More than 30 minutes of sleep during the daytime can lead to a heart rhythm condition called atrial fibrillation (a-fib), shows a new study, which is yet to be published in a peer-reviewed journal.

一项新的研究表明，白天睡眠超过30分钟会导致一种名为心房纤颤(a-fib)的心律状况，该研究尚未在同行评审期刊上发表。

Atrial fibrillation is a cardiac disorder that causes irregular and sometimes very rapid heart rhythm. This can lead to blood clots in the heart, thereby increasing the risk of stroke and other cardiac ailments, according to Mayo Clinic. The condition predominantly occurs in the heart's upper chamber, Health Day reported.

心房颤动是一种心脏疾病，会导致不规则的、甚至非常快速的心律。据梅奥诊所称，这可能会导致心脏血栓，从而增加中风和其他心脏疾病的风险。据《健康日》报道，这种情况主要发生在心脏的上腔。

Over 20,000 Spanish university graduates participated in the study. They were grouped under three categories: the ones who don't nap, those who nap less than 30 minutes and those who nap 30 minutes or more each day. During the follow-up period of 14 years, 131 participants developed a-fib.

超过2万名西班牙大学毕业生参与了这项研究。他们被分为三类:不午睡的人、午睡少于30分钟的人和每天午睡30分钟或更长时间的人。在14年的随访期间，131名参与者患上了心房纤颤。

Researchers found those who took longer naps were twice at the risk of developing the disorder compared to those who slept less during the day. Those who didn't nap at all were in the no-risk zone.

研究人员发现，与白天睡眠较少的人相比，午睡时间较长的人患这种疾病的风险是后者的两倍。那些根本不午睡的人则没有这种风险。

The study indicated that people who napped for fewer than 15 minutes had a 42% lesser chance of developing a-fib, and those whose sleep routine was limited between 15 to 30 minutes had a 56% reduced risk of a-fib as compared to long nappers.

研究表明，睡眠时间少于15分钟的人患心房纤颤的几率要低42%，而那些睡眠时间限制在15到30分钟之间的人患心房纤颤的风险要比午睡时间长的人低56%。

The study has just established a link between long naps and a-fib, it doesn't explain its cause and effects.

这项研究只是确立了长时间小睡和心房纤颤之间的联系，并没有解释其因果关系。