We searched PubMed for articles in English with the term “atrial septal defect” in the title from Jan 1, 2003, to April 24, 2013. We also searched for multiple combinations of the terms “atrial septal defect” AND relevant terms such as “pregnancy”, “pulmonary hypertension”, “Eisenmenger syndrome”, “arrhythmias”, “outcomes”, “surgery”, “device”, “percutaneous”, “gene”. We also retrieved relevant articles from the reference list of key articles. Whenever possible, we prioritised articles
SeminarAtrial septal defects
Introduction
Atrial septal defects belong to a group of congenital cardiac anomalies that allow communication between the left and right sides of the heart. These interatrial communications include several distinct defects in the cardiac terminations of the systemic and pulmonary veins (sinus venosus and coronary sinus defects) and in the interatrial septum (atrial septal defects). Patent foramen ovale is a normal communication during fetal life and is commonly encountered after birth. In this Seminar we review the anatomy, pathophysiology, and recent developments in the management of interatrial communications in children and adults. We focus on haemodynamically important atrial septal defects in patients who do not have major associated congenital cardiac anomalies.
Section snippets
Incidence and causes
Defects of the atrial septum are the third most common type of congenital heart disease, with an estimated incidence of 56 per 100 000 livebirths.1 With improved recognition of clinically silent defects by echocardiography, recent estimates are about 100 per 100 000 livebirths.2 About 65–70% of patients with a secundum defect, roughly 50% of those with a primum atrial septal defect, and 40–50% of those with a sinus venosus defect are female.
Most atrial septal defects are sporadic with no
Developmental considerations
Knowledge of the development of the atrial septum and its neighbouring systemic and pulmonary veins forms the basis for the classification of interatrial communications. Atrial septation involves septum primum, septum secundum, and the atrioventricular canal septum. Figure 1 shows key elements of atrial septation.39, 40, 41, 42, 43
Normal development of the atrial septum results in formation of the fossa ovalis, which includes two anatomical elements: first, muscular boundaries contributed by
Patent foramen ovale
Patent foramen ovale is the space between a well developed (valve-competent) septum primum and a normally formed septum secundum (figure 3). It is a normal interatrial communication during fetal life, characterised by streaming of oxygen-rich flow from the ductus venosus and, to a lesser extent, from the inferior vena cava, through the foramen ovale to the left atrium. After birth, left atrial pressure normally exceeds right atrial pressure and, septum primum apposes septum secundum, and the
Defect size
The natural history of isolated atrial communications varies according to anatomical type, size, and patient-specific factors. Sinus venosus and primum defects are usually associated with a haemodynamically significant shunt, do not decrease in size, and usually need surgical closure. By contrast, the natural history of secundum defects vary widely. Spontaneous closure occurs frequently in young patients with small defects. Hanslik and colleagues,61 in a study of 200 consecutive patients
Clinical
On physical examination, most young patients with an isolated secundum atrial septal defect are acyanotic and can have few or no symptoms. The precordium is often hyperdynamic to palpation. The second heart sound is characteristically widely split without respiratory variations. The intensity of the pulmonary component of the second heart sound (P2) corresponds to the pulmonary artery pressure with a loud sound indicating pulmonary hypertension. A soft systolic ejection murmur is usually heard
Indications and contraindication for defect closure
Closure of an atrial septal defect is indicated in the presence of a haemodynamically significant shunt that causes enlargement of right heart structures, irrespective of symptoms (class I, level of evidence B).86, 87 Before the advent of non-invasive imaging, a haemodynamically significant shunt was classically defined by a pulmonary-to-systemic flow ratio greater than 1·5, which is the magnitude of shunt needed for a right-sided volume overload and pulmonary overcirculation. Other indications
Unrepaired defects
An isolated atrial septal defect can occasionally go undiagnosed for decades. It accounts for 25–30% of congenital heart disease cases diagnosed in adulthood.130 Although many young adults have no subjective symptoms, exercise testing usually unveils subnormal exercise capacity.131 With advancing age, however, overt symptoms of fatigue, exercise intolerance, shortness of breath, palpitations, and manifestations of heart failure become prevalent and survival rate is reduced.77 Onset of ischaemic
Search strategy and selection criteria
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