Abnormal chest X-ray as seen in a patient of<unk>  Most individuals with a significant<unk>  are diagnosed in utero or in early childhood with the use of ultrasonography or auscultation of the heart sounds during physical examination. Some individuals with an<unk>  have surgical correction of their<unk>  during childhood. The development of signs and symptoms due to an<unk>  are related to the size of the intracardiac shunt. Individuals with a larger shunt tend to present with symptoms at a younger age. Adults with an uncorrected<unk>  present with symptoms of dyspnea on exertion (shortness of breath with minimal exercise), congestive heart failure, or cerebrovascular accident (stroke). They may be noted on routine testing to have an abnormal chest X-ray or an abnormal ECG and may have<unk>  fibrillation. If the<unk>  causes a left-to-right shunt, the pulmonary vasculature in both lungs may appear dilated on chest X-ray, due to the increase in pulmonary blood flow. Physical examination The physical findings in an adult with an<unk>  include those related directly to the intracardiac shunt and those that are secondary to the right heart failure that may be present in these individuals. In unaffected individuals, respiratory variations occur in the splitting of the second heart sound (S2). During respiratory inspiration, the negative intrathoracic pressure causes increased blood return into the right side of the heart. The increased blood volume in the right ventricle causes the pulmonic valve to stay open longer during ventricular systole. This causes a normal delay in the P2 component of S2. During expiration, the positive intrathoracic pressure causes decreased blood return to the right side of the heart. The reduced volume in the right ventricle allows the pulmonic valve to close earlier at the end of ventricular systole, causing P2 to occur earlier. In individuals with an<unk> , a fixed splitting of S2 occurs because the extra blood return during inspiration gets equalized between the left and right<unk> due to the communication that exists between the<unk> in individuals with<unk> . The right ventricle can be thought of as continuously overloaded because of the left-to-right shunt, producing a widely split S2. Because the<unk> are linked via the<unk> , inspiration produces no net pressure change between them, and has no effect on the splitting of S2. Thus, S2 is split to the same degree during inspiration as expiration, and is said to be “fixed”. Echocardiography In transthoracic echocardiography, an<unk>  may be seen on color flow imaging as a jet of blood from the left atrium to the right atrium. If agitated saline is injected into a peripheral vein during echocardiography, small air bubbles can be seen on echocardiographic imaging. Bubbles traveling across an<unk>  may be seen either at rest or during a cough. (Bubbles only flow from right atrium to left atrium if the right<unk>  pressure is greater than left<unk> . Because better visualization of the<unk> is achieved with transesophageal echocardiography, this test may be performed in individuals with a suspected<unk>  which is not visualized on transthoracic imaging. Newer techniques to visualize these defects involve intracardiac imaging with special catheters typically placed in the venous system and advanced to the level of the heart. This type of imaging is becoming more common and involves only mild sedation for the patient typically. If the individual has adequate echocardiographic windows, use of the echocardiogram to measure the cardiac output of the left ventricle and the right ventricle independently is possible. In this way, the shunt fraction can be estimated using echocardiography. Transcranial doppler bubble study A less invasive method for detecting a PFO or other<unk> s than transesophagal ultrasound is transcranial Doppler with bubble contrast. This method reveals the cerebral impact of the<unk>  or PFO. Electrocardiogram The ECG findings in<unk>  vary with the type of defect the individual has. Individuals with<unk> s may have a prolonged PR interval (a first-degree heart block). The prolongation of the PR interval is probably due to the enlargement of the<unk> common in<unk> s and the increased distance due to the defect itself. Both of these can cause an increased distance of internodal conduction from the SA node to the AV node. In addition to the PR prolongation, individuals with a primum<unk>  have a left axis deviation of the QRS complex, while those with a secundum<unk>  have a right axis deviation of the QRS complex. Individuals with a sinus venosus<unk>  exhibit a left axis deviation of the P wave (not the QRS complex). A common finding in the ECG is the presence of incomplete right bundle branch block, which is so characteristic that if it is absent, the diagnosis of<unk>  should be reconsidered. File:UOTW 54 - Ultrasound of the Week 1.ASD with pulmonary embolism resulting in a right-to-left shunting of blood File:UOTW 54 - Ultrasound of the Week 2.ASD with pulmonary embolism resulting in a right-to-left shunting of blood File:UOTW 54 - Ultrasound of the Week 3.ASD with pulmonary embolism resulting in a right-to-left shunting of blood
Atrial septal defect
Atrioventricular septal defect
Heart septal defect
Ventricular septal defect
Aortopulmonary septal defect
Tricuspid atresia
Persistent truncus arteriosus
Double inlet left ventricle