Interatrial Defect - Erler Zimmer 3D anatomy Series MP2032

This dissection model highlighting an Interatrial Defect is part of the exclusive Monash 3D anatomy series, a comprehensive series of human dissections reproduced with ultra-high resolution color 3D printing.

Clinical Story.

A 10-year-old girl with a known congenital heart was admitted for surgery due to the recent onset of cyanosis and heart failure. On examination, she was breathless with a blood pressure of 105/60 mm/Hg and a heart rate of 140/min. There was a loud heart murmur in the left fourth intercostal space adjacent to the sternum. Jugular venous pressure was elevated and there were bilateral basal pulmonary crepitations but no peripheral edema. At the time of surgery, the defect was repaired; however, death followed sudden postoperative deterioration of unknown cause.

Pathology

The heart is seen from the left side. The left atrium was opened to show a large ovoid defect of 3.5 cm maximum diameter in the interatrial septum. Only a small posteroinferior crescent border of the septum remains. The left ventricle is small and the right ventricle is hypertrophied (see posterior part of the specimen where part of the right postero-lateral wall of the right ventricle was cut to demonstrate the thickened wall). The pulmonary artery, seen to the left of the atrial cavities, is greatly enlarged. The smallest vessel seen lying over the cut end of the pulmonary artery is the aortic arch. The cut edge of an 8-mm-diameter lumen immediately below the cut end of the pulmonary artery is the left auricular appendage.

Further Information.

Interatrial septal defect is usually asymptomatic in early childhood, even if large. Symptoms may not develop until adult life. The onset of symptoms is due to reversal of the initial left-right shunt due to increased right ventricular hypertrophy and pulmonary hypertension. The resulting right-left shunt is associated with cyanosis and dyspnea and eventually leads to congestive heart failure.

There are several types of interatrial septal defects, including:

Secundum - This is the most common type of ASD and occurs in the middle of the wall between the atria (atrial septum). Primum - This defect occurs in the lower part of the atrial septum and may occur with other congenital heart problems.
Venous sinus - This rare defect usually occurs in the upper part of the atrial septum and is often associated with other congenital heart problems.

Coronary sin us - In this rare defect, part of the wall between the coronary sinus-which is part of the heart's venous system-and the left atrium is missing.
It is not known why all interatrial septal defects occur, but some congenital heart defects appear to be familial and sometimes occur with other genetic problems, such as Trisomy 21 (Down syndrome). Certain conditions during pregnancy may increase the risk of having a baby with a heart defect, including acute infections such as rubella infection; drug, tobacco or alcohol use or exposure to certain substances (such as cocaine) during the first trimester of pregnancy; and underlying systemic conditions, such as diabetes or systemic lupus erythematosus.

What advantages does the Monash University anatomical dissection collection offer over plastic models or plastinated human specimens?

• Each body replica has been carefully created from selected patient X-ray data or human cadaver specimens selected by a highly trained team of anatomists at the Monash University Center for Human Anatomy Education to illustrate a range of clinically important areas of anatomy with a quality and fidelity that cannot be achieved with conventional anatomical models-this is real anatomy, not stylized anatomy.
• Each body replica has been rigorously checked by a team of highly trained anatomists at the Center for Human Anatomy Education, Monash University, to ensure the anatomical accuracy of the final product.
• The body replicas are not real human tissue and therefore not subject to any barriers of transportation, import, or use in educational facilities that do not hold an anatomy license. The Monash 3D Anatomy dissection series avoids these and other ethical issues that are raised when dealing with plastinated human remains.