The ostium primum atrial septal defect consists of the absence of the interatrial septum in the atrioventricular canal portion, which causes interatrial left to right shunting. The malformation may occur by itself or in association with an inlet ventricular septal defect, as part of an atrioventricular septal defect. When the ventricular septal defect is absent, the atrioventricular valves are part of a single five-leaflet valve that adheres to the interventricular septum. The anterior leaflet of the mitral valve has a cleft as part of this malformation.
Presentation
Symptoms of ostium primum atrial septal defect depend on the magnitude of the shunt and that of the associated mitral regurgitation. Patients may be asymptomatic or may exhibit tachypnea and tachycardia, exacerbated with exercise, but they may also be present at rest. An effort such as feeding leads to diaphoresis, dyspnea and increased work of breathing that ultimately results in failure to thrive, especially if congestive heart failure due to pulmonary congestion is present. The thorax appears hyperinflated, with prominent Harrison grooves.
Symptoms may not appear during infancy, but as the child grows older and consist of exertional dyspnea, palpitations due to atrial fibrillation or flutter, as the atria dilate [1] or to sinus tachycardia that is a compensatory mechanism of heart failure. Sometimes right heart failure signs appear first. Paradoxical embolism may also occur. Cyanosis only appears once Eisenmenger syndrome has developed especially if there is no concomitant pulmonary stenosis.
The clinical examination may show a displaced apical impulse, a palpable dilated pulmonary artery, a widely split second heart sound (S2) with a loud pulmonary component in the presence of pulmonary hypertension and a variety of murmurs: a diastolic rumble due to the large flow through the tricuspid valve, a murmur of tricuspid regurgitation due to the pulmonary hypertension or one of mitral regurgitation due to the anterior leaflet cleft. As left and right atrial pressures equalize, the jugular venous pressure reflects left atrial pressure.
As pulmonary hypertension sets in, the splitting of S2 becomes more narrow and eventually disappears, as does the diastolic tricuspid rumble; the tricuspid regurgitation becomes more audible and a Graham-Steel pulmonary regurgitation diastolic murmur appears.
Entire Body System
- Atrial Septal Defect
Abstract Two-dimensional and Doppler echocardiography were compared with cardiac catheterization and angiography in the preoperative evaluation of ostium primum atrial septal defect. [ncbi.nlm.nih.gov]
The ostium primum atrial septal defect is a defect in the atrial septum at the level of the tricuspid and mitral valves. [en.wikipedia.org]
Chest x-ray quiz: an atrial septal defect. AustCrit Care. 2000; 13: 96–119. [pacificejournals.com]
@article{2f3736db292247ff958d482159b9c2e0, title = "Late results of mitral cleft closure for ostium primum atrial septal defect in adolescents and adults", abstract = "Although patients with ostium primum atrial septal defect are believed to develop symptoms [ohsu.pure.elsevier.com]
The ostium primum atrial septal defect is the most basic form of atrial canal or atrioventricular septal defect. [remedyland.com]
- Surgical Procedure
Fontan procedure The Fontan procedure is an open heart surgical procedure used in children with a defect in the structure of the heart and great vessels which are present at birth. [remedyland.com]
For 6 months following catheterization or surgical closure of an ASD, antibiotics are recommended before routine dental work or surgical procedures to prevent infective endocarditis (an infection of the inner surface of the heart). [kidshealth.org]
Where can I get surgical repair for Atrial Septal Defect? Cost of procedure performed in the US: $48,000. All prices are in US dollars and include the cost of the procedure and minimum hospital stay. [medsolution.com]
procedures. 3 Conclusion ASD is characterized by a defect in the interatrial septum producing a left-to-right shunt and is one of the more commonly recognized congenital cardiac anomalies presenting in adulthood. [uspharmacist.com]
- Trisomy 21
As noted earlier, children with trisomy 21 are at higher risk than the general population of developing pulmonary vascular obstructive disease at a younger age. [emedicine.com]
Some patients, particularly those with trisomy 21, may develop a junctional escape rhythm postoperatively. Atrial pacing restores AV synchrony and may provide benefit in reducing AV valve insufficiency and increasing cardiac output. [emedicine.medscape.com]
Both secundum and primum atrial septal defect have been found to be associated with trisomy 21 ( Down syndrome ). 3) In a study done by Weiss et al. maternal prognosis with pulmonary arterial disease in pregnancy was found to depend on the early diagnosis [wikidoc.org]
- Sepsis
Late postoperative deaths occurred in five patients (15%) and were related to myocardial infarction, stroke, hepatic failure, renal failure or sepsis. [onlinejacc.org]
Gastrointestinal
- Regurgitation
[…] or severe LAVV regurgitation at 6 months Morbidity/mortality The presence and degree of associated mitral regurgitation and/or left ventricle-to-right atrium shunting generally determine the symptoms. [emedicine.com]
[…] due to the pulmonary hypertension or one of mitral regurgitation due to the anterior leaflet cleft. [symptoma.com]
Persistent apical systolic murmur suggestive of mitral regurgitation was heard in five patients (42%) after the operation. No clinically significant mitral regurgitation was noted in these patients. [ohsu.pure.elsevier.com]
Doppler assessment of mitral regurgitation correlated well with angiographic (93% agreement) and intraoperative (85% agreement) assessments of mitral regurgitation to within two diagnostic categories on the six level scoring system used. [ncbi.nlm.nih.gov]
Once regurgitation develops, the leaflets tend to thicken, making valve repair less successful. [emedicine.medscape.com]
- Failure to Thrive
An effort such as feeding leads to diaphoresis, dyspnea and increased work of breathing that ultimately results in failure to thrive, especially if congestive heart failure due to pulmonary congestion is present. [symptoma.com]
Occasionally, repair may be recommended at an earlier age because of significant congestive heart failure (CHF) or failure to thrive, especially if associated with significant mitral regurgitation. [emedicine.medscape.com]
Coronary sinus septal defect (4) Typical Presenting symptoms- Asymptomatic CHF in infancy and failure to thrive Exercise intolerance and shortness of breath, usually in the second decade of life Atrial arrhythmias Stroke secondary to paradoxical emboli [pedclerk.bsd.uchicago.edu]
Symptoms of Atrial Septal Defect (ASD, Ostium Secundum Defect) Most are asymptomatic until later in life; Susceptibility to chest infections is common; Subtle failure to thrive may occur in some children; Exertional dyspnoea ( shortness of breath ) and [healthengine.com.au]
Cardiovascular
- Heart Disease
[…] of Adults With Congenital Heart Disease). [wikidoc.org]
Keywords: Congenital Heart Disease, Birth Defect of the Heart, Arrhythmia, Stroke, Congestive Heart Failure, Valvular Heart Disease [medsolution.com]
From Wikiecho Atrial septal defects (ASD) are a group of congenital heart diseases characterised by defect in the inter atrial septum allowing blood flow from one atrium to the other. They are among the most common congenital heart diseases. [wikiecho.org]
Fyfe DA, Kline CH: Fetal echocardiographic diagnosis of congenital heart disease. Pediatr Clin North Am 1990;37:45–67. Chiba Y, Kanzaki T, Kobayashi H, Murakami M, Yutani C: Evaluation of fetal structural heart disease using color flow mapping. [karger.com]
The risk of congenital heart disease is higher for children of parents with congenital heart disease, whether in the father or the mother. [mayoclinic.org]
- Heart Murmur
Secondly, in some cases a systolic heart murmur may be auscultated, reflecting increased flow across the pulmonic valve. [pathwaymedicine.org]
When signs and symptoms do occur, heart murmur is the most common. A heart murmur is an extra or unusual sound heard during a heartbeat. Often, a heart murmur is the only sign of an ASD. [pediatricct.surgery.ucsf.edu]
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]
</p><p>An ASD is usually suspected when a doctor hears a heart murmur with their stethoscope. A heart murmur is the swooshing sound of blood flow through the heart, which can be either normal or abnormal. [aboutkidshealth.ca]
- Systolic Murmur
Persistent apical systolic murmur suggestive of mitral regurgitation was heard in five patients (42%) after the operation. No clinically significant mitral regurgitation was noted in these patients. [ohsu.pure.elsevier.com]
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]
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]
Auscultation typically reveals a grade 2 to 3/6 midsystolic (or ejection systolic) murmur and a widely split, fixed S2 at the upper left sternal border in children. [babiesonline.co.za]
In a II and III intercostal space to the left of the sternum, a moderate systolic murmur can be heard as a result of increased flow through the pulmonary valve. [remedyland.com]
Psychiatrical
- Withdrawn
The catheter was then withdrawn slowly, aiming the tip toward the patient’s left shoulder, until it passed through the ASD. The catheter was then advanced into the LA. [dovepress.com]
Post-procedure care Device closure procedure When the procedure is complete, the catheter(s) will be withdrawn. Several gauze pads and a large piece of medical tape will be placed on the site where the catheter was inserted to prevent bleeding. [childrensnational.org]
The left atrial disc is initially delivered into the left atrium and under fluoroscopic and TEE guidance, withdrawn to position it against the left side of the atrial septum occluding the ASD. [fac.org.ar]
What to Expect After Atrial Septal Defect Repair Device Closure Procedure When the procedure is complete, the catheter(s) will be withdrawn, and a small bandage is applied. [choc.org]
Neurologic
- Stroke
Intracardiac devices for stroke prevention. Prev Cardiol. 2006;9:1-7. Tobis MJ, Azarbal Z. Does patent foramen ovale promote cryptogenic stroke and migraine headache. Tex Heart Inst J. 2005;32:362-65. Kizer JR, Devereux RB. Clinical practice. [rarediseases.org]
If another stroke recurs on medicines, patients may be referred to have a PFO or small ASD closed (see below). There are now special studies in progress to determine whether medications or closure of the PFO is better at preventing stroke. [heart.org]
Larger defects can cause serious problems, including: Right-sided heart failure Heart rhythm abnormalities (arrhythmias) Increased risk of a stroke Shortened life span Less common serious complications may include: Pulmonary hypertension. [mayoclinic.org]
Workup
Chest radiography reveals right heart enlargement and pulmonary congestion with increased pulmonary vascular markings; if the mitral regurgitation is severe, the left heart may also appear enlarged. The pulmonary trunk and proximal right pulmonary artery may be dilated [2].
Echocardiography is the main diagnostic method. The ostium primum atrial septal defect is seen in the apical four chamber view as a lack of substance in the inferior part of the atrial septum. Parasternal and subcostal short axis views are more suitable for the evaluation of the mitral valve cleft and other mitral abnormalities: double orifice or single papillary muscle. Left ventricle outflow tract is long and narrow and may be obstructed by the abnormal mitral valve.
Color Doppler evaluates the direction of the atrial shunt, mitral, tricuspid and pulmonary regurgitations and identifies associated interventricular or left ventricle to right atrium communications.
Pulsed Doppler helps to evaluate systolic pulmonary artery pressure, based on tricuspid regurgitation peak velocity, while continuous Doppler is useful in identifying left ventricular outflow tract obstruction if present.
Transesophageal echocardiography is seldom used in the preoperative evaluation, being reserved for poor acoustic window patients, but is valuable in the intraoperative setting to evaluate mitral stenosis, residual mitral and tricuspid regurgitation or left ventricular outflow tract obstruction. This method also better describes the margins of the defect, usually represented by the septum primum and the atrioventricular valve annulus [3].
The electrocardiogram may reveal sinus rhythm, atrial flutter or fibrillation [4] [5] [6]. The sinus node may be displaced, leading to negative P waves [7]. The right atrium overload, pictured as peaked P wave in leads D II, D III, V1 and V3R and first-degree atrioventricular block may be present. Right ventricle hypertrophy markers or incomplete right bundle branch block may be present. If mitral valve regurgitation is severe, the left ventricle may be hypertrophied and the left atrium may be overloaded and enlarged leading to a P wave duration of more than 0,08 sec and/or inversion in leads V1 or V3.
Cardiac catheterization is seldom necessary in this disease and is reserved for the evaluation of pulmonary vascular obstructive disease and in cases where systemic/pulmonary debt ratio (Qp/Qs0 needs to be invasively calculated. This procedure allows the direct measurement of intracardiac and pulmonary artery pressures and the calculation of pulmonary resistance. In addition, cardiac anatomy and associated malformations such as additional atrial or ventricular septal defects, patent ductus arteriosus, coarctation of the aorta or anomalous pulmonary venous return are best described by this method.
Cardiac magnetic resonance imaging is another reliable method to assess right ventricular size and function and cardiac anatomy, in general [8].
Axis
- Left Axis Deviation
In primum defects left axis deviation is seen in most patients with an axis of > -30 degrees and very few patients have right axis deviation. [en.wikipedia.org]
The left axis deviation is most probably related to early activation of the postero-basal left ventricular wall (patients with short H-V) and/or late activation of the antero-lateral left ventricular wall (patients with normal H-V). [circ.ahajournals.org]
Left axis deviation (-20 to -60 deg) is always present. q in I & avL (counterclockwise loop). qRs in v5 & v6 due to LV volume overload. Chest X-ray RA, RV and LV enlargement. LA is inconspicuous despite MR due to presence of ASD. [heartpearls.com]
In Primum defects left axis deviation is seen in most patients with an axis of > -30 degrees and very few patients have right axis deviation. [ipfs.io]
The 12-lead ECG will show an incomplete right bundle branch block and left axis deviation (in contrast to the secundum ASD which has a right axis deviation). [healio.com]
- Right Axis Deviation
In primum defects left axis deviation is seen in most patients with an axis of > -30 degrees and very few patients have right axis deviation. [en.wikipedia.org]
Normal axis or right axis deviation due to right ventricular diastolic overload. Right atrial abnormality ( may not be observed in children ). [metealpaslan.com]
In Primum defects left axis deviation is seen in most patients with an axis of > -30 degrees and very few patients have right axis deviation. [ipfs.io]
The 12-lead ECG will show an incomplete right bundle branch block and left axis deviation (in contrast to the secundum ASD which has a right axis deviation). [healio.com]
EKG: in ostium secundum defect: right axis deviation & an rSr' pattern. in ostium primum: left axis deviation & superior orientation & counterclockwise rotation of the QRS loop in the frontal plane. [enotes.tripod.com]
PR Interval
- Prolonged PR Interval
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]
Patients with ASD may have a prolonged PR interval. [ijcva.com]
Individuals with atrial septal defects may have a prolonged PR interval (a first degree heart block). [marmur.com]
Individuals with atrial septal defects may have a prolonged PR interval (a first-degree heart block). [en.wikipedia.org]
Blocks
- Right Bundle Branch Block
When a person is suspected of having an ASD based on the findings of an incomplete right bundle branch block with a rSr' or rSR', the frontal plane QRS should be examined. [en.wikipedia.org]
When you suspect a patient has an ASD based on the findings of an incomplete Right Bundle Branch Block with a rSr' or rSR' the next thing you should do is examine the frontal plane QRS. [ipfs.io]
The 12-lead ECG will show an incomplete right bundle branch block and left axis deviation (in contrast to the secundum ASD which has a right axis deviation). [healio.com]
The most frequent ECG abnormalities in ASD are right bundle branch block (RBBB) pattern or rsR' pattern in lead C1. Complete RBBB is observed less frequently. [metealpaslan.com]
The right atrium overload, pictured as peaked P wave in leads D II, D III, V1 and V3R and first-degree atrioventricular block may be present. Right ventricle hypertrophy markers or incomplete right bundle branch block may be present. [symptoma.com]
- Incomplete Right Bundle Branch Block
When a person is suspected of having an ASD based on the findings of an incomplete right bundle branch block with a rSr' or rSR', the frontal plane QRS should be examined. [en.wikipedia.org]
When you suspect a patient has an ASD based on the findings of an incomplete Right Bundle Branch Block with a rSr' or rSR' the next thing you should do is examine the frontal plane QRS. [ipfs.io]
The 12-lead ECG will show an incomplete right bundle branch block and left axis deviation (in contrast to the secundum ASD which has a right axis deviation). [healio.com]
The right atrium overload, pictured as peaked P wave in leads D II, D III, V1 and V3R and first-degree atrioventricular block may be present. Right ventricle hypertrophy markers or incomplete right bundle branch block may be present. [symptoma.com]
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]
- First-Degree Atrioventricular Block
Prolongation of the PR interval: first degree atrioventricular block ( less frequent than ostium primum ASD ). Crochetage sign : notched R wave in inferior limb leads ( may disappear after closure of the defect ). [metealpaslan.com]
The right atrium overload, pictured as peaked P wave in leads D II, D III, V1 and V3R and first-degree atrioventricular block may be present. Right ventricle hypertrophy markers or incomplete right bundle branch block may be present. [symptoma.com]
Jugular Venous Pressure
- Prominent A-Wave
If MR is present, the findings of ASD may be modified Prominent v wave in JVP LV type apex IE may occur (unlike secundum ASD) ECG Incomplete RBBB pattern in v1 as in secundum ASD. [heartpearls.com]
Hypertrophy
- Biventricular Hypertrophy
Katz-Wachtel phenomenon (biventricular hypertrophy pattern) is observed. Dr. Mahmut Gokdemir has donated this ECG to our website. Click here for a more detailed ECG ECG 6. Fiftynine years old woman who was operated for ASD 23 years ago. [metealpaslan.com]
Other ECG Findings
- Abnormal ECG
They may be noted on routine testing to have an abnormal chest X-ray or an abnormal ECG and may have atrial fibrillation. [en.wikipedia.org]
Treatment
The only successful treatment solutions is surgical treatment or artificial closure of the defect. Right time for surgical treatment can only be based on need for surgery and risks of surgery. [remedyland.com]
Transverse sections of the anterior mitral leaflet echo were examined in 11 patients with this malformation who subsequently received surgical treatment. [ncbi.nlm.nih.gov]
Please consult your own licensed physician regarding diagnosis and treatment of any medical condition! Please see also our disclaimer. This site complies with the HONcode standard for health information: verify here. Database updated 2019-02-19. [diseasesdatabase.com]
Diagnosis [ edit ] Classification [ edit ] A defect in the ostium primum is occasionally classified as an atrial septal defect, [1] but it is more commonly classified as an atrioventricular septal defect. [2] [3] Treatment [ edit ] Hemodynamically significant [en.wikipedia.org]
You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments. [rarediseases.info.nih.gov]
Prognosis
The long term prognosis is excellent. Pulmonary hypertension with shunt reversal is a contraindication for surgery, however the pulmonary hypertension can frequently be treated with medicines. [en.wikipedia.org]
Complications Congestive heart failure Pulmonary arterial hypertension Prognosis Excellent prognosis if treated Sinus Venosus Atrial Septal Defect with Partial Anomalous Pulmonary Venous Return. [learningradiology.com]
Surgery, if necessary, is performed at a young age with an excellent prognosis. [heartlifeinsurance.com]
Etiology
[…] iM StIll stUdInG Published on Mar 28, 2015 ATRIAL SEPTAL DEFECT ASD - CF, ETIOLOGY ,PATHO -PHYSIOLOGY, SIGNS & SYM, MANAGEMENT.....ETC ATRIAL SEPTAL DEFECT ( ASD) 1. ATRIAL SEPTAL DEFECT AKSHAY AGRAWAL 2. CONTENTS 1. Introduction 2. Defination 3. [slideshare.net]
However, those who develop a stroke require further workup to identify the etiology. In those where a comprehensive evaluation is performed and an obvious etiology is not identified, they are defined as having a cryptogenic stroke. [en.wikipedia.org]
Etiology During normal embryonic development, the right horn of the sinus venosus encompasses the right superior vena cava (SVC) and inferior vena cava (IVC). [emedicine.medscape.com]
Ongoing controversies regarding etiology, diagnosis, treatment There are two dominant controversies regarding ostium secundum ASDs. [clinicaladvisor.com]
Twenty-five (9%) of the 280 patients included in our series had serious tricuspid valve insufficiency (3 out of 3) The etiology of tricuspid insufficiency, like mitral valve insufficiency, may depend on anatomical changes or mixoid degeneration, but more [revespcardiol.org]
Epidemiology
Epidemiology Male : Female = 1:2 Most commonly seen in children 8. [slideshare.net]
Epidemiologic features: The Framingham Study. Am Heart J 1983;106:571-6. 8. Hickey AJ, Wolfers J, Wilcken DE. Mitral valve prolapse, prevalence in an Australian population. Med J Aust 1981;1:31-3. 9. Guy FC, MacDonald RP, Fraser DB, Smith ER. [ispub.com]
Epidemiology United States data Sinus venosus atrial septal defects represent approximately 1% of congenital cardiac lesions. [emedicine.medscape.com]
Epidemiology [ 1 ] ASDs are the third most common congenital heart disease and occur as an isolated anomaly in 5% to 10% of all congenital heart defects. [patient.info]
Pathophysiology
Pathophysiology 6. Clinical features 7. Investigations 8. Risk Factors 9. Management 3. Introduction Septal defects are more common eg of non cyanotic heart disease. Most common congenital heart disease in adults. [slideshare.net]
A few other conditions result in pathophysiology similar to that of ASDs are discussed below although the atrial septum may be completely normal in such conditions. [pathwaymedicine.org]
Pathophysiology In patients with acyanotic atrial septal defect (ASD), the shunt follows the left atrium - right atrium - right ventricle route. [metealpaslan.com]
Pathophysiology Atrial septal defects allow blood to shunt from the left atrium to the right atrium. Shunting is minimal during infancy, but typically increases with age as the right ventricle becomes more compliant. [vhlab.umn.edu]
Pathophysiology The more common sinus venosus type defect (often referred to as the "usual type") occurs in the upper atrial septum and is contiguous with the superior vena cava (SVC). [emedicine.medscape.com]
Prevention
Follow-up in this series suggests that surgical correction may prevent these developments. [ncbi.nlm.nih.gov]
Prevention In most cases, atrial septal defects can't be prevented. If you're planning to become pregnant, schedule a preconception visit with your health care provider. This visit should include: Getting tested for immunity to rubella. [mayoclinic.org]
What about preventing endocarditis? Most children with an ASD are not at increased risk for developing endocarditis. [heart.org]
A health care provider may recommend the atrial septal defect be closed for a child with a large atrial septal defect, even if there are few symptoms, to prevent problems later in life. [cdc.gov]
Several gauze pads and a large piece of medical tape will be placed on the site where the catheter was inserted to prevent bleeding. [childrensnational.org]
References
- Gatzoulis MA, Freeman MA, Siu SC, et al. Atrial arrhythmia after surgical closure of atrial septal defects in adults. N Engl J Med. 1999; 340: 839–846.
- Reading M. Chest x-ray quiz: an atrial septal defect. Aust Crit Care. 2000; 13: 96–119.
- Tobis J, Shenoda M. Percutaneous treatment of patent foramen ovale and atrial septal defects. J Am Coll Cardiol 2012;60:1722-32.
- Heller J, Hagege AA, Besse B, et al. “Crochetage” (notch) on R wave in inferior limb leads: a new independent electrocardiographic sign of atrial septal defect. J Am Coll Cardiol. 1996; 27: 877–882
- Zufelt K, Rosenberg HC, Li MD, Joubert GI. The electrocardiogram and the secundum atrial septal defect: a reexamination in the era of echocardiography. Can J Cardiol. 1998; 14: 227–232.
- Guray U, Guray Y, Yylmaz MB, et al. Evaluation of P wave duration and P wave dispersion in adult patients with secundum atrial septal defect during normal sinus rhythm. Int J Cardiol. 2003; 91: 75–79.
- Jost CH, Connolly HM, Danielson GK, et al. Sinus venosus atrial septal defect: long-term postoperative outcome for 115 patients. Circulation. 2005; 112: 1953–1958.
- Prasad SK, Soukias N, Hornung T, et al. Role of magnetic resonance angiography in the diagnosis of major aortopulmonary collateral arteries and partial anomalous pulmonary venous drainage. Circulation. 2004; 109: 207–214.