Truncus arteriosus

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Truncus arteriosus
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Heart of human embryo of about twenty-four days. (Truncus arteriosus visible at top.)
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Diagrams to illustrate the transformation of the bulbus cordis. Ao. Truncus arteriosus. Au. Atrium. B. Bulbus cordis. RV. Right ventricle. LV. Left ventricle. P. Pulmonary artery.
Details
Precursor Cardiogenic area
Gives rise to Aorta, pulmonary artery
System Cardiovascular system
Identifiers
MeSH D014338
TE arteriosus_by_E5.11.1.8.1.0.4 E5.11.1.8.1.0.4
FMA 70301
Anatomical terminology

The truncus arteriosus is a structure that is present during embryonic development.[ clarification needed ] It is an arterial trunk that originates from both ventricles of the heart that later divides into the aorta and the pulmonary trunk. [1]

Contents

Structure

The truncus arteriosus and bulbus cordis are divided by the aorticopulmonary septum. The truncus arteriosus gives rise to the ascending aorta and the pulmonary trunk. The caudal end of the bulbus cordis gives rise to the smooth parts (outflow tract) of the left and right ventricles (aortic vestibule & conus arteriosus respectively). [2] The cranial end of the bulbus cordis (also known as the conus cordis) gives rise to the aorta and pulmonary trunk with the truncus arteriosus.

This makes its appearance in three portions.

  1. Two distal ridge-like thickenings project into the lumen of the tube: the truncal and bulbar ridges. [3] These increase in size, and ultimately meet and fuse to form a septum (aorticopulmonary septum), which takes a spiral course toward the proximal end of the truncus arteriosus. It divides the distal part of the truncus into two vessels, the aorta and pulmonary artery, which lie side by side above, but near the heart the pulmonary artery is in front of the aorta.
  2. Four endocardial cushions appear in the proximal part of the truncus arteriosus in the region of the future semilunar valves; the manner in which these are related to the aortic septum is described below.
  3. Two endocardial thickenings—anterior and posterior—develop in the bulbus cordis and unite to form a short septum; this joins above with the aortic septum and below with the ventricular septum. The septum grows down into the ventricle as an oblique partition, which ultimately blends with the ventricular septum in such a way as to bring the bulbus cordis into communication with the pulmonary artery, and through the latter with the sixth pair of aortic arches; while the left ventricle is brought into continuity with the aorta, which communicates with the remaining aortic arches.

Clinical significance

Failure of the truncus arteriosus to close results in the condition known as persistent truncus arteriosus, a rare congenital heart defect. This is often just referred to as truncus arteriosus. Echocardiography is used to diagnose this condition. [4] [5] [6] Other pathologies of the truncus arteriosus include transposition of the great vessels (arteries in this case), and tetralogy of Fallot. [7]

Related Research Articles

<span class="mw-page-title-main">Aorta</span> Largest artery in the human body

The aorta is the main and largest artery in the human body, originating from the left ventricle of the heart, branching upwards immediately after, and extending down to the abdomen, where it splits at the aortic bifurcation into two smaller arteries. The aorta distributes oxygenated blood to all parts of the body through the systemic circulation.

<span class="mw-page-title-main">Heart valve</span> A flap of tissue that prevent backflow of blood around the heart

A heart valve is a biological one-way valve that allows blood to flow in one direction through the chambers of the heart. Four valves are usually present in a mammalian heart and together they determine the pathway of blood flow through the heart. A heart valve opens or closes according to differential blood pressure on each side.

<span class="mw-page-title-main">Ventricle (heart)</span> Chamber of the heart

A ventricle is one of two large chambers located toward the bottom of the heart that collect and expel blood towards the peripheral beds within the body and lungs. The blood pumped by a ventricle is supplied by an atrium, an adjacent chamber in the upper heart that is smaller than a ventricle. Interventricular means between the ventricles, while intraventricular means within one ventricle.

<span class="mw-page-title-main">Pulmonary artery</span> Artery in pulmonary circulation carrying deoxygenated blood from heart to lungs

A pulmonary artery is an artery in the pulmonary circulation that carries deoxygenated blood from the right side of the heart to the lungs. The largest pulmonary artery is the main pulmonary artery or pulmonary trunk from the heart, and the smallest ones are the arterioles, which lead to the capillaries that surround the pulmonary alveoli.

<span class="mw-page-title-main">Congenital heart defect</span> Defect in the structure of the heart that is present at birth

A congenital heart defect (CHD), also known as a congenital heart anomaly, congenital cardiovascular malformation, and congenital heart disease, is a defect in the structure of the heart or great vessels that is present at birth. A congenital heart defect is classed as a cardiovascular disease. Signs and symptoms depend on the specific type of defect. Symptoms can vary from none to life-threatening. When present, symptoms are variable and 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.

<span class="mw-page-title-main">Persistent truncus arteriosus</span> Medical condition

Persistent truncus arteriosus (PTA), often referred to simply as truncus arteriosus, is a rare form of congenital heart disease that presents at birth. In this condition, the embryological structure known as the truncus arteriosus fails to properly divide into the pulmonary trunk and aorta. This results in one arterial trunk arising from the heart and providing mixed blood to the coronary arteries, pulmonary arteries, and systemic circulation. For the International Classification of Diseases (ICD-11), the International Paediatric and Congenital Cardiac Code (IPCCC) was developed to standardize the nomenclature of congenital heart disease. Under this system, English is now the official language, and persistent truncus arteriosus should properly be termed common arterial trunk.

In cardiology, the cardiac skeleton, also known as the fibrous skeleton of the heart, is a high-density homogeneous structure of connective tissue that forms and anchors the valves of the heart, and influences the forces exerted by and through them. The cardiac skeleton separates and partitions the atria from the ventricles .The heart's cardiac skeleton comprises four dense connective tissue rings that encircle the mitral and tricuspid atrioventricular (AV) canals and extend to the origins of the pulmonary trunk and aorta. This provides crucial support and structure to the heart while also serving to electrically isolate the atria from the ventricles.

A right-to-left shunt is a cardiac shunt which allows blood to flow from the right heart to the left heart. This terminology is used both for the abnormal state in humans and for normal physiological shunts in reptiles.

<span class="mw-page-title-main">Arterial switch operation</span> Open heart surgical procedure

Arterial switch operation (ASO) or arterial switch, is an open heart surgical procedure used to correct dextro-transposition of the great arteries (d-TGA).

<span class="mw-page-title-main">Bulbus cordis</span>

The bulbus cordis is a part of the developing heart that lies ventral to the primitive ventricle after the heart assumes its S-shaped form. The superior end of the bulbus cordis is also called the conotruncus.

<span class="mw-page-title-main">Infundibulum (heart)</span> Feature of chordate cardiac anatomy

The infundibulum is a conical pouch formed from the upper and left angle of the right ventricle in the chordate heart, from which the pulmonary trunk arises. It develops from the bulbus cordis. Typically, the infundibulum refers to the corresponding internal structure, whereas the conus arteriosus refers to the external structure. Defects in infundibulum development can result in a heart condition known as tetralogy of Fallot.

<span class="mw-page-title-main">Ventricular outflow tract</span>

A ventricular outflow tract is a portion of either the left ventricle or right ventricle of the heart through which blood passes in order to enter the great arteries.

<span class="mw-page-title-main">Aorticopulmonary septum</span> Anatomical entity

The aorticopulmonary septum is developmentally formed from neural crest, specifically the cardiac neural crest, and actively separates the aorta and pulmonary arteries and fuses with the interventricular septum within the heart during heart development.

The heart is the first functional organ in a vertebrate embryo. There are 5 stages to heart development.

The following outline is provided as an overview of and topical guide to cardiology, the branch of medicine dealing with disorders of the human heart. The field includes medical diagnosis and treatment of congenital heart defects, coronary artery disease, heart failure, valvular heart disease and electrophysiology. Physicians who specialize in cardiology are called cardiologists.

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.

Neural crest cells are multipotent cells required for the development of cells, tissues and organ systems. A subpopulation of neural crest cells are the cardiac neural crest complex. This complex refers to the cells found amongst the midotic placode and somite 3 destined to undergo epithelial-mesenchymal transformation and migration to the heart via pharyngeal arches 3, 4 and 6.

<span class="mw-page-title-main">Heart development</span> Prenatal development of the heart

Heart 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.

Fetal aortic stenosis is a disorder that occurs when the fetus’ aortic valve does not fully open during development. The aortic valve is a one way valve that is located between the left ventricle and the aorta, keeping blood from leaking back into the ventricle. It has three leaflets that separate when the ventricle contracts to allow blood to move from the ventricle to the aorta. These leaflets come together when the ventricle relaxes.

The LeCompte maneuver is a technique used in open heart surgery, primarily on infants and children. The maneuver entails cutting the main pulmonary artery and moving it anterior to the aorta before reattaching the pulmonary artery during the following reconstruction of the great vessels. It allows the surgeon to reconstruct the right ventricular outflow tract without needing to connect the proximal and distal sections with a graft. It also enables the surgeon to avoid compressing the coronary arteries and relieves compression of the bronchi in cases where the pulmonary artery is severely dilated or aneurysmal. If both pulmonary arteries are not mobilized adequately, they can become stretched, leading to pulmonic stenosis.

References

PD-icon.svgThis article incorporates text in the public domain from page 514 of the 20th edition of Gray's Anatomy (1918)

  1. Jaggers, James; Cole, Charles R. (2019). "55. Truncus Arteriosus". In Ungerleider, Ross M.; Nelson, Kristen; Cooper, David S.; Meliones, Jon N.; Jacobs, Jeffrey (eds.). Critical Heart Disease in Infants and Children (3rd ed.). Philadelphia: Elsevier. pp. 661–669. ISBN   978-1-4557-0760-7.
  2. Le, T., Bhushan, V., et al. 'First Aid for the USMLE STEP1'. 2009.
  3. Le, Tao; Bhushan, Vikas; Vasan, Neil (2010). First Aid for the USMLE Step 1: 2010 20th Anniversary Edition . USA: The McGraw-Hill Companies, Inc. pp.  123. ISBN   978-0-07-163340-6.
  4. "Truncus Arteriosus | Pediatric Echocardiography".
  5. "Truncus Arteriosus Imaging: Overview, Radiography, Computed Tomography". 16 October 2021.
  6. "Truncus arteriosus - Diagnosis and treatment - Mayo Clinic". Mayo Clinic .
  7. Le, Tao; Bhushan, Vikas; Vasan, Neil (2010). First Aid for the USMLE Step 1: 2010 20th Anniversary Edition . USA: The McGraw-Hill Companies, Inc. pp.  123. ISBN   978-0-07-163340-6.