title: Evaluation of left atrial contraction contribution to left ventricular filling using cardiovascular magnetic resonance.
abstract: OBJECTIVE
  To describe a new method to quantify the left atrial contraction contribution (ACC) to left ventricular (LV) filling using cardiovascular magnetic resonance (CMR).
  
  
  METHODS
  We assessed 120 normal subjects (50% female) using steady-state free precession CMR volumetry. Volumes measurements were performed using short axis and rotational long axis views. The percentage of ACC was calculated by dividing the LV filling volume resulting from left atrial (LA) contraction by the LV stroke volume (LVSV).
  
  
  RESULTS
  The described method was well reproducible. The ACC in normal subjects was 15 ± 5% for ages <40 years, 28 ± 8% for ages 40 to 55 years, and 38 ± 5% for ages >55 years. When adjusted for age, ie, dividing the ACC percentage by age, a value between 0.4 and 0.7 was found to represent the normal range of ACC at any age.
  
  
  CONCLUSIONS
  The study presents a new and accurate CMR volumetric method to quantify ACC to LV filling. ACC ranges from 10%-40%, depending on age.
authors.affiliation: Stephenson Cardiovascular MR Centre at the Libin Cardiovascular Institute of Alberta, Department of Cardiac Sciences, University of Calgary, Calgary, Alberta, Canada. tariqmfh@yahoo.com
authors.forename: Tariq
authors.initials: T
authors.lastname: Alhogbani
authors.forename: Oliver
authors.initials: O
authors.lastname: Strohm
authors.forename: Matthias G
authors.initials: MG
authors.lastname: Friedrich
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019571:Arrhythmogenic Right Ventricular Dysplasia / Q000175:diagnosis* / Q000235:genetics / Q000503:physiopathology*; D001783:Blood Flow Velocity; D002306:Cardiac Volume / Q000502:physiology; D003971:Diastole / Q000502:physiology; D015150:Echocardiography, Doppler; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology*; D015588:Observer Variation; D011446:Prospective Studies; D012016:Reference Values; D016277:Ventricular Function, Left / Q000502:physiology*; D055815:Young Adult