Branko Furst
Albany Medical College, USA
Title: Functional Morphology of the Heart Calls for a Revised Circulation Model
Biography
Biography: Branko Furst
Abstract
The debate whether the heart is a pressure or a flow generating pump continues to be a subject of debate amongst clinicians and cardiovascular physiologists. It is based on the assumption that the heart, a hollow muscular organ equipped with valves, impels the blood through the systemic and pulmonary circuits. It will be argued that the longstanding issue over the nature of the heart’s function can be resolved by adopting the phenomenon-based, evolutionary model of circulation. The model shows that the movement of blood is the primary phenomenon generated at the levels of the capillaries. It exists before the functional maturity of the heart and is intricately linked with metabolic demands of the tissues. The pressure in the vessels, therefore, is a derived phenomenon resulting from the rhythmic interruption of flow by the heart in combination with the dynamic response of the peripheral vasculature. The heart thus functions as an impedance-pump generating pressure, but not the flow of blood. The proposed model will be supported by examples from comparative anatomy and congenital heart defects, including atrial and ventricular septal defects, Eisenmenger syndrome, hypoplastic left heart syndrome and its palliation – the Fontan circulation.