Eileen Wong

Myxomatous Mitral Valve Disease (the most common cause of CHF)

The myxomatous mitral valve is the most common form of valvular heart disease. The pathological presentation of myxomatous mitral valve disease varies between valve thickness, degree of leaflet prolapse and the presence or absence of flail leaflets.

Myxomatous Mitral Valve Disease:  The most common cause is idiopathic myxomatous degeneration. MVP is usually benign, but complications include mitral regurgitation, endocarditis, and chordal rupture.

Decreased Cardiac Output causes chain reactions

Renin Angiotensin Aldosterone System (RAAS System)  causes fluid retention and peripheral vasoconstriction. Elevating blood pressure.

Atrial Pressures are elevated. That causes back ups and resultant fluid accumulations

You’d recognize typical CHF signs including exercise intolerance and syncope

In cats just appetite loss, vomiting and isolating behavior. Not so much on coughing in cats. May not have a murmur. Is usually left sided CHF.

Right sided CHF <in cats> can look like saddle thrombus.

Dog signs CHF typical of the stuff I’d recognize. Huh! Low temperature sometimes.

Work Up

Blood pressure

  • Central Venous Pressure
  • Doppler and sphygmometer

Radiographs are pretty much “”best practices” and considered “necessary” for definitive diagnosis of CHF

Dogs:

  • Hallmark left sided cardiomegaly – dorsal displacement of the trachea
  • Vessels coming off the top of the heart (anterioventral) are thickened, more radiopaque, defined.
  • Enlarged heart

Cats:

  • Increased sternal contact suggesting enlarged / elongated heart
  • Lateral cardiac silhouette should be no more than 5 thoracic vertebrae or 4 intercostal spaces
  • VD cardiac silhouette should not take up more than 2/3 of the anterior chest.

Oxygen therapy:   E-Collar wrapped in a plastic bag or cellophane with O2 feed into that collar / diving bell

Furosemide therapy.  Up to 6mg/lb over the day. IV is best and dosed every 30-60 minutes tapering to every 4 hours. IV drip is better than bolus dosing.

Vetmedin – Make beats stronger due to calcium channel sensitization (positive inotrope), (and as an ARB) vasodilation. Excellent. Rapidly absorbed.

Vetmedin is excellent in cats with only 3% adverse reactions, mostly GI signs. 6x increased survival times.

Nitroglycerin paste 1/4″ strip under some tape to avoid human contact, alternating ears Q 6-8 hours –> vasodilation

Arterial dilators allow hearts to move more blood into aorta (decreased afterload) example is Amlodipine and Nitroprusside.

Shit I won’t probably endeavor:  Dobutamine, Positive pressure / mechanical ventilation,

CHF cases already “as you do” Furosemide/Vetmedin/Enalapril – watch resting heart rate*. Limit sodium.

*Most sensitive monitor of CHF appearance / management.

CHF Cats management: Same as dogs PLUS anti-thrombotic drugs.

 

 

 

 

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