Q. My doctor told me that I have “low ejection fraction,” but I feel fine. How can this be? I thought this was part of heart failure and would make someone feel bad. Should I do anything about it, even though I don’t have any symptoms?
问：我的医生告诉我，我的射血分数很低（LVEF），但是我自我感觉良好。这是怎么回事？我想，这个指标应该是心脏衰竭的表现，会让病人感觉很差的（但是我却没有）。我该做点什么么，即便我没有任何症状？
A. Your ejection fraction is the amount of blood your heart squeezes out with each beat. The typical heart fills with a half-cup of blood (four ounces) and ejects a bit over half that with each heartbeat. A normal ejection fraction is in the range of 55–70%.
答：你的射血分数，代表了你的心脏每次跳动能够射出的血液数量。一个典型的心脏，里面大概有半杯血液（4盎司），每次跳动大概喷射出一半多一点血液。一个正常的射血分数范围在 55-70% 之间。
A low ejection fraction is usually a sign that the heart is abnormally enlarged, thickened, or stiffened. Although it can cause problems such as shortness of breath, inability to exercise, swelling of the feet and lower legs, and fatigue or weakness, some people with a low ejection fraction feel fine.
低射血分数，通常是心脏异常变大、变厚或变得没弹性（stiff）的信号。尽管它可能导致一些问题，比如呼吸短促，无法进行锻炼，小腿和脚部浮肿，乏力或者虚弱，然而，仍有一些人没有任何不适感。
As you mentioned, low ejection fraction is often a hallmark of heart failure. Taking an ACE inhibitor can help ward off this condition. A series of major clinical trials called the Studies of Left Ventricular Dysfunction (SOLVD) showed that this type of drug helped delay or prevent progression to heart failure in people with a low ejection fraction but no symptoms.
就像你提到的那样，低射血分数，通常是心脏衰竭的特征。摄入ACE（血管紧张素转化酶）抑制剂可以避免这种状况（估计说的是住院）。一系列临床实验（叫做左心室机能障碍研究 SOLVD）表明，这种类型的药物可以延迟或者阻止低射血分数但是无症状患者的心脏衰竭进程。
— Richard T. Lee, M.D.Associate Editor, Harvard Heart Letter