A novel heart structure and work mode hypothesis: parasitic ventricle theory.

Parasitic ventricle hypothesis: a normal human heart is composed of four chambers that include two atria and two ventricles; the left ventricle is juxtaposed to the right ventricle. The left ventricle receives arterial blood from the left atrium and then ejects it into the general circulation, while the right ventricle receives venous blood from the right atrium and ejects it into the pulmonary circulation. So this structure restricts the arterial blood from mixing with the venous blood. But the heart of the patients suffering from single ventricle is composed of only one ventricle, and the patients can survive for several years, but eventually they die of hypoxemia induced by mixing up of arterial and venous blood in single ventricle. Based on these observations, we hypothesized that if an artificial akinesic ventricle device made of a biomaterial (such as pericardium autograft) (named as parasitic ventricle) is put into the single ventricle chamber of such patients, it would function as the right ventricle, and the single ventricle chamber is rendered to function as the left ventricle. Unlike the normal heart, this parasitic relationship enables to form a new type of heart structure. It has been found that the parasitic ventricle works relying on the function of the single ventricle, and the relationship of parasitism can be established between the two ventricles, "left ventricle" containing "right ventricle". This kind of heart structure can prevent the venous blood from mixing with the arterial blood; therefore, the patient in the absence of hypoxemia may survive longer. The theory is a completely new heart structure and work mode theory. We hope that this theory can open a new way to design a new operative procedure for effectively anatomically treating a patient with single ventricle. In addition, it may supply a new theory for designing a new total artificial heart with many advantages.