Right bundle branch blockA right bundle branch block (RBBB) is a heart block in the right bundle branch of the electrical conduction system. During a right bundle branch block, the right ventricle is not directly activated by impulses travelling through the right bundle branch. The left ventricle, however, is still normally activated by the left bundle branch. These impulses are then able to travel through the myocardium of the left ventricle to the right ventricle and depolarize the right ventricle this way.
Heart developmentHeart development, also known as cardiogenesis, refers to the prenatal development of the heart. This begins with the formation of two endocardial tubes which merge to form the tubular heart, also called the primitive heart tube. The heart is the first functional organ in vertebrate embryos. The tubular heart quickly differentiates into the truncus arteriosus, bulbus cordis, primitive ventricle, primitive atrium, and the sinus venosus. The truncus arteriosus splits into the ascending aorta and the pulmonary trunk.
Environmental toxicants and fetal developmentEnvironmental toxicants and fetal development is the impact of different toxic substances from the environment on the development of the fetus. This article deals with potential adverse effects of environmental toxicants on the prenatal development of both the embryo or fetus, as well as pregnancy complications. The human embryo or fetus is relatively susceptible to impact from adverse conditions within the mother's environment. Substandard fetal conditions often cause various degrees of developmental delays, both physical and mental, for the growing baby.
Atrial septostomyAtrial septostomy is a surgical procedure in which a small hole is created between the upper two chambers of the heart, the atria. This procedure is primarily used to palliate dextro-Transposition of the great arteries or d-TGA (often imprecisely called transposition of the great arteries), a life-threatening cyanotic congenital heart defect seen in infants. It is performed prior to an arterial switch operation. Atrial septostomy has also seen limited use as a surgical treatment for pulmonary hypertension.
