Edit concept Question Editor Create issue ticket

Atrial Septal Defect

ASD

Atrial septal defect (ASD) is a congenital malformation characterized by a communication between the atrial chambers of the heart.


Presentation

History

ASDs are usually asymptomatic in infancy and childhood. In most cases, the symptoms manifest by the third decade of life. Due to paucity of symptoms, most times ASDs go undetected in childhood. Most cases of ASD, even moderate to large ASDs, do not manifest symptoms during childhood. Some cases of ASD may show common symptoms like fatigue, dyspnoea on exertion, exercise intolerance and frequent respiratory infections during childhood. In childhood, an accidental finding of a heart murmur on routine examination or an abnormal finding on chest radiograph or echocardiogram (ECG) may help to diagnose ASD.

Signs and symptoms

The signs and symptoms are dependent on various other factors like pulmonary arterial hypertension, atrial arrhythmias and other ASD complications. As age progresses, the heart musculature too ages leading to manifestation of signs and symptoms. In adults, common symptoms include shortness of breath, exhaustion, palpitations, atrial arrhythmia, syncope and stroke.

Complications

These include infective endocarditis, hypertrophy of the right atrium and the right ventricle, pulmonary arterial hypertension, paradoxical embolization, stroke, cardiac failure especially right side failure, arrhythmias, palpitations secondary to supra-ventricular arrhythmias, or recurrent respiratory infections. In rare cases, it may lead to reversal of the shunting that is from right to left (Eisenmenger syndrome).

Fatigue
  • We present the case of a 44-year-old methamphetamine abuser who had a 3-month history of worsening fatigue and near-syncope. She had elevated cardiac enzyme levels and right-sided heart strain.[ncbi.nlm.nih.gov]
  • Adults and, rarely, adolescents may present with exercise intolerance, dyspnea, fatigue, and atrial arrhythmias. A soft midsystolic murmur at the upper left sternal border with wide and fixed splitting of the 2nd heart sound (S2) is common.[msdmanuals.com]
  • Children with symptomatic ASD s may fatigue easily, have rapid breathing with shortness of breath, and grow slowly. Our program has been tracking atrial septal defect among live births in select counties since 2005 and gradually expanding statewide.[health.state.mn.us]
  • Some cases of ASD may show common symptoms like fatigue, dyspnoea on exertion, exercise intolerance and frequent respiratory infections during childhood.[symptoma.com]
  • If the defect is large, however, symptoms may include fatigue, sweating, shortness of breath, or rapid breathing. In women, an ASD may be first diagnosed during pregnancy, when the heart's output increases.[uwhealth.org]
Down Syndrome
  • It can be ostium primum, especially in individuals with Down's syndromes, usually asymptomatic, sometimes resulting in a paradoxical embolis, which can potentially lead to a stroke.[khanacademy.org]
  • McMahon, Congenital Heart Disease in Down Syndrome, Advances in Research on Down Syndrome, 10.5772/intechopen.71060, (2018).[doi.org]
  • Risk Factors Factors that increase the risk of having a child with an atrial septal defect include: Smoking by the mother during pregnancy Down syndrome Symptoms Symptoms of atrial septal defect include: Tiring easily during activity Sweating Rapid breathing[semc.org]
  • syndrome – patients with Down syndrome have higher rates of ASDs, especially a particular type that involves the ventricular wall. [28] As many as one half of Down syndrome patients have some type of septal defect. [28] Ebstein's anomaly [29] – about[en.wikipedia.org]
Pulmonary Valve Stenosis
  • It is reported to be associated with cardiovascular disorders including atrial septal defect, anomalous pulmonary venous return, aortopulmonary window, pulmonary valve stenosis, mitral valve prolapse, tetralogy of Fallot, truncus arteriosus, and patent[ncbi.nlm.nih.gov]
  • Typically, pulmonary valve stenosis has an associated systolic ejection click, the murmur of pulmonary valve stenosis tends to be more harsh than the systolic murmur associated with an ASD, and diastole is quiet.[clinicaladvisor.com]
  • Pulmonary valve stenosis. This is the most common valve defect in newborns. Babies with severe cases often have strained right ventricles. Your doctor can usually treat it with a catheter procedure.[webmd.com]
  • valve stenosis Q22.2 Congenital pulmonary valve insufficiency Q22.3 Other congenital malformations of pulmonary valve Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.[icd10data.com]
  • It should be possible to identify double-chambered RV echocardiographically, although limited visualisation may make it hard to distinguish between a jet through a VSD, the subinfundibular stenosis and possible infundibular or pulmonary valve stenosis[dx.doi.org]
Hemoptysis
  • Erythrocytosis • The use of air bubble filters on all intravenous lines to prevent air embolism with flushes and infusions • Avoiding routine phlebotomy by monitoring blood count and symptoms • Observation for anemia and thrombocytopenia • Management of hemoptysis[emoryhealthcare.org]
Heart Disease
  • Author information 1 1Department of Pediatric Cardiology and Nephrology,Graduate School of Medical Science,Kyoto Prefectural University of Medicine,Kyoto,Japan. 2 2Pediatric Heart Disease & Adult Congenital Heart Disease Center,Showa University Hospital[ncbi.nlm.nih.gov]
  • The UAB Congenital Heart Disease Program offers the most advanced care for structural heart disease, which often requires lifetime monitoring and care.[uabmedicine.org]
  • Ebstein's anomaly is a rare congenital heart disorder, accounting for 1% of all cases of congenital heart disease.[ncbi.nlm.nih.gov]
  • An isolated atrial septal defect (ASD) can occasionally go unrecognized for decades and accounts for 25-30% of congenital heart disease cases diagnosed in adulthood.[ncbi.nlm.nih.gov]
Heart Murmur
  • At the initial visit, he presented with recurrent lower respiratory infection, heart murmur, psychomotor retardation, inverted nipples, and cerebellar atrophy.[ncbi.nlm.nih.gov]
  • A patient with an ASD often comes to attention due to the presence of a heart murmur. This simply refers to the sound that blood is making as it flows through the heart.[pediatricheartspecialists.com]
  • The defect is often detected by a heart murmur or a noticeable delay in the closure of the pulmonary valve. If the defect is large, however, symptoms may include fatigue, sweating, shortness of breath, or rapid breathing.[uwhealth.org]
  • In childhood, heart murmurs typically are normal findings. In fact, the murmur that is associated with an ASD may sound like a normal heart murmur.[clinicaladvisor.com]
  • Your child's doctor may have heard a heart murmur when listening to your child's heart with a stethoscope. The heart murmur is from the abnormal flow of blood through the heart. Your child may need to see a pediatric cardiologist for a diagnosis.[stlouischildrens.org]
Mitral Valve Prolapse
  • It is reported to be associated with cardiovascular disorders including atrial septal defect, anomalous pulmonary venous return, aortopulmonary window, pulmonary valve stenosis, mitral valve prolapse, tetralogy of Fallot, truncus arteriosus, and patent[ncbi.nlm.nih.gov]
  • The outlook in the syndrome of mitral valve prolapse may be less benign than is usually believed.[ncbi.nlm.nih.gov]
  • valve prolapse. 9 21 It has been suggested that the redundancy of the atrial septum and the mitral (and/or tricuspid) valve may be secondary to a similar inherent deficiency in the connective tissue. 8 In the present study, a mitral valve prolapse was[ahajournals.org]
  • valve prolapse Lutembacher syndrome anomalous pulmonary venous return (especially with sinus venosus defects) total anomalous pulmonary venous return (TAPVR) partial anomalous pulmonary venous return (PAPVR) A patent foramen ovale (PFO) is a form of[radiopaedia.org]
  • The association with mitral valve prolapse is interesting, as it has been suggested that both abnormalities reflect redundancy of endocardial tissue. 12 Up to 28% of patients who suffer from migraines with an aura have an ASA.[appliedradiology.com]
Systolic Murmur
  • The history of the present illness included paroxysmal atrial flutter which was untreated, but she had not developed heart failure.At admission, auscultation of the chest revealed moist rales and systolic murmur but did not clearly show the presence of[ncbi.nlm.nih.gov]
  • Clinically, the patient had typical features of PE with chest computed tomography (CT) revealing a Haller index of 4.4 and a grade 2 systolic murmur being heard the loudest at the 2nd-3rd intercostal space, abutting the left sternal border.[ncbi.nlm.nih.gov]
  • Murmurs • Pulmonary ejection systolic murmur – Increased pulmonary flow • Tricuspid murmur – is heard over left sternal edge louder on inspiration • Graham-Steell murmur – of pulmonary regurgitation if pulmonary hypertension 13. • Late systolic murmur[slideshare.net]
  • There is further turbulent flow into the pulmonary artery causing the systolic murmur.[easyauscultation.com]
  • Chest auscultation classically reveals an ejection systolic murmur heard at the left upper sternal border, attributed to increased flow across the pulmonary valve rather than blood shunting across the defect itself 7 .[radiopaedia.org]
Cardiac Signs and Symptoms
Psychomotor Retardation
  • At the initial visit, he presented with recurrent lower respiratory infection, heart murmur, psychomotor retardation, inverted nipples, and cerebellar atrophy.[ncbi.nlm.nih.gov]

Workup

On physical examination, there is presence of right ventricular pulsation due to higher diastolic filling and increased stroke volume. The pulmonary artery is dilated and hence, its pulsations are palpable. S2 is widely split and fixed in most cases of ASD.

Moderate to large, left to right shunt produces a systolic ejection murmur in the second inter-costal space at the upper left sternal border. Increased flow across the tricuspid valve causes a mid-diastolic rumbling murmur in cases with large left to right shunt.

An apical systolic murmur of mitral regurgitation may be present in cases with primum ASD. In cases of severe pulmonary arterial hypertension, atrial shunt reversal (Eisenmenger syndrome) may occur which leads to cyanosis and clubbing.

Electrocardiography

In ostium secundum ASD, the electrocardiogram shows right axis deviation and right bundle branch block. In ostium primum ASD, it shows left axis deviation and right bundle branch block. In sinus venosus ASD, it shows left axis deviation and a negative P wave in lead III.

Imaging

The chest X-ray shows a dilated pulmonary artery, prominent pulmonary vascular markings, and enlarged right atrial and ventricular chambers in patients with significant left to right shunting.

Doppler echocardiography and contrast echocardiography provide details of the defect. It has been found that Doppler echocardiography may be inaccurate often in estimating the pulmonary artery pressure and cardiac output while evaluating patients with pulmonary hypertension as sequelae to ASD [4]. Transthoracic echocardiography (TTE) is a non-invasive imaging procedure for ostium primum and ostium secundum ASDs. For sinus venosus, the imaging procedure of choice is transesophageal echocardiography (TEE).

Use of non-invasive tools like echocardiography, right heart catheterization (RHC) and tissue Doppler imaging (TDI) for detecting pulmonary hypertension and right heart dysfunction are absolutely essential [5]. MRI and CT can be useful in the evaluation of patients with ASDs. Cardiac catheterization will aid in the diagnosis when the non-invasive techniques are not conclusive of the diagnosis [6].

Left Axis Deviation
  • When an ostium primum atrial defect is present, the ECG reveals left axis deviation. When an ostium secundum atrial septal defect is present, the ECG reveals right axis deviation.[healio.com]
  • In ostium primum ASD, it shows left axis deviation and right bundle branch block. In sinus venosus ASD, it shows left axis deviation and a negative P wave in lead III.[symptoma.com]
  • ECG Right axis deviation in 85% of cases Left axis deviation and prolonged PR interval seen in ostium primum Right Atrial enlargement 16.[slideshare.net]
  • axis deviation characteristic of ostium primum defects and anatomical distortion of the left bundle branch fascicles associated first degree AV block right axis deviation suggests ostium secundum defect low atrial ectopic rhythms negative P wave polarity[radiopaedia.org]
Right Bundle Branch Block
  • The impact of incomplete right bundle branch block (IRBBB) and ASD diameter (  5 and KEYWORDS: Crochetage on R wave; Inferior leads; Pediatric; Secundum atrial septal defect[ncbi.nlm.nih.gov]
  • EMAIL PRINT SAVE EMAIL SAVE An atrial septal defect should show a right bundle branch block, or RBBB ― sometimes incomplete ― on ECG. This is partially due to the right ventricular volume and pressure overload that occurs.[healio.com]
  • Electrocardiography In ostium secundum ASD, the electrocardiogram shows right axis deviation and right bundle branch block. In ostium primum ASD, it shows left axis deviation and right bundle branch block.[symptoma.com]
Incomplete Right Bundle Branch Block
  • The impact of incomplete right bundle branch block (IRBBB) and ASD diameter (  5 and KEYWORDS: Crochetage on R wave; Inferior leads; Pediatric; Secundum atrial septal defect[ncbi.nlm.nih.gov]
  • ECG incomplete right bundle branch block (RBBB morphology with QRS duration between 110-120 ms) increased specificity with crochetage sign in the inferior (II, III, aVF) leads right precordial (V1-3) "defective T waves" describes biphasic morphology,[radiopaedia.org]
  • Investigations ECG ECG may be normal in infants and children with small shunts Typical findings include a tall P wave indicating right atrial enlargement, incomplete right bundle branch block pattern (rsR' in V1), and right axis deviation.[patient.info]
  • 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 ASD should be reconsidered.[en.wikipedia.org]
  • Voltage evidence of right ventricular hypertrophy may be seen in all ASDs, often in the form of “incompleteright bundle-branch block, with the more extreme forms usually found in patients with pulmonary hypertension.[circ.ahajournals.org]
Third Degree Atrioventricular Block
  • A new third degree atrioventricular block occurred in 1 patient who recovered 1 week later. During the follow-up period, we found no recurrence, no thrombosis, no device embolization, no device failure, and no cases of death.[ncbi.nlm.nih.gov]
Right Ventricular Hypertrophy
  • If a significant shunt is present, ECG may show right axis deviation, right ventricular hypertrophy, or right ventricular conduction delay (an rSR ′ pattern in V1with a tall R ′ ).[merckmanuals.com]
  • Mild right ventricular hypertrophy Inverted P waves in Sinous Venosus type Right Bundle Branch Block is seen which is partial or complete 17.[slideshare.net]
  • Right ventricular hypertrophy may be seen. ECG: May show some right bundle branch block and right axis deviation.[myvmc.com]
  • Most patients have varying degrees of right ventricular hypertrophy on electrocardiography. Other findings on electrocardiography predict the likely location of the defect in the atrial septum.[clinicaladvisor.com]
  • First-degree AV block, left-axis deviation, voltage evidence of right ventricular hypertrophy. D, Eisenmenger ASD.[circ.ahajournals.org]
Biventricular Hypertrophy
  • Transthoracic echocardiography confirmed the location of the ASD, with a left-to-right cardiac shunt, moderate to severe tricuspid insufficiency, moderate pulmonary hypertension (60 mm Hg), four chamber dilatation and biventricular hypertrophy.[ncbi.nlm.nih.gov]
Biventricular Hypertrophy
  • Transthoracic echocardiography confirmed the location of the ASD, with a left-to-right cardiac shunt, moderate to severe tricuspid insufficiency, moderate pulmonary hypertension (60 mm Hg), four chamber dilatation and biventricular hypertrophy.[ncbi.nlm.nih.gov]

Treatment

Small ASDs may close spontaneously. Larger defects require surgical intervention. Medical therapy can be used to treat the symptoms of ASD, but surgical intervention is a must for the closure of the defect. The operation for closure of Sinus venosus ASD has low mortality as well as low morbidity with improvement occurring irrespective of the age at which the surgery is performed [7].

Transcatheter closure of ASD secundum defect using Occlutech Figull-N occlude is safer and more efficient in severely symptomatic patients less than 2 years of age [8].

Prognosis

ASDs with small defects may close spontaneously in some children. Larger defects require surgical intervention. Medical therapy can be used to treat the symptoms of ASD, but surgical intervention is a must for the closure of the defect. The operation for closure of Sinus venosus ASD has low mortality as well as low morbidity with improvement occurring irrespective of the age at which the surgery is performed [7].

Transcatheter closure of ASD secundum defect using Occlutech Figulla-N occlude is safer and more efficient in severely symptomatic patients less than 2 years of age [8].

If left untreated, there is a high risk of developing atrial arrhythmias and morbidity at later ages, making closure of defects with significant hemodynamic changes a necessary choice [9].

Chance of survival of patients with untreated ASD beyond third or fourth decade of their life is less than 50%. Given risks associated with surgery, it is advisable to repair the defect as early as possible to avert hemodynamic sequelae [10].

Etiology

ASDs mostly occur due to genetic mutations. Along with a genetic predisposition, certain maternal environmental factors (for example alcohol, drugs or metabolic diseases) can be responsible for the defects.

When problems occur in the development of the heart and its structures, it can result in ASDs. The different types of ASDs are formed due to incomplete fusion of certain parts of heart musculature as seen in the four type explained above.

Epidemiology

ASDs account for 10% of all congenital heart diseases. Incidence of ostium secundum ASDs is 75%, of ostium primum is 15-20% & of sinus venosus is 5-10%. Coronary ASDs are rare.

The incidence of ASDs in females is twice as those in males.

Sex distribution
Age distribution

Pathophysiology

The extent of the left to right atrial shunting will depend on the size of the defect, the relative ventricular compliance, vascular resistance and accompanying congenital defects. When the ASD is small, the shunting is not significant.

In cases of larger defects, the extent of the shunting is significant and can lead to volume overload of the right atria and right ventricle. This raises the filling pressure of the right side of the heart causing the right ventricle to pump out more blood as compared to the left ventricle.

The overloading of the right side of the heart will cause an overload of the entire pulmonary circulation leading to pulmonary hypertension eventually. This will further force the right ventricle to generate higher pressures to overcome the pulmonary hypertension which may even lead to right ventricular failure.

In cases where ASD is left untreated, the increased pressure on the right side of the heart causes reversal of the shunt i.e. right to left shunting (Eisenmenger syndrome). This will cause mixing of the oxygenated and non-oxygenated blood in the heart. Once in circulation, this inevitably leads to cyanosis.

Prevention

There are no guidelines for prevention of ASD.

Summary

Atrial septal defect (ASD) is a congenital defect in the septum between the two atria of the heart. ASD results in pulmonary venous return going directly to the right atrium from the left atrium [1] [2] [3]. The significance of the complications of ASD will depend on the size of the defect and shunt. The presence of any associated anomalies will lead to further complications.

There are four types of ASD, depending on where these defects are found. The most common is Ostium Secundum defect which occurs in the middle of the atrial septum. It can be associated with partial anomalous pulmonary venous return. The second type of ASD is Ostium Primum defect which is a form of atrioventricular septal defect with shunting at atrial level. It can be associated with mitral regurgitation. The least common type of ASD is Sinus Venosus defect which occurs in the superior aspect of the atrial septum involving the superior vena cava. A variation of this involves the inferior vena cava. The rarest type of ASD is Coronary sinus defect. It involves direct communication of the coronary sinus and the left atrium.

Patient Information

Atrial septal defect (ASD) is a heart defect present since birth in which there is a hole in the wall that separates the upper heart chambers (atria) from the ventricles/other atrium.

The septal defects are located in different parts of the atrial septum and they can be of different sizes. A "shunt" is the presence of a net flow of blood through the defect, either from left to right or right to left.

The size of the defect, size of the shunt, and associated anomalies, can lead to a range of diseases from no significant cardiac complication to right-sided volume overload, pulmonary arterial hypertension or even atrial arrhythmias.

ASDs are usually asymptomatic in infancy and childhood. In most cases the symptoms appear by the third decade of life. Most cases of ASD, even moderate to large ASDs do not manifest symptoms during childhood. Hence, ASDs go undetected in childhood due to lack of symptoms.

Cardiac murmurs can be detected on auscultation in some cases which may be a clue that a child has an ASD. Common symptoms include dyspnoea, easy fatigue, palpitations, exercise intolerance and recurrent respiratory infections. The significance of the complications will depend on the size of the defect and shunt. The presence of any associated anomalies will lead to further complications.

ASDs once diagnosed can be treated successfully with few or no complications. Transthoracic echocardiography and transesophageal echocardiography are common non-invasive imaging techniques used to diagnose ASDs. Cardiac catheterization is the invasive technique used.

Small ASDs may close naturally after birth. If the ASD is left untreated it may lead to arrhythmias, pulmonary arterial hypertension, reversal of shunting and heart failure. Larger defects are treated through surgery. Medical therapy can be used to treat the symptoms of ASD, but surgical intervention is a must for the closure of the defect. 

References

Article

  1. Braunwald E. Atrial septal defect. In: Braunwald E, ed. Heart Disease: A Text of Cardiovascular Medicine. 1992. 4th ed. Philadelphia, Pa: WB Saunders; 1992:906-8
  2. Goldman L, Braunwald E. Primary Cardiology. Philadelphia, Pa: WB Saunders; 1998:394-411. 
  3. Child J, Friedman W. Harrison’s Principles of Internal Medicine. 16th ed. McGraw Hill. Chapter 218. Congenital Heart Disease in the adult.
  4. Fisher MR, Forfia PR et al. Accuracy of Doppler Echocardiography in the Hemodynamic assessment of Pulmonary Hypertension. Am J Respir Crit Care Med. 2009 April 1; 179(7): 615–621.
  5. Constantinescu T, Magda SL, et al. New Echocardiographic Tehniques in Pulmonary Arterial Hypertension vs. Right Heart Catheterization – A Pilot Study. Maedica (Buchar). 2013 June; 8(2): 116–123.
  6. Davidson CJ, Bonow RO. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Saunders; Philadelphia: 2011. Chapter 20. Cardiac catheterization.
  7. Jost CH, Connolly HM, Danielson GK, et al. Sinus venosus atrial septal defect: long-term postoperative outcome for 115 patients. Circulation. Sep 27 2005; 112(13):1953-8.
  8. Ammar RI, Hegazy RA. Transcatheter closure of secundum ASD using Occlutech Figulla-N device in symptomatic children younger than 2 years of age. J Invasive Cardiol. 2013 Feb; 25(2):76-9.
  9. Feltes TF, Bacha E, Beekman RH 3rd, et al. Indications for cardiac catheterization and intervention in pediatric cardiac disease: a scientific statement from the American Heart Association. American Heart Association Congenital Cardiac Defects Committee of the Council on Cardiovascular Disease in the Young; Council on Clinical Cardiology; Council on Cardiovascular Radiology and Intervention. Circulation. 2011; 123(22):2607-2652.
  10. Lakhdhar R, Drissa M Drisa H. Natural history of atrial septal defect in the sixth decade: study of 5 cases. Tunis Med. 2013 Apr; 91(4):243-7.

Ask Question

5000 Characters left Format the text using: # Heading, **bold**, _italic_. HTML code is not allowed.
By publishing this question you agree to the TOS and Privacy policy.
• Use a precise title for your question.
• Ask a specific question and provide age, sex, symptoms, type and duration of treatment.
• Respect your own and other people's privacy, never post full names or contact information.
• Inappropriate questions will be deleted.
• In urgent cases contact a physician, visit a hospital or call an emergency service!
Last updated: 2019-07-11 21:08