Professor Antonio F. Corno, a cardiac surgeon specialized in congenital heart defects, is about to begin a research project that at first glance seems entirely unrelated to his specialty: he will be using cardiac ultrasound and MRI technology to study the unique anatomy and function of frog hearts. Finding himself in unusual situations isn’t indeed new for Professor Corno. For instance, he is often invited at mathematics conferences as lone medical doctor among crowds of mathematicians. And mathematics will help guide his next research project as he focuses on a special subset of the 1% of children born with a congenital heart defect, that is the 10% of them
born with only a single functioning ventricle.
In children with a single ventricle, one of the ventricles may be missing or may be too small to provide adequate blood circulation. In a normal heart, the right ventricle pumps deoxygenated venous blood to the lungs where it can be cleansed of waste carbon dioxide and be replenished with fresh oxygen before returning to the heart. The left ventricle pumps the oxygenated blood through the aorta and out to the rest of the body. In children with only one ventricle there is an abnormal and inefficient circulation because their heart uses the only available ventricle to pump
the mixed deoxygenated and oxygenated blood to the lungs and through the aorta and into the rest of the body. This usually results in inadequately oxygenated blood being pumped into the body. When blood oxygenation is insufficient, muscle function is significantly decreased and all body organs may not develop and function properly. Without treatment, 90% of children born with a single ventricle heart defect won’t live past the age of 12 months. Until few decades ago, it was not possible to operate successfully on children born with this condition.
It has been Professor Corno’s passion for more than 30 years to study single ventricle hearts in children in order to improve their quality of life though surgical intervention. He knew that some animals like turtles and frogs have only one ventricle so they have now become an important area of investigation in his research; he mainly focuses his research on frogs, as turtles, he explains, are quite rare and very expensive, while frogs are more readily available. Notably, some species of frogs live actively 25 to 30 years with a single ventricle, while children with a single ventricle heart have nowhere near such a lifespan and they suffer very poor health. The
difference is that frogs are able to manage circulation to their lungs as well as circulation throughout their bodies with a single ventricle.
Professor Corno’s research project will search for anything in the functioning of the frog’s single ventricle that can be utilized to modify the treatments currently available for the human heart. He will collect cardiac ultrasound and MRI imaging of the frogs’ hearts to map the functional contractility of the single ventricle and to determine how the heart manages the efficient distribution of blood both to the lungs and to the body. Once these data are collected, mathematicians will study the flow distribution of the blood. The next step, says Professor Corno, will be to induce hypoxia in the frogs by reducing the amount of oxygen in the frogs’
blood to mimic the condition of ill children who are usually severely hypoxic from birth. By observing how the frogs’ hearts react to and compensate for a hypoxic state, he hopes to find something that can be duplicated in the heart of children with single ventricle heart defects. Professor Corno cautions that, at this stage, this is purely experimental research that will likely lead to more questions rather than answers, and that it is still very far from any clinical application.