Definition: Clinically, the ECG R wave represents ventricular repolarization, and a poor rise indicates a decrease in ventricular voltage. Various causes of decreased ventricular voltage can induce a decreasing R wave (PRWP). It is most often clinically considered to be associated with small anterior and anterior interventricular wall infarcts. In contrast, elevated R waves are seen in various diseases causing pulmonary hypertension or early repolarization, mostly in COPD, hypertrophic cardiomyopathy, etc. Clinical significance: 1. Acute cardiac injury and PRWP Often acute injury areas show conduction block, resulting in a slowing of R-wave rise, widening of QRS wave time, and prolongation of ventricular wall excitation time greater than 0.45 s. At this time, the detection rate of anterior wall and anterior interval wall infarction with decreasing R-wave is about 40%, which is of greater clinical value. And the incidence of PRWP in ST-segment elevation without Q-wave infarction is higher than that with Q-wave type. 2, after cardiac injury and PRWP old anterior wall infarction R wave decrement is very common, the incidence is also about 40%. 3, myocarditis and PRWP Why do many young people have PRWP during the induction physical examination, consider related to myocarditis with partial hypertrophy of the myocardium, left ventricular injury, pericardial inflammation, pericardial effusion, etc. PRWP exists to varying degrees in both the acute and post-acute phases, and only in cases where myocardial repair is better does this condition not exist. 4, other organic diseases and PRWP Hypertension, pulmonary heart disease, pleuritis, pleural thickening adhesions, pneumothorax, chest wall tumors (including breast hyperplasia, tumors), hyperthyroid heart disease, alcoholic heart disease, rheumatic heart disease, anemic heart disease, etc. can occur PRWP. 5, functional also called reversible PRWP For example, strenuous exercise, fatigue, alcoholism, lack of sleep, mental stress, fever, a For example, PRWP can be temporarily manifested by intense exercise, fatigue, alcoholism, sleep deprivation, stress, fever, transient hypoglycemia, right-sided heart, incorrect lead placement, pregnancy, etc.