Abstract 17474: The Morphological Change of Left Ventricular Outflow Tract by Aging
Background: The Area of left ventricular outflow tract (LVOT) is now calculated with LVOT diameter on the assumption that it's shape is a circle. The latest development of three dimensional echocardiography (3DE) can visualize LVOT directly. The morphological change of LVOT by aging is not clear.
Methods: we evaluated 50 cases (mean age 61 years, 24 male ) which have normal left ventricular ejection fraction with transthoracic echocardiography. We recorded conventional left ventricular morphology with two dimensional echocardiography and recorded 3DE of parasternal long axis view and analyzed LVOT area (LVOT-A) and long (D1) and short axis (D2) of LVOT diameter at end diastole.
Results: LVOT showed elliptical shape and LVOT-A obtained with 3DE was larger than the LVOT-A calculated with LVOT diameter (3.9±0.6cm2 v.s.3.1±0.6cm2;p<0.01). We divided these study population into 2 groups according with age. GroupIwas composed with less than 60 years (mean age 45 years n=21), GroupII was more than 60 years ( mean age 72 years n=29). LVOT-A was similar in both Group (4.2±0.5cm2 v.s.3.9±0.8cm2;n.s.). D2/D1 was smaller in GroupII (0.8±0.1 v.s. 0.7±0.1;p<0.01) due to smaller D2 in Group II (2.0±0.2cm v.s.1.8±0.2cm;p<0.01). D2 in Group II became shorter correlating with medium E' obtained with tissue Doppler echocardiography (r=0.77;p<0.01)
Conclusion:. LVOT became more elliptical shape with aging. This LVOT morphological change could be correlated with left ventricular diastolic dysfunction. LVOT-A obtained with conventional LVOT diameter was underestimated because of the elliptical deformation of LVOT.
- © 2010 by American Heart Association, Inc.