Premature beats

Introduction Premature beat (cardiovascular) is referred to as premature beat. It refers to the heart beat caused by premature impulses issued by the ectopic pacemaker, which is the most common arrhythmia. Can occur on the basis of sinus or atopic (such as atrial fibrillation) heart rhythm. It may occur occasionally or frequently, and may occur irregularly or regularly after each or every number of normal beats to form a bipolar or premature beat. According to the origin, it can be divided into four types: sinus, atrial, atrioventricular junction and ventricular. Among them, ventricular premature beats are the most common, followed by atrial and less common. Sinus premature beats are rare.

Cause

First, premature beats can occur in normal people. However, patients with cardiac neurosis and organic heart disease are more likely to develop. Emotional, nervous, fatigue, indigestion, excessive smoking, drinking or drinking tea can cause seizures, or no obvious incentives, digitalis, expectorant, quinidine, sympathomimetic drugs, chloroform, ring Toxic effects such as propane anesthetics, potassium deficiency, and cardiac surgery or cardiac catheterization can be caused. Coronary heart disease, advanced mitral valve disease, heart disease, myocarditis, hyperthyroidism, mitral valve prolapse, etc. are often prone to premature beats.

Second, it may be produced in a variety of ways:

(1) The abnormality caused by abnormal self-discipline is abnormal:

1 Under certain conditions, such as the sinus impulse to reach the ectopic pace point, due to the Weidensky phenomenon, the threshold potential is lowered and the diastolic phase is changed to cause premature beat.

2 The lesions of the atrial, ventricular or Pueraria cell membranes change the permeability of different ions, which transforms the fast-reacting fibers into slow-reacting fibers. The diastole is automatically depolarized and accelerated, and the self-discipline is enhanced, resulting in premature beats.

The sinus impulse reaches the ectopic pacemaker point, causing the threshold potential level to move down. Thus, the ectopic pacemaker diastolic depolarization reaches the threshold potential before the basic rhythm pacemaker point and causes premature beats.

(2) Reentry phenomenon - circular reentry or focal micro-return:

If the reentry pathway is the same, the premature beat pattern is consistent. If the conduction velocity is consistent in the reentry, the pairing time of the premature beat and the previous beat is fixed.

(3) Parallel contraction.

(4) Triggered activity.

an examination

Related inspection

Electrocardiogram pulse

(1) History and symptoms:

Due to the different sensitivity of the patient, there is no obvious discomfort or only heart palpitations, precordial discomfort or cardiac arrest. Inquiries about the history of hypertension, coronary heart disease, cardiomyopathy, and rheumatic heart disease can help to understand the cause of premature beats and guide treatment. Pay attention to the question of whether there is a history of cold, fever, or diarrhea in the near future to help patients with acute viral myocarditis. The use of digitalis drugs, antiarrhythmic drugs, and diuretics sometimes induces premature beats.

(2) Physical examination found:

In addition to the original positive signs of basic heart disease, the heart can be found in a regular heart rhythm, the first heart sounds appearing earlier, and the second heart sounds are weakened, which may be accompanied by the weakening or disappearance of the pulse.

(3) Auxiliary inspection:

Electrocardiogram has a diagnostic value for premature beats. Atrial premature beats have an abnormal P wave in front of the QRS wave, and there is an incomplete compensation period. The QRS waveform is more consistent with the normal QRS waveform. The QRS wave that appears early in the premature ventricular contraction is consistent with the normal QRS wave. There is no P wave before, and the compensation period is complete. The QRS wave broad deformity that appeared early in the premature ventricular contraction was complete and the compensation period was complete. The 24-hour dynamic electrocardiogram can record in detail how much premature beats occur, the regularity of the occurrence, and the therapeutic effect. Blood myocardial enzymology is feasible in patients with suspected myocarditis. Cardiac ultrasonography can detect cardiomyopathy and some patients with coronary heart disease. Long-term use of diuretics and suspected digitalis poisoning should determine blood electrolytes, if necessary, determine the concentration of blood digitalis.

Differential diagnosis

The normal pulsation of the heart originates from the sinus node, and if it is emitted from other parts of the heart, it is medically called premature beat. Premature beats can be divided into four types: sinus, atrial, knot, and ventricular. The most common is ventricular, followed by atrial, and sinus is rare. In the clinically seen ectopic rhythm, premature beats are the most common, divided into functional and pathological categories. Functional premature beats generally do not require special treatment. Pathological premature beats need to be dealt with in time, otherwise it may cause serious consequences and even life-threatening. Therefore, not only doctors, the average person should understand and master the differential knowledge of functional and pathological premature beats, and make timely judgments, which is of great significance for the prevention and treatment of diseases.

(1) Functional premature beats

It is not uncommon among young and middle-aged people, and most of them cannot find pathological incentives. It is often caused by nervousness, overwork, smoking, alcoholism, drinking tea, and drinking coffee. It usually occurs before quiet or before going to sleep, and the premature beat disappears after exercise. Functional premature beats generally do not affect the health of the body. After a period of time, most of these premature beats will be cured, so there is no need for treatment. However, we should pay attention to the combination of work and rest, avoid excessive tension and fatigue, be optimistic, have regular life, not overeating, excessive drinking, and proper physical exercise every day.

(2) pathological premature beats

Premature beats often occur in patients with myocarditis, coronary atherosclerotic heart disease, rheumatic heart disease, hyperthyroidism, mitral valve prolapse and digitalis poisoning. This is a pathological premature beat, which is common in the following situations: occurs in the elderly or children. The number of premature beats increases after exercise. The original diagnosed as a heart disease, ECG examination often has other abnormal ECG changes in addition to premature beats. For pathological premature beats, it should be highly valued, and the hospital should be electrocardiogram in the morning, and treated under the guidance of a doctor. If there is a severe and frequent premature beat, it is best to be hospitalized for observation and treatment.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.