title: The Impact of Infarct Location and Extent on LV Motion Patterns: Implications for Dyssynchrony Assessment.
abstract: This study sought to investigate the influence of scar extent and location on the motion pattern of the left ventricle (LV) and its interaction with LV conduction delays.
  
  
  
  Different echocardiographic parameters have been proposed to identify responders to cardiac resynchronization therapy based on the detection of LV mechanical dyssynchrony. However, the impact of infarct scar on the diagnostic performance of these parameters remains unknown.
  
  
  
  We included 11 healthy volunteers and 122 patients with normal and severely reduced function, wide and narrow QRS, as well as with and without infarct scar. Location and extent of infarct scar was defined by contrast-enhanced cardiac magnetic resonance. Influence of infarct scar on the motion pattern of the LV was examined by measuring direction and amplitude of apical rocking. The influence of scar on different echocardiographic dyssynchrony parameters was investigated.
  
  
  
  Scar in the absence of conduction delay caused most apical rocking in the presence of 3 to 4 infarct segments. Pure apical infarction caused no rocking. In wide QRS patients without infarct scar, apical rocking was mainly dominated by the conduction delay, whereas in wide QRS patients with ischemic cardiomyopathy, this pattern was modulated by the scar. Apical rocking was inversely related to scar extent (r = -0.54, p < 0.05). Apical rocking was better associated with cardiac resynchronization therapy response than conventional dyssynchrony measurements.
  
  
  
  LV motion patterns are mainly dominated by conduction delays, but they are also modulated by infarct scar. Higher scar burden resulted in less pronounced apical rocking. Apical rocking is more strongly associated with cardiac resynchronization therapy response than with conventional echocardiographic parameters and may therefore be used as a screening parameter.
authors.affiliation: Department of Cardiology, University Hospital Gasthuisberg, Catholic University Leuven, Leuven, Belgium.
authors.forename: Brecht
authors.initials: B
authors.lastname: Steelant
authors.affiliation: Department of Cardiology, University Hospital Gasthuisberg, Catholic University Leuven, Leuven, Belgium.
authors.forename: Ivan
authors.initials: I
authors.lastname: Stankovic
authors.affiliation: Department of Cardiology, University Hospital Gasthuisberg, Catholic University Leuven, Leuven, Belgium.
authors.forename: Ine
authors.initials: I
authors.lastname: Roijakkers
authors.affiliation: Department of Cardiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
authors.forename: Marit
authors.initials: M
authors.lastname: Aarones
authors.affiliation: Department of Radiology, University Hospital Gasthuisberg, Catholic University Leuven, Leuven, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: Bogaert
authors.affiliation: Department of Radiology, University Hospital Gasthuisberg, Catholic University Leuven, Leuven, Belgium.
authors.forename: Walter
authors.initials: W
authors.lastname: Desmet
authors.affiliation: Department of Cardiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
authors.forename: Svend
authors.initials: S
authors.lastname: Aakhus
authors.affiliation: Department of Cardiology, University Hospital Gasthuisberg, Catholic University Leuven, Leuven, Belgium. Electronic address: jens.uwe.voigt@gmx.net.
authors.forename: Jens-Uwe
authors.initials: JU
authors.lastname: Voigt
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D002037:Bundle-Branch Block / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D058406:Cardiac Resynchronization Therapy; D016022:Case-Control Studies; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D009206:Myocardium / Q000473:pathology*; D011237:Predictive Value of Tests; D012720:Severity of Illness Index; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D016277:Ventricular Function, Left; D055815:Young Adult
keywords: cardiac resynchronization therapy; conduction delay; contrast-enhanced cardiac magnetic resonance; myocardial infarction