Shortness of breath
Chest pain
Fainting spells (syncope), particularly during physical exertion or stress
In some cases, individuals with bradycardia may not experience any noticeable symptoms, especially if the heart rate is only mildly slow.
What causes bradycardia?
Several common factors that may contribute to the development of bradycardia include:
Aging: As individuals age, the heart's electrical system may naturally slow down, leading to bradycardia.
Heart disease: Conditions such as coronary artery disease, myocardial infarction (heart attack) and structural heart diseases such as heart valve disorders may disrupt the heart's electrical impulses, causing bradycardia.
Medications: Certain medications—particularly those that affect the heart's electrical conduction system, like beta-blockers, certain types of calcium channel blockers and sometimes antiarrhythmic drugs—may lead to bradycardia.
Electrolyte imbalances: Abnormal levels of potassium, sodium or other electrolytes in the blood may affect the heart's electrical impulses, potentially causing bradycardia.
Other health conditions: Hypothyroidism (underactive thyroid), sleep apnea, autoimmune diseases such as lupus and many other medical conditions may also contribute to bradycardia.
Diagnosis of bradycardia
Diagnosing bradycardia typically involves a combination of clinical evaluation and diagnostic tests, such as:
Electrocardiogram (EKG): This is a simple, noninvasive test that records the electrical activity of the heart and can identify abnormalities in the heart's rhythm, including bradycardia.
A Holter monitor: This is a portable EKG device worn by a person for 24-72 hours to continuously monitor heart activity. This helps capture intermittent bradycardia episodes that may not be detected during a standard EKG, which only captures 10 seconds of heart rhythm.
An event monitor (longer-term telemetry): This is similar to a Holter monitor, but it’s worn for up to 28 days. This device is used to monitor heart rhythm over a more extended period, particularly to help capture infrequent symptoms.
Bradycardia treatments
Once bradycardia is diagnosed, treatment is sometimes initiated. The appropriate treatment for bradycardia depends on the underlying cause, severity of symptoms and overall health of the patient.
Avoiding medications that slow the heart rate (aka nodal blocking agents): If bradycardia is medication-induced, adjusting or discontinuing medications like beta-blockers, calcium channel blockers or digoxin may resolve bradycardia.
Pacemaker placement: In cases where bradycardia is symptomatic and persistent, a pacemaker may be necessary. A pacemaker is a small, implantable device that helps the heart beat at a normal rate. Pacemakers are designed to activate only when the heart rate drops below a set threshold or when the heart's natural electrical signals fail to maintain an adequate heart rate. The procedure to implant a pacemaker involves the placement of leads (thin wires) into the heart through a vein under local anesthesia.
Living with bradycardia
Bradycardia is a condition characterized by a slower-than-normal heart rate, potentially causing symptoms ranging from mild discomfort to severe complications like fainting or heart failure. Prompt diagnosis allows healthcare providers to determine the cause and severity of bradycardia accurately and whether treatment is needed.
As a cardiology fellow at Montefiore Health System, I’ve seen how modern medicine can help manage bradycardia, and with proper treatment, patients almost always return to their normal lives. If you suspect you or someone you know may have bradycardia, seeking medical attention for proper evaluation and management is crucial to maintaining heart health and overall well-being.
