There is a long effective refractory period after primary premature beats, which is called compensatory interval. Skeletal muscle will not produce premature contraction and compensatory interval, because the effective refractory period of skeletal muscle is relatively short.
The occurrence of premature beats may have no obvious inducement, but it is related to emotional excitement, sudden increase of blood pressure, excessive drinking, smoking, drinking strong tea and coffee, constipation, abdominal distension, indigestion, insomnia, sudden change of body position and other factors.
Atrial premature beats caused by this reason are more likely to appear before sleep or at rest, and decrease or disappear after exercise or after heart rate increases. Atrial premature beats can also be caused by direct mechanical stimulation of the heart (such as heart surgery or cardiac catheterization).
When the first sinus node excitation immediately after premature beats reaches the ventricular muscle, it often falls within the effective refractory period of premature beats, so it can't cause ventricular excitation and contraction, forming a "loss", and it can't cause ventricular contraction until the next sinus node excitation reaches the ventricle.
Extended data:
In addition to the positive signs of the original basic heart disease, it can be found that the regular rhythm of the heart appears early heartbeat, followed by a longer interval (compensatory interval), and the first heart sound is enhanced and the second heart sound is weakened in the early stage, which may be accompanied by the weakening or disappearance of this pulse.
Keep a regular life and proper physical exercise, don't stay up late, don't watch TV or sit in front of the computer for a long time; Walking, playing Tai Ji Chuan and using some fitness equipment for fitness training will bring long-term benefits to your health.
Quit smoking and avoid drinking heavily, because smoking and drinking are the main inducing factors of coronary heart disease. To maintain emotional stability, we need to straighten out the relationship between work, life and study. High emotional tension and fluctuation are the main causes of functional premature beats.
Baidu encyclopedia-compensatory interval
Baidu encyclopedia-premature beats