http://www.medworm.com/index.php?rid=7642854&cid=c_64_7_f&fid=33703&url=http%3A%2F%2Fajpheart.physiology.org%2Fcgi%2Fcontent%2Fabstract%2F305%2F7%2FH1098%3Frss%3D1
http://www.medworm.com/index.php?rid=7642854&cid=c_64_7_f&fid=33703&url=http%3A%2F%2Fajpheart.physiology.org%2Fcgi%2Fcontent%2Fabstract%2F305%2F7%2FH1098%3Frss%3D1