This is called intractable or severe angina , the severity of which is designated by classes .

这被称为难以治愈的或严重的心绞痛，严重性被级别指定。

Researchers believe the loss of these blood vessels contributes to the pain of chronic , severe angina .

研究员认为这些血管的损失是产生慢性疼痛，严重心绞痛的原因。

Other heart conditions such as angina and heart attacks contribute to the disease , according to the u.s. national library of medicine .

根据美国国家医学图书馆记载的资料，它还可能引发其他心脏疾病，如心绞痛或心肌梗塞。

Short sleep duration was associated with angina , while both sleeping too little and sleeping too much were associated with heart attack and stroke , the study says .

研究表明心绞痛与较短的睡眠持续时间有关，心脏病发作和中风则与睡得太少或者睡得太多有关。

It also took twice as long until they experienced angina pain on a treadmill compared to the placebo group , and , when they felt pain , it went away faster with rest .

相比安慰剂组他们在跑步机上经历心绞痛也需要两倍长的时间，并且当他们感到疼痛时，休息一下也能更快的赶走疼痛。