Acquired CV Disease Cats Flashcards
What is the cause of the majority of acquired cardiac disease in cats?
Cardiomyopathy (can be complex cardiopathy)
- congenital and primary arrythmias also possible but less common
- 1* valvular disease VERY RARE
- pericardial disease much less common than dogs
What are the 4 main types of cardiomyopathy?
> hypertrophic (HCM)
dilated (DCM)
restrictive (RCM)
arrythmogenic RV (AVRC)
Potential 2* myocardial diseases in cats?
- hyperthyroid myocardial disease
- hypertensive myocardial disease
- cardiomyopathy 2* to hypersomatotropism (acromegaly)
What are the key features of HCM?
- concentric Lv hypertrophy (diastolic septum/free wall thickness >6mm)
- poor LV relaxation (stiff)
- primary diastolic dysfunction
- later stages see poor systolic function due to LV scarring
- myocyte dissaray
> narrowed coronary aa. can lead to myocardial infarction
What are the key features of RCM?
- much less common than HCM and DCM
- marked atrial dilation
- no LV hypertrophy or dilation
- stiff LV
- myocyte dissarray
What are the key features of ARVC?
- left heart normal
- severe dilation of RA, RV
- RV wall thinning
- fibrofatty replacement
What does SAM describe? What predisposes this?
- systolic anterior motion
- mitral valve leaflets flap over and cause LVOTO
> valve leaflets may be especially long
> worse with septal hypertrophy
> worse with ^ sympathetic tone
> seen with HCM
What is the cause of HCM?
> Idiopathic or genetic
- NOT 2* to hypertension, aortic stenosis or hyperthyroidism
What is seen in advanced HCM?
- left atrial dilation
- left artrial contractile dysfucntion (-> thrombus formation)
- left ventricular systolic dysfunction (-> ^ atrial pressure)
What occours with HCM?
Dynamic left ventricular outflow tract obstruction (SAM)
- causes mitral regurgitation
Which cats are most commonly seen with HCM?
- young adult males but can be seen in all ages
- maine coons, ragdolls, persians predisposed BUT majority non-pedigree
Presenting signs for HCM?
- asymptomatic
- respiratory distress (suggests heart failure)
- hind limb paralysis due to aortic thromboembolism
- sudden death
PE findings with HCM?
- +- variable intensity murmur (may be present when young but disappear when older due to LV necrosis and fibrosis replacing the hyerptrophied muscle)
-priminant apical pulse - +- gallop sounds
- +- tachypneoa and crackles
> physical exam MAY be completely NORMAL
What concurrent clinical signs make prgonsis of HCM worse?
Arrythmia
What may be seen on radiograph with HCM?
> LV hypertrophy -> long cardiac sillhouette on lateral
> pulmonary oedema or plerual effusion (CHF)
What is the one main indicator of prognosis in cats with myocardial disease?
LA enlargement
What is seen on echo with HCM?
- LV enlargement, diastolic wall thickness >6mm
- SAM causing DLVOTO and murmur
Prognosis for HCM?
- good short term if LA normal
- poor if clinical singns, LA enlargement and ATE (aortic thromboembolism)
What is DCM characterised by?
- dilation of all 4 chambers
- thinning of ventricular walls
- hypokinesis (systolic dysfunction)
What was DCM historically associated with? Is this a common problem now?
taurine deficiency - rarely seen now, most diagnosed cats have normal taurine
Clinical presentatino of DCM
- middle aged/old cats
- taurine-deficient cats if fed on dog food
- output (forward) failure (hypotension, hypothermia, BRADYCARDIA cf. dogs tachycardia)
- murmur quiet/absent but gallop may be present
- thromboembolic disease common
Echo findings with DCM?
- dilated SPHERICAL LV
- fractional shortening 14mm
Prognosis for DCM?
Grave
What are the 2 forms of restrictive cardiomyopathy?
- endomyocardial (severe endomyocardial scarring, bridging scars etc.) seen commonly in oriental breeds
- myocardial (normal LV dimensions)
> both forms have severe atrial enlargement
