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.