Echocardiographic estimation of critical left ventricular size in infants with isolated aortic valve stenosis

Abstract

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 ± 0.4 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 cm²as 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 cm²in 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.