What is significant sinus bradycardia?

In general, sinus bradycardia refers to a slower than normal heart rate originating from the sinus node, where the sinoatrial node of the heart emits electrical impulses at a frequency lower than the normal range, resulting in a significantly reduced heart rate. It is generally defined as fewer than 60 heartbeats per minute in adults. Sinus bradycardia may be caused by long-term physical exercise, sleep states, medication effects, hypothyroidism, myocarditis, and other factors. If discomfort occurs, timely medical consultation is recommended. Detailed analysis is as follows:

1. Long-term physical exercise

Long-term exercise training can lead to well-developed cardiac muscles and improved pumping efficiency. Thus, the heart does not need to beat as frequently during rest, resulting in sinus bradycardia. No specific treatment is required, but regular cardiac health monitoring is recommended.

2. Sleep state

During deep sleep, the body is in a relaxed state and the heart rate naturally decreases under autonomic nervous system regulation. Maintaining good sleep habits is important. If symptoms arise from excessively low heart rate, consulting a doctor to determine whether further evaluation is needed is advised.

3. Medication effects

Medications such as beta-blockers, calcium channel blockers, and digitalis preparations may suppress the excitability of myocardial cells, leading to sinus bradycardia, which may be accompanied by symptoms like dizziness and fatigue. Dosage adjustment or discontinuation should be carried out under a physician's guidance based on individual circumstances.

4. Hypothyroidism

Long-term insufficient iodine intake may induce hypothyroidism, slowing myocardial cell metabolism and causing sinus bradycardia, which may be accompanied by symptoms such as fatigue and constipation. Treatment should follow medical advice, using medications such as levothyroxine sodium tablets, thyroid extract tablets, and hydrocortisone injection.

5. Myocarditis

Viral infections caused by bacteria, fungi, spirochetes, and other pathogens can lead to myocarditis, damaging myocardial cells and potentially causing sinus bradycardia. This is usually accompanied by symptoms such as chest pain, palpitations, and shortness of breath. It is recommended to follow medical advice and use medications such as Guanxin Danshen dripping pills, Wenxin granules, and coenzyme Q10 capsules for treatment.

In daily life, maintaining healthy lifestyle habits, engaging in appropriate physical activity, ensuring 7–9 hours of sleep per day, and undergoing regular cardiac health monitoring are recommended.