New guidelines for treating a stroke

(ABC) -- The American Stroke Association says treatment to dissolve blood clots caused by acute or ischemic strokes should begin within 60 minutes after arriving at the hospital.

Another revision to the 2007 ASA guidelines is that the window for treating some stroke patients with clot-dissolving therapy could be extended – up to four and a half hours in some select cases.

Previously, the ASA guidelines merely stated that clot-dissolving therapies be administered within three hours of the onset of stroke symptoms. Failure to receive timely medical treatment in the initial period after a stroke could result in more serious or long-term damage.