Scientists of the Department of Animal Biology of the University of Malaga have discovered the cellular mechanism that originates coronary arterio-ventricular fistulae, a congenital anomaly that, in severe cases, may lead to death.
José María Pérez Pomares, Professor on the UMA, and in addition member of IBIMA-Plataforma BIONAND, has conducted this study in collaboration with researchers of the National Center of Cardiovascular Research (CNIC) of Madrid, the Maternity and Kid’s Hospital of Malaga, the Center for Applied Medical Research (CIMA) of Pamplona, and the Necker Hospital and Pasteur/Imagine Institute of Paris. The outcomes have been published within the scientific journal Experimental and molecular medicine, of the celebrated publishing company Nature.
Aberrant connections
Coronary fistulae are aberrant connections between different blood vessels of the coronary system, large arteries or veins (aorta, pulmonary or cava) or other parts of the guts, resembling its chambers (atria and ventricles). Probably the most common coronary fistula is precisely this last type, the one connecting one coronary artery to the within the guts, the style of fistula that has been studied by these researchers of the University of Malaga.
It’s estimated that between 0.21 and 5.8 percent of the population have coronary anomalies, and between 0.1 and 0.2 percent of the patients that undergo medical examination of their coronary arteries have a fistula. “It’s a comparatively low incidence rate, although now we have to keep in mind that, in lots of cases, the presence of this defect isn’t diagnosed”, explains Pérez Pomares.
While fistulae are sometimes small and don’t entail serious conditions or complications, allowing those affected to steer a standard life, the most important fistulae may associate to serious complications, resembling endocarditis -infection of the tissue that covers the guts internally-, hypertrophy or dilatation of ventricular partitions or sudden death.
“The pathology corelates with other heart conditions; the spectrum is extremely variable”, says the Professor on the UMA.
Early diagnosis
It is understood that this congenital malformation appears during embryonic development, although thus far there was limited information on its origin.
Due to this fact, Pérez Pomares, who chaired the Working Group on Development, Anatomy & Pathology of the European Society of Cardiology for 2 years (2018-2020), has led certainly one of the few studies that explains the causes of this defect, a study which will help improve early diagnosis of any such anomalies and other associated pathologies.
Results suggest that the looks of discontinuities within the ventricular wall lies within the origin of this coronary defect.
The Professor on the UMA points out that cardiac chambers have three tissue layers: endocardium, probably the most inner tissue; myocardium, the thick central layer, which enables the contraction of the atria and ventricles and, due to this fact, blood circulation; and epicardium, which covers the external surface of the organ.
When the endocardium and the epicardium anomalously come into contact during early stages of embryonic development, normally since the myocardium that separates these two layers present abnormally thinner regions or porous zones, a connection is generated between the surface and the inside of the guts, which is able to mature in a fistula.
In conducting this study, Pérez Pomares’ team worked on genetic and experimental animal models, but they might also study human samples of a specific case of paediatric coronary fistula. These samples were obtained through informed consent for research purposes. The outcomes open the door to discover recent candidate genes for early diagnosis of those congenital anomalies and their associated risks.
Source:
Journal reference:
Palmquist-Gomes, P., et al. (2023). Origin of congenital coronary arterio-ventricular fistulae from anomalous epicardial and myocardial development. Experimental & Molecular Medicine. doi.org/10.1038/s12276-022-00913-x.