ECHOCARDIOGRAPHIC ESTIMATION OF CRITICAL LEFT-VENTRICULAR SIZE IN INFANTS WITH ISOLATED AORTIC-VALVE STENOSIS

With the current trend to performing surgical valvotomy for infantile aortic stenosis without cardiac catheterization, there is a need to develop echocardiographic criteria for adequacy of left ventricular size. The echocardiograms and catheterization data of all 25 infants < 3 months of age undergoing aortic valvotomy for isolated aortic valve stenosis from September 1980 through July 1990 were reviewed. Significant differences (p < 0.05) between the survivors and nonsurvivors were noted for age at operation (30 +/- 28 vs. 3 +/- 1.5 days), mitral valve diameter (10.1 +/- 1.7 vs. 7.7 +/- 1.5 mm), left ventricular end-diastolic dimension (18.4 +/- 6.4 vs. 11.4 +/- 3 mm), left atrial dimensions (15.3 +/- 3.8 vs. 10 +/- 2.4 mm), left ventricular cross-sectional area on the parasternal long-axis echocardiogram (4 +/- 1.9 vs. 2 +/- 1.9 cm2) and angiographically determined left ventricular end-diastolic volume (43 +/- 23 vs. 11 +/- 5 ml/m2). There was no difference with respect to patient weight, body surface area, aortic root dimension or left ventricular ejection fraction. Left ventricular cross-sectional area < 2 cm2 as measured on the parasternal long-axis echocardiogram was found in 5 of 7 nonsurvivors and 0 of 12 survivors, making this a risk factor for perioperative death (p < 0.05). Left ventricular end-diastolic dimension < 13 mm was found in 5 of 6 nonsurvivors and 2 of 17 survivors, making this another risk factor for early mortality (p < 0.05). There was good correlation between angiographic left ventricular end-diastolic volume and both left ventricular cross-sectional area and end-diastolic dimension. It is concluded that a left ventricular cross-sectional area < 2 cm2 in infants with critical aortic stenosis is useful as an adjunct in assessing the critical left ventricular size that is not adequate for survival after valvotomy.