Causes of bradycardia

1, physiological reason-sinus bradycardia can occur when vagus nerve tension is enhanced. Teenagers and athletes are more common. The frequency of sinus rhythm slows down with age, so the elderly will also have bradycardia.

2, pathological reasons-common myocarditis, coronary heart disease or cardiomyopathy involving sinus node; Hypothyroidism, etc.

Bradycardia is 40~60 beats/min. If there is no organic heart disease, it will generally not cause obvious symptoms. If the heart rate is lower than 40 beats/min, there will be symptoms of decreased cardiac output, such as dizziness, chest tightness and sudden syncope.

The most common causes of bradycardia are pathological sinus bradycardia, sinus arrest, sinus block and atrioventricular block.

Pathological sinus bradycardia is characterized by slow heartbeat and discomfort. Most of the causes are sick sinus syndrome, acute myocardial infarction, hypothyroidism, increased intracranial pressure or the use of drugs that can slow down the heart rate (such as betaloc, verapamil, digitalis, reserpine, etc.). ).

Sinus arrest, sinus atrial block and atrioventricular block are characterized by long-term cardiac arrest. The causes of this situation are sick sinus syndrome, degenerative changes of conduction system, congenital atrioventricular conduction tissue, myocarditis, myocardial infarction and so on. It is very dangerous to stop for more than 3 seconds, which will cause malignant ventricular arrhythmia and lead to sudden death.

Therefore, those who often have fatigue, heart discomfort, dizziness, transient blackness or syncope should pay attention to counting their pulse when they are calm and have discomfort. If you are not a regular sports person, your heart rate is always very slow during the day, especially less than 50 beats per minute, or your pulse is obviously slow when you feel unwell, or you should pay attention to it when you stop for a long time. You should go to the cardiac arrhythmia clinic of the hospital for a detailed examination.