How is ventricular premature contraction caused?

summary

Ventricular premature beat is one of the most common arrhythmias, which refers to the premature activation of the myocardium originated from the area below the bifurcation of his bundle, leading to premature ventricular depolarization. Normal people can also have ventricular premature contraction. How is that ventricular premature contraction caused?

How is ventricular premature contraction caused?

1. Autonomic nerve function is one of the most common causes of ventricular premature contraction. When autonomic nerve dysfunction, whether vagus nerve excitation or sympathetic nerve excitation, can make myocardial fast and slow fiber excitability out of balance, can make refractory period and conduction velocity change, cause reentrant ventricular premature contraction. Excessive catecholamine secretion increases the automaticity of ventricular autonomic cells and leads to ventricular premature contraction. Excessive intake of tobacco, wine, tea, coffee, mental stress, fatigue, long-term insomnia, eating too much, neurasthenia, autonomic nervous dysfunction, menopause and other factors are related to the occurrence of premature ventricular contractions.

2. The left ventricular false chordae tendineae and ventricular premature contractions were detected by echocardiography in 56% - 75% of patients with ventricular premature contractions but without evidence of organic heart disease. Ventricular premature contractions caused by false chordae tendineae are benign premature contractions, which need not be treated if they occur infrequently.

3. Ventricular premature contractions in organic heart disease are also more common in organic factors, such as ischemic cardiomyopathy, coronary heart disease, pulmonary heart disease, rheumatic valvular heart disease, hyperthyroid heart disease, etc; Various causes of myocarditis, cardiomyopathy, heart failure, whether it is acute diffuse myocardial disease, or focal lesions, can be due to ischemia, hypoxia, inflammatory damage, resulting in increased excitability of ectopic rhythm points or affect the refractory period or conduction velocity of myocardial fibers, resulting in ventricular premature contraction.

matters needing attention

The occurrence of ventricular premature contractions has a large diurnal variation, which is usually more common in the morning than at night, and more common after meals than before meals. Therefore, it is necessary to record 24-hour electrocardiogram in order to truly understand the frequency of ventricular premature beat. The frequency of ventricular premature contractions is different every 24 hours or every hour.