Cor triatriatum (or triatrial heart) is a

congenital heart defect 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 h ...

where the left atrium (cor triatriatum sinistrum) or right atrium (cor triatriatum dextrum) is subdivided by a thin

membrane A membrane is a selective barrier; it allows some things to pass through but stops others. Such things may be molecules, ions, or other small particles. Membranes can be generally classified into synthetic membranes and biological membranes. Bi ...

, resulting in three atrial chambers (hence the name). Cor triatriatum represents 0.1% of all

congenital A birth defect is an abnormal condition that is present at childbirth, birth, regardless of its cause. Birth defects may result in disability, disabilities that may be physical disability, physical, intellectual disability, intellectual, or dev ...

cardiac malformations and may be associated with other cardiac defects in as many as 50% of cases. The

may be complete or may contain one or more fenestrations of varying size. Cor triatriatum sinistrum is more common. In this defect, there is typically a proximal chamber that receives the pulmonic veins and a distal (true) chamber located more

anteriorly Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek language, Greek roots, describe something in its standard anatomical position. Thi ...

where it empties into the

mitral valve The mitral valve ( ), also known as the bicuspid valve or left atrioventricular valve, is one of the four heart valves. It has two Cusps of heart valves, cusps or flaps and lies between the atrium (heart), left atrium and the ventricle (heart), ...

. The membrane that separates the atrium into two parts varies significantly in size and shape. It may appear similar to a diaphragm or be funnel-shaped, band-like, entirely intact (imperforate) or contain one or more openings (fenestrations) ranging from small, restrictive-type to large and widely open. In the

pediatric Pediatrics (American English) also spelled paediatrics (British English), is the branch of medicine that involves the medical care of infants, children, adolescents, and young adults. In the United Kingdom, pediatrics covers many of their youth ...

population, this anomaly may be associated with major

cardiac lesions such as

tetralogy of Fallot Tetralogy of Fallot (TOF), formerly known as Steno-Fallot tetralogy, is a congenital heart defect characterized by four specific cardiac defects. Classically, the four defects are: * Pulmonary stenosis, which is narrowing of the exit from the r ...

, double outlet right ventricle,

coarctation of the aorta Coarctation of the aorta (CoA) is a congenital condition whereby the aorta is narrow, usually in the area where the ductus arteriosus ( ligamentum arteriosum after regression) inserts. The word ''coarctation'' means "pressing or drawing toget ...

, partial anomalous pulmonary venous connection, persistent left

superior vena cava The superior vena cava (SVC) is the superior of the two venae cavae, the great venous trunks that return deoxygenated blood from the systemic circulation to the right atrium of the heart. It is a large-diameter (24 mm) short length vei ...

with unroofed

coronary sinus The coronary sinus () is the largest vein of the heart. It drains over half of the deoxygenated blood from the heart muscle into the right atrium. It begins on the backside of the heart, in between the left atrium, and left ventricle; it begi ...

ventricular septal defect A ventricular septal defect (VSD) is a defect in the ventricular septum, the wall dividing the left and right ventricles of the heart. It's a common heart problem present at birth ( congenital heart defect). The extent of the opening may vary ...

, atrioventricular septal (endocardial cushion) defect, and common

atrioventricular canal Atrioventricular (having to do with an Atrium (anatomy), atrium and Ventricle (heart), ventricle) can refer to: *Left atrioventricular opening *Atrioventricular fistula *Atrioventricular node *Atrioventricular valves, the mitral valve and tricuspid ...

. Rarely,

asplenia Asplenia is the absence of normal spleen function and is associated with some serious infection risks. Hyposplenism is the condition of reduced ('hypo-'), but not absent, splenic functioning. ''Functional'' asplenia occurs when splenic tissue is ...

polysplenia Polysplenia is a congenital disease manifested by multiple small accessory spleens, rather than a single, full-sized, normal spleen. Polysplenia sometimes occurs alone, but it is often accompanied by other developmental abnormalities. Conditions ...

has been reported in these patients. In the adult, cor triatriatum is frequently an isolated finding.

Cause

Cor triatriatum dextrum is extremely rare and results from the complete persistence of the right sinus valve of the embryonic heart. The membrane divides the right atrium into a proximal (upper) and a distal (lower) chamber. The upper chamber receives the

venous blood Venous blood is deoxygenated blood which travels from the peripheral blood vessels, through the venous system into the right atrium of the heart. Deoxygenated blood is then pumped by the right ventricle to the lungs via the pulmonary artery whi ...

from both

vena cavae In anatomy, the ''venae cavae'' (; ''vena cava'' ; ) are two large veins (great vessels) that return deoxygenated blood from the body into the heart. In humans they are the superior vena cava and the inferior vena cava, and both empty into the ...

and the lower chamber is in contact with the

tricuspid valve The tricuspid valve, or right atrioventricular valve, is on the right dorsal side of the mammalian heart, at the superior portion of the right ventricle. The function of the valve is to allow blood to flow from the right atrium to the right vent ...

and the right atrial appendage.

Mechanism and Symptoms

The natural history of this defect depends on the size of the communicating orifice between the upper and lower atrial chambers. If the communicating orifice is small, the patient is critically ill and may succumb at a young age (usually during infancy) to congestive

heart failure Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome caused by an impairment in the heart's ability to Cardiac cycle, fill with and pump blood. Although symptoms vary based on which side of the heart is affected, HF ...

and

pulmonary edema Pulmonary edema (British English: oedema), also known as pulmonary congestion, is excessive fluid accumulation in the tissue or air spaces (usually alveoli) of the lungs. This leads to impaired gas exchange, most often leading to shortness ...

. If the connection is larger, patients may present in childhood or young adulthood with a clinical picture similar to that of

mitral stenosis Mitral stenosis is a valvular heart disease characterized by the Stenosis, narrowing of the opening of the mitral valve of the heart. It is almost always caused by Rheumatic Heart Disease, rheumatic valvular heart disease. Normally, the mitral va ...

. As the malformed membrane calcifies with age, thus further narrowing such opening, decreased

cardiac output In cardiac physiology, cardiac output (CO), also known as heart output and often denoted by the symbols Q, \dot Q, or \dot Q_ , edited by Catherine E. Williamson, Phillip Bennett is the volumetric flow rate of the heart's pumping output: tha ...

produces features of pulmonary venous

hypertension Hypertension, also known as high blood pressure, is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not cause symptoms i ...

and right heart failure—including symptoms of

dyspnea Shortness of breath (SOB), known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing discomfort that ...

and

orthopnea Orthopnea or orthopnoea is shortness of breath (dyspnea) that occurs when lying flat, causing the person to have to sleep propped up in bed or sitting in a chair. It is commonly seen as a late manifestation of heart failure, resulting from fluid ...

, easy fatigability,

palpitations Palpitations occur when a person becomes aware of their heartbeat. The heartbeat may feel hard, fast, or uneven in their chest. Symptoms include a very fast or irregular heartbeat. Palpitations are a sensory symptom. They are often described as ...

and

shortness of breath Shortness of breath (SOB), known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing discomfort that con ...

, among others. Cor triatriatum may also be an incidental finding when it is nonobstructive.

Diagnosis

Primarily diagnosed with imaging, such as

echocardiogram Echocardiography, also known as cardiac ultrasound, is the use of ultrasound to examine the heart. It is a type of medical imaging, using standard ultrasound or Doppler ultrasound. The visual image formed using this technique is called an echo ...

(ultrasound of the heart), CT, and/or

MRI Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to generate pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and rad ...

Treatment

Treatment of Cor triatriatum varies among cases and is dependent upon presentation of symptoms—incidental finding of the condition in

asymptomatic Asymptomatic (or clinically silent) is an adjective categorising the medical conditions (i.e., injuries or diseases) that patients carry but without experiencing their symptoms, despite an explicit diagnosis (e.g., a positive medical test). P ...

patients does not typically require immediate medical management, but for those exhibiting

and

pulmonary congestion The lungs are the primary organs of the respiratory system in many animals, including humans. In mammals and most other tetrapods, two lungs are located near the backbone on either side of the heart. Their function in the respiratory syste ...

, surgical intervention is required. The disorder can be treated surgically by removing the membrane dividing the atrium. The

surgery Surgery is a medical specialty that uses manual and instrumental techniques to diagnose or treat pathological conditions (e.g., trauma, disease, injury, malignancy), to alter bodily functions (e.g., malabsorption created by bariatric surgery s ...

, which usually occurs by first excising the diaphragm and then closing the

atrial septum The interatrial septum is the wall of tissue that separates the right and left atria of the heart. Structure The interatrial septum is a that lies between the left atrium and right atrium of the human heart. The interatrial septum lies at angle ...

, has a reported survival of 90% at five years, with almost all patients becoming

post-surgery.

References

Sources

* * * * * * * * * * * *

External links

* {{Congenital malformations and deformations of circulatory system Congenital heart defects Cardiology