The atrioventricular node or AV node is a part of the electrical conduction system of the heart that coordinates the top of the heart. It electrically connects the atria and ventricles. The AV node lies at the lower back section of the interatrial septum near the opening of the coronary sinus, and conducts the normal electrical impulse from the atria to the ventricles. The AV node is quite compact.
Atrial septal defect (ASD) is a congenital heart defect in which blood flows between the atria of the heart. Some flow is a normal condition both pre-birth and immediately post-birth via the foramen ovale; however, when this does not naturally close after birth it is referred to as a patent (open) foramen ovale (PFO). It is common in patients with a congenital atrial septal aneurysm (ASA).
The ostium primum atrial septal defect is a defect in the atrial septum at the level of the tricuspid and mitral valves. This is sometimes known as an endocardial cushion defect because it often involves the endocardial cushion, which is the portion of the heart where the atrial septum meets the ventricular septum and the mitral valve meets the tricuspid valve.
A congenital heart defect (CHD), also known as a congenital heart anomaly and congenital heart disease, is a defect in the structure of the heart or great vessels that is present at birth. Signs and symptoms depend on the specific type of defect. Symptoms can vary from none to life-threatening. When present, symptoms may include rapid breathing, bluish skin (cyanosis), poor weight gain, and feeling tired. CHD does not cause chest pain. Most congenital heart defects are not associated with other diseases. A complication of CHD is heart failure.
A ventricular septal defect (VSD) is a defect in the ventricular septum, the wall dividing the left and right ventricles of the heart. The extent of the opening may vary from pin size to complete absence of the ventricular septum, creating one common ventricle. The ventricular septum consists of an inferior muscular and superior membranous portion and is extensively innervated with conducting cardiomyocytes.
Ebstein's anomaly is a congenital heart defect in which the septal and posterior leaflets of the tricuspid valve are displaced towards the apex of the right ventricle of the heart. It is classified as a critical congenital heart defect accounting for <1% of all congenital heart defects presenting in ≈1 per 200,000 live births. Ebstein anomaly is the congenital heart lesion most commonly associated with supraventricular tachycardia.
The atrium or auricle is the upper chamber through which blood enters the ventricles of the heart. There are two atria in the human heart – the left atrium receives blood from the pulmonary (lung) circulation, and the right atrium receives blood from the venae cavae. The atria receive blood while relaxed (diastole), then contract (systole) to move blood to the ventricles. All animals with a closed circulatory system have at least one atrium. Humans have two atria.
Atrioventricular septal defect (AVSD) or atrioventricular canal defect (AVCD), also known as "common atrioventricular canal" (CAVC) or "endocardial cushion defect" (ECD), is characterized by a deficiency of the atrioventricular septum of the heart. It is caused by an abnormal or inadequate fusion of the superior and inferior endocardial cushions with the mid portion of the atrial septum and the muscular portion of the ventricular septum.
The interatrial septum is the wall of tissue that separates the right and left atria of the heart.
During heart development of a human embryo, the single primitive atrium becomes divided into right and left by a septum, the septum primum. The septum primum grows downward into the single atrium.
The foramen secundum, or ostium secundum is a foramen in the septum primum, a precursor to the interatrial septum of the human heart.
In the developing heart, the atria are initially open to each other, with the opening known as the primary interatrial foramen or ostium primum. The foramen lies beneath the edge of septum primum and the endocardial cushions. It progressively decreases in size as the septum grows downwards, and disappears with the formation of the atrial septum.
The proper development of the atrioventricular canal into its prospective components to create a clear division between the four compartments of the heart and ensure proper blood movement through the heart, are essential for proper heart function. When this process does not happen correctly, a child will develop atrioventricular canal defect which occurs in 2 out of every 10,000 births. It also has a correlation with Down syndrome because 20% of children with Down syndrome suffer from atrioventricular canal disease as well. This is a very serious condition and surgery is necessary within the first six months of life for a child. Half of the children who are untreated with this condition die during their first year due to heart failure or pneumonia.
The heart is the first functional organ in a vertebrate embryo. There are 5 stages to heart development.
Aortopulmonary septal defect is a rare congenital heart disorder accounting for only 0.1-0.3% of congenital heart defects worldwide. It is characterized by a communication between the aortic and pulmonary arteries, with preservation of two normal semilunar valves. It is the result of an incomplete separation of the aorticopulmonary trunk that normally occurs in early fetal development with formation of the spiral septum. Aortopulmonary septal defects occur in isolation in about half of cases, the remainder are associated with more complex heart abnormalities.
Heart septal defect refers to a congenital heart defect of one of the septa of the heart.
Pacemaker syndrome is a condition that represents the clinical consequences of suboptimal atrioventricular (AV) synchrony or AV dyssynchrony, regardless of the pacing mode, after pacemaker implantation. It is an iatrogenic disease—an adverse effect resulting from medical treatment—that is often underdiagnosed. In general, the symptoms of the syndrome are a combination of decreased cardiac output, loss of atrial contribution to ventricular filling, loss of total peripheral resistance response, and nonphysiologic pressure waves.
The atrioventricular septum is a septum of the heart between the right atrium (RA) and the left ventricle (LV).
Stella Van Praagh was a pediatric cardiologist and pathologist at Children's Hospital Boston. She was internationally known for her contributions to the pathology of congenital heart disease.
