INTRODUCTION
Left ventricular outflow tract obstruction (LVOTO/AS) malformations
account for approximately 14% of all congenital heart disease
(CHD)1,2. Types of lesions include subaortic membrane,
bicuspid aortic valve, and supravalvular aortic stenosis. These may
occur individually or in association with other anomalies such as
coarctation of aorta or hypoplastic left heart3. All
lesions result in varying degrees of systolic flow obstruction from the
left ventricle (LV) to the ascending aorta4.
Pregnancy is a state of increased physiologic demand and profound
hemodynamic changes which results in increased preload and cardiac
output5–7. As such, valvular Doppler gradients are
expected to increase with normal pregnancy. While women with LVOTO/AS
are routinely assessed with echocardiography throughout preconception
and pregnancy, there is a paucity of knowledge regarding the impact of
pregnancy on LVOTO/AS and what can be considered a physiological vs.
pathological change8–10. Furthermore, this has not
been studied in conjunction with sub-clinical changes in left
ventricular function measured by global longitudinal strain (GLS), which
has emerged as an important measure of subclinical left ventricular
dysfunction with a prognostic role in patients with cardiac
disease11–14. In particular, among patients with
moderate AS or asymptomatic severe AS and preserved LVEF, impaired left
ventricular GLS has been shown to be associated with increased risk for
progression and a marker for earlier
intervention15–18.
The objectives of this study were to determine among women with
congenital LVOTO/AS: 1) changes in LVOT Doppler gradients over the
course of pregnancy and postpartum as compared to controls; 2) changes
in left ventricular function evaluated by left ventricular ejection
fraction (LVEF) and GLS over the course of pregnancy and postpartum as
compared to controls; and 3) if there is an association between LVOT
Doppler gradients and left ventricular function with clinical outcomes.