Changes

==Diagnosis==

==Diagnosis==

===History===

===History===

Animals may remain asymtomatic for years. Typical reported signs include exercise intolerance and dyspnoea as a result of reduced cardiac output and a ventilation perfusion mismatch due to pulmonary oedema. A progressive cough often during rest or recumbancy is frequently seen and needs to be distinguished from primary respiratory disease. Sudden death is possible due to a left atrial tear or advanced pulmonary oedema.

 

*Sudden death due to left atrial tear and pulmonary oedema

===Clinical Signs===

===Clinical Signs===

* Left apical systollic murmur

* Left apical systollic murmur

===Diagnostic imaging===

===Diagnostic imaging===

====Radiography====

====Radiography====

*Cardiomegaly with dorsal displacement of the trachea

Left Lateral, right lateral and ventrodorsal views of the thorax are needed. The key radiographic signs associated with mitral valve dysplasia and resulting left sided congestive heart failure are cardiomegaly, pulmonary venous congestion (enlarged pulmonary arteries and veins) and pulomary oedema. Cardiomegaly may lead to dorsal displacement of the trachea.

 

Evidence of Right sided congestive heart failure maybe evident in severe cases e.g. distended caudal vena cava, hepatomegaly, ascites, pleural effusions.

Evidence of Right sided congestive heart failure maybe evident in severe cases e.g. distended caudal vena cava, hepatomegaly, ascites, pleural effusions.

====Echocardiography====

====Echocardiography====

*Left Atrial enlargement

Evidence of left atrial and left venrticular enlargement is visible on echocardiography. The 'fractional shortening' is also increased which is measured as the percentage change in the left ventricular diameter during systole and is used as a measure of systollic function. It is also possible to see structural changes in the valve leaflets in some cases. The regurgitant jet of blood can be detected using colour doppler and evidence of turbulent flow.

* Increased Fractional Shortening ( The % change in the left venticular diameter during systole used as a measure of systollic function)

*Malformed Valve leaflets

*Evidence of the regurgitant jet and turbulent flow using colour doppler

===Electrocardiogram (ECG)===

===Electrocardiogram (ECG)===

*Enlarged Left Atrium (Wide P Wave)

A resting ECG trace may show evidence of an enlarge left atrium (Wide P Wave), an enlarged left ventricle (Tall R wave, wide QRS complex, shift of mean electrical axis to the left) and rhythm disturbances such as sinus tacchycardia, atrial fibrillation, atrial premature complexes and atrial Tacchycardia.

*Enlarged Left Ventricle (Tall R wave, wide QRS complex, shift of mean electrical axis to the left)

*Rhythm disturbances - Sinus Tacchycardia, Atrial Fibrillation, Atrial premature complexes,Atrial Tacchycardia.

===Laboratory Tests===

===Laboratory Tests===

* Tilley,L.P., Smith, F.W.K, Oyama, M., Sleeper, M. (2007) '''Manual of Canine and Feline Cardiology''' ''Saunders''.

* Tilley,L.P., Smith, F.W.K, Oyama, M., Sleeper, M. (2007) '''Manual of Canine and Feline Cardiology''' ''Saunders''.

[[Category:Cardiovascular_System_-_Developmental_Pathology]][[Category:To_Do_-_KatieB]]

[[Category:Cardiovascular_System_-_Developmental_Pathology]][[Category:To_Do_-_review]]