Left Ventricular Diastolic Function and Characteristics in Fetal Aortic Stenosis

Abstract

Fetal aortic valvuloplasty (FAV) has shown promise in averting progression of mid-gestation aortic stenosis (AS) to hypoplastic left heart syndrome in a subset of patients. Patients who achieve biventricular circulation after FAV frequently have left ventricular (LV) diastolic dysfunction (DD). This study evaluates DD in fetuses with AS by comparing echocardiographic indices of LV diastolic function in fetuses undergoing FAV (n=20) to controls (n=40) and evaluates for LV factors associated with DD in FAV patients. We also compared pre- and post-FAV DD variables (n=16). Median gestational age (24 weeks, range 18–29 weeks) and fetal heart rate were similar between FAV and controls. Compared to controls, FAV patients had universally abnormal LV diastolic parameters including fused mitral inflow E and A waves (p=0.008), higher E velocity(p<0.001), shorter mitral inflow time (p=0.001), lower LV lateral annulus E′ (p<0.001), septal E′ (p=0.003) and higher E/E′ (p<0.001) than controls. FAV patients had abnormal right ventricular mechanics with higher tricuspid inflow E velocity (p<0.001), and shorter tricuspid inflow time (p=0.03). Worse LV diastolic function (lower LV E′) was associated with higher endocardial fibroelastosis (EFE) grade (r=0.74, p<0.001), large LV volume (r=0.55, p=0.013) and sphericity (r=0.58, P=0.009) and with lower LV pressure by mitral regurgitation jet (r=−0.68, p<0.001). Post-FAV, fewer patients had fused mitral inflow E and A than pre-FAV (p=0.05) and septal E′ was higher (=0.04). In conclusion, fetuses with mid-gestation AS have evidence of marked DD. Worse DD is associated with larger, more spherical LV, with more extensive EFE and lower LV pressure.

Hypoplastic left heart syndrome: a review

“…In the case of MVS or MVA the hypoplasia is caused by the decreased preload and pressure in the LV (3, 6). Dilated cardiomyopathy and endocardial fibroelastosis might be independent factors causing HLHS (7–9). …”

Clinical characteristics and outcomes in patients with endocardial fibroelastosis associated with critical aortic stenosis with biventricular circulation

“…Furthermore, several studies have found an association between the higher mortality rates in these patients and the small size of the left ventricles as well as the presence of EFE. [1,5,10] Aortic balloon valvuloplasties and surgical valvotomies offer similar short-and mid-term palliation. However, balloon valvuloplasty patients have higher reintervention rates but shorter hospital and ICU stays and reduced immediate morbidity.…”

“…[1,10] In fact, Friedman et al [10] determined that the more extensive the EFE in a patient, the worse the diastolic dysfunction.…”

“…[8,9] In several studies, the use of fetal aortic balloon valvuloplasties has been effective in preventing midgestational aortic stenosis from developing into HLHS and EFE in a subset of patients. [10,[16][17][18] However, this procedure must be performed before significant left heart hypoplasia occurs and should not be carried out on fetuses with aortic stenosis that will not progress to HLHS. McElhinley et al [5] reported that fetal EFE severity corresponded with some indices related to left heart size, geometry, and function as well as the probability of a postnatal biventricular outcome.…”

“…[2,[7][8][9] Furthermore, smaller left ventricular size, progressive hypertrophy of the left ventricular wall, and greater hyperechogenicity of the endocardium can be seen as the gestational age increases, and the endocardial thickening gives rise to a decrease in left ventricular compliance, impaired diastolic function, and global hypokinesia. [5,10] Endocardial fibroelastosis is characterized by an opaque, pearly-white thickening caused by the proliferation of collagen and elastic fibers. It occurs initially in the subendocardial region and rarely extends to the subepicardial region.…”