Bradicardie

Bradicardia is a medical term describing a heart rate that is slower than normal. For adults at rest, a heart rate below 60 beats per minute (bpm) is generally considered bradicardia. However, this threshold can vary, and a low heart rate is not always indicative of a problem. Athletes, for instance, often have naturally slower resting heart rates due to improved cardiovascular conditioning.

The causes of bradicardia are diverse. It can be a consequence of aging, where the heart's electrical system may become less efficient. Certain medications, particularly those used to treat high blood pressure or heart rhythm disorders, can also slow the heart rate. Underlying medical conditions such as hypothyroidism, electrolyte imbalances, or an infection like Lyme disease can contribute. Furthermore, damage to the heart muscle from a heart attack or other heart disease can impair its ability to pump effectively, leading to a slow heart rate.

Symptoms of bradicardia can range from none to severe, depending on the underlying cause and the degree of slowing. Mild cases might be asymptomatic. However, significant bradicardia can lead to reduced blood flow to the brain and body, causing symptoms like dizziness, fainting (syncope), fatigue, shortness of breath, and chest pain. In severe instances, it can result in confusion or even cardiac arrest.

Diagnosis involves a medical history, physical examination, and often an electrocardiogram (ECG or EKG) to assess the heart's electrical activity. Further tests may be needed to identify the cause. Treatment for bradicardia depends on its severity and the presence of symptoms. If no symptoms are present and the cause is benign, no treatment may be necessary. If symptomatic, treatment aims to address the underlying cause. In cases of severe or persistent bradicardia due to electrical conduction issues, a pacemaker may be implanted to regulate the heart rate.