Chapter 56 - Hypertrophic Cardiomyopathy Flashcards
What is the definition of HCM?
Myocardial disease defined by idiopathic left ventricular hypertrophy
What are secondary causes of HCM?
Systemic hypertension, hyperthyroidism
What is “pseudo-hypertrophy”?
Dehydration causing the appearance of HCM
What happens in end-stage HCM? (describe progression)
Systolic dysfunction (diastolic dysfunction in early stage) and ventricular wall thinning
What is the pathophysiology of hypertrophic obstructive cardiomyopathy?
Left ventricular wall obstruction + mitral regurgitation–> mitral valve becomes malpositioned and progressively obstructs the left ventricular outflow tract
Pathophysiology of primary HCM?
Genetic mutation–>cardiomyocyte stress–>hypertrophy–>excess collagen production–>myofiber disarray = increased myocardial stiffness and delayed relaxation = increased LV filling pressure
Where is the most common location of thrombus formation in cats with HCM? And the most common location of thromboembolus?
Left auricle and left atrium with dislodgement most commonly in the aortic trifurcation
What is the most common cause of morbidity and mortality in cats with ATE?
Acidosis, hyperkalemia, renal dysfunction and arrhythmias secondary to reperfusion injury
What are potential antecedent events noted prior to diagnosed ATE?
Hospitalization, boarding, IV fluid administration, anesthesia, corticosteroids
What is the gold standard diagnostic test to determine HCM? (Antemortem)
Echocardiography–represented by end-diastolic LV wall thickness and interventricular septum and/or free wall >6mm.
What is recommended for chronic therapy of HCM patients?
Furosemide 1-2 mg/kg PO q8-12h, ACEI 0.25-0.5 mg/kg PO q12h, Anticoagulant, pimobendan on a case-by-case basis (may worsen LVOT)
