Two pathogenic theories behind cardiac insufficiency

1. The retrograde theory

The reduction in contractile power of the myocardium causes the cavities of the heart to not be fully emptied, hence the residual systolic blood and the ventricular diastolic pressure rise. Alongside the aforementioned, the atrial pressure rises, and the flow of venous blood is obstructed. When the insufficiency is affecting the left ventricle, the pressure in the left atrium and pulmonary veins rises in retrograde fashion. Stasis emerges in the pulmonary circulation.

When the insufficiency is affecting the right ventricle, the pressure in the venous systemic circulation. This causes stasis in the liver, kidneys, etc, and accumulation of liquids in the intercellular spaces, which eventually leads to edema.

This theory is contested, because in cases such as adhesive pericarditis, tricuspid stenosis or in the ligation of the vena cava inferior it occurs that there is no edema for substantial amounts of time, regardless of the rise in venous pressure.

2. The anterograde theory

According to this theory the heart cannot contract with as much vigour as it used to, hence the cardiac debit is reduced, the renal flux is reduced and so is the glomerular filtration. In this manner, there is water and sodium retention, and as a consequence the volume of blood increases alongside the venous pressure, which eventually cause the edema.

What this theory does not account for is that it cannot explain the partial decompensations that may occur, such as for example the rise in pressure in the pulmonary circulation. According to the theory, the retention of water and sodium should have global effects on the entire circulatory system.

Hence, both methods have their flaws, and in many ways complete one-another.

Cardiac insufficiency affecting the left ventricle is characterized by engorged, congested lungs. As the lungs develop chronic stases, the lungs become more rigid and dark brown in coloration. Cardiac insufficiency affecting the right ventricle is characterized by an enlargement of the liver which increases in consistency, the liver develops red areas in the center and yellowish areas in the periphery of the lobule as a result of the lipid dystrophy. In more advanced cases cardiac cirrhosis of the liver occurs.

Medically Reviewed by a doctor on 19 Jun 2018
Medical Author: Dr. med. Diana Hysi