Difference between revisions of "Atrial Septal Defect"

Revision as of 14:58, 6 October 2008

CARDIOLOGY ()Map CARDIOVASCULAR CONDITIONS (Map)

Vary rare in horses

Rarely seen as a single defect in dogs & cats

Signalment

Genetics & Predisposed Breeds: Old English Sheepdog, Doberman Pincher, Boxer, Samoyed

Description

Atrial septal defects occur when the interatrial septum is not completely formed or the foramen ovale has failed to close. The resulting patency between the atria allows shunting of blood.

Normally small atrial septal defects cause blood to travel from the higher pressure conditions in the left side to the lower pressure conditions in the right side. However, larger defects cause pulmonary hypertension with or without pulmonic stenosis causes shunting to occur in either both directions or from right to left.

Left to Right shunting can cause blood volume overload of the right atrium, right ventricle, and pulmonary circulation

Right to Left shunting can cause blood volume overload of the left atrium

Eisenmenger's physiology= Left to right shunts create pulmonary overcirculation. Pulmonary overcirculation leads to gross changes in the pulmonary vasculature causing an increased pulmonary vascular resistance and the development of pulmonary hypertension. Right ventricular pressures are elevated as a result making shunts reverse when the pressure on the right side of the heart exceeds that of the left. Deoxygenated blood is then able to access the peripheral circulation. Cyanosis is a direct effect of this phenomenon.

Atrial septal defects are normally located higher in the septum with dogs and lower in the septum with cats

Cats with low atrial septal defects are likely to have an endocardial cushion defect complex

Diagnosis

History & Clinical Signs

-Often no clinical signs are detected

-Exercise intolerance

-Dyspnea

-Syncope

-Cyanosis (right to left shunting)

-Signs of heart failure may be present:

ascites (right sided heart failure)

dyspnea

peripheral edema

pleural effusion

Physical Exam

Heart Murmurs

-Soft systolic murmur around left heart base (due to pulmonic stenosis)

-Soft systolic murmur around pulmonic and tricuspid valves (usually heard due to increased blood flow)

-Soft diastolic murmur on right side (tricuspid stenosis; RARE)

Radiographic Findings

-None with small defects

-Right atrial and ventricular enlargement

-May or may not have pulmonary artery enlargement

-Pulmonary overcirculation

Echocardiographic Findings

Care: artefacts can imitate atrial septal defects

-Right atrial and ventricular dilation

-Septal defect

Doppler exam will document abnormal flow through defect

Electrocardiographic (ECG)

-Normal or pattern of right ventricular enlargement

Treatment

-Usually treatment is not necessary with small atrial septal defects

-Treat right sided congestive heart failure when present

-Severe atrial septal defects may need pulmonary artery banding (decreases pulmonary blood flow and therefore volume overload), but this procedure is often only palliative

Prognosis

-Depends on the severity of the atrial septal defect and any other additional defects

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-{{OpenPagesTop}}
+{{review}}
-Also known as: '''''ASD - Persistent Foramen Ovale'''''
+{{toplink
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+|linkpage =Cardiology - WikiClinical
+|linktext =Cardiology
+|sublink1=Cardiovascular Conditions - WikiClinical
+|subtext1=CARDIOVASCULAR CONDITIONS
+|maplink1= Cardiovascular Conditions (Content Map) - WikiClinical
+|pagetype=Clinical
+}}
+<br>
+{{dog}}{{cat}}{{horse}}
+*Vary rare in horses
+*Rarely seen as a single defect in dogs & cats
+===Signalment===
+Genetics & Predisposed Breeds: Old English Sheepdog, Doberman Pincher, Boxer, Samoyed
+===Description===
+*Atrial septal defects occur when the interatrial septum is not completely formed or the foramen ovale has failed to close. The resulting patency between the atria allows shunting of blood.
+*Normally small atrial septal defects cause blood to travel from the higher pressure conditions in the left side to the lower pressure conditions in the right side. However, larger defects cause pulmonary hypertension with or without pulmonic stenosis causes shunting to occur in either both directions or from right to left.
+*Left to Right shunting can cause blood volume overload of the right atrium, right ventricle, and pulmonary circulation
+*Right to Left shunting can cause blood volume overload of the left atrium
+*Eisenmenger's physiology= Left to right shunts create pulmonary overcirculation. Pulmonary overcirculation leads to gross changes in the pulmonary vasculature causing an increased pulmonary vascular resistance and the development of pulmonary hypertension. Right ventricular pressures are elevated as a result making shunts reverse when the pressure on the right side of the heart exceeds that of the left. Deoxygenated blood is then able to access the peripheral circulation. Cyanosis is a direct effect of this phenomenon.
+*Atrial septal defects are normally located higher in the septum with dogs and lower in the septum with cats
+*Cats with low atrial septal defects are likely to have an endocardial cushion defect complex
+===Diagnosis===
+====History & Clinical Signs====
+-Often no clinical signs are detected
+-Exercise intolerance
+-Dyspnea
+-Syncope
+-Cyanosis (right to left shunting)
+-Signs of heart failure may be present:
+*ascites (right sided heart failure)
+*dyspnea
+*peripheral edema
+*pleural effusion
+====Physical Exam====
-== Introduction  ==
+'''Heart Murmurs'''
-ASD is very rare in horses and is also rarely seen as a single defect in dogs and cats. Predisposed breeds include Old English Sheepdog, Doberman Pincher, Boxer, Samoyed.
+-Soft systolic murmur around left heart base (due to pulmonic stenosis)
-Atrial septal defects occur when the interatrial septum is not completely formed or the foramen ovale has failed to close. The resulting patency between the atria allows shunting of blood. Normally small atrial septal defects cause blood to travel from the higher pressure conditions in the left side to the lower pressure conditions in the right side. However, larger defects cause [[Pulmonary Hypertension|pulmonary hypertension]] with or without [[Pulmonic Stenosis|pulmonic stenosis]] causing shunting to occur in either both directions or from right to left. Left to Right shunting can cause blood volume overload of the right atrium, right ventricle, and pulmonary circulation. Right to left shunting can cause blood volume overload of the left atrium.
+-Soft systolic murmur around pulmonic and tricuspid valves (usually heard due to increased blood flow)
-Eisenmenger's physiology is when left to right shunts create pulmonary overcirculation. Pulmonary overcirculation leads to gross changes in the pulmonary vasculature causing an increased pulmonary vascular resistance and the development of pulmonary hypertension. Right ventricular pressures are elevated as a result making shunts reverse when the pressure on the right side of the heart exceeds that of the left. Deoxygenated blood is then able to access the peripheral circulation. Cyanosis is a direct effect of this phenomenon. Atrial septal defects are normally located higher in the septum with dogs and lower in the septum with cats. Cats with low atrial septal defects are likely to have an endocardial cushion defect complex.
-== Clinical Signs  ==
+-Soft diastolic murmur on right side (tricuspid stenosis; RARE)
-Often no clinical signs are detected. There may be signs of exercise intolerance, dyspnea, syncope, cyanosis (right to left shunting). Signs of [[:Category:Heart Failure|heart failure]] may be present such as ascites (right sided heart failure), dyspnea, peripheral [[Oedema|oedema]] and pleural [[:Category:Effusions|effusion]].
+====Radiographic Findings====
-== Diagnosis  ==
+-None with small defects
-History and clinical signs are indicative of heart failure.
+-Right atrial and ventricular enlargement
-Upon physical examination a soft systolic [[Heart Murmurs|murmur]] around left heart base (due to pulmonic stenosis) may be heard as well as a soft systolic murmur around pulmonic and tricuspid valves (usually heard due to increased blood flow) and a soft diastolic murmur on right side ([[Tricuspid Valve Dysplasia|tricuspid stenosis]]; RARE).
+-May or may not have pulmonary artery enlargement
-On radiographic examination, often there will be no findings. Occasionally you may see right atrial and ventricular enlargement. There may or may not be pulmonary artery enlargement and pulmonary overcirculation.
+-Pulmonary overcirculation
-Echocardiographic findings may show right atrial and ventricular dilation and a septal defect. Doppler exam will document abnormal flow through defect.
+====Echocardiographic Findings====
-Electrocardiograph (ECG) will show a normal result or pattern of right ventricular enlargement.
+Care: artefacts can imitate atrial septal defects
-== Treatment  ==
+-Right atrial and ventricular dilation
-Usually treatment is not necessary with small atrial septal defects. You can treat right sided congestive heart failure when present. Severe atrial septal defects may need pulmonary artery banding (decreases pulmonary blood flow and therefore volume overload), but this procedure is often only palliative.
+-Septal defect
-== Prognosis  ==
+Doppler exam will document abnormal flow through defect
-Depends on the severity of the atrial septal defect and any other additional defects.
+====Electrocardiographic (ECG)====
+-Normal or pattern of right ventricular enlargement
-{{review}}
+===Treatment===
+-Usually treatment is not necessary with small atrial septal defects
+-Treat right sided congestive heart failure when present
+-Severe atrial septal defects may need pulmonary artery banding (decreases pulmonary blood flow and therefore volume overload), but this procedure is often only palliative
-{{OpenPages}}
+===Prognosis===
-[[Category:Cardiovascular_System_-_Developmental_Pathology]] [[Category:Expert_Review]] [[Category:Cardiac_Diseases_-_Dog]] [[Category:Cardiac_Diseases_-_Cat]] [[Category:Cardiac_Diseases_-_Horse]] [[Category:Cardiac_Diseases_-_Cattle]] [[Category:Cardiac_Diseases_-_Pig]]
+-Depends on the severity of the atrial septal defect and any other additional defects
-[[Category:Cardiology Section]]