History

Fact Explanation
None Most patients are asymptomatic.
Recurrent chest infections Due to pulmonary congestion.
Paroxysmal nocturnal dyspnea, Orthopnea, and shortness of breath on exertion These symptoms occur with late development of heart failure.
Arrhythmia Although uncommon in pediatric patients, evidence has shown patients with ASD have a considerable rate of sinus arrhythmia. Furthermore, untreated ASD can cause atrial dilatation and atrial arrhythmia in later life (around the age of 40) [2]
Cyanosis (both peripheral and central) If the ASD remains untreated for a long time, the right ventricle hypertrophies, causing pulmonary hypertension. Once this occurs, the usual shunt through the ASD reverses, and blood flows from right to left. This is called Eisenmenger's syndrome.
Clubbing Same as above.
References
  1. FINLEY J P, S T NUGENT, W HELLENBRAND, M CRAIG, and D A GILLIS. Mar 1989. Sinus arrhythmia in children with atrial septal defect: an analysis of heart rate variability before and after surgical repair. Br Heart J. 61(3): 280–284.
  2. M A GATZOULIS, M A FREEMAN, S C SIU, G D WEBB, L HARRIS. Atrial arrhythmia after surgical closure of atrial septal defects in adults. N Engl J Med. 1999; 340: 839–846.

Examination

Fact Explanation
Mild left precordial bulge on inspection of the precordium Left parasternal lift due to right ventricular dilatation. [1] This occurs with increased precordial activity and suggests cardiac enlargement. Such bulges can often best be appreciated by having the child lay supine with the examiner looking up from the child’s foot end.
Left parasternal heave The right atrium hypertrophies and the heart is pushed towards the precordium; thus the left parasternal heave can be palpated.
A fixed and widely split second heart sound Normally, the duration of right ventricular ejection varies with respiration, with inspiration increased right ventricular volume delays the closure of the pulmonary valve, increasing the split of second heart sound. With an ASD, right ventricular diastolic volume is constantly increased and the ejection time is prolonged throughout all phases of respiration. [2]
An ejection systolic murmur best heard in the left sternal edge. The left to right shunt increases the right ventricular output. This causes increased blood flow through the right ventricular outflow tract resulting in a flow murmur.
Features of right sided heart failure. Eg: Increased Jugular venous pressure (JVP), tender hepatomegaly and peripheral edema With the development of right sided heart failure the right ventricle and the right atrium fails to adapt and function as an effective pump. This results in back flow of blood causing increased JVP. Hepatic congestion causes tender hepatomegaly.
Clinical features of other co-existing valvular anomalies may be detected. Eg: mitral valve abnormalities, and aortic valve abnormalities. [3] The finding of such co-existent valvular anomalies would be in favour of Ostium primum ASD (OP-ASD), as opposed to Ostium secundum ASD (OS-ASD); however neither can be confidently confirmed clinically.
References
  1. BROWN J H and FONG E W, MD. Case Based Pediatrics For Medical Students and Residents. Department of Pediatrics, University of Hawaii John A. Burns School of Medicine. March 2003
  2. NELSON. 2011. Sinus Venosus Atrial Septal Defect. Nelson textbook of pediatrics. edited by Robert M. Kliegman. Bonita F. Stanton. Joseph W. St. Geme III. Nina F. Schor. Richard E. Behrman. Elsevier. chapter 420.3
  3. R S LAPPEN, A J MUSTER, F S IDRISS, TW RIGGS, M ILBAWI, M H PAUL, S BHARATI, M LEV. Masked subaortic stenosis in ostium primum atrial septal defect: recognition and treatment. Am J Cardiol. 1983 Aug;52(3):336-40

Differential Diagnoses

Fact Explanation
ASD coronary sinus This is also a malformation of the common wall between the superior vena cava (SVC) and the right-sided pulmonary veins and results in an interatrial communication. [1]
ASD sinus venosus When an associated ASD is present with partial anomalous pulmonary venous return, it is generally of the sinus venosus type, or less frequently, of the secundum type. [2]
Atrioventricular septal defects Deficiency or the absence of the atrio-ventricular septum. [3]
Partial Anomalous Pulmonary Venous Circulation When an ASD is detected by echocardiography, one must always search for associated partial anomalous pulmonary venous return. The history, physical signs, and electrocardiographic and CXR findings are indistinguishable from those of an isolated OS ASD.
Pulmonary stenosis (PS) (both infundibular PS and Valvar PS) PS causes turbulent blood flow across the Pulmonary valve causing an ejection systolic murmur.
References
  1. ROESS D. PASCOE, JAE K. CAROLE A. WARNES, GORDON K. DANIELSON, JAMIL TAJIK A, JAMES B. SEWARD. Diagnosis of Sinus Venosus Atrial Septal Defect With Transesophageal Echocardiography. Circulation.1996; 94: 1049-1055. http://circ.ahajournals.org/content/94/5/1049.full
  2. NELSON. 2011. Sinus Venosus Atrial Septal Defect. Nelson textbook of pediatrics. edited by Robert M. Kliegman. Bonita F. Stanton. Joseph W. St. Geme III. Nina F. Schor. Richard E. Behrman. Elsevier. chapter 420.4
  3. MEISNER H, GUENTHER T. Atrioventricular Septal Defect. Pediatric Cardiology, July 1998, Volume 19, Issue 4, pp 276-281 http://link.springer.com/article/10.1007%2Fs002469900309?LI=true

Investigations - for Diagnosis

Fact Explanation
Chest X-ray Enlarged right ventricle and atrium is seen depending on the size of the ASD. The lateral view demonstrates the enlargement of the right ventricle better than the antero-posterior view [1]. Enlarged pulmonary vessels and increased pulmonary vascular markings may be seen due to increased pulmonary blood flow. In some patients, the CXR may be completely normal. [2,3]
Electrocardiogram (EKG) Left axis deviation is seen in OP-ASD; whereas right axis deviation and partial right bundle branch block are seen in OS-ASD. The RSR' pattern in V1 and in other right ventricular leads is also detected in ASD.
2D Echo-cardiogram 2D Echo cardiogram, when combined with color Doppler, demonstrates the defect in the interatrial septum. 2D Echo-cardiogram demonstrates the features of right ventricular overload, including increased end-diastolic right ventricular dimensions. This will enable to detect other co-existing anomalies as well.
Diagnostic cardiac catheterization Although invasive and has a significant radiation exposure risk cardiac catheterisation confirms the presence of the defect and allows measurement of the shunt ratio and pulmonary pressure and resistance.
References
  1. NELSON. 2011. Sinus Venosus Atrial Septal Defect. Nelson textbook of pediatrics. edited by Robert M. Kliegman. Bonita F. Stanton. Joseph W. St. Geme III. Nina F. Schor. Richard E. Behrman. Elsevier. chapter 420.2
  2. EGEBLAD H, J BERNING, F EFSEN, A WENNEVOLD. Non-invasive diagnosis in clinically suspected atrial septal defect of secundum or sinus venosus type: value of combining chest x-ray, phonocardiography, and M-mode echocardiography. Br Heart J. 1980; 44: 317–321.
  3. M READING. Chest x-ray quiz: an atrial septal defect. Aust Crit Care. 2000; 13: 96–119.

Investigations - Fitness for Management

Fact Explanation
Chest X Ray (CXR) Features of heart failure will be evident on CXR. Eg: Pulmonary congestion, Kerley B-lines, Cardiomegaly, Fluid in the fissures.
Cardiac catheterization This helps in detecting the degree of pulmonary hypertension, and the direction of blood flow through the ASD and aids in deciding whether or not to close the shunt. Severe pulmonary hypertension and shunt reversal are usually contraindications for shunt closure. [1]
References
  1. GARY WEBB, MICHAEL A. GATZOULIS. Atrial Septal Defects in the Adult, Recent Progress and Overview. Circulation. 2006; 114: 1645-1653 http://circ.ahajournals.org/content/114/15/1645.full

Investigations - Followup

Fact Explanation
Post-operative 2D Echo-cardiogram This will confirm the complete closure of the ASD six months after the surgery, but this need not be repeated regularly. [1]
References
  1. PATRICK A. CALVERT, ANDREW A. KLEIN. Anaesthesia for percutaneous closure of atrial septal defects. Contin Educ Anaesth Crit Care Pain (2008) 8 (1): 16-20. http://ceaccp.oxfordjournals.org/content/8/1/16.full

Investigations - Screening/Staging

Fact Explanation
Prenatal Ultra Sound Scan (USS) Routine anomaly scan provides the four chamber view of the fetal heart. Although USS is operator dependent, presence of associated other malformations significantly increases the prenatal detection rate. [1]
References
  1. GARNE E, STOLL C, CLEMENTI M. Evaluation of prenatal diagnosis of congenital heart diseases by ultrasound: experience from 20 European registries. 12 DEC 2002. Volume 17, Issue 5, pages 386–391

Management - General Measures

Fact Explanation
Pharmacological management of Heart failure [1] If heart failure is present it is an added risk to undergo general anesthesia and associated with a significant complication rate. [2]
Treatment of respiratory tract infections This is an independent risk factor for the development of perioperative respiratory adverse events. [3,4]
Management of arrhythmia Arrhythmia should be treated preoperatively. [5]
References
  1. MASUTANI S, SENZAKI H. Left ventricular function in adult patients with atrial septal defect: implication for development of heart failure after transcatheter closure. J Card Fail. 2011 Nov;17(11):957-63. http://www.ncbi.nlm.nih.gov/pubmed/22041334
  2. MURPHY TW, SMITH JH, RANGER MR, HAYNES SR. General anesthesia for children with severe heart failure. Pediatr Cardiol. 2011 Feb;32(2):139-44. http://www.ncbi.nlm.nih.gov/pubmed/21140261
  3. BORDET F, ALLAOUCHICHE B, LANSIAUX S, COMBET S, POUYAU A, TAYLOR P, BONNARD C, CHASSARD D. Risk factors for airway complications during general anaesthesia in paediatric patients. Paediatr Anaesth. 2002 Nov; 12(9):762-9.
  4. vON UNGERN-STERNBERG BS, BODA K, CHAMBERS NA, REBMANN C, JOHNSON C, SLY PD, HABRE W. Risk assessment for respiratory complications in paediatric anaesthesia: a prospective cohort study. Lancet. 2010 Sep 4; 376(9743):773-83
  5. BERNARD M. KARNATH, Preoperative Cardiac Risk Assessment. Am Fam Physician. 2002 Nov 15;66(10):1889-1897 http://www.aafp.org/afp/2002/1115/p1889.html

Management - Specific Treatments

Fact Explanation
Open surgical closure Large defects are best closed with open surgery.
Device closure (Eg: Amplatzer device) A small defect with minimal left to right shunt is best for device closure. [1]
References
  1. MICHAEL VOGEL, FELIX BERGER, INGO DAHNERT, PETER EWERT, PETER E LANGE. Treatment of atrial septal defects in symptomatic children aged less than 2 years of age using the Amplatzer septal occluder. Cardiology in the Young / Volume 10 / Issue 05 / September 2000, pp 534-537