title: Research explains how sleep duration affects the heart.  Even sleeping too many hours a night can be hazardous.
mesh_terms: D015438:Health Behavior; D006304:Health Status; D006801:Humans; D009203:Myocardial Infarction / Q000517:prevention & control*; D010353:Patient Education as Topic; D012890:Sleep; D013997:Time Factors; D014851:Wakefulness