Lecture 14 9/17/24 Flashcards
What is cardiomyopathy?
-primary heart muscle disorder in which the heart muscle is structurally and functionally abnormal
What is dilated cardiomyopathy?
left ventricular dilation and systolic myocardial dysfunction +/- right ventricular involvement
What causes ventricular dilation in DCM?
hypokinesis
What is the etiopathogenesis of DCM?
-cardiomyocytes in the mature individual cannot reproduce to correct abnormalities and/or damage
-dilated heart works at mechanical disadvantage
-dilation tends to be progressive
What can cause systolic myocardial dysfunction?
-loss of cardiomyocytes due to necrosis
-ultrastructural abnormalities of the contractile apparatus
-persistent tachycardia
-nutritional deficiencies
Why is DCM considered a phenotype?
it is an “end-stage heart” that can result from virtually any pathologic insult to the myocardium
What are the potential pathways of DCM?
-toxic
-metabolic
-immune
-infective
-nutritional
Which dogs have a genetic predisposition for DCM?
-doberman pinscher
-great dane
-newfoundland
-irish wolfhound
What is the pathophysiology of DCM?
-impaired systolic myocardial function results in progressive ventricular dilation
-high ventricular filling pressures are reflected back upon the upstream capillary bed
-reflection results in edema and/or cavitary effusion
What is the typical signalment of DCM patients?
-large or giant breed dog
-middle aged
-doberman, boxer, great dane, irish wolfhound, or cocker spaniel
What are the clinical signs seen in DCM patients?
related to CHF:
-dyspnea
-cough
-weight loss
-syncope
-ascites
What are the physical exam findings seen in DCM patients?
-soft systolic murmur of MR origin and/or gallop sounds
-arrhythmia
-crackles suggestive of pulmonary edema
-tachycardia
-ascites
What are the diagnostic findings for DCM on chest rads?
-enlargement of cardiac silhouette
-LAE with pulmonary infiltrates (left CHF)
What are the diagnostic findings for DCM on ECG?
-ventricular arrhythmias/AFib
-chamber hypertrophy patterns
-intraventricular conduction disturbances
What are the diagnostic findings for DCM on echo?
-increased end-systolic and end-diastolic volumes
-secondary MR