What Are the Common Causes of a Low Heart Rate?

Heart rate refers to the number of heartbeats per minute in a normal person's quiet state, also known as the quiet heart rate, which is generally 60 to 100 beats per minute, and can vary individually due to age, gender, or other physiological factors. Generally speaking, the younger the heart, the faster the heart rate, the elderly heartbeat slower than young people, the heart rate of women faster than men of the same age, these are normal physiological phenomena. In the quiet state, the normal heart rate for adults is 60 to 100 beats per minute, and the ideal heart rate should be 55 to 70 beats per minute (the heart rate of athletes is slower than that of ordinary adults, generally about 50 beats per minute).

Basic Information

Visiting department

Cardiology

Multiple groups

Heart patient

Common symptoms

Palpitations, chest tightness, etc.

Factors related to abnormal heart rate

Heart rate changes are closely related to heart disease. If the heart rate exceeds 160 beats / minute, or less than 40 beats / minute, it is mostly seen in patients with heart disease, such as palpitations, chest tightness and other discomforts, and detailed examination should be carried out early to treat the cause.

Tachycardia

Adults with a heart rate of more than 100 beats / minute (generally no more than 160 beats / minute) are called sinus tachycardia. They are commonly found in excitement, agitation, smoking, alcohol, tea or coffee, or infections, fever, Shock, anemia, hypoxia, hyperthyroidism, heart failure and other pathological conditions, or after application of atropine, epinephrine, ephedrine and other drugs.

Bradycardia

Adults with a heart rate of less than 60 beats / minute (generally 45 beats / minute or more) are called sinus bradycardia and can be seen in healthy people and athletes who have been engaged in heavy physical labor for a long time; or in hypothyroidism and intracranial pressure Increased, obstructive jaundice, and overdose of digitalis, quinidine, or propranolol. If the heart rate is less than 40 beats / minute, the condition of sick sinus node syndrome and atrioventricular block should be considered. Atrial fibrillation should be considered if the pulse strength is uneven, uneven, and the pulse rate is less than the heart rate.

3. Correct view of sinus bradycardia

Many people will have sinus bradycardia with irregularities, which is normal for most people, so don't worry too much. Sinus bradycardia refers to whether or not this symptom occurs in people with a heart rate below 60 beats / minute, which is related to the frequency of the bradycardia and the cause of the bradycardia. In a quiet state, if the heart rate of an adult is between 50 and 60 beats per minute, there are generally no obvious symptoms. In particular, some well-trained athletes and people who have been engaged in manual labor for a long time will not show obvious symptoms even when their heart rate is about 40 beats / minute in a quiet state. However, if the heart rate of the average person is between 40 and 50 beats per minute, symptoms such as chest tightness, fatigue, and dizziness will occur. If the heart rate drops to 35 to 40 beats per minute, hemodynamic changes will occur, which will cause heart and brain organs. The blood supply was affected, causing chest pain, dizziness, syncope, and even sudden death. If you don't feel any discomfort, don't bother with the "sinus bradycardia accompanied by irregularities" mentioned in the ECG, but if you have chest discomfort, fatigue, dizziness and other discomfort symptoms, you should immediately go to the hospital for further examination, such as dynamic electrocardiogram, cardiac ultrasound Wait for the examination to understand the cause of bradycardia. If the heartbeat is slow, you can use a pacemaker to relieve the symptoms and improve the prognosis.

Causes of Sinus Bradycardia

Extracardial cause

Most of them work through the nerves and humoral mechanisms through the extracardiac nerves, or directly affect the sinoatrial node and cause sinus bradycardia.

(1) Physiological In normal sleep, sinus bradycardia may occur due to increased vagal tone, and the heart rate may be about 50 times / minute, and some may be about 40 times / minute. Athletes can be around 50 times per minute during the day and as low as about 38 times per minute at night. Manual workers also often experience sinus bradycardia. Can be found in young and old.

(2) Increased intracranial pressure caused by increased excitability of the vagus nerve center such as meningitis, cerebral hemorrhage, brain tumors, encephalitis, brain trauma, etc., jaundice, neurosis, vascular inhibitory collapse and schizophrenia, etc. Causes vagus nerve excitement, reduces the autonomic nature of the sinoatrial node and causes sinus bradycardia.

(3) Excited reflex vagus nerves such as compression of the eyeballs, compression of the carotid sinus, stimulation of the pharynx, nausea and vomiting, breath hold, swallowing, severe cough, anxiety, and Valsalva and Muller actions can also be seen in gastric dilatation, intestinal obstruction, urinary Tied stones, gallstones and other diseases can cause reflex vagus nerve excitement and sinus bradycardia.

(4) Reduced metabolism such as hypothermia, severe malnutrition cachexia, hypopituitarism, hypothyroidism, etc.

(5) Certain drugs caused by the drug can increase the excitability of the vagus nerve or directly inhibit the function of the sinoatrial node and cause sinus bradycardia, such as blood pressure lowering drugs such as reserpine, antihypertensive, guanethidine, receptors Blockers, digitalis, quinidine, procainamide, phenytoin, sedatives, neostigmine, and anesthetics.

(6) The extreme or recovery period of certain infectious diseases, such as typhoid fever, diphtheria, and influenza.

(7) Patients with electrolyte disorders hyperkalemia, uremia or changes in blood pH.

(8) Peptic ulcer with sinus bradycardia. In the pathogenesis, gastric acid secretion is mainly controlled by the vagus nerve tension, which can cause sinus bradycardia when its excitability increases.

(9) Familial sinus bradycardia

2. Impaired sinus node function

Refers to sinus bradycardia caused by sinus node damage (such as inflammation, ischemia, poisoning, or degenerative damage). In addition, it can be seen in myocardial damage, such as myocarditis, pericarditis, endocarditis, cardiomyopathy, myocardial infarction, and myocardial sclerosis. It may also be caused by transient sinus node inflammation, ischemia, and toxic damage.

3. Acute myocardial infarction

The incidence of sinus bradycardia is 20% to 40%, with the highest incidence in the early stages of acute myocardial infarction (especially inferior wall infarction).

Heart rate daily care

Increased heart rate is harmful to health, shortens lifespan, and increases the incidence and mortality of cardiovascular disease. How to keep your resting heart rate around 60 beats / minute:

Sports

Often participating in a variety of exercises of appropriate intensity will slow down the resting heart rate. Although the heart rate is increased during exercise, exercise can improve the heart function and slow down the resting heart rate. The general suitable exercise heart rate is "170-age". For a 50-year-old, it is advisable to control the exercise heart rate at 120 beats / minute. Too fast means that the amount of exercise is too large, and the effect cannot be achieved. Before exercise, you should feel comfortable and free from fatigue. Generally, exercise should not exceed 1 hour, and the optimal time for each exercise is 30 minutes to 60 minutes, and you should exercise at least 3 times a week.

2. Correct your bad lifestyle

Staying up late, smoking, and drinking can make your resting heart rate faster. Drink less strong tea, especially not before bedtime, otherwise it may lead to insomnia. Should also have regular bowel movements to maintain smooth bowel movements.

3. Maintain proper weight

Obesity will increase the burden on the heart and increase the heart rate. Therefore, obese people should maintain proper weight through fitness exercises and diet adjustment.

4. Keep your peace of mind

The centrality of life should be peaceful. Don't always be anxious and angry. If your heart rate is too fast due to tension and anger, you can gradually calm down by listening to music and meditating.

5. Drug treatment

Certain diseases, such as high blood pressure and coronary heart disease, can increase the heart rate. You can take medicine according to your doctor's order to slow down the heart rate, protect the heart, reduce and control myocardial ischemic events, improve heart function, and prolong life.