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==Overview==

==Overview==

Dilated cardiomyopathy (DCM) is now an uncommon feline cardiomyopathy, representing ~10% of cardiomyopathies. Previously, DCM was associated with taurine deficiency.  However, the discovery of this in 1987 led to supplementation of commercial feline diets with adequate taurine.  The rare cases of taurine deficiency observed since then are generally the consequence of vegetarian, vegan or canine diets to cats. It is difficult to differentiate true DCM, which is a primary systolic failure of the myocardium, from other forms of cardiac pathology which may result in a 'DCM phenotype'. Examples include the end stage of undiagnosed valvular diases (mitral dysplasia), ischaemic myocardial disease (HCM) or sustained tachycardia (tachycardia-induced cardiomyopathy).  

Dilated cardiomyopathy (DCM) is now an uncommon feline cardiomyopathy, representing ~10% of cardiomyopathies. Previously, DCM was associated with taurine deficiency.  However, the discovery of this in 1987 led to supplementation of commercial feline diets with adequate taurine.  The rare cases of taurine deficiency observed since then are generally the consequence of vegetarian, vegan or canine diets to cats. It is difficult to differentiate idiopathic DCM, which is a primary systolic failure of the myocardium, from other forms of cardiac pathology which may result in a 'DCM phenotype'. Examples include the end stage of undiagnosed valvular diases (mitral dysplasia), ischaemic myocardial disease (HCM) or sustained tachycardia (tachycardia-induced cardiomyopathy). Idiopathic DCM is a diagnosis of exclusion of other causes of secondary myocardial failure.

==Pathophysiology==

==Pathophysiology==

===Echocardiography===

===Echocardiography===

====Two dimensional (2D) and M-mode====

====Two dimensional (2D) and M-mode====

* Increased end diastolic LV diameter

DCM is defined as primary myocardial failure, which can be diagnosed by a reduced fractional shortening and increased LV end-systolic diameter.  Eccentric hypertrophy, which occurs as a result of volume overload, results in an increased end-diastolic diameter. Left atrial (LA) dilation occurs secondary to elevated LV filling pressures. Global systolic dysfunction resulting in dilation of all-four cardiac chambers is frequently observed in cases of DCM. Mild atrioventricular valve (mitral, tricuspid) insufficiency is common.  This occurs secondary to dilation of the valve annulus and distortion of the papillary muscles, such that the valve no longer seals closed within the dilated heart during systole. Spontaneous echocontrast and thrombi within the dilated atria are common findings. Mild pericardial effusion is also frequently identified.

* Increased end systolic LV diameter ≥14mm

===Taurine Levels===

===Taurine Levels===

Although taurine deficiency is now a rare cause of DCM, it is worth ruling out due to its potentially reversible nature. Taurine levels are measured in plasma or whole blood.

Although taurine deficiency is now a rare cause of DCM, it is worth ruling out due to its potentially reversible nature. Taurine levels are measured in plasma or whole blood.

==References==

==References==