In a ventricular septal rupture, what changes are expected in cardiac output and SvO2?

In the context of a ventricular septal rupture, the primary physiological changes involve the dynamics of blood flow due to the abnormal communication between the left and right ventricles. In this condition, the left-to-right shunt can lead to an increase in pulmonary blood flow and may alter the overall distribution of cardiac output.

Typically, after a ventricular septal rupture, the left ventricle pumps a portion of its output into the right ventricle due to the pressure gradient created by the systemic circulation being higher than that of the pulmonary circulation. This leads to a decrease in effective systemic flow, as a fraction of blood is diverted away from the systemic circuit. However, the overall cardiac output may initially appear to be augmented due to the increased venous return to the heart as a result of the increased flow to the lungs.

As for the mixed venous oxygen saturation (SvO2), the increased pulmonary venous return can lead to a higher oxygen content in the blood returning to the left atrium, resulting in increased SvO2 values. This happens because the right ventricle is not entirely compromised and is adequately supplying blood to the pulmonary circuit, which enhances oxygenation due to the increased volume of blood returning from the lungs.

In summary, in