In the fetus, which ventricle is thicker?

Prepare for the Fetal Echocardiography Test. Utilize flashcards and multiple-choice questions that come with hints and explanations. Ace your exam preparation!

In the fetus, wall thickness of the ventricles reflects who has the higher workload. The pulmonary circuit is very high in resistance before birth, so the right ventricle works against a strong afterload and sustains a large portion of the cardiac output through the ductus arteriosus to reach the systemic circulation. That sustained higher workload makes the right ventricular muscle wall thicker than the left. After birth, the lungs expand, pulmonary resistance drops, and the left ventricle takes on the greater systemic workload, so the left ventricle becomes relatively thicker. So, a thicker right ventricle is a normal finding in fetal life.