Cardiac structure and function in normal pregnancy

To review the published data on maternal cardiac adaptation to pregnancy.

Normal pregnancy is characterized by significant changes in the cardiovascular system. Studies on systemic arterial system and heart remodelling in pregnancy provide somewhat uniform results. In normal pregnancy, left ventricle mass, cardiac output and arterial compliance increase, whereas total vascular resistance decreases. In contrast, findings on left ventricular systolic and diastolic chamber and myocardial function are conflicting.

The major limitation of earlier studies on left ventricular systolic function is the use of ejection-phase indices that are dependent on loading conditions. Even when tissue Doppler velocity and deformation indices were measured, studies interpreted diastolic indices in isolation, rather than using validated diagnostic algorithms which account for the interdependency of cardiac events. Furthermore, the strong age-dependency of diastolic function indices was not accounted for in the majority of assessments and none of the studies diagnose or grade diastolic dysfunction. Future studies should aim to use appropriate control individuals, age-adjusted cutoff of cardiac diastolic indices and extended tissue Doppler velocity and deformation indices to provide objective information about chamber and myocardial function.