The Impact of Mechanical Forces in Heart Morphogenesis

C ongenital heart disease (CHD) is the most common birth defect in humans and results from deficient cardiac development, a complex process that is not completely understood. The heart starts to function before its morphogenesis is complete and the increasing needs of the growing embryo for oxygen and nutrients demand a proportional increase in the performance of the organ. We review recent findings supporting the hypothesis that the activity of the developing heart influences its morphogenesis and that internal or external factors, which significantly modify its functional capability, can in turn, induce anatomic cardiac defects. We propose that a role for early cardiac contraction in heart development is supported by recent experimental evidence and that the Notch pathway acts as a key transducer between hemodynamic stimuli and cardiogenesis.