title: Cardiac resynchronization therapy: role of patient selection.
abstract: Cardiac resynchronization therapy (CRT) is a well-accepted and effective therapy for treating patients with a wide QRS complex, significant left ventricular systolic dysfunction, and symptoms of advanced heart failure. However, approximately 25% to 30% of patients fail to respond to this therapy. Most large studies have used electrical dyssynchrony (wide QRS) as a main entrance criterion. Emerging data suggest that mechanical dyssynchrony may be a more important factor in selecting appropriate candidates for CRT. New echocardiographic (ECHO) imaging modalities such as tissue Doppler imaging, three-dimensional ECHO, and speckle tracking ECHO are able to quantify left ventricular mechanical dyssynchrony. These techniques are currently being used to assist in the selection of patients for CRT. Recently published and ongoing studies are addressing the use of CRT in patients who do not meet the standard criteria, such as patients with atrial fibrillation, mild to moderate heart failure, narrow QRS complex, and acute myocardial infarction.
authors.affiliation: Department of Research, St. Paul Heart Clinic,255 North Smith Avenue, Suite 100,St. Paul, MN 55102, USA. abank@stphc.com
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Bank
authors.forename: Aaron S
authors.initials: AS
authors.lastname: Kelly
authors.forename: Kevin V
authors.initials: KV
authors.lastname: Burns
authors.forename: Stuart W
authors.initials: SW
authors.lastname: Adler
mesh_terms: D001281:Atrial Fibrillation / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy; D002304:Cardiac Pacing, Artificial; D017147:Defibrillators, Implantable; D015150:Echocardiography, Doppler; D004554:Electric Countershock; D006329:Heart Conduction System / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D015337:Multicenter Studies as Topic; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy; D010138:Pacemaker, Artificial; D018579:Patient Selection; D016032:Randomized Controlled Trials as Topic; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy