Difference between revisions of "Tricuspid Valve Dysplasia"

Revision as of 11:39, 15 March 2011

Introduction

This is a condition which is common in dogs and cats, quite common in horses and rare in large animals. Predisposed breeds of dog include the Labrador Retrievers, German Shepherds, Boxers and Great Danes. It is the second most common congenital abnormality seen in cats.

The condition should be described as a congenital malformation of the tricuspid valve (right atrioventricular valve) and its supporting structures (chordae tendineae, papillary muscles, valvular leaflets) results in tricuspid stenosis (narrowing) or regurgitation (insufficiency). Tricuspid valve dysplasia leads to increased volume load on the right atrium and ventricle towards the end of diastole. A stenotic tricuspid valve can limit ventricular filling during diastole and increased pressure as a result of increased volume can cause right-sided congestive heart failure.

Clinical Signs

Often presence of a murmour on physical exam is the only clinical sign. Other clinical signs vary depending on the severity of the disease but will include exercise intolerance, dyspnea, weight loss, poor appetite and abdominal distension.

Diagnosis

Physical examination findings will reveal a right-sided soft systolic murmur (tricuspid regurgitation), a right-sided diastolic murmur and jugular pulses & distension in severe cases. Femoral pulses are usually normal to weak and there may be signs of right-sided congestive heart failure in severe cases.

Radiographic findings may include right atrial and right ventricular enlargement, caudal vena cava enlargement, pulmonary underperfusion and signs of right sided heart failure. Echocardiographic findings inlcude right ventricular and atrial dilation and abnormalities of the tricuspid valve. Doppler shows tricuspid regurgitation and/or stenosis. Electrocardiographic (ECG) study can show classic signs of right atrial and ventricular enlargement, atrial arrhythmias as well as ventricular conduction problems.

Treatment

Treatment is usually palliative. Signs of right sided congestive heart failure can be controlled pharmacologically, as can arrhythmias. Thoracocentesis should be performed when needed to relieve pleural effusion. Abdominocentesis when needed to relieve peritoneal effusion.

Prognosis

Mild to moderate cases can lead a normal life. Severe cases have a poor prognosis, however, if heart failure is controlled these patients can live several years.

References

Ettinger, S.J. and Feldman, E. C. (2000) Textbook of Veterinary Internal Medicine Diseases of the Dog and Cat Volume 2 (Fifth Edition) W.B. Saunders Company
Ettinger, S.J, Feldman, E.C. (2005) Textbook of Veterinary Internal Medicine (6th edition, volume 2)W.B. Saunders Company
Fossum, T. W. et. al. (2007) Small Animal Surgery (Third Edition) Mosby Elsevier
Merck & Co (2008) The Merck Veterinary Manual (Eighth Edition) Merial
Nelson, R.W. and Couto, C.G. (2009) Small Animal Internal Medicine (Fourth Edition) Mosby Elsevier.

@@ Line 1: / Line 1: @@
+== Introduction<br> ==
-*Common in dogs & cats
+This is a condition which is common in dogs and cats, quite common in horses and rare in large animals. Predisposed breeds of dog include the Labrador Retrievers, German Shepherds, Boxers and Great Danes. It is the second most common congenital abnormality seen in cats.
-*Rare in large animals
+The condition should be described as a congenital malformation of the tricuspid valve (right atrioventricular valve) and its supporting structures (chordae tendineae, papillary muscles, valvular leaflets) results in tricuspid stenosis (narrowing) or regurgitation (insufficiency). Tricuspid valve dysplasia leads to increased volume load on the right atrium and ventricle towards the end of diastole.&nbsp;A stenotic tricuspid valve can limit ventricular filling during diastole and increased pressure as a result of increased volume can cause right-sided congestive heart failure.
-*Horses do get tricuspid atresia
+<br>
-===Signalment===
+== Clinical Signs<br> ==
-Genetics & Predisposed Breeds: Labrador Retrievers, German Shepherds, Boxers, Great Danes
+Often presence of a murmour on physical exam is the only clinical sign. Other clinical signs vary depending on the severity of the disease but will include exercise intolerance, dyspnea, weight loss, poor appetite and abdominal distension.&nbsp;
-===Description===
+<br>
-*Congenital malformation of the tricuspid valve (right atrioventricular valve) and its supporting structures (chordae tendineae, papillary muscles, valvular leaflets) results in tricuspid stenosis (narrowing) or regurgitation (insufficiency)
+== Diagnosis<br> ==
-*Tricuspid valve dysplasia leads to increased volume load on the right atrium and ventricle towards the end of diastole.
+Physical examination findings will reveal a right-sided soft systolic murmur (tricuspid regurgitation), a right-sided diastolic murmur and jugular pulses &amp; distension in severe cases. Femoral pulses are usually normal to weak and there may be signs of right-sided congestive heart failure in severe cases.
-*A stenotic tricuspid valve can limit ventricular filling during diastole.
+Radiographic findings may include right atrial and right ventricular enlargement, caudal vena cava enlargement, pulmonary underperfusion and signs of right sided heart failure. Echocardiographic findings inlcude right ventricular and atrial dilation and abnormalities of the tricuspid valve.&nbsp;Doppler shows tricuspid regurgitation and/or stenosis.&nbsp;Electrocardiographic (ECG) study can show classic signs of right atrial and ventricular enlargement, atrial arrhythmias as well as ventricular conduction problems.
-*Increased pressure as a result of increased volume can cause right-sided congestive heart failure.
+<br>
-===Diagnosis===
+== Treatment ==
-====History & Clinical Signs====
--Exercise intolerance
+Treatment is usually palliative. Signs of right sided congestive heart failure can be controlled pharmacologically, as can arrhythmias. Thoracocentesis should be performed when needed to relieve pleural effusion. Abdominocentesis when needed to relieve peritoneal effusion. <br>
--Dyspnea
+<br>
--Weight Loss
+== Prognosis ==
--Poor appetite
+Mild to moderate cases can lead a normal life. Severe cases have a poor prognosis, however, if heart failure is controlled these patients can live several years.<br>
--Abdominal distension
+<br>
-====Physical Exam====
+== References<br> ==
--Right-sided soft systolic murmur (tricuspid regurgitation)
+Ettinger, S.J. and Feldman, E. C. (2000) Textbook of Veterinary Internal Medicine Diseases of the Dog and Cat Volume 2 (Fifth Edition) W.B. Saunders Company<br>Ettinger, S.J, Feldman, E.C. (2005) Textbook of Veterinary Internal Medicine (6th edition, volume 2)W.B. Saunders Company<br>Fossum, T. W. et. al. (2007) Small Animal Surgery (Third Edition) Mosby Elsevier <br>Merck &amp; Co (2008) The Merck Veterinary Manual (Eighth Edition) Merial<br>Nelson, R.W. and Couto, C.G. (2009) Small Animal Internal Medicine (Fourth Edition) Mosby Elsevier. <br><br>
--Right-sided diastolic murmur
+<br>
--Jugular pulses & distension (severe case)
+<br>
--Femoral pulses are normal to weak
+<br>
--Signs of right-sided congestive heart failure (severe case)
+[[Category:Cardiovascular_System_-_Developmental_Pathology]] [[Category:To_Do_-_Review]] [[Category:Cardiac_Diseases_-_Dog]] [[Category:Cardiac_Diseases_-_Cat]] [[Category:Cardiac_Diseases_-_Horse]]
-====Radiographic Findings====
--Right atrial and right ventricular enlargement
--Caudal vena cava enlargement
--Pulmonary underperfusion
--Signs of right sided heart failure
-====Echocardiographic Findings====
--Right ventricular and atrial dilation
--Abnormalities of tricuspid valve
-Doppler shows tricuspid regurgitation and/or stenosis
-====Electrocardiographic (ECG)====
--Classic signs of right atrial and ventricular enlargement
--Atrial arrhythmias
--Ventricular conduction problems
-===Treatment===
-Palliative Treatment
--Pharmacologically control right sided congestive heart failure
--Pharmacologically control arrhythmias
--Thoracentesis when needed to relieve pleural effusion
--Abdominocentesis when needed to relieve peritoneal effusion
-===Prognosis===
-'''Mild/Moderate Cases'''
--Normal life
-'''Severe Cases'''
--Poor (However, if heart failure is controlled these patients can live several years.)
-==From Pathology==
-Tricuspid regurgitation results in volume overload of the right atrium and may progress to right heart failure.<br>
-'''''Ebstein's Anomaly:''''' Atrioventricular ring is displaced ventrally into the right ventricle so that part of the wall of the right atrium is made up of ventricular wall.
-''Incidence:''
-*Second most common congenital anomaly seen in cats.
-*Also reported in large breeds of dog including Weimeraner.
-''Clinical Signs:''
-*Often the murmur is the only clinical sign; low grade and pansystolic with increased intensity over the tricuspid area.
-*May also see right sided failure, signs include; ascites, hepatomegaly and splenomegaly.
-''Diagnosis:''
-*Right ventricular enlargement on radiology and ECG.
-[[Category:Cardiovascular_System_-_Developmental_Pathology]]
-[[Category:To_Do_-_Cardiovascular]]
-[[Category:Cardiac Diseases - Dog]][[Category:Cardiac Diseases - Cat]][[Category:Cardiac Diseases - Horse]]