Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ Key Features +++ Essentials of Diagnosis ++ Fixed, widely split S2, right ventricular (RV) heave Grade I–III/VI systolic ejection murmur at the pulmonary area Large shunts cause a diastolic flow murmur at the lower left sternal border (increased flow across the tricuspid valve) ECG shows rsR´ in lead V1 Frequently asymptomatic +++ General Considerations ++ Defined as an opening in the atrial septum permitting the shunting of blood between the atria There are three major types Ostium secundum Ostium primum Sinus venosus Ostium secundum Most common type Occurs in 10% of patients with congenital heart disease Two times more common in females than in males Represents an embryologic deficiency in the septum secundum or too large of a central hole in the septum primum Most often sporadic but may be familial or have a genetic basis (Holt-Oram syndrome) Ostium primum: associated with atrioventricular septal defects Sinus venosus defect: frequently associated with abnormal pulmonary venous return +++ Clinical Findings +++ Symptoms and Signs ++ Most infants and children have no cardiovascular symptoms Exercise intolerance, easy fatigability or, rarely, heart failure in older children Cyanosis does not occur unless RV dysfunction occurs, usually as a result of pulmonary hypertension Peripheral pulses are normal and equal The heart is usually hyperactive, with an RV heave felt best at the mid to lower left sternal border S2 at the pulmonary area is widely split and often fixed In ostium secundum Atrial arrhythmias or pulmonary vascular disease may develop after third decade Irreversible pulmonary hypertension resulting in cyanosis Right heart failure can occur and is a life-limiting process (Eisenmenger syndrome) +++ Diagnosis +++ Imaging ++ Radiographs May show cardiac enlargement In large defects, The main pulmonary artery may be dilated Pulmonary vascular markings may be increased Echocardiography Shows a dilated right atrium and RV Direct visualization of the exact anatomic location and demonstration of a left-to-right shunt through the defect confirms the diagnosis and has eliminated the need for cardiac catheterization prior to surgical or catheter closure of the defect Assessment of all pulmonary veins should be made to rule out associated anomalous pulmonary venous return +++ Diagnostic Procedures ++ Electrocardiography Shows right axis deviation In the right precordial leads, an rsR´ pattern is usually present Atrioventricular block may be seen when a mutation in the cardiac homeobox gene (NKX2-5) is present Cardiac catheterization: rarely needed for diagnostic purposes +++ Treatment ++ Surgical or catheterization closure is generally recommended for symptomatic children with a large atrial level defect and associated right heart dilation In the asymptomatic child with a large hemodynamically significant defect, closure is performed electively at age 1–3 years Most defects are amenable to nonoperative device closure during ... Your Access profile is currently affiliated with [InstitutionA] and is in the process of switching affiliations to [InstitutionB]. Please select how you would like to proceed. Keep the current affiliation with [InstitutionA] and continue with the Access profile sign in process Switch affiliation to [InstitutionB] and continue with the Access profile sign in process Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Error: Incorrect UserName or Password Username Error: Please enter User Name Password Error: Please enter Password Sign in Forgot Password? Forgot Username? Download the Access App: iOS | Android Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free profile for additional features.