β阻滞剂在急性心肌梗塞早期的治疗作用

The Treatment Effect of β-Paralyzer on Acute Myocardial Infarction in the Early Period

急性心肌梗塞 (AMI)早期血液中儿茶酚胺水平增高 ,会触发室性早搏、室性心动过速和室颤等心律失常。儿茶酚胺的持续过度增高 ,可导致心率增快 ,心肌耗氧量明显增加 ,同时通过儿茶酚胺直接的心脏毒性作用 ,以及增加外周阻力和心室壁应力 ,增加心脏前后负荷 ,使心肌梗塞面积扩展 ,加重左心室重构。β阻滞剂可拮抗儿茶酚胺对心脏的毒性作用 ,提高室颤阈 ,抗心律失常 ,抗血小板聚集和减轻心脏血管损害 ,降低外周阻力和心室壁应力 ,减轻心脏前后负荷 ,缩小梗塞面积而预防或改善梗塞后心室重构 ,减少心律失常和猝死 ,使住院期死亡或非死亡性再梗塞

In the early period of acute myocardial infarction, because of the high level of catecholamine, the arrhymia, such as ventricular extrasytole, ventricular tachycardia and ventricular fibrillation are often seen. The constant high level of catecholamine may increase the heart rate, the oxygen consumption of cardiac muscle and the toxicity on heart. As the peripheral resistance increasing, the burden of heart is increased. As the result, the area of myocardial infarction is enlarged. β paralyzer may protect the heart from the toxicity of catecholamine, anti arrhymia, anti platelet aggregation and decrease the peripheral resistance and the rate of sudden death. So it can be used in patients of acute myocardial infarction in early period and reduce the complications remarkably.