Bradicardia

Bradycardia refers to a heart rate that is slower than normal. For adults at rest, a heart rate below 60 beats per minute is generally considered bradycardia. However, what is considered normal can vary, and some individuals, especially athletes, may have a resting heart rate below 60 that is not indicative of a problem.

The causes of bradycardia can be varied. It can be a normal physiological adaptation, as seen in well-trained athletes. Other causes include aging, damage to heart tissue from heart disease or heart attack, congenital heart defects, certain medications such as beta-blockers and opioids, electrolyte imbalances, hypothyroidism, and neurological conditions. In some cases, bradycardia can be a symptom of a more serious underlying condition.

Symptoms of bradycardia can range from none to severe, depending on the underlying cause and how slowly the heart is beating. When symptoms do occur, they may include dizziness, fainting (syncope), fatigue, shortness of breath, chest pain, and difficulty concentrating. In severe cases, very slow heart rates can lead to heart failure or sudden cardiac arrest.

Diagnosis typically involves a physical examination, an electrocardiogram (ECG or EKG) to measure the heart's electrical activity, and sometimes Holter monitoring or an event monitor to track heart rate over a longer period. Blood tests may be done to check for underlying causes like thyroid problems or electrolyte imbalances.

Treatment depends on the severity of the bradycardia and its cause. If bradycardia is asymptomatic and caused by something benign like exercise training, no treatment may be necessary. If it is causing symptoms or is due to a reversible cause, treatment might involve addressing the underlying condition, adjusting medications, or implanting a pacemaker to help regulate the heart rate.