What are the causes of sinus bradycardia?
Disease description:
I always feel chest pain, and after examination, sinus bradycardia was found. What causes sinus bradycardia?
Doctor's answer (1)
Dr. Tian Hongbo
Sinus bradycardia refers to an electro-physiological impulse frequency originating from the sinoatrial node that is lower than the normal range. This condition can be caused by various factors:
1. Physiological causes: Individuals who engage in long-term physical exercise, such as athletes, may naturally have a slower heart rate due to strong cardiac reserve function. During nighttime sleep, heart rate usually decreases because the heart does not need to beat rapidly during the resting state. Some elderly individuals may also have slower heart rates due to aging.
2. Pathological causes: Ischemia—for example, impaired sinoatrial node function due to ischemia can lead to a slower heart rate; hypothyroidism, where insufficient thyroid hormone results in a decreased basal metabolic rate, potentially causing bradycardia; myocardial infarction, where coronary artery blockage leads to myocardial ischemia and necrosis, which may trigger sinus bradycardia.
3. Medication effects: Beta-blockers, calcium channel blockers, and others can slow the heart rate.
If sinus bradycardia does not cause symptoms and does not affect daily life, treatment may not be necessary. However, if symptoms such as dizziness, fatigue, or syncope occur, or if the heart rate is excessively slow, prompt medical attention is required.
