Changes

===Echocardiography===

===Echocardiography===

This is the diagnostic test of choice for identification of RCM and excluding other cardiomyopathies.

This is the diagnostic test of choice for identification of RCM and excluding other cardiomyopathies.

 

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

'''Two-dimensional (2D) and M-mode''' imaging may reveal pronounced dilation of one or both atria and normal diameter and thickness of the ventricular chambers. Within the left atrium it is often possible to identify areas of spontaneous echo-contrast, reflecting blood stasis, or thrombi. The left atrium and the left auricular appendage should be carefully examined for this reason.  It is useful to measure left auricular appendage flow velocity.  Even in the absence of thrombi, evidence suggests that if velocity is <0.2 m/s on pulsed wave Doppler, the cat is at risk of thromboembolic complications.

Imaging may reveal pronounced dilation of one or both atria and normal diameter and thickness of the ventricular chambers. Within the left atrium it is often possible to identify areas of spontaneous echo-contrast, reflecting blood stasis, or thrombi. The left atrium and the left auricular appendage should be carefully examined for this reason.  It is useful to measure left auricular appendage flow velocity.  Even in the absence of thrombi, evidence suggests that if velocity is <0.2 m/s on pulsed wave Doppler, the cat is at risk of thromboembolic complications.

 

=====Endomyocardial form of Restrictive Cardiomyopathy (eRCM)=====

====Endomyocardial form of Restrictive Cardiomyopathy (eRCM)====

This form of RCM is characterised by severe endomyocardial fibrosis with a 'bridging scar' crossing the left ventricle.  This endomyocardial bridging scar may be associated with left ventricular obstruction during systole.  In early forms, focal left ventricular hypertrophy may be evident, which over time progresses to the formation of a 'bridging scar'.

This form of RCM is characterised by severe endomyocardial fibrosis with a 'bridging scar' crossing the left ventricle.  This endomyocardial bridging scar may be associated with left ventricular obstruction during systole.  In early forms, focal left ventricular hypertrophy may be evident, which over time progresses to the formation of a 'bridging scar'.

 

=====Myocardial form of Restrictive Cardiomyopathy (mRCM)=====

====Myocardial form of Restrictive Cardiomyopathy (mRCM)====

In this form of RCM, the left ventricle appears normal, but there is concurrent left atrial or biatrial enlargement.

In this form of RCM, the left ventricle appears normal, but there is concurrent left atrial or biatrial enlargement.

 

'''Doppler echocardiography''' is important to assess diastolic function. Mitral inflow and pulmonary venous inflow should be assessed from a left apical 4 chamber view.

Doppler is important to assess diastolic function. Mitral inflow and pulmonary venous inflow should be assessed from a left apical 4 chamber view.

 

=====Mitral Inflow=====

====Mitral Inflow====

Mitral inflow is assessed by positioning the pulse wave Doppler sample volume between the tips of the open mitral valve leaflets. In the normal animal this demonstrates two phases:

Mitral inflow is assessed by positioning the pulse wave Doppler sample volume between the tips of the open mitral valve leaflets. In the normal animal this demonstrates two phases:

*E wave (Early filling) which is a consequence of active relaxation of the left ventricle, and the pressure gradient between the left atrium and left ventricle.

*E wave (Early filling) which is a consequence of active relaxation of the left ventricle, and the pressure gradient between the left atrium and left ventricle.

The E/A ratio is an index used to estimate diastolic function, an E/A >2 confirms a restrictive filling pattern and diastolic dysfunction.

The E/A ratio is an index used to estimate diastolic function, an E/A >2 confirms a restrictive filling pattern and diastolic dysfunction.

 

=====Pulmonary Venous Inflow=====

====Pulmonary Venous Inflow====

==Treatment==

==Treatment==

==Prognosis==

==Prognosis==